- Linaro-mm-sig - lists.linaro.org

[PATCH] drm: base prime/dma-buf support (v5)

by Dave Airlie

From: Dave Airlie <airlied(a)redhat.com> This adds the basic drm dma-buf interface layer, called PRIME, The main APIs exposed to userspace allow translating a 32-bit object handle to a file descriptor, and a file descriptor to a 32-bit object handle. The flags value is currently limited to O_CLOEXEC. Acknowledgements: Daniel Vetter: lots of review Rob Clark: cleaned up lots of the internals and did lifetime review. v2: rename some functions after Chris preferred a green shed fix IS_ERR_OR_NULL -> IS_ERR v3: Fix Ville pointed out using buffer + kmalloc v4: add locking as per ickle review v5: allow re-exporting the original dma-buf (Daniel) Signed-off-by: Dave Airlie <airlied(a)redhat.com> --- drivers/gpu/drm/Kconfig | 1 + drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_drv.c | 4 + drivers/gpu/drm/drm_fops.c | 7 + drivers/gpu/drm/drm_gem.c | 9 ++ drivers/gpu/drm/drm_prime.c | 299 +++++++++++++++++++++++++++++++++++++++++++ include/drm/drm.h | 14 ++- include/drm/drmP.h | 62 +++++++++ 8 files changed, 396 insertions(+), 2 deletions(-) create mode 100644 drivers/gpu/drm/drm_prime.c diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index cc11488..e354bc0 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -9,6 +9,7 @@ menuconfig DRM depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && MMU select I2C select I2C_ALGOBIT + select DMA_SHARED_BUFFER help Kernel-level support for the Direct Rendering Infrastructure (DRI) introduced in XFree86 4.0. If you say Y here, you need to select diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index a858532..c20da5b 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -12,7 +12,7 @@ drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \ drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \ drm_crtc.o drm_modes.o drm_edid.o \ drm_info.o drm_debugfs.o drm_encoder_slave.o \ - drm_trace_points.o drm_global.o + drm_trace_points.o drm_global.o drm_prime.o drm-$(CONFIG_COMPAT) += drm_ioc32.o diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 0b65fbc..6116e3b 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -136,6 +136,10 @@ static struct drm_ioctl_desc drm_ioctls[] = { DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED), + + DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED), diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 7348a3d..cdfbf27 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -271,6 +271,9 @@ static int drm_open_helper(struct inode *inode, struct file *filp, if (dev->driver->driver_features & DRIVER_GEM) drm_gem_open(dev, priv); + if (drm_core_check_feature(dev, DRIVER_PRIME)) + drm_prime_init_file_private(&priv->prime); + if (dev->driver->open) { ret = dev->driver->open(dev, priv); if (ret < 0) @@ -571,6 +574,10 @@ int drm_release(struct inode *inode, struct file *filp) if (dev->driver->postclose) dev->driver->postclose(dev, file_priv); + + if (drm_core_check_feature(dev, DRIVER_PRIME)) + drm_prime_destroy_file_private(&file_priv->prime); + kfree(file_priv); /* ======================================================== diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 0ef358e..83114b5 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -35,6 +35,7 @@ #include <linux/mman.h> #include <linux/pagemap.h> #include <linux/shmem_fs.h> +#include <linux/dma-buf.h> #include "drmP.h" /** @file drm_gem.c @@ -232,6 +233,10 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle) idr_remove(&filp->object_idr, handle); spin_unlock(&filp->table_lock); + if (obj->import_attach) + drm_prime_remove_imported_buf_handle(&filp->prime, + obj->import_attach->dmabuf); + if (dev->driver->gem_close_object) dev->driver->gem_close_object(obj, filp); drm_gem_object_handle_unreference_unlocked(obj); @@ -527,6 +532,10 @@ drm_gem_object_release_handle(int id, void *ptr, void *data) struct drm_gem_object *obj = ptr; struct drm_device *dev = obj->dev; + if (obj->import_attach) + drm_prime_remove_imported_buf_handle(&file_priv->prime, + obj->import_attach->dmabuf); + if (dev->driver->gem_close_object) dev->driver->gem_close_object(obj, file_priv); diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c new file mode 100644 index 0000000..ff566eb --- /dev/null +++ b/drivers/gpu/drm/drm_prime.c @@ -0,0 +1,299 @@ +/* + * Copyright © 2012 Red Hat + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + * + * Authors: + * Dave Airlie <airlied(a)redhat.com> + * Rob Clark <rob.clark(a)linaro.org> + * + */ + +#include <linux/export.h> +#include <linux/dma-buf.h> +#include "drmP.h" + +/* + * DMA-BUF/GEM Object references and lifetime overview: + * + * On the export the dma_buf holds a reference to the exporting GEM + * object. It takes this reference in handle_to_fd_ioctl, when it + * first calls .prime_export and stores the exporting GEM object in + * the dma_buf priv. This reference is released when the dma_buf + * object goes away in the driver .release function. + * + * On the import the importing GEM object holds a reference to the + * dma_buf (which in turn holds a ref to the exporting GEM object). + * It takes that reference in the fd_to_handle ioctl. + * It calls dma_buf_get, creates an attachment to it and stores the + * attachment in the GEM object. When this attachment is destroyed + * when the imported object is destroyed, we remove the attachment + * and drop the reference to the dma_buf. + * + * Thus the chain of references always flows in one direction + * (avoiding loops): importing_gem -> dmabuf -> exporting_gem + */ + +struct drm_prime_member { + struct list_head entry; + struct dma_buf *dma_buf; + uint32_t handle; +}; + +int drm_gem_prime_handle_to_fd(struct drm_device *dev, + struct drm_file *file_priv, uint32_t handle, uint32_t flags, + int *prime_fd) +{ + struct drm_gem_object *obj; + void *buf; + + obj = drm_gem_object_lookup(dev, file_priv, handle); + if (!obj) + return -ENOENT; + + mutex_lock(&file_priv->prime.lock); + /* re-export the original imported object */ + if (obj->import_attach) { + get_dma_buf(obj->import_attach->dmabuf); + *prime_fd = dma_buf_fd(obj->import_attach->dmabuf, flags); + drm_gem_object_unreference_unlocked(obj); + mutex_unlock(&file_priv->prime.lock); + return 0; + } + + if (obj->export_dma_buf) { + get_dma_buf(obj->export_dma_buf); + *prime_fd = dma_buf_fd(obj->export_dma_buf, flags); + drm_gem_object_unreference_unlocked(obj); + } else { + buf = dev->driver->gem_prime_export(dev, obj, flags); + if (IS_ERR(buf)) { + /* normally the created dma-buf takes ownership of the ref, + * but if that fails then drop the ref + */ + drm_gem_object_unreference_unlocked(obj); + mutex_unlock(&file_priv->prime.lock); + return PTR_ERR(buf); + } + obj->export_dma_buf = buf; + *prime_fd = dma_buf_fd(buf, flags); + } + mutex_unlock(&file_priv->prime.lock); + return 0; +} +EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); + +int drm_gem_prime_fd_to_handle(struct drm_device *dev, + struct drm_file *file_priv, int prime_fd, uint32_t *handle) +{ + struct dma_buf *dma_buf; + struct drm_gem_object *obj; + int ret; + + dma_buf = dma_buf_get(prime_fd); + if (IS_ERR(dma_buf)) + return PTR_ERR(dma_buf); + + mutex_lock(&file_priv->prime.lock); + + ret = drm_prime_lookup_imported_buf_handle(&file_priv->prime, + dma_buf, handle); + if (!ret) { + ret = 0; + goto out_put; + } + + /* never seen this one, need to import */ + obj = dev->driver->gem_prime_import(dev, dma_buf); + if (IS_ERR(obj)) { + ret = PTR_ERR(obj); + goto out_put; + } + + ret = drm_gem_handle_create(file_priv, obj, handle); + drm_gem_object_unreference_unlocked(obj); + if (ret) + goto out_put; + + ret = drm_prime_add_imported_buf_handle(&file_priv->prime, + dma_buf, *handle); + if (ret) + goto fail; + + mutex_unlock(&file_priv->prime.lock); + return 0; + +fail: + /* hmm, if driver attached, we are relying on the free-object path + * to detach.. which seems ok.. + */ + drm_gem_object_handle_unreference_unlocked(obj); +out_put: + dma_buf_put(dma_buf); + mutex_unlock(&file_priv->prime.lock); + return ret; +} +EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); + +int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv) +{ + struct drm_prime_handle *args = data; + uint32_t flags; + + if (!drm_core_check_feature(dev, DRIVER_PRIME)) + return -EINVAL; + + if (!dev->driver->prime_handle_to_fd) + return -ENOSYS; + + /* check flags are valid */ + if (args->flags & ~DRM_CLOEXEC) + return -EINVAL; + + /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ + flags = args->flags & DRM_CLOEXEC; + + return dev->driver->prime_handle_to_fd(dev, file_priv, + args->handle, flags, &args->fd); +} + +int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv) +{ + struct drm_prime_handle *args = data; + + if (!drm_core_check_feature(dev, DRIVER_PRIME)) + return -EINVAL; + + if (!dev->driver->prime_fd_to_handle) + return -ENOSYS; + + return dev->driver->prime_fd_to_handle(dev, file_priv, + args->fd, &args->handle); +} + +/* + * drm_prime_pages_to_sg + * + * this helper creates an sg table object from a set of pages + * the driver is responsible for mapping the pages into the + * importers address space + */ +struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) +{ + struct sg_table *sg = NULL; + struct scatterlist *iter; + int i; + int ret; + + sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); + if (!sg) + goto out; + + ret = sg_alloc_table(sg, nr_pages, GFP_KERNEL); + if (ret) + goto out; + + for_each_sg(sg->sgl, iter, nr_pages, i) + sg_set_page(iter, pages[i], PAGE_SIZE, 0); + + return sg; +out: + kfree(sg); + return NULL; +} +EXPORT_SYMBOL(drm_prime_pages_to_sg); + +/* helper function to cleanup a GEM/prime object */ +void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) +{ + struct dma_buf_attachment *attach; + struct dma_buf *dma_buf; + attach = obj->import_attach; + if (sg) + dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); + dma_buf = attach->dmabuf; + dma_buf_detach(attach->dmabuf, attach); + /* remove the reference */ + dma_buf_put(dma_buf); +} +EXPORT_SYMBOL(drm_prime_gem_destroy); + +void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) +{ + INIT_LIST_HEAD(&prime_fpriv->head); + mutex_init(&prime_fpriv->lock); +} +EXPORT_SYMBOL(drm_prime_init_file_private); + +void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) +{ + struct drm_prime_member *member, *safe; + list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { + list_del(&member->entry); + kfree(member); + } +} +EXPORT_SYMBOL(drm_prime_destroy_file_private); + +int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle) +{ + struct drm_prime_member *member; + + member = kmalloc(sizeof(*member), GFP_KERNEL); + if (!member) + return -ENOMEM; + + member->dma_buf = dma_buf; + member->handle = handle; + list_add(&member->entry, &prime_fpriv->head); + return 0; +} +EXPORT_SYMBOL(drm_prime_add_imported_buf_handle); + +int drm_prime_lookup_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle) +{ + struct drm_prime_member *member; + + list_for_each_entry(member, &prime_fpriv->head, entry) { + if (member->dma_buf == dma_buf) { + *handle = member->handle; + return 0; + } + } + return -ENOENT; +} +EXPORT_SYMBOL(drm_prime_lookup_imported_buf_handle); + +void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) +{ + struct drm_prime_member *member, *safe; + + mutex_lock(&prime_fpriv->lock); + list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { + if (member->dma_buf == dma_buf) { + list_del(&member->entry); + kfree(member); + } + } + mutex_unlock(&prime_fpriv->lock); +} +EXPORT_SYMBOL(drm_prime_remove_imported_buf_handle); diff --git a/include/drm/drm.h b/include/drm/drm.h index 34a7b89..64ff02d 100644 --- a/include/drm/drm.h +++ b/include/drm/drm.h @@ -617,6 +617,17 @@ struct drm_get_cap { __u64 value; }; +#define DRM_CLOEXEC O_CLOEXEC +struct drm_prime_handle { + __u32 handle; + + /** Flags.. only applicable for handle->fd */ + __u32 flags; + + /** Returned dmabuf file descriptor */ + __s32 fd; +}; + #include "drm_mode.h" #define DRM_IOCTL_BASE 'd' @@ -673,7 +684,8 @@ struct drm_get_cap { #define DRM_IOCTL_UNLOCK DRM_IOW( 0x2b, struct drm_lock) #define DRM_IOCTL_FINISH DRM_IOW( 0x2c, struct drm_lock) -#define DRM_IOCTL_GEM_PRIME_OPEN DRM_IOWR(0x2e, struct drm_gem_open) +#define DRM_IOCTL_PRIME_HANDLE_TO_FD DRM_IOWR(0x2d, struct drm_prime_handle) +#define DRM_IOCTL_PRIME_FD_TO_HANDLE DRM_IOWR(0x2e, struct drm_prime_handle) #define DRM_IOCTL_AGP_ACQUIRE DRM_IO( 0x30) #define DRM_IOCTL_AGP_RELEASE DRM_IO( 0x31) diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 574bd1c..dd73104 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -91,6 +91,7 @@ struct drm_device; #define DRM_UT_CORE 0x01 #define DRM_UT_DRIVER 0x02 #define DRM_UT_KMS 0x04 +#define DRM_UT_PRIME 0x08 /* * Three debug levels are defined. * drm_core, drm_driver, drm_kms @@ -150,6 +151,7 @@ int drm_err(const char *func, const char *format, ...); #define DRIVER_IRQ_VBL2 0x800 #define DRIVER_GEM 0x1000 #define DRIVER_MODESET 0x2000 +#define DRIVER_PRIME 0x4000 #define DRIVER_BUS_PCI 0x1 #define DRIVER_BUS_PLATFORM 0x2 @@ -215,6 +217,11 @@ int drm_err(const char *func, const char *format, ...); drm_ut_debug_printk(DRM_UT_KMS, DRM_NAME, \ __func__, fmt, ##args); \ } while (0) +#define DRM_DEBUG_PRIME(fmt, args...) \ + do { \ + drm_ut_debug_printk(DRM_UT_PRIME, DRM_NAME, \ + __func__, fmt, ##args); \ + } while (0) #define DRM_LOG(fmt, args...) \ do { \ drm_ut_debug_printk(DRM_UT_CORE, NULL, \ @@ -238,6 +245,7 @@ int drm_err(const char *func, const char *format, ...); #else #define DRM_DEBUG_DRIVER(fmt, args...) do { } while (0) #define DRM_DEBUG_KMS(fmt, args...) do { } while (0) +#define DRM_DEBUG_PRIME(fmt, args...) do { } while (0) #define DRM_DEBUG(fmt, arg...) do { } while (0) #define DRM_LOG(fmt, arg...) do { } while (0) #define DRM_LOG_KMS(fmt, args...) do { } while (0) @@ -410,6 +418,12 @@ struct drm_pending_event { void (*destroy)(struct drm_pending_event *event); }; +/* initial implementaton using a linked list - todo hashtab */ +struct drm_prime_file_private { + struct list_head head; + struct mutex lock; +}; + /** File private data */ struct drm_file { int authenticated; @@ -437,6 +451,8 @@ struct drm_file { wait_queue_head_t event_wait; struct list_head event_list; int event_space; + + struct drm_prime_file_private prime; }; /** Wait queue */ @@ -652,6 +668,12 @@ struct drm_gem_object { uint32_t pending_write_domain; void *driver_private; + + /* dma buf exported from this GEM object */ + struct dma_buf *export_dma_buf; + + /* dma buf attachment backing this object */ + struct dma_buf_attachment *import_attach; }; #include "drm_crtc.h" @@ -890,6 +912,20 @@ struct drm_driver { int (*gem_open_object) (struct drm_gem_object *, struct drm_file *); void (*gem_close_object) (struct drm_gem_object *, struct drm_file *); + /* prime: */ + /* export handle -> fd (see drm_gem_prime_handle_to_fd() helper) */ + int (*prime_handle_to_fd)(struct drm_device *dev, struct drm_file *file_priv, + uint32_t handle, uint32_t flags, int *prime_fd); + /* import fd -> handle (see drm_gem_prime_fd_to_handle() helper) */ + int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv, + int prime_fd, uint32_t *handle); + /* export GEM -> dmabuf */ + struct dma_buf * (*gem_prime_export)(struct drm_device *dev, + struct drm_gem_object *obj, int flags); + /* import dmabuf -> GEM */ + struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev, + struct dma_buf *dma_buf); + /* vga arb irq handler */ void (*vgaarb_irq)(struct drm_device *dev, bool state); @@ -1509,6 +1545,32 @@ extern int drm_vblank_info(struct seq_file *m, void *data); extern int drm_clients_info(struct seq_file *m, void* data); extern int drm_gem_name_info(struct seq_file *m, void *data); + +extern int drm_gem_prime_handle_to_fd(struct drm_device *dev, + struct drm_file *file_priv, uint32_t handle, uint32_t flags, + int *prime_fd); +extern int drm_gem_prime_fd_to_handle(struct drm_device *dev, + struct drm_file *file_priv, int prime_fd, uint32_t *handle); + +extern int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv); +extern int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv); + +extern struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages); +extern void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg); + + +void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv); +void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv); +int drm_prime_add_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle); +int drm_prime_lookup_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle); +void drm_prime_remove_imported_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf); + +int drm_prime_add_dma_buf(struct drm_device *dev, struct drm_gem_object *obj); +int drm_prime_lookup_obj(struct drm_device *dev, struct dma_buf *buf, + struct drm_gem_object **obj); + #if DRM_DEBUG_CODE extern int drm_vma_info(struct seq_file *m, void *data); #endif -- 1.7.7.6

13 years, 2 months

6
5
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[PATCH 00/14] DMA-mapping framework redesign preparation

by Marek Szyprowski

Hello eveyone, On Linaro Memory Management meeting in Budapest (May 2011) we have discussed about the design of DMA mapping framework. We tried to identify the drawbacks and limitations as well as to provide some a solution for them. The discussion was mainly about ARM architecture, but some of the conclusions need to be applied to cross-architecture code. The first issue we identified is the fact that on some platform (again, mainly ARM) there are several functions for allocating DMA buffers: dma_alloc_coherent, dma_alloc_writecombine and dma_alloc_noncoherent (not functional now). For each of them there is a match dma_free_* function. This gives us quite a lot of functions in the public API and complicates things when we need to have several different implementations for different devices selected in runtime (if IOMMU controller is available only for a few devices in the system). Also the drivers which use less common variants are less portable because of the lacks of dma_alloc_writecombine on other architectures. The solution we found is to introduce a new public dma mapping functions with additional attributes argument: dma_alloc_attrs and dma_free_attrs(). This way all different kinds of architecture specific buffer mappings can be hidden behind the attributes without the need of creating several versions of dma_alloc_ function. dma_alloc_coherent() can be wrapped on top of new dma_alloc_attrs() with NULL attrs parameter. dma_alloc_writecombine and dma_alloc_noncoherent can be implemented as a simple wrappers which sets attributes to DMA_ATTRS_WRITECOMBINE or DMA_ATTRS_NON_CONSISTENT respectively. These new attributes will be implemented only on the architectures that really support them, the others will simply ignore them defaulting to the dma_alloc_coherent equivalent. The next step in dma mapping framework update is the introduction of dma_mmap/dma_mmap_attrs() function. There are a number of drivers (mainly V4L2 and ALSA) that only exports the DMA buffers to user space. Creating a userspace mapping with correct page attributes is not an easy task for the driver. Also the DMA-mapping framework is the only place where the complete information about the allocated pages is available, especially if the implementation uses IOMMU controller to provide a contiguous buffer in DMA address space which is scattered in physical memory space. Usually these drivers don't touch the buffer data at all, so the mapping in kernel virtual address space is not needed. We can introduce DMA_ATTRIB_NO_KERNEL_MAPPING attribute which lets kernel to skip/ignore creation of kernel virtual mapping. This way we can save previous vmalloc area and simply some mapping operation on a few architectures. This patch series is a preparation for the above changes in the public dma mapping API. The main goal is to modify dma_map_ops structure and let all users to use for implementation of the new public funtions. The proof-of-concept patches for ARM architecture have been already posted a few times and now they are working resonably well. They perform conversion to dma_map_ops based implementation and add support for generic IOMMU-based dma mapping implementation. To get them merged we first need to get acceptance for the changes in the common, cross-architecture structures. More information about these patches can be found in the following threads: http://www.spinics.net/lists/linux-mm/msg19856.html http://www.spinics.net/lists/linux-mm/msg21241.html http://lists.linaro.org/pipermail/linaro-mm-sig/2011-September/000571.html http://lists.linaro.org/pipermail/linaro-mm-sig/2011-September/000577.html http://www.spinics.net/lists/linux-mm/msg25490.html The patches are prepared on top of Linux Kernel v3.2-rc6. I would appreciate any comments and help with getting this patch series into linux-next tree. The idea apllied in this patch set have been also presented during the Kernel Summit 2011 and ELC-E 2011 in Prague, in the presentation 'ARM DMA-Mapping Framework Redesign and IOMMU integration'. I'm really sorry if I missed any of the relevant architecture mailing lists. I've did my best to include everyone. Feel free to forward this patchset to all interested developers and maintainers. I've already feel like a nasty spammer. Best regards Marek Szyprowski Samsung Poland R&D Center Patch summary: Andrzej Pietrasiewicz (9): X86: adapt for dma_map_ops changes MIPS: adapt for dma_map_ops changes PowerPC: adapt for dma_map_ops changes IA64: adapt for dma_map_ops changes SPARC: adapt for dma_map_ops changes Alpha: adapt for dma_map_ops changes SH: adapt for dma_map_ops changes Microblaze: adapt for dma_map_ops changes Unicore32: adapt for dma_map_ops changes Marek Szyprowski (5): common: dma-mapping: introduce alloc_attrs and free_attrs methods common: dma-mapping: remove old alloc_coherent and free_coherent methods common: dma-mapping: introduce mmap method common: DMA-mapping: add WRITE_COMBINE attribute common: DMA-mapping: add NON-CONSISTENT attribute Documentation/DMA-attributes.txt | 19 +++++++++++++++++++ arch/alpha/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/alpha/kernel/pci-noop.c | 10 ++++++---- arch/alpha/kernel/pci_iommu.c | 10 ++++++---- arch/ia64/hp/common/sba_iommu.c | 11 ++++++----- arch/ia64/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/ia64/kernel/pci-swiotlb.c | 9 +++++---- arch/ia64/sn/pci/pci_dma.c | 9 +++++---- arch/microblaze/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/microblaze/kernel/dma.c | 10 ++++++---- arch/mips/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/mips/mm/dma-default.c | 8 ++++---- arch/powerpc/include/asm/dma-mapping.h | 24 ++++++++++++++++-------- arch/powerpc/kernel/dma-iommu.c | 10 ++++++---- arch/powerpc/kernel/dma-swiotlb.c | 4 ++-- arch/powerpc/kernel/dma.c | 10 ++++++---- arch/powerpc/kernel/ibmebus.c | 10 ++++++---- arch/powerpc/platforms/cell/iommu.c | 16 +++++++++------- arch/powerpc/platforms/ps3/system-bus.c | 13 +++++++------ arch/sh/include/asm/dma-mapping.h | 28 ++++++++++++++++++---------- arch/sh/kernel/dma-nommu.c | 4 ++-- arch/sh/mm/consistent.c | 6 ++++-- arch/sparc/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/sparc/kernel/iommu.c | 10 ++++++---- arch/sparc/kernel/ioport.c | 18 ++++++++++-------- arch/sparc/kernel/pci_sun4v.c | 9 +++++---- arch/unicore32/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/unicore32/mm/dma-swiotlb.c | 4 ++-- arch/x86/include/asm/dma-mapping.h | 26 ++++++++++++++++---------- arch/x86/kernel/amd_gart_64.c | 11 ++++++----- arch/x86/kernel/pci-calgary_64.c | 9 +++++---- arch/x86/kernel/pci-dma.c | 3 ++- arch/x86/kernel/pci-nommu.c | 6 +++--- arch/x86/kernel/pci-swiotlb.c | 12 +++++++----- arch/x86/xen/pci-swiotlb-xen.c | 4 ++-- drivers/iommu/amd_iommu.c | 10 ++++++---- drivers/iommu/intel-iommu.c | 9 +++++---- drivers/xen/swiotlb-xen.c | 5 +++-- include/linux/dma-attrs.h | 2 ++ include/linux/dma-mapping.h | 13 +++++++++---- include/linux/swiotlb.h | 6 ++++-- include/xen/swiotlb-xen.h | 6 ++++-- lib/swiotlb.c | 5 +++-- 43 files changed, 305 insertions(+), 182 deletions(-) -- 1.7.1.569.g6f426

13 years, 2 months

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[GIT PULL] DMA-mapping framework updates for 3.4

by Marek Szyprowski

Hi Linus, Please pull the dma-mapping framework updates for v3.4 since commit c16fa4f2ad19908a47c63d8fa436a1178438c7e7: Linux 3.3 with the top-most commit e749a9f707f1102735e02338fa564be86be3bb69 common: DMA-mapping: add NON-CONSISTENT attribute from the git repository at: git://git.infradead.org/users/kmpark/linux-samsung dma-mapping-next Those patches introduce a new alloc method (with support for memory attributes) in dma_map_ops structure, which will later replace dma_alloc_coherent and dma_alloc_writecombine functions. Thanks! Best regards Marek Szyprowski Samsung Poland R&D Center Patch summary: Andrzej Pietrasiewicz (9): X86: adapt for dma_map_ops changes MIPS: adapt for dma_map_ops changes PowerPC: adapt for dma_map_ops changes IA64: adapt for dma_map_ops changes SPARC: adapt for dma_map_ops changes Alpha: adapt for dma_map_ops changes SH: adapt for dma_map_ops changes Microblaze: adapt for dma_map_ops changes Unicore32: adapt for dma_map_ops changes Marek Szyprowski (6): common: dma-mapping: introduce alloc_attrs and free_attrs methods Hexagon: adapt for dma_map_ops changes common: dma-mapping: remove old alloc_coherent and free_coherent methods common: dma-mapping: introduce mmap method common: DMA-mapping: add WRITE_COMBINE attribute common: DMA-mapping: add NON-CONSISTENT attribute Documentation/DMA-attributes.txt | 19 +++++++++++++++++++ arch/alpha/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/alpha/kernel/pci-noop.c | 10 ++++++---- arch/alpha/kernel/pci_iommu.c | 10 ++++++---- arch/hexagon/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/hexagon/kernel/dma.c | 9 +++++---- arch/ia64/hp/common/sba_iommu.c | 11 ++++++----- arch/ia64/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/ia64/kernel/pci-swiotlb.c | 9 +++++---- arch/ia64/sn/pci/pci_dma.c | 9 +++++---- arch/microblaze/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/microblaze/kernel/dma.c | 10 ++++++---- arch/mips/cavium-octeon/dma-octeon.c | 16 ++++++++-------- arch/mips/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/mips/mm/dma-default.c | 8 ++++---- arch/powerpc/include/asm/dma-mapping.h | 24 ++++++++++++++++-------- arch/powerpc/kernel/dma-iommu.c | 10 ++++++---- arch/powerpc/kernel/dma-swiotlb.c | 4 ++-- arch/powerpc/kernel/dma.c | 10 ++++++---- arch/powerpc/kernel/ibmebus.c | 10 ++++++---- arch/powerpc/kernel/vio.c | 14 ++++++++------ arch/powerpc/platforms/cell/iommu.c | 16 +++++++++------- arch/powerpc/platforms/ps3/system-bus.c | 13 +++++++------ arch/sh/include/asm/dma-mapping.h | 28 ++++++++++++++++++---------- arch/sh/kernel/dma-nommu.c | 4 ++-- arch/sh/mm/consistent.c | 6 ++++-- arch/sparc/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/sparc/kernel/iommu.c | 10 ++++++---- arch/sparc/kernel/ioport.c | 18 ++++++++++-------- arch/sparc/kernel/pci_sun4v.c | 9 +++++---- arch/unicore32/include/asm/dma-mapping.h | 18 ++++++++++++------ arch/unicore32/mm/dma-swiotlb.c | 4 ++-- arch/x86/include/asm/dma-mapping.h | 26 ++++++++++++++++---------- arch/x86/kernel/amd_gart_64.c | 11 ++++++----- arch/x86/kernel/pci-calgary_64.c | 9 +++++---- arch/x86/kernel/pci-dma.c | 3 ++- arch/x86/kernel/pci-nommu.c | 6 +++--- arch/x86/kernel/pci-swiotlb.c | 12 +++++++----- arch/x86/xen/pci-swiotlb-xen.c | 4 ++-- drivers/iommu/amd_iommu.c | 10 ++++++---- drivers/iommu/intel-iommu.c | 9 +++++---- drivers/xen/swiotlb-xen.c | 5 +++-- include/linux/dma-attrs.h | 2 ++ include/linux/dma-mapping.h | 13 +++++++++---- include/linux/swiotlb.h | 6 ++++-- include/xen/swiotlb-xen.h | 6 ++++-- lib/swiotlb.c | 5 +++-- 47 files changed, 338 insertions(+), 206 deletions(-)

13 years, 2 months

2
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消灭▲财务黑▲洞

by 财务黑洞

财务黑洞无情-消灭漏洞有道【培训时间】2012年4月13-14日深圳 4月20-21日上海 4月27-28日北京 6月9-10日深圳 6月15-16日上海 7月6-7日北京【培训对象】公司股东、董事长、经理以及企业其他中高层管理人员。【培训费用】￥2800元/人（提供讲义、午餐、发票、茶点等） ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【课程背景】邓老师告诉你：如何发现财务健康的DNA密码如何做到：消灭财务漏洞避免财务黑洞确保经营成果中国企业财务黑洞问题诊断与防范行家，消灭财务黑洞专题研究第一人。用百度搜索“消灭财务漏洞”6个字达260多万条，影响巨大！用谷歌搜索“邓鸿老师”4个字达到1000多万条，是否徒有虚名？培训目标： 1、企业财务黑洞是由多方面因素造成的，财务黑洞的封杀要有专业指导、丰富的实践经验和恰当的方式方法。 2、企业的财务工作好坏不单只是财务部的事情，是企业综合管理水平的体现。邓老师以自己多年所经历的，许多老板用昂贵的金钱甚至是生命为代价所换来的丰富案例，策您警醒，让你吃人家之堑长自己之智。 3、经常听到会计人员抱怨：老板不重视财务。你不妨请你的老板来听一场邓老师的《消灭财务黑洞》的课程，也许是你送给老板的最好礼物！也是给自己工作的最好帮助；经常听到我们的会计抱怨：同事不配合、不理解、不支持我们的财务工作。你不妨建议老板请邓老师去给你的公司全体员工上一堂《消灭财务黑洞》的课程，你的工作环境是不是会得到显著改善？你不妨试一试？课程100%为落地可操作的方法与工具，绝对实战、实效、实用！授课方式：专题讲授、互动交流、案例分析 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【课程大纲】序言： 1、什么是黑洞？ 2、什么是财务黑洞？ 3、织网与补网一、财务黑洞的八大原发病毒（一）收款黑洞 1、常规收款手段为什么失效？ 2、货款要不回为什么还要倒赔钱？ 3、案例：合同纠纷背后的货款欺诈陷阱 4、消灭财务黑洞： A、结合案件一些证据和日常单据明白问题在哪里？ B、如何解决和防范诊断出来的问题？（二）付款黑洞 1、公司有没有资金紧张的时候？资金紧张怎么办？你是怎么做的？为什么说你的做法是错误的，是在自己制造财务黑洞，或者说是自掘陷阱！ 2、错误表现在两个极端：（1）一个极端是忽悠、再忽悠（有的）到骗；（2）另一个极端是扛、死扛、扛到死，把自己弄得很悲壮 3、消灭财务黑洞：（1）惨淡经营、死扛、扛到死有没有必要？（2）提供两种解决办法，供参考：办法一、你能不能挑出可以帮助你暂时渡过难关的那些供应商？暂时继续占用一下人家的资金。办法二、有没有第三条路可走？第三条路怎么走？案例：企业暂停经营撇债（三）税务黑洞 1、内外两套账，为什么税务一查一个准？ 2、是什么原因？因为有三道坎迈不过去：第一道坎：合同与账本，两张皮不黏！第二道坎：资金账户似迷宫，剪不断来理还乱第三道坎：账实要相符，神仙也犯难 3、面对三道坎，你是不是就束手无策？消灭财务黑洞，道在哪里？案例：桌上放收款单据的故事的后续故事（四）投资黑洞 1、投资前-- 练就火眼金睛问题：（1）没有看清合作方，搞清楚其真实意图，让表面现象所迷惑；（2）对产权状况不清，盲目投资；（3）公司收购的两大猫腻如何识破猫腻？避免陷于巨大财务黑洞？ 2、投资合作中-- 给我一双慧眼，不要聪明人办傻事问题：（1）是投资入股还是借款？（2）问题形成后处理方法要得当 3、投资后-- 半睁半闭眼睛，要吃小亏避免上大当。（五）融资黑洞 1、不懂融资，要多作功课，不要犯吃饭不看菜，裁衣不量体常识错误。表现： 1、喜欢包装，“临时抱佛脚” 2、盲目相信中介，迷信能人和关系功课之一：企业所处的发展阶段不同融资渠道有别功课之二：用好企业现有的有效资源是融资的关键。功课之三：认识资金和其能够提供的金融产品，不要做瞎子摸象 2、为了融资而融资，一条道走到黑表现： a、抛开实业玩概念； b、盲目相信过度包装。 3、企业在融资时如何防骗？（六）沟通黑洞 1、采购绑架财务 2、销售尾巴何其多？某物业管理公司的案例三招解决公司沟通黑洞（七）成本黑洞 1、企业成本核算的基本要求 2、案例：原材料成本 X 2 = 销售价的故事（八）管理黑洞 1、会计由谁来招聘？人事部和老板招聘的会计有什么错？ 2、会计工作能不能胜任由谁来考察？ 3、会计经常换有什么严重后果？ 4、账实严重不相符谁之过？ 5、案例：（1）逾期未提交出口单据，税局认定“内销”，补税和滞纳金等500多万元。（2）单据不齐，1000余万出口退税遇阻。二、财务黑洞根源探究 1、曲突徙薪亡恩泽，焦头烂额为上客。 ----忙救火，疏预防 2、麦克唐纳牧师的故事 ----只知其一，不知其二；或者说：知其然不知其所以然。 3、犯用人之忌！（1）用老乡 a、老乡老乡，背后一枪 b、老乡靠得住，母猪能上树（2）用老婆老婆做出纳，管住了钱还有什么没有管住？ 4、四大认识误区最害人，现在明白来得及。三、消灭财务黑洞之道（一）练就消灭财务黑洞的上乘功法 1、五个前提条件 2、织网与补网，你做何选择？ 3、审查方法介绍（1）业务循环审查法（2）五大审查技术方法介绍（二）四级定位防范财务黑洞咨询系统介绍 A、消灭财务黑洞咨询服务方法 1、发现财务黑洞是一项复杂的系统专业工程 2、抓住8大高发点，以点带面，寻根探源，让财务黑洞无可逃遁。 B、四级定位图介绍?? ? 1级：人（财务）行，制度、流程也行解决办法：执行偏差的案例 2级：人（财务）行，制度流程不行 3级：人（财务）不行，制度流程行 4级：人（财务）不行，制度流程也不行案例：理清了一团乱麻四、警惕财务黑洞的变种病毒案例1：外派黑洞：养虎为患案例2：材料黑洞：空运费大于机器价值案例案例3：保密黑洞：老板被敲诈案例4：收购公司黑洞案例5：某公司海外上市劫 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【讲师介绍】邓鸿中国企业财务黑洞问题诊断与防范行家，消灭财务黑洞专题研究第一人 --深圳市福中达投资控股有限公司财务总监 --深圳市多丽电子商务产业园财务顾问 --亚太集团会计师事务所有限公司深圳所合伙人亚太集团会计师事务所有限公司深圳所注册会计师、执业年限12年、会计、审计、财务管理岗位及顾问工作从业年限28年。资深注册会计师、香港城市大学国际会计硕士，亚太集团会计师事务所有限公司深圳总部合伙人。企业各类财务漏洞、财务黑洞问题的咨询诊断与防范行家。资深财务管理、审计、咨询从业者，担任过多家企业财务顾问，从事企业财务管理、咨询和投融资工作达二十多年, 具有较强的综合协调沟通问题能力，主持及参与的项目达三位数以上，具有较为丰富的财务管理、企业投融资、审计、评估、税收筹划、财务税收顾问经验。 ? ? 熟悉国家财务制度和相关政策法规，熟悉国家税收法律法规，熟悉公司改制及上市制度及程序、熟悉财政、税务、工商、劳动人事等政府各部门办事程序及方法，熟悉银行等金融机构投融资技巧并有一定的投融资渠道。有较强的文字功力，能将工作中发现的问题及改进办法整理发表，曾在中国著名《财经》杂志、《会计月刊》、《公司金融》等报刊杂志上发表百多篇文章，《公司金融》杂志更是开辟专栏连载财务黑洞研究方面的系列文章。本人的经验总结性文章《财务黑洞案例实录》在中国会计界最高学府“国家会计学院”“中国会计视野”网站发表一天就达2500多浏览量，创该站记录，时至今日热度不减，第二天就已被收入“中国会计视野”精品文库，仅该网站网友留言就达200多条，转载网站达几万家，上至企业老板，下至大学学生都将该文当做教科书，备受关注和引发热议。在《公司金融》（国内统一刊号：CN44-1563/F 国际标准连续出版刊号：ISSN 1671-6728）杂志上连载的文章有： 1、《私募融资背后的商业谎言》 2009年10月1日总第42期 2、财务黑洞启示录（一）--《内外账的老思维要不得了》 2009年11月1日总第44期 3、财务黑洞启示录（二）--《单据丢失酝酿严重税务后果》2009年11月16日总第45期 4、财务黑洞启示录（三）--《表述模糊引发十年官司》 2009年12月1日总第46期 5、财务黑洞启示录（四）--《合同纠纷背后的货款欺诈陷阱》2010年1月1日总第48期 6、财务黑洞启示录（五）--《友情信任反成投资陷阱》 2010年1月16日总第49期 7、财务黑洞启示录（六）--《资产收购中隐藏的猫腻》 2010年2月1日总第50期培训风格 1.邓鸿老师有很强的现场亲和力、敏锐的学员洞察力以及丰富的授课经验，了解成年人学习的特点，把复杂的问题说得通俗易懂。 2.授课风格既稳重，但又不乏幽默和风趣，采用多样化的互动授课方式，营造轻松愉快的学习气氛，充分调动学员的听课积极性。 3.授课内容既有理论深度，又注重实用效果，使学员在培训后，能在工作中解决实际问题，体现培训真正的价值。培训现场互动性很强，有很强的控场能力，倡导“家常式的互动性强”的授课理念。邓老师提倡实用、实在、实际、实战的培训风格，用专业、专注、方向、方法凝聚学员的满意。 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 深.圳报.名.热.线：０７５５- - ６１.２８.２５.７１陈小姐上.海报.名.热.线: ０２１- - ５１.８７.３７.０８张先生温馨提示:(每期限40人,如需参加请提前预定) QQ订位!-1078861118 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ ▲请将以下报名表内容填写后发送到：chinasypx(a)foxmail.xn--com-s18docw0dhtoqp48a05g9vuvzhmss763etxf01o3s3g! 　　　　　　　　　　　报名回执表　　我单位共_______人报.名参加财务黑洞无情-消灭漏洞有道 4月13-14日深圳□ 4月20-21日上海□ 4月27-28日北京□ 单位名称：_____________________________________________ 联系人：_____________ 联系电话：_______________ 手机：_______________ 图文传真：_____________ 电子信箱：_____________________________________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 总费用：___________ 元整。付款方式：□ 现金　□ 支票　□ 转帐　　（请选择打“√”）备注: 1.请您把报名回执认真填好后回传我司，为确保您报名无误,请您再次电话确认! 2.本课程可根据企业需要组织内训。

13 years, 2 months

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[GIT PULL]: dma-buf updates for 3.4

by Sumit Semwal

Hi Linus, Could you please pull the dma-buf updates for 3.4? This includes the following key items: - kernel cpu access support, - flag-passing to dma_buf_fd, - relevant Documentation updates, and - some minor cleanups and fixes. These changes are needed for the drm prime/dma-buf interface code that Dave Airlie plans to submit in this merge window. Thanks, and best regards, ~Sumit. The following changes since commit c16fa4f2ad19908a47c63d8fa436a1178438c7e7: Linux 3.3 (2012-03-18 16:15:34 -0700) are available in the git repository at: git://git.linaro.org/people/sumitsemwal/linux-dma-buf.git for-linus-3.4 Daniel Vetter (3): dma-buf: don't hold the mutex around map/unmap calls dma-buf: add support for kernel cpu access dma_buf: Add documentation for the new cpu access support Dave Airlie (1): dma-buf: pass flags into dma_buf_fd. Laurent Pinchart (4): dma-buf: Constify ops argument to dma_buf_export() dma-buf: Remove unneeded sanity checks dma-buf: Return error instead of using a goto statement when possible dma-buf: Move code out of mutex-protected section in dma_buf_attach() Rob Clark (2): dma-buf: add get_dma_buf() dma-buf: document fd flags and O_CLOEXEC requirement Sumit Semwal (2): dma-buf: add dma_data_direction to unmap dma_buf_op dma-buf: correct dummy function declarations. Documentation/dma-buf-sharing.txt | 120 ++++++++++++++++++++++++++- drivers/base/dma-buf.c | 165 +++++++++++++++++++++++++++++++------ include/linux/dma-buf.h | 97 +++++++++++++++++++-- 3 files changed, 345 insertions(+), 37 deletions(-)

13 years, 2 months

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消灭财务黑洞 !

by 财务黑洞

财务黑洞无情-消灭漏洞有道【培训时间】2012年4月13-14日深圳 4月20-21日上海 4月27-28日北京 6月9-10日深圳 6月15-16日上海 7月6-7日北京【培训对象】公司股东、董事长、经理以及企业其他中高层管理人员。【培训费用】￥2800元/人（提供讲义、午餐、发票、茶点等） ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【课程背景】邓老师告诉你：如何发现财务健康的DNA密码如何做到：消灭财务漏洞避免财务黑洞确保经营成果中国企业财务黑洞问题诊断与防范行家，消灭财务黑洞专题研究第一人。用百度搜索“消灭财务漏洞”6个字达260多万条，影响巨大！用谷歌搜索“邓鸿老师”4个字达到1000多万条，是否徒有虚名？培训目标： 1、企业财务黑洞是由多方面因素造成的，财务黑洞的封杀要有专业指导、丰富的实践经验和恰当的方式方法。 2、企业的财务工作好坏不单只是财务部的事情，是企业综合管理水平的体现。邓老师以自己多年所经历的，许多老板用昂贵的金钱甚至是生命为代价所换来的丰富案例，策您警醒，让你吃人家之堑长自己之智。 3、经常听到会计人员抱怨：老板不重视财务。你不妨请你的老板来听一场邓老师的《消灭财务黑洞》的课程，也许是你送给老板的最好礼物！也是给自己工作的最好帮助；经常听到我们的会计抱怨：同事不配合、不理解、不支持我们的财务工作。你不妨建议老板请邓老师去给你的公司全体员工上一堂《消灭财务黑洞》的课程，你的工作环境是不是会得到显著改善？你不妨试一试？课程100%为落地可操作的方法与工具，绝对实战、实效、实用！授课方式：专题讲授、互动交流、案例分析 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【课程大纲】序言： 1、什么是黑洞？ 2、什么是财务黑洞？ 3、织网与补网一、财务黑洞的八大原发病毒（一）收款黑洞 1、常规收款手段为什么失效？ 2、货款要不回为什么还要倒赔钱？ 3、案例：合同纠纷背后的货款欺诈陷阱 4、消灭财务黑洞： A、结合案件一些证据和日常单据明白问题在哪里？ B、如何解决和防范诊断出来的问题？（二）付款黑洞 1、公司有没有资金紧张的时候？资金紧张怎么办？你是怎么做的？为什么说你的做法是错误的，是在自己制造财务黑洞，或者说是自掘陷阱！ 2、错误表现在两个极端：（1）一个极端是忽悠、再忽悠（有的）到骗；（2）另一个极端是扛、死扛、扛到死，把自己弄得很悲壮 3、消灭财务黑洞：（1）惨淡经营、死扛、扛到死有没有必要？（2）提供两种解决办法，供参考：办法一、你能不能挑出可以帮助你暂时渡过难关的那些供应商？暂时继续占用一下人家的资金。办法二、有没有第三条路可走？第三条路怎么走？案例：企业暂停经营撇债（三）税务黑洞 1、内外两套账，为什么税务一查一个准？ 2、是什么原因？因为有三道坎迈不过去：第一道坎：合同与账本，两张皮不黏！第二道坎：资金账户似迷宫，剪不断来理还乱第三道坎：账实要相符，神仙也犯难 3、面对三道坎，你是不是就束手无策？消灭财务黑洞，道在哪里？案例：桌上放收款单据的故事的后续故事（四）投资黑洞 1、投资前-- 练就火眼金睛问题：（1）没有看清合作方，搞清楚其真实意图，让表面现象所迷惑；（2）对产权状况不清，盲目投资；（3）公司收购的两大猫腻如何识破猫腻？避免陷于巨大财务黑洞？ 2、投资合作中-- 给我一双慧眼，不要聪明人办傻事问题：（1）是投资入股还是借款？（2）问题形成后处理方法要得当 3、投资后-- 半睁半闭眼睛，要吃小亏避免上大当。（五）融资黑洞 1、不懂融资，要多作功课，不要犯吃饭不看菜，裁衣不量体常识错误。表现： 1、喜欢包装，“临时抱佛脚” 2、盲目相信中介，迷信能人和关系功课之一：企业所处的发展阶段不同融资渠道有别功课之二：用好企业现有的有效资源是融资的关键。功课之三：认识资金和其能够提供的金融产品，不要做瞎子摸象 2、为了融资而融资，一条道走到黑表现： a、抛开实业玩概念； b、盲目相信过度包装。 3、企业在融资时如何防骗？（六）沟通黑洞 1、采购绑架财务 2、销售尾巴何其多？某物业管理公司的案例三招解决公司沟通黑洞（七）成本黑洞 1、企业成本核算的基本要求 2、案例：原材料成本 X 2 = 销售价的故事（八）管理黑洞 1、会计由谁来招聘？人事部和老板招聘的会计有什么错？ 2、会计工作能不能胜任由谁来考察？ 3、会计经常换有什么严重后果？ 4、账实严重不相符谁之过？ 5、案例：（1）逾期未提交出口单据，税局认定“内销”，补税和滞纳金等500多万元。（2）单据不齐，1000余万出口退税遇阻。二、财务黑洞根源探究 1、曲突徙薪亡恩泽，焦头烂额为上客。 ----忙救火，疏预防 2、麦克唐纳牧师的故事 ----只知其一，不知其二；或者说：知其然不知其所以然。 3、犯用人之忌！（1）用老乡 a、老乡老乡，背后一枪 b、老乡靠得住，母猪能上树（2）用老婆老婆做出纳，管住了钱还有什么没有管住？ 4、四大认识误区最害人，现在明白来得及。三、消灭财务黑洞之道（一）练就消灭财务黑洞的上乘功法 1、五个前提条件 2、织网与补网，你做何选择？ 3、审查方法介绍（1）业务循环审查法（2）五大审查技术方法介绍（二）四级定位防范财务黑洞咨询系统介绍 A、消灭财务黑洞咨询服务方法 1、发现财务黑洞是一项复杂的系统专业工程 2、抓住8大高发点，以点带面，寻根探源，让财务黑洞无可逃遁。 B、四级定位图介绍?? ? 1级：人（财务）行，制度、流程也行解决办法：执行偏差的案例 2级：人（财务）行，制度流程不行 3级：人（财务）不行，制度流程行 4级：人（财务）不行，制度流程也不行案例：理清了一团乱麻四、警惕财务黑洞的变种病毒案例1：外派黑洞：养虎为患案例2：材料黑洞：空运费大于机器价值案例案例3：保密黑洞：老板被敲诈案例4：收购公司黑洞案例5：某公司海外上市劫 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 【讲师介绍】邓鸿中国企业财务黑洞问题诊断与防范行家，消灭财务黑洞专题研究第一人 --深圳市福中达投资控股有限公司财务总监 --深圳市多丽电子商务产业园财务顾问 --亚太集团会计师事务所有限公司深圳所合伙人亚太集团会计师事务所有限公司深圳所注册会计师、执业年限12年、会计、审计、财务管理岗位及顾问工作从业年限28年。资深注册会计师、香港城市大学国际会计硕士，亚太集团会计师事务所有限公司深圳总部合伙人。企业各类财务漏洞、财务黑洞问题的咨询诊断与防范行家。资深财务管理、审计、咨询从业者，担任过多家企业财务顾问，从事企业财务管理、咨询和投融资工作达二十多年, 具有较强的综合协调沟通问题能力，主持及参与的项目达三位数以上，具有较为丰富的财务管理、企业投融资、审计、评估、税收筹划、财务税收顾问经验。 ? ? 熟悉国家财务制度和相关政策法规，熟悉国家税收法律法规，熟悉公司改制及上市制度及程序、熟悉财政、税务、工商、劳动人事等政府各部门办事程序及方法，熟悉银行等金融机构投融资技巧并有一定的投融资渠道。有较强的文字功力，能将工作中发现的问题及改进办法整理发表，曾在中国著名《财经》杂志、《会计月刊》、《公司金融》等报刊杂志上发表百多篇文章，《公司金融》杂志更是开辟专栏连载财务黑洞研究方面的系列文章。本人的经验总结性文章《财务黑洞案例实录》在中国会计界最高学府“国家会计学院”“中国会计视野”网站发表一天就达2500多浏览量，创该站记录，时至今日热度不减，第二天就已被收入“中国会计视野”精品文库，仅该网站网友留言就达200多条，转载网站达几万家，上至企业老板，下至大学学生都将该文当做教科书，备受关注和引发热议。在《公司金融》（国内统一刊号：CN44-1563/F 国际标准连续出版刊号：ISSN 1671-6728）杂志上连载的文章有： 1、《私募融资背后的商业谎言》 2009年10月1日总第42期 2、财务黑洞启示录（一）--《内外账的老思维要不得了》 2009年11月1日总第44期 3、财务黑洞启示录（二）--《单据丢失酝酿严重税务后果》2009年11月16日总第45期 4、财务黑洞启示录（三）--《表述模糊引发十年官司》 2009年12月1日总第46期 5、财务黑洞启示录（四）--《合同纠纷背后的货款欺诈陷阱》2010年1月1日总第48期 6、财务黑洞启示录（五）--《友情信任反成投资陷阱》 2010年1月16日总第49期 7、财务黑洞启示录（六）--《资产收购中隐藏的猫腻》 2010年2月1日总第50期培训风格 1.邓鸿老师有很强的现场亲和力、敏锐的学员洞察力以及丰富的授课经验，了解成年人学习的特点，把复杂的问题说得通俗易懂。 2.授课风格既稳重，但又不乏幽默和风趣，采用多样化的互动授课方式，营造轻松愉快的学习气氛，充分调动学员的听课积极性。 3.授课内容既有理论深度，又注重实用效果，使学员在培训后，能在工作中解决实际问题，体现培训真正的价值。培训现场互动性很强，有很强的控场能力，倡导“家常式的互动性强”的授课理念。邓老师提倡实用、实在、实际、实战的培训风格，用专业、专注、方向、方法凝聚学员的满意。 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ 主办单位:中国商业培训网深.圳报.名.热.线：０７５５- - ６１.２８.２５.７１陈小姐上.海报.名.热.线: ０２１- - ５１.８７.３７.０８张先生温馨提示:(每期限40人,如需参加请提前预定) QQ订位!-1078861118 ≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡ ▲请将以下报名表内容填写后发送到：chinasypx(a)foxmail.xn--com-s18docw0dhtoqp48a05g9vuvzhmss763etxf01o3s3g! 　　　　　　　　　　　报名回执表　　我单位共_______人报.名参加财务黑洞无情-消灭漏洞有道 4月13-14日深圳□ 4月20-21日上海□ 4月27-28日北京□ 单位名称：_____________________________________________ 联系人：_____________ 联系电话：_______________ 手机：_______________ 图文传真：_____________ 电子信箱：_____________________________________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 参会人：_____________ 总费用：___________ 元整。付款方式：□ 现金　□ 支票　□ 转帐　　（请选择打“√”）备注: 1.请您把报名回执认真填好后回传我司，为确保您报名无误,请您再次电话确认! 2.本课程可根据企业需要组织内训。

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企业税务稽查★规避技巧

by 稽查组

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13 years, 2 months

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[PATCH] dma-buf: Correct dummy function declarations.

by Sumit Semwal

While testing, I found that we need to correct some of the dummy declarations. When I send my pull request to Linus, I wish to squash these changes into the original patches from Daniel. Could you please review? Best regards, ~Sumit ========= Dummy functions for the newly added cpu access ops are needed for compilation when dma-buf framework is not compiled-in. Also, the introduction of flags in dma_buf_fd needs to be added to dummy functions as well. Signed-off-by: Sumit Semwal <sumit.semwal(a)linaro.org> --- include/linux/dma-buf.h | 26 +++++++++++++------------- 1 files changed, 13 insertions(+), 13 deletions(-) diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index f08028e..779aaf9 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -189,7 +189,7 @@ static inline struct dma_buf *dma_buf_export(void *priv, return ERR_PTR(-ENODEV); } -static inline int dma_buf_fd(struct dma_buf *dmabuf) +static inline int dma_buf_fd(struct dma_buf *dmabuf, int flags) { return -ENODEV; } @@ -216,36 +216,36 @@ static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, return; } -static inline int dma_buf_begin_cpu_access(struct dma_buf *, - size_t, size_t, - enum dma_data_direction) +static inline int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, + size_t start, size_t len, + enum dma_data_direction dir) { return -ENODEV; } -static inline void dma_buf_end_cpu_access(struct dma_buf *, - size_t, size_t, - enum dma_data_direction) +static inline void dma_buf_end_cpu_access(struct dma_buf *dmabuf, + size_t start, size_t len, + enum dma_data_direction dir) { } -static inline void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long) +static inline void *dma_buf_kmap_atomic(struct dma_buf *db, unsigned long pnum) { return NULL; } -static inline void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, - void *) +static inline void dma_buf_kunmap_atomic(struct dma_buf *db, unsigned long pnum, + void *vaddr) { } -static inline void *dma_buf_kmap(struct dma_buf *, unsigned long) +static inline void *dma_buf_kmap(struct dma_buf *db, unsigned long pnum) { return NULL; } -static inline void dma_buf_kunmap(struct dma_buf *, unsigned long, - void *) +static inline void dma_buf_kunmap(struct dma_buf *db, unsigned long pnum, + void *vaddr) { } #endif /* CONFIG_DMA_SHARED_BUFFER */ -- 1.7.5.4

13 years, 2 months

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dma-buf pull request content

by Sumit Semwal

Hello all, I intend to send the pull request to Linus by Monday - the set below looks to me to be the current content that it'd have on top of 3.3. [You can view this in for-next branch at git://git.linaro.org/people/sumitsemwal/linux-dma-buf.git] I think I could take the userspace mmap patch if we reach a consensus on which one to take (Rob's?, Daniel's?) - I guess we are most likely to agree on Daniel's, with possibly the suggestion from Rob about including IOCTLS but leaving them out of dmabuf ops for this release. Daniel, Rob: would you think I can have an agreed-upon patch by tomorrow afternoon? Then I could push it into for-next by tomorrow, and send a pull request by Monday? Also, if you think I've missed out something, please let me know. Daniel Vetter (3): dma-buf: don't hold the mutex around map/unmap calls dma-buf: add support for kernel cpu access dma_buf: Add documentation for the new cpu access support Dave Airlie (1): dma-buf: pass flags into dma_buf_fd. Laurent Pinchart (4): dma-buf: Constify ops argument to dma_buf_export() dma-buf: Remove unneeded sanity checks dma-buf: Return error instead of using a goto statement when possible dma-buf: Move code out of mutex-protected section in dma_buf_attach() Rob Clark (2): dma-buf: add get_dma_buf() dma-buf: document fd flags and O_CLOEXEC requirement Sumit Semwal (1): dma-buf: add dma_data_direction to unmap dma_buf_op -- Thanks and regards, Sumit Semwal Linaro Kernel Engineer - Graphics working group Linaro.org │ Open source software for ARM SoCs

13 years, 2 months

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[PATCH] dma-buf: document fd flags and O_CLOEXEC requirement

by Rob Clark

From: Rob Clark <rob(a)ti.com> Otherwise subsystems will get this wrong and end up with a second export ioctl with the flag and O_CLOEXEC support added. Signed-off-by: Rob Clark <rob(a)ti.com> Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> --- Updated version of Daniel's original documentation patch with (hopefully) improved wording, and a better description of the motivation. Documentation/dma-buf-sharing.txt | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-) diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt index 225f96d..3b51134 100644 --- a/Documentation/dma-buf-sharing.txt +++ b/Documentation/dma-buf-sharing.txt @@ -223,6 +223,24 @@ Miscellaneous notes: - Any exporters or users of the dma-buf buffer sharing framework must have a 'select DMA_SHARED_BUFFER' in their respective Kconfigs. +- In order to avoid fd leaks on exec, the FD_CLOEXEC flag must be set + on the file descriptor. This is not just a resource leak, but a + potential security hole. It could give the newly exec'd application + access to buffers, via the leaked fd, to which it should otherwise + not be permitted access. + + The problem with doing this via a separate fcntl() call, versus doing it + atomically when the fd is created, is that this is inherently racy in a + multi-threaded app[3]. The issue is made worse when it is library code + opening/creating the file descriptor, as the application may not even be + aware of the fd's. + + To avoid this problem, userspace must have a way to request O_CLOEXEC + flag be set when the dma-buf fd is created. So any API provided by + the exporting driver to create a dmabuf fd must provide a way to let + userspace control setting of O_CLOEXEC flag passed in to dma_buf_fd(). + References: [1] struct dma_buf_ops in include/linux/dma-buf.h [2] All interfaces mentioned above defined in include/linux/dma-buf.h +[3] https://lwn.net/Articles/236486/ -- 1.7.5.4

13 years, 2 months

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[PATCH 1/4] dma-buf: don't hold the mutex around map/unmap calls

by Daniel Vetter

The mutex protects the attachment list and hence needs to be held around the callbakc to the exporters (optional) attach/detach functions. Holding the mutex around the map/unmap calls doesn't protect any dma_buf state. Exporters need to properly protect any of their own state anyway (to protect against calls from their own interfaces). So this only makes the locking messier (and lockdep easier to anger). Therefore let's just drop this. v2: Rebased on top of latest dma-buf-next git. Signed-off-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> Reviewed-by: Rob Clark <rob.clark(a)linaro.org> --- drivers/base/dma-buf.c | 5 ----- include/linux/dma-buf.h | 2 +- 2 files changed, 1 insertions(+), 6 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 3c8c023..5641b9c 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -258,9 +258,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL); - mutex_lock(&attach->dmabuf->lock); sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); - mutex_unlock(&attach->dmabuf->lock); return sg_table; } @@ -282,10 +280,7 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; - mutex_lock(&attach->dmabuf->lock); attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); - mutex_unlock(&attach->dmabuf->lock); - } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index bc4203dc..24e0f48 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -88,7 +88,7 @@ struct dma_buf { struct file *file; struct list_head attachments; const struct dma_buf_ops *ops; - /* mutex to serialize list manipulation and other ops */ + /* mutex to serialize list manipulation and attach/detach */ struct mutex lock; void *priv; }; -- 1.7.7.5

13 years, 2 months

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[PATCH] [RFC] dma-buf: mmap support

by Daniel Vetter

Let's have some competition here for dma_buf mmap support ;-) Compared to Rob Clarke's RFC I've ditched the prepare/finish hooks and corresponding ioctls on the dma_buf file. The major reason for that is that many people seem to be under the impression that this is also for synchronization with outstanding asynchronous processsing. I'm pretty massively opposed to this because: - It boils down reinventing a new rather general-purpose userspace synchronization interface. If we look at things like futexes, this is hard to get right. - Furthermore a lot of kernel code has to interact with this synchronization primitive. This smells a look like the dri1 hw_lock, a horror show I prefer not to reinvent. - Even more fun is that multiple different subsystems would interact here, so we have plenty of opportunities to create funny deadlock scenarios. I think synchronization is a wholesale different problem from data sharing and should be tackled as an orthogonal problem. Now we could demand that prepare/finish may only ensure cache coherency (as Rob intended), but that runs up into the next problem: We not only need mmap support to facilitate sw-only processing nodes in a pipeline (without jumping through hoops by importing the dma_buf into some sw-access only importer), which allows for a nicer ION->dma-buf upgrade path for existing Android userspace. We also need mmap support for existing importing subsystems to support existing userspace libraries. And a loot of these subsystems are expected to export coherent userspace mappings. So prepare/finish can only ever be optional and the exporter /needs/ to support coherent mappings. Given that mmap access is always somewhat fallback-y in nature I've decided to drop this optimization, instead of just making it optional. If we demonstrate a clear need for this, supported by benchmark results, we can always add it in again later as an optional extension. Other differences compared to Rob's RFC is the above mentioned support for mapping a dma-buf through facilities provided by the importer. Which results in mmap support no longer being optional. Note taht this dma-buf mmap patch does _not_ support every possible insanity an existing subsystem could pull of with mmap: Because it does not allow to intercept pagefaults and shoot down ptes importing subsystems can't add some magic of their own at these points (e.g. to automatically synchronize with outstanding rendering or set up some special resources). I've done a cursory read through a few mmap implementions of various subsytems and I'm hopeful that we can avoid this (and the complexity it'd bring with it). Additonally I've extended the documentation a bit to explain the hows and whys of this mmap extension. Comments, reviews and flames highly welcome. Cheers, Daniel --- Documentation/dma-buf-sharing.txt | 84 +++++++++++++++++++++++++++++++++--- drivers/base/dma-buf.c | 64 +++++++++++++++++++++++++++- include/linux/dma-buf.h | 16 +++++++ 3 files changed, 156 insertions(+), 8 deletions(-) diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt index a6d4c37..c42a4a5 100644 --- a/Documentation/dma-buf-sharing.txt +++ b/Documentation/dma-buf-sharing.txt @@ -29,13 +29,6 @@ The buffer-user in memory, mapped into its own address space, so it can access the same area of memory. -*IMPORTANT*: [see https://lkml.org/lkml/2011/12/20/211 for more details] -For this first version, A buffer shared using the dma_buf sharing API: -- *may* be exported to user space using "mmap" *ONLY* by exporter, outside of - this framework. -- with this new iteration of the dma-buf api cpu access from the kernel has been - enable, see below for the details. - dma-buf operations for device dma only -------------------------------------- @@ -313,6 +306,83 @@ Access to a dma_buf from the kernel context involves three steps: enum dma_data_direction dir); +Direct Userspace Access/mmap Support +------------------------------------ + +Being able to mmap an export dma-buf buffer object has 2 main use-cases: +- CPU fallback processing in a pipeline and +- supporting existing mmap interfaces in importers. + +1. CPU fallback processing in a pipeline + + In many processing pipelines it is sometimes required that the cpu can access + the data in a dma-buf (e.g. for thumbnail creation, snapshots, ...). To avoid + the need to handle this specially in userspace frameworks for buffer sharing + it's ideal if the dma_buf fd itself can be used to access the backing storage + from userspace using mmap. + + Furthermore Android's ION framework already supports this (and is otherwise + rather similar to dma-buf from a userspace consumer side with using fds as + handles, too). So it's beneficial to support this in a similar fashion on + dma-buf to have a good transition path for existing Android userspace. + + No special interfaces, userspace simply calls mmap on the dma-buf fd. + +2. Supporting existing mmap interfaces in exporters + + Similar to the motivation for kernel cpu access it is again important that + the userspace code of a given importing subsystem can use the same interfaces + with a imported dma-buf buffer object as with a native buffer object. This is + especially important for drm where the userspace part of contemporary OpenGL, + X, and other drivers is huge, and reworking them to use a different way to + mmap a buffer rather invasive. + + The assumption in the current dma-buf interfaces is that redirecting the + initial mmap is all that's needed. A survey of some of the existing + subsystems shows that no driver seems to do any nefarious thing like syncing + up with outstanding asynchronous processing on the device or allocating + special resources at fault time. So hopefully this is good enough, since + adding interfaces to intercept pagefaults and allow pte shootdowns would + increase the complexity quite a bit. + + Interface: + int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, + unsigned long); + + If the importing subsystem simply provides a special-purpose mmap call to set + up a mapping in userspace, calling do_mmap with dma_buf->file will equally + achieve that for a dma-buf object. + +3. Implementation notes for exporters + + Because dma-buf buffers have invariant size over their lifetime, the dma-buf + core checks whether a vma is too large and rejects such mappings. The + exporter hence does not need to duplicate this check. + + Because existing importing subsystems might presume coherent mappings for + userspace, the exporter needs to set up a coherent mapping. If that's not + possible, it needs to fake coherency by manually shooting down ptes when + leaving the cpu domain and flushing caches at fault time. Note that all the + dma_buf files share the same anon inode, hence the exporter needs to replace + the dma_buf file stored in vma->vm_file with it's own if pte shootdown is + requred. This is because the kernel uses the underlying inode's address_space + for vma tracking (and hence pte tracking at shootdown time with + unmap_mapping_range). + + If the above shootdown dance turns out to be too expensive in certain + scenarios, we can extend dma-buf with a more explicit cache tracking scheme + for userspace mappings. But the current assumption is that using mmap is + always a slower path, so some inefficiencies should be acceptable. + + Exporters that shoot down mappings (for any reasons) shall not do any + synchronization at fault time with outstanding device operations. + Synchronization is an orthogonal issue to sharing the backing storage of a + buffer and hence should not be handled by dma-buf itself. This is explictly + mentioned here because many people seem to want something like this, but if + different exporters handle this differently, buffer sharing can fail in + interesting ways depending upong the exporter (if userspace starts depending + upon this implicit synchronization). + Miscellaneous notes ------------------- diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 07cbbc6..f3b923c 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -44,8 +44,26 @@ static int dma_buf_release(struct inode *inode, struct file *file) return 0; } +static int dma_buf_mmap_internal(struct file *file, struct vm_areat_struct *vma) +{ + struct dma_buf *dmabuf; + + if (!is_dma_buf_file(file)) + return -EINVAL; + + /* check for overflowing the buffer's size */ + if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > + dmabuf->size >> PAGE_SHIFT) + return -EINVAL; + + dmabuf = file->private_data; + + return dmabuf->ops->mmap(dmabuf, vma); +} + static const struct file_operations dma_buf_fops = { .release = dma_buf_release, + .mmap = dma_buf_mmap_internal, }; /* @@ -82,7 +100,8 @@ struct dma_buf *dma_buf_export(void *priv, const struct dma_buf_ops *ops, || !ops->unmap_dma_buf || !ops->release || !ops->kmap_atomic - || !ops->kmap)) { + || !ops->kmap + || !ops->mmap)) { return ERR_PTR(-EINVAL); } @@ -406,3 +425,46 @@ void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num, dmabuf->ops->kunmap(dmabuf, page_num, vaddr); } EXPORT_SYMBOL_GPL(dma_buf_kunmap); + + +/** + * dma_buf_mmap - Setup up a userspace mmap with the given vma + * @dma_buf: [in] buffer that should back the vma + * @vma: [in] vma for the mmap + * @pgoff: [in] offset in pages where this mmap should start within the + * dma-buf buffer. + * + * This function adjusts the passed in vma so that it points at the file of the + * dma_buf operation. It alsog adjusts the starting pgoff and does bounds + * checking on the size of the vma. Then it calls the exporters mmap function to + * set up the mapping. + * + * Can return negative error values, returns 0 on success. + */ +int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, + unsigned long pgoff) +{ + if (WARN_ON(!dmabuf || !vma)) + return -EINVAL; + + /* check for offset overflow */ + if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff) + return -EOVERFLOW; + + /* check for overflowing the buffer's size */ + if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) > + dmabuf->size >> PAGE_SHIFT) + return -EINVAL; + + /* readjust the vma */ + if (vma->vm_file) + fput(vma->vm_file); + + vma->vm_file = dmabuf->file; + get_file(vma->vm_file); + + vma->vm_pgoff = pgoff; + + return dmabuf->ops->mmap(dmabuf, vma); +} +EXPORT_SYMBOL_GPL(dma_buf_mmap); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index ee7ef99..d254630 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -61,6 +61,10 @@ struct dma_buf_attachment; * This Callback must not sleep. * @kmap: maps a page from the buffer into kernel address space. * @kunmap: [optional] unmaps a page from the buffer. + * @mmap: used to expose the backing storage to userspace. Note that the + * mapping needs to be coherent - if the exporter doesn't directly + * support this, it needs to fake coherency by shooting down any ptes + * when transitioning away from the cpu domain. */ struct dma_buf_ops { int (*attach)(struct dma_buf *, struct device *, @@ -92,6 +96,8 @@ struct dma_buf_ops { void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *); void *(*kmap)(struct dma_buf *, unsigned long); void (*kunmap)(struct dma_buf *, unsigned long, void *); + + int (*mmap)(struct dma_buf *, struct vm_area_struct *vma); }; /** @@ -167,6 +173,9 @@ void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long); void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *); void *dma_buf_kmap(struct dma_buf *, unsigned long); void dma_buf_kunmap(struct dma_buf *, unsigned long, void *); + +int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, + unsigned long); #else static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, @@ -247,6 +256,13 @@ static inline void dma_buf_kunmap(struct dma_buf *, unsigned long, void *) { } + +static inline int dma_buf_mmap(struct dma_buf *, + struct vm_area_struct *vma, + unsigned long pgoff) +{ + return -ENODEV; +} #endif /* CONFIG_DMA_SHARED_BUFFER */ #endif /* __DMA_BUF_H__ */ -- 1.7.7.5

13 years, 2 months

4
7
0 0

税务风险~规避技~巧与实务

by 企业税务稽查

��ҵ˰��˰��չ�ܼ��ʵ�� ʱ��ص㣺2012��4��19-20��Ϻ� 2012��4��26-27�ձ�� 2012��4��28-29�� γ̷��ã�2800Ԫ/�ˣ��Ϸѡ��ͼ��ȣ� �ڿζ��󣺲��ܾ��Լ��߼��Ӫ��Ա;��ܼࡢ��ܡ� ˰��˰��ܡ��ʻ�ơ�˰��ƵȾ��ʿ�� ԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡ� �� : ˰��ҵ��Ե�һ����ܶ��ҵ��ǰ��˰��ơ��ص㣻�� ҵΪʲô�ᱻ��顢��鲿��Ҫ��ʲô��ô�飿��ĳ��ֻ�ʹ��ҵ��ټ�� ˰��գ� ��2011��ҵ˰��˰��չ�ܼ��ʵ�񡷿γ��Ҫ��⣺ 1��Ϊʲô��ǵ��ҵ�ᱻ��飿��ǵ��ҵû�У� 2��˰��Ҫ��ҵ�Բ飬ʲô��Բ�˰��ز��⣿ 3��ҵ��Щ��˰ҵ��Ƚ��״��⣿��Щ��ڻ��ʱ�ᱻ˰��ص��ע�� 4��Ǳ��ȥ�Ĳ��񱨱��¶��˰��⣿ 5��ڵ��ҵ��Ҫ��Щ˰��⣿ 6��˰��֤�ݵ��Ѽ��Ҫ��Щ�ֶΡ�� 7��ҵ��⣬��ǻ��ʲô��Ĵ�� Ӧ��̼��ܴ��»�С��С�»��ˣ� �ԡԡԡԡԡԡԡ� �� : 1��׼ȷ��ҵ��ٵ�˰��ƣ� 2��˰��鹤��Ļ��򡢻��֪��֪�ˣ��ս�� 3��׼ȷ��ҵ��ٵľ��˰��⼰��ȷ�Ľ��취�� 4��޶Ƚ��˰��գ��ҵ��ʧ�� 5��˰��ǶȽ��񱨱��ǰ��˰��գ� 6��ѡ��ȷ��˰��Ӧ�Բ��ԣ�ʹ��˾�Ͳ�˰��Ա�е��С�ķ��Σ� �ԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡ� �� : ��T�� һ��֣�˰��ҵӦ�Բ��˰�� һ��˰��Ʒ�� 1��˰��飬��ҵ�ĸ��̬�� 2��˰��ĸ��ƣ� 3��2010��˰��鹤��Ļعˣ� 4��2011��˰��鹤��Ŀ�ꡢ��񼰻��ص�� ˰��뷽�� 1��ҵ��ԭ��ķ�� 2��˰��鹤��̼��鲿��ڲ�ְ�ܻ��֣� 3��˰��鰸�� 4��˰��֤��Ѽ� ��˰��۷��Ӧ�� 1��˰��е�˰�� 2��˰��Υ��Ϊ�ķ�� 3��˰��еĹ�ͨ�� 4��˰��۵ķ�� 5��Σ��صļ�� ġ��˰�� 1��˰��Ĺ��Ҫ�� 2��˰��Ļ�� 3��˰��Ĺ�� 4��˰��ԭ�� 5��˰��ķ�չ 6��ѡ��ķ�� T�� ڶ��֣��ҵ�Բ��볣��˰��Ǳ��˰��շ�� һ��˰��Բ� 1��˰��Բ鶨��붨λ 2��ҵ˰��Բ��Ӧ�Բ�� 3��Ŀ��Բ鼼�� 4��ҵ��Բ鼼�� ֵ˰ҵ�񳣼��⼰��Ҫ��鷽�� 1��˰��˳��⼰��鷽�� 2��˰��Χ��⼰��鷽�� 3��˰�ʳ��⼰��鷽�� 4��˰���⼰��鷽�� 5��˰���⼰��鷽�� 6��ֿ�ƾ֤��⼰��鷽�� 7��˰��泣��⼰��鷽�� Ӫҵ˰ҵ�񳣼��⼰��Ҫ��鷽�� 1��˰�˳��⼰��鷽�� 2��˰��Χ��˰�ʳ��⼰��鷽�� 3��˰Ӫҵ���⼰��鷽�� 4��Ŀ��⼰��鷽�� ġ��ҵ��˰ҵ�񳣼��⼰��Ҫ��鷽�� 1��Ŀ��⼰��鷽�� 2��۳��Ŀ��⼰��鷽�� 3��ʲ��⼰��鷽�� 4��˰��Żݳ��⼰��鷽�� 5��ö��⼰��鷽�� 6��Ӧ��˰���⼰��鷽�� 塢��˰ҵ�񳣼��⼰��Ҫ��鷽�� 1��˰�˳��⼰��鷽�� 2��۽��˳��⼰��鷽�� 3��˰��Χ��⼰��鷽�� 4��˰��볣��⼰��鷽�� 5��˰��볣��⼰��鷽�� 6��˰��ļ�� ˰��ҵ�񳣼��⼰��Ҫ��鷽�� 1��˰��⼰��鷽�� 2�� ˰��⼰��鷽�� 3��Դ˰��⼰��鷽�� 4��ʹ��˰��⼰��鷽�� 5��ӡ��˰��⼰��鷽�� 6��ֵ˰��⼰��鷽�� T�� ֣�˰��Ʋ��չ�� һ��˰׼�򡪻��˰��չ�� 1��Բ�� 2��ʱ�Բ�� ʲ�ҵ��׼��˰��չ�� 1��̶��ʲ� 2��ʲ� 3��ڴ�̯�� 4��Ͷ��ʲ� 5�� ׼��˰��˰�� 1��Ʒ�� 2�� 3��ö��ʲ�ʹ��Ȩ�� ġ��ɱ��û��˰��Ƚϼ��˰�� 1��̶��ʲ�֧��޷ѵĿ۳� 2��Ͷ��֧�� 3��Ӫҵ��֮��ҵ��֧�� 4��Ծ��۳� 5��ʲ��ʧ 6��Ϣ֧�� 7��Ѻ�Ӷ��Ŀ۳� �塢��ҵ��׼��˰�� 1��ǻ��ʲ�� 2��ծ�� 豸Ҫ�� 1��ֳֻ�Ͳ 2��ͶӰ�ǣ��ѵʦ�Ա�� 3��װ��װ�� ԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡ� ��T�� ʦ��: �´Ӵ��绪�˽�ʦ500ǿ��й��ѧ��̹��˶ʿ��MBA��й�ע��ʦ��CPA��ע��˰��ʦ ��CPT��й�ĿǰΨһ�ݺᡰ��˰��Դ��ս�Թ��ġ��ܡ�ʵս�ɹ��ר�� ѵʦ��й��˰�γ��󻯵�һ�ˡ��´Ӵ��ʦĿǰΪ�й��ܲ��ѵ��л��ѵ��ɹ�� Ͱ�ֱ��ҡ��ҷ�չ��ĸ�ίԱ�ᡰ��й��ί�ᡢ�۳ɻ��ѧԺ��й��ѧ ѧ��˰�ﻮʦ��֤��Ŀ��й��ҵ��ϻ��֤��Ŀ��Ƹ��ʦ��о�Ժ��Ƹ��ڡ��㽭�� ѧ�ܲðࡢ�Ϻ��ͨ��ѧ��̩��ѧԺ��ѧԺ��Ƹ��ʦ��ν��ｭ��֬��Ʒ��ܡ� ��ﻯ��˾��ܾ��ݴ󹫻��ʦ��ϯע��ʦ��Ϻ��ͨ��Ƽ��޹�˾ ��ϯ��٣�CFO��̩��ͨҩҵ��޹�˾��ܼࡣ��ͨ��ѯ��˰�ﻮ��ʱ��ҵ�ڲ� ��ƶ��ơ��Ŀ��Է��Ŀ��ʵȣ��Ⱥ�Ϊȫ��ʮ��ҵ�ṩ��ѯ��Ϊ��ټ��ҵ�� ҵ��ѵ��񣬴��ɹ��ٰ��δ��͹��Ρ��ġ��˰��չ��˰�ﻮ�� ʵս��ҵ��˰��Ӧ�Բ��Լ�ʵʩ��ĺ��˰��˰��շ��ز��ҵ�� ֵ˰��ʵ��˰�ﻮ��ɡ��и��߸��˰��˰�ﻮ��ǲ��Ĳ�� Ӧ��˿��ͻ��ù��ڲ��չ��»��׼��Ӧ�þ�Ҫ��ȫ��Ԥ�� ҵ�Ĳ��ɱ��ʤʵս��ҵ�ɱ��ơ��ղ��ʵ��˰�ﻮ�� ڲ��ڲ��Ƽ��շ��ȿγ��ҵ��ʿ�� ַ��ͻ��й��š��й�ʯ�͡��й�ʯ��й��С��й��С��ӽ��긣��š� ��ǿͳ��µ��ɽ��硢��֯���ǻ��ѹ��¡��л�� 칤��ϡ��˴Ｏ�š�ӥ�μ��š��Ƶꡢ��Ʒ��з�չ��ĸ�ίԱ�ᡢ̨��о�� ó��ίԱ�ᡢ��ּ��š��š��˹ɷݡ��ҩҵ��ǡ��ȷɳ�ҵ��ɭ̩��硢 ��̩ʵҵ��˴��ߡ��򻪷��Ρ��ص�ء��㽭��ѧ��ݴ�ѧ��ݽ��ѧԺ��Ϻ��ͨ�� ѧ��Ԫ��š��š��ͨ�ͳ��Ϲ��ܡ��ҩҵ��̵ؼ��š��չ��ï��š� �󻪼��š��ɭ��Ϻ��̲ݼ��š��ǵ��Ƽ��Ͽ��š��й����缯�š��ļ�� ɷݡ��й��Ϸ�ȼ��š��ҵ��š��ǹ��衢��ϲ��š��뼯�š��㱦�ɷݡ�� ơ�ơ��֤ȯ�� ڿη��ڶг��Ĭ��ǳ��ʵս��ʵ�á�ʵЧ�� ԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡ� �� .��.��.֯��ŵ˹��ҵ��ѯ��޹�˾ �� .�� .��.��.�ߣ��- - ��.��.��.�� С�� .�� .��.��.��: �� - - ��.��.��.�� ԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡԡ� ��뽫��±��д��͵��chinasypx@foxmail.com��Ա��ڵ�һʱ��ϵ! �� ִ �� ҵ�λ��_______�˱�.��μӡ��ҵ˰��˰��չ�ܼ��ʵ�� λ��ƣ�_____________________________________________ �� ϵ �ˣ�_____________ ��ϵ�绰��_______________ �ֻ��_______________ ͼ�Ĵ��棺_____________ ��䣺_____________________________________ �� ˣ�_____________ �� ˣ�_____________ �� ˣ�_____________ �� ˣ�_____________ �� ˣ�_____________ �� ˣ�_____________ �� ã�___________ Ԫ�� ʽ�� 𡡡� ֧ Ʊ�� ת �ʡ��ѡ��򡰡̡�� ע: 1.��ѱ��ִ��ú�ش��˾��Ϊȷ��,��ٴε绰ȷ��! 2.��γ̿ɸ��ҵ��Ҫ��֯��ѵ��

13 years, 2 months

1
0
0 0

[PATCH 0/4] Miscellaneous dma-buf patches

by Laurent Pinchart

Hi Sumit, Here are 4 dma-buf patches that fix small issues. Laurent Pinchart (4): dma-buf: Constify ops argument to dma_buf_export() dma-buf: Remove unneeded sanity checks dma-buf: Return error instead of using a goto statement when possible dma-buf: Move code out of mutex-protected section in dma_buf_attach() drivers/base/dma-buf.c | 26 +++++++++++--------------- include/linux/dma-buf.h | 8 ++++---- 2 files changed, 15 insertions(+), 19 deletions(-) -- Regards, Laurent Pinchart

13 years, 2 months

4
13
0 0

[PATCH 00/10] Integration of videobuf2 with dmabuf

by Tomasz Stanislawski

Hello everyone, This patchset is an incremental patch to patchset created by Sumit Semwal [1]. The patches are dedicated to help find a better solution for support of buffer sharing by V4L2 API. It is expected to start discussion on final installment for dma-buf in vb2-dma-contig allocator. Current version of the patches contain little documentation. It is going to be fixed after achieving consensus about design for buffer exporting. Moreover the API between vb2-core and the allocator should be revised. The amount of changes to vb2-dma-contig.c was significant making the difference patch very difficult to read. Therefore the patch was split into two parts. One removes old file, the next patch creates the version of the file. The patchset contains extension for DMA API and its implementation for ARM architecture. Therefore the patchset should be applied on the top of: http://git.infradead.org/users/kmpark/linux-2.6-samsung/shortlog/refs/heads… After applying patches from [2] and [1]. v1: List of changes since [1]. - support for DMA api extension dma_get_pages, the function is used to retrieve pages used to create DMA mapping. - small fixes/code cleanup to videobuf2 - added prepare and finish callbacks to vb2 allocators, it is used keep consistency between dma-cpu acess to the memory (by Marek Szyprowski) - support for exporting of DMABUF buffer in V4L2 and Videobuf2, originated from [3]. - support for dma-buf exporting in vb2-dma-contig allocator - support for DMABUF for s5p-tv and s5p-fimc (capture interface) drivers, originated from [3] - changed handling for userptr buffers (by Marek Szyprowski, Andrzej Pietrasiewicz) - let mmap method to use dma_mmap_writecombine call (by Marek Szyprowski) [1] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/4296… [2] https://lkml.org/lkml/2011/12/26/29 [3] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/3635… Marek Szyprowski (2): [media] media: vb2: remove plane argument from call_memop and cleanup mempriv usage media: vb2: add prepare/finish callbacks to allocators Tomasz Stanislawski (8): arm: dma: support for dma_get_pages v4l: vb2: fixes for DMABUF support v4l: add buffer exporting via dmabuf v4l: vb2: add buffer exporting via dmabuf v4l: vb2: remove dma-contig allocator v4l: vb2-dma-contig: code refactoring, support for DMABUF exporting v4l: fimc: integrate capture i-face with dmabuf v4l: s5p-tv: mixer: integrate with dmabuf arch/arm/include/asm/dma-mapping.h | 8 + arch/arm/mm/dma-mapping.c | 44 ++ drivers/media/video/s5p-fimc/fimc-capture.c | 11 +- drivers/media/video/s5p-tv/mixer_video.c | 11 +- drivers/media/video/v4l2-compat-ioctl32.c | 1 + drivers/media/video/v4l2-ioctl.c | 11 + drivers/media/video/videobuf2-core.c | 114 ++++- drivers/media/video/videobuf2-dma-contig.c | 754 +++++++++++++++++++++------ include/linux/dma-mapping.h | 2 + include/linux/videodev2.h | 1 + include/media/v4l2-ioctl.h | 1 + include/media/videobuf2-core.h | 10 +- 12 files changed, 789 insertions(+), 179 deletions(-) -- 1.7.5.4

13 years, 2 months

6
36
0 0

[PATCH v4 0/4] Add CMA heap for ION memory manager

by benjamin.gaignard＠stericsson.com

From: Benjamin Gaignard <benjamin.gaignard(a)linaro.org> The goal of those patches is to allow ION clients (drivers or userland applications) to use Contiguous Memory Allocator (CMA). To get more info about CMA: http://lists.linaro.org/pipermail/linaro-mm-sig/2012-February/001328.html patches version 4: - add ION_HEAP_TYPE_DMA heap type in ion_heap_type enum. - CMA heap is now a "native" ION heap. - add ion_heap_create_full function to keep backward compatibilty. - clean up included files in CMA heap - ux500-ion is using ion_heap_create_full instead of ion_heap_create patches version 3: - add a private field in ion_heap structure instead of expose ion_device structure to all heaps - ion_cma_heap is no more a platform driver - ion_cma_heap use ion_heap private field to store the device pointer and make the link with reserved CMA regions - provide ux500-ion driver and configuration file for snowball board to give an example of how use CMA heaps patches version 2: - fix comments done by Andy Green Benjamin Gaignard (4): fix ion_platform_data definition add private field in ion_heap structure add CMA heap add test/example driver for ux500 platform arch/arm/mach-ux500/board-mop500.c | 77 +++++++++++++++++++ drivers/gpu/ion/Kconfig | 6 ++ drivers/gpu/ion/Makefile | 4 +- drivers/gpu/ion/ion_cma_heap.c | 129 ++++++++++++++++++++++++++++++++ drivers/gpu/ion/ion_heap.c | 14 +++- drivers/gpu/ion/ion_priv.h | 11 +++ drivers/gpu/ion/ux500/Makefile | 1 + drivers/gpu/ion/ux500/ux500_ion.c | 142 ++++++++++++++++++++++++++++++++++++ include/linux/ion.h | 5 +- 9 files changed, 386 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/ion/ion_cma_heap.c create mode 100644 drivers/gpu/ion/ux500/Makefile create mode 100644 drivers/gpu/ion/ux500/ux500_ion.c

13 years, 2 months

1
4
0 0

Re: [Linaro-mm-sig] [PATCH] RFC: dma-buf: userspace mmap support

by Alan Cox

> If the API was to also be used for synchronization it would have to > include an atomic "prepare multiple" ioctl which blocked until all > the buffers listed by the application were available. In the same Too slow already. You are now serializing stuff while what we want to do really is nobody_else_gets_buffers_next([list]) on available(buffer) dispatch_work(buffer) so that you can maximise parallelism without allowing deadlocks. If you've got a high memory bandwith and 8+ cores the 'stop everything' model isn't great. > This might be a good argument for keeping synchronization and cache > maintenance separate, though even ignoring synchronization I would > think being able to issue cache maintenance operations for multiple > buffers in a single ioctl might present some small efficiency gains. > However as Rob points out, CPU access is already in slow/legacy > territory. Dangerous assumption. I do think they should be separate. For one it makes the case of synchronization needed but hardware cache management much easier to split cleanly. Assuming CPU access is slow/legacy reflects a certain model of relatively slow CPU and accelerators where falling off the acceleration path is bad. On a higher end processor falling off the acceleration path isn't a performance matter so much as a power concern. > KDS we differentiated jobs which needed "exclusive access" to a > buffer and jobs which needed "shared access" to a buffer. Multiple > jobs could access a buffer at the same time if those jobs all Makes sense as it's a reader/writer lock and it reflects MESI/MOESI caching and cache policy in some hardware/software assists. > display controller will be reading the front buffer, but the GPU > might also need to read that front buffer. So perhaps adding > "read-only" & "read-write" access flags to prepare could also be > interpreted as shared & exclusive accesses, if we went down this > route for synchronization that is. :-) mmap includes read/write info so probably using that works out. It also means that you have the stuff mapped in a way that will bus error or segfault anyone who goofs rather than give them the usual 'deep weirdness' behaviour you get with mishandling of caching bits. Alan

13 years, 2 months

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Re: [Linaro-mm-sig] [PATCH] RFC: dma-buf: userspace mmap support

by Alan Cox

> > dma-buf file descriptor. Userspace access to the buffer should be > > bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to > > give the exporting driver a chance to deal with cache synchronization > > and such for cached userspace mappings without resorting to page There should be flags indicating if this is necessary. We don't want extra syscalls on hardware that doesn't need it. The other question is what info is needed as you may only want to poke a few pages out of cache and the prepare/finish on its own gives no info. > E.g. If another device was writing to the buffer, the prepare ioctl > could block until that device had finished accessing that buffer. How do you avoid deadlocks on this ? We need very clear ways to ensure things always complete in some form given multiple buffer owner/requestors and the fact this API has no "prepare-multiple-buffers" support. Alan

13 years, 2 months

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[PATCH] dma-buf: pass flags into dma_buf_fd.

by Dave Airlie

From: Dave Airlie <airlied(a)redhat.com> We need to pass the flags into dma_buf_fd at this point, so the flags end up doing the right thing for O_CLOEXEC. Signed-off-by: Dave Airlie <airlied(a)redhat.com> --- drivers/base/dma-buf.c | 5 +++-- include/linux/dma-buf.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index c9a945f..3c8c023 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -107,17 +107,18 @@ EXPORT_SYMBOL_GPL(dma_buf_export); /** * dma_buf_fd - returns a file descriptor for the given dma_buf * @dmabuf: [in] pointer to dma_buf for which fd is required. + * @flags: [in] flags to give to fd * * On success, returns an associated 'fd'. Else, returns error. */ -int dma_buf_fd(struct dma_buf *dmabuf) +int dma_buf_fd(struct dma_buf *dmabuf, int flags) { int error, fd; if (!dmabuf || !dmabuf->file) return -EINVAL; - error = get_unused_fd(); + error = get_unused_fd_flags(flags); if (error < 0) return error; fd = error; diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index a885b26..891457a 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -117,7 +117,7 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *dmabuf_attach); struct dma_buf *dma_buf_export(void *priv, const struct dma_buf_ops *ops, size_t size, int flags); -int dma_buf_fd(struct dma_buf *dmabuf); +int dma_buf_fd(struct dma_buf *dmabuf, int flags); struct dma_buf *dma_buf_get(int fd); void dma_buf_put(struct dma_buf *dmabuf); -- 1.7.6

13 years, 2 months

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[PATCH] dma-buf: add get_dma_buf()

by Rob Clark

From: Rob Clark <rob(a)ti.com> Works in a similar way to get_file(), and is needed in cases such as when the exporter needs to also keep a reference to the dmabuf (that is later released with a dma_buf_put()), and possibly other similar cases. Signed-off-by: Rob Clark <rob(a)ti.com> --- Minor update on original to add a missing #include include/linux/dma-buf.h | 15 +++++++++++++++ 1 files changed, 15 insertions(+), 0 deletions(-) diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 891457a..bc4203dc 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -30,6 +30,7 @@ #include <linux/scatterlist.h> #include <linux/list.h> #include <linux/dma-mapping.h> +#include <linux/fs.h> struct dma_buf; struct dma_buf_attachment; @@ -110,6 +111,20 @@ struct dma_buf_attachment { void *priv; }; +/** + * get_dma_buf - convenience wrapper for get_file. + * @dmabuf: [in] pointer to dma_buf + * + * Increments the reference count on the dma-buf, needed in case of drivers + * that either need to create additional references to the dmabuf on the + * kernel side. For example, an exporter that needs to keep a dmabuf ptr + * so that subsequent exports don't create a new dmabuf. + */ +static inline void get_dma_buf(struct dma_buf *dmabuf) +{ + get_file(dmabuf->file); +} + #ifdef CONFIG_DMA_SHARED_BUFFER struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, struct device *dev); -- 1.7.5.4

13 years, 2 months

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Re: [Linaro-mm-sig] [PATCH] RFC: dma-buf: userspace mmap support

by Rob Clark

On Fri, Mar 16, 2012 at 12:24 PM, Tom Cooksey <tom.cooksey(a)arm.com> wrote: > >> From: Rob Clark <rob(a)ti.com> >> >> Enable optional userspace access to dma-buf buffers via mmap() on the >> dma-buf file descriptor. Userspace access to the buffer should be >> bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to >> give the exporting driver a chance to deal with cache synchronization >> and such for cached userspace mappings without resorting to page >> faulting tricks. The reasoning behind this is that, while drm >> drivers tend to have all the mechanisms in place for dealing with >> page faulting tricks, other driver subsystems may not. And in >> addition, while page faulting tricks make userspace simpler, there >> are some associated overheads. > > Speaking for the ARM Mali T6xx driver point of view, this API looks > good for us. Our use-case for mmap is glReadPixels and > glTex[Sub]Image2D on buffers the driver has imported via dma_buf. In > the case of glReadPixels, the finish ioctl isn't strictly necessary > as the CPU won't have written to the buffer and so doesn't need > flushing. As such, we'd get an additional cache flush which isn't > really necessary. But hey, it's glReadPixels - it's supposed to be > slow. :-) > > I think requiring the finish ioctl in the API contract is a good > idea, even if the CPU has only done a ro access as it allows future > enhancements*. To "fix" the unnecessary flush in glReadPixels, I > think we'd like to keep the finish but see an "access type" > parameter added to prepare ioctl indicating if the access is ro or > rw to allow the cache flush in finish to be skipped if the access > was ro. As Rebecca says, a debug feature could even be added to > re-map the pages as ro in prepare(ro) to catch naughty accesses. I'd > also go as far as to say the debug feature should completely unmap > the pages after finish too. Though for us, both the access-type > parameter and debug features are "nice to haves" - we can make > progress with the code as it currently stands (assuming exporters > start using the API that is). Perhaps it isn't a bad idea to include access-type bitmask in the first version. It would help optimize a bit the cache operations. > Something which also came up when discussing internally is the topic > of mmap APIs of the importing device driver. For example, I believe > DRM has an mmap API on GEM buffer objects. If a new dma_buf import > ioctl was added to GEM (maybe the PRIME patches already add this), > how would GEM's bo mmap API work? My first thought is maybe we should just dis-allow this for now until we have a chance to see if there are any possible issues with an importer mmap'ing the buffer to userspace. We could possible have a helper dma_buf_mmap() fxn which in turn calls dmabuf ops->mmap() so the mmap'ing is actually performed by the exporter on behalf of the importer. > > * Future enhancements: The prepare/finish bracketing could be used > as part of a wider synchronization scheme with other devices. > E.g. If another device was writing to the buffer, the prepare ioctl > could block until that device had finished accessing that buffer. > In the same way, another device could be blocked from accessing that > buffer until the client process called finish. We have already > started playing with such a scheme in the T6xx driver stack we're > terming "kernel dependency system". In this scheme each buffer has a > FIFO of "buffer consumers" waiting to access a buffer. The idea > being that a "buffer consumer" is fairly abstract and could be any > device or userspace process participating in the synchronization > scheme. Examples would be GPU jobs, display controller "scan-out" > jobs, etc. > > So for example, a userspace application could dispatch a GPU > fragment shading job into the GPU's kernel driver which will write > to a KMS scanout buffer. The application then immediately issues a > drm_mode_crtc_page_flip ioctl on the display controller's DRM driver > to display the soon-to-be-rendered buffer. Inside the kernel, the > GPU driver adds the fragment job to the dma_buf's FIFO. As the FIFO > was empty, dma_buf calls into the GPU kernel driver to tell it it > "owns" access to the buffer and the GPU driver schedules the job to > run on the GPU. Upon receiving the drm_mode_crtc_page_flip ioctl, > the DRM/KMS driver adds a scan-out job to the buffer's FIFO. > However, the FIFO already has the GPU's fragment shading job in it > so nothing happens until the GPU job completes. When the GPU job > completes, the GPU driver calls into dma_buf to mark its job > complete. dma_buf then takes the next job in its FIFO which the KMS > driver's scanout job, calls into the KMS driver to schedule the > pageflip. The result? A buffer gets scanned out as soon as it has > finished being rendered without needing a round-trip to userspace. > Sure, there are easier ways to achieve that goal, but the idea is > that the mechanism can be used to synchronize access across multiple > devices, which makes it useful for lots of other use-cases too. > > > As I say, we have already implemented something which works as I > describe but where the buffers are abstract resources not linked to > dma_buf. I'd like to discuss the finer points of the mechanisms > further, but if it's looking like there's interest in this approach > we'll start re-writing the code we have to sit on-top of dma_buf > and posting it as RFCs to the various lists. The intention is to get > this to mainline, if mainline wants it. :-) I think we do need some sort of 'sync object' (which might really just be a 'synchronization queue' object) in the kernel. It probably shouldn't be built-in to dma-buf, but I expect we'd want the dma_buf struct to have a 'struct sync_queue *' (or whatever it ends up being called). The sync-queue seems like a reasonable approach for pure cpu-sw based synchronization. The only thing I'm not sure is how to also deal with hw that supports any sort of auto synchronization without cpu sw involvement. BR, -R > Personally, what I particularly like about this approach to > synchronization is that it doesn't require any interfaces to be > modified. I think/hope that makes it easier to port existing drivers > and sub-systems to take advantage of it. The buffer itself is the > synchronization object and interfaces already pass buffers around so > don't need modification. There are of course some limitations with > this approach, the main one we can think of being that it can't > really be used for A/V sync. It kinda assumes "jobs" in the FIFO > should be run as soon as the preceding job completes, which isn't > the case when streaming real-time video. Though nothing precludes > more explicit sync objects being used in conjunction with this > approach. > > > Cheers, > > Tom > > > > > > _______________________________________________ > dri-devel mailing list > dri-devel(a)lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel

13 years, 2 months

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[PATCH] RFC: dma-buf: userspace mmap support

by Rob Clark

From: Rob Clark <rob(a)ti.com> Enable optional userspace access to dma-buf buffers via mmap() on the dma-buf file descriptor. Userspace access to the buffer should be bracketed with DMA_BUF_IOCTL_{PREPARE,FINISH}_ACCESS ioctl calls to give the exporting driver a chance to deal with cache synchronization and such for cached userspace mappings without resorting to page faulting tricks. The reasoning behind this is that, while drm drivers tend to have all the mechanisms in place for dealing with page faulting tricks, other driver subsystems may not. And in addition, while page faulting tricks make userspace simpler, there are some associated overheads. In all cases, the mmap() call is allowed to fail, and the associated dma_buf_ops are optional (mmap() will fail if at least the mmap() op is not implemented by the exporter, but in either case the {prepare,finish}_access() ops are optional). For now the prepare/finish access ioctls are kept simple with no argument, although there is possibility to add additional ioctls (or simply change the existing ioctls from _IO() to _IOW()) later to provide optimization to allow userspace to specify a region of interest. For a final patch, dma-buf.h would need to be split into what is exported to userspace, and what is kernel private, but I wanted to get feedback on the idea of requiring userspace to bracket access first (vs. limiting this to coherent mappings or exporters who play page faltings plus PTE shoot-down games) before I split the header which would cause conflicts with other pending dma-buf patches. So flame-on! --- drivers/base/dma-buf.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 22 ++++++++++++++++++++++ 2 files changed, 64 insertions(+), 0 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index c9a945f..382b78a 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -30,6 +30,46 @@ static inline int is_dma_buf_file(struct file *); +static int dma_buf_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct dma_buf *dmabuf; + + if (!is_dma_buf_file(file)) + return -EINVAL; + + dmabuf = file->private_data; + + if (dmabuf->ops->mmap) + return dmabuf->ops->mmap(dmabuf, file, vma); + + return -ENODEV; +} + +static long dma_buf_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct dma_buf *dmabuf; + + if (!is_dma_buf_file(file)) + return -EINVAL; + + dmabuf = file->private_data; + + switch (_IOC_NR(cmd)) { + case _IOC_NR(DMA_BUF_IOCTL_PREPARE_ACCESS): + if (dmabuf->ops->prepare_access) + return dmabuf->ops->prepare_access(dmabuf); + return 0; + case _IOC_NR(DMA_BUF_IOCTL_FINISH_ACCESS): + if (dmabuf->ops->finish_access) + return dmabuf->ops->finish_access(dmabuf); + return 0; + default: + return -EINVAL; + } +} + + static int dma_buf_release(struct inode *inode, struct file *file) { struct dma_buf *dmabuf; @@ -45,6 +85,8 @@ static int dma_buf_release(struct inode *inode, struct file *file) } static const struct file_operations dma_buf_fops = { + .mmap = dma_buf_mmap, + .unlocked_ioctl = dma_buf_ioctl, .release = dma_buf_release, }; diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index a885b26..cbdff81 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -34,6 +34,17 @@ struct dma_buf; struct dma_buf_attachment; +/* TODO: dma-buf.h should be the userspace visible header, and dma-buf-priv.h (?) + * the kernel internal header.. for now just stuff these here to avoid conflicting + * with other patches.. + * + * For now, no arg to keep things simple, but we could consider adding an + * optional region of interest later. + */ +#define DMA_BUF_IOCTL_PREPARE_ACCESS _IO('Z', 0) +#define DMA_BUF_IOCTL_FINISH_ACCESS _IO('Z', 1) + + /** * struct dma_buf_ops - operations possible on struct dma_buf * @attach: [optional] allows different devices to 'attach' themselves to the @@ -49,6 +60,13 @@ struct dma_buf_attachment; * @unmap_dma_buf: decreases usecount of buffer, might deallocate scatter * pages. * @release: release this buffer; to be called after the last dma_buf_put. + * @mmap: [optional, allowed to fail] operation called if userspace calls + * mmap() on the dmabuf fd. Note that userspace should use the + * DMA_BUF_PREPARE_ACCESS / DMA_BUF_FINISH_ACCESS ioctls before/after + * sw access to the buffer, to give the exporter an opportunity to + * deal with cache maintenance. + * @prepare_access: [optional] handler for PREPARE_ACCESS ioctl. + * @finish_access: [optional] handler for FINISH_ACCESS ioctl. */ struct dma_buf_ops { int (*attach)(struct dma_buf *, struct device *, @@ -72,6 +90,10 @@ struct dma_buf_ops { /* after final dma_buf_put() */ void (*release)(struct dma_buf *); + int (*mmap)(struct dma_buf *, struct file *, struct vm_area_struct *); + int (*prepare_access)(struct dma_buf *); + int (*finish_access)(struct dma_buf *); + }; /** -- 1.7.5.4

13 years, 2 months

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expected userspace prime/dma-buf usage

by Dave Airlie

Just wondering how we expect userspace to use dma-buf/prime interfaces. Currently I see one driver in sharing the buffer with handle->fd, then passing the fd to the other driver and it using fd->handle, do we then expect the importing driver to close the fd? Dave.

13 years, 2 months

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[PATCH v3 0/4] Add CMA heap for ION memory manager

by benjamin.gaignard＠stericsson.com

From: benjamin gaignard <benjamin.gaignard(a)linaro.org> The goal of those patches is to allow ION clients (drivers or userland applications) to use Contiguous Memory Allocator (CMA). To get more info about CMA: http://lists.linaro.org/pipermail/linaro-mm-sig/2012-February/001328.html patches version 3: - add a private field in ion_heap structure instead of expose ion_device structure to all heaps - ion_cma_heap is no more a platform driver - ion_cma_heap use ion_heap private field to store the device pointer and make the link with reserved CMA regions - provide ux500-ion driver and configuration file for snowball board to give an example of how use CMA heaps patches version 2: - fix comments done by Andy Green Benjamin Gaignard (1): fix ion_platform_data definition add private field in ion_heap structure add CMA heap add test/example driver for ux500 platform arch/arm/mach-ux500/board-mop500.c | 80 +++++++++++++++++++ drivers/gpu/ion/Kconfig | 6 ++ drivers/gpu/ion/Makefile | 2 + drivers/gpu/ion/cma/Makefile | 1 + drivers/gpu/ion/cma/ion_cma_heap.c | 126 ++++++++++++++++++++++++++++++ drivers/gpu/ion/cma/ion_cma_heap.h | 11 +++ drivers/gpu/ion/ion_priv.h | 2 + drivers/gpu/ion/ux500/Makefile | 1 + drivers/gpu/ion/ux500/ux500_ion.c | 147 ++++++++++++++++++++++++++++++++++++ include/linux/ion.h | 2 +- 10 files changed, 377 insertions(+), 1 deletions(-) create mode 100644 drivers/gpu/ion/cma/Makefile create mode 100644 drivers/gpu/ion/cma/ion_cma_heap.c create mode 100644 drivers/gpu/ion/cma/ion_cma_heap.h create mode 100644 drivers/gpu/ion/ux500/Makefile create mode 100644 drivers/gpu/ion/ux500/ux500_ion.c

13 years, 2 months

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[PATCH 0/3] Add CMA heap for ION memory manager

by benjamin.gaignard＠stericsson.com

From: benjamin gaignard <benjamin.gaignard(a)linaro.org> The goal of those patches is to allow ION clients (drivers or userland applications) to use Contiguous Memory Allocator (CMA). To get more info about CMA: http://lists.linaro.org/pipermail/linaro-mm-sig/2012-February/001328.html patches version 2: fix comments done by Andy Green Benjamin Gaignard (3): make struct ion_device available for other heap fix ion_platform_data definition add CMA heap drivers/gpu/ion/Kconfig | 5 + drivers/gpu/ion/Makefile | 1 + drivers/gpu/ion/cma/Makefile | 1 + drivers/gpu/ion/cma/ion_cma_heap.c | 217 ++++++++++++++++++++++++++++++++++++ drivers/gpu/ion/ion.c | 20 ---- drivers/gpu/ion/ion_priv.h | 22 ++++ include/linux/ion.h | 2 +- 7 files changed, 247 insertions(+), 21 deletions(-) create mode 100644 drivers/gpu/ion/cma/Makefile create mode 100644 drivers/gpu/ion/cma/ion_cma_heap.c

13 years, 2 months

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