From: Dave Airlie airlied@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@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@redhat.com + * Rob Clark rob.clark@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