Linaro-mm-sig July 2012

linaro-mm-sig@lists.linaro.org

19 participants
22 discussions

[PATCHv6 0/2] ARM: replace custom consistent dma region with vmalloc

by Marek Szyprowski

Hello! This is yet another quick update on the patchset which replaces custom consistent dma regions usage in dma-mapping framework in favour of generic vmalloc areas created on demand for each allocation. The main purpose for this patchset is to remove 2MiB limit of dma coherent/writecombine allocations. This version addresses a few more cleanups pointed by Minchan Kim. This patch is based on vanilla v3.5 release. Best regards Marek Szyprowski Samsung Poland R&D Center Changelog: v6: - more cleanups of minor issues pointed by Minchan Kim, moved arm_dma_mmap() changes into separate patch v5: http://thread.gmane.org/gmane.linux.kernel.mm/83096 - fixed another minor issues pointed by Minchan Kim: added more comments here and there, changed pr_err() + stack_dump() to WARN(), added a fix for no-MMU systems v4: http://thread.gmane.org/gmane.linux.kernel.mm/80906 - replaced arch-independent VM_DMA flag with ARM-specific VM_ARM_DMA_CONSISTENT flag v3: http://thread.gmane.org/gmane.linux.kernel.mm/80028 - rebased onto v3.4-rc2: added support for IOMMU-aware implementation of dma-mapping calls, unified with CMA coherent dma pool - implemented changes requested by Minchan Kim: added more checks for vmarea->flags & VM_DMA, renamed some variables, removed obsole locks, squashed find_vm_area() exporting patch into the main redesign patch v2: http://thread.gmane.org/gmane.linux.kernel.mm/78563 - added support for atomic allocations (served from preallocated pool) - minor cleanup here and there - rebased onto v3.4-rc7 v1: http://thread.gmane.org/gmane.linux.kernel.mm/76703 - initial version Patch summary: Marek Szyprowski (2): mm: vmalloc: use const void * for caller argument ARM: dma-mapping: remove custom consistent dma region Documentation/kernel-parameters.txt | 2 +- arch/arm/include/asm/dma-mapping.h | 2 +- arch/arm/mm/dma-mapping.c | 486 ++++++++++++----------------------- arch/arm/mm/mm.h | 3 + include/linux/vmalloc.h | 9 +- mm/vmalloc.c | 28 ++- 6 files changed, 194 insertions(+), 336 deletions(-) -- 1.7.1.569.g6f426

12 years, 4 months

[PATCHv7 00/15] Integration of videobuf2 with dmabuf

by Tomasz Stanislawski

Hello everyone, This patchset adds support for DMABUF [2] importing to V4L2 stack. The support for DMABUF exporting was moved to separate patchset due to dependency on patches for DMA mapping redesign by Marek Szyprowski [4]. This patchset depends on new scatterlist constructor [5]. v7: - support for V4L2_MEMORY_DMABUF in v4l2-compact-ioctl32.c - cosmetic fixes to the documentation - added importing for vmalloc because vmap support in dmabuf for 3.5 was pull-requested - support for dmabuf importing for VIVI - resurrect allocation of dma-contig context - remove reference of alloc_ctx in dma-contig buffer - use sg_alloc_table_from_pages - fix DMA scatterlist calls to use orig_nents instead of nents - fix memleak in vb2_dc_sgt_foreach_page (use orig_nents instead of nents) v6: - fixed missing entry in v4l2_memory_names - fixed a bug occuring after get_user_pages failure - fixed a bug caused by using invalid vma for get_user_pages - prepare/finish no longer call dma_sync for dmabuf buffers v5: - removed change of importer/exporter behaviour - fixes vb2_dc_pages_to_sgt basing on Laurent's hints - changed pin/unpin words to lock/unlock in Doc v4: - rebased on mainline 3.4-rc2 - included missing importing support for s5p-fimc and s5p-tv - added patch for changing map/unmap for importers - fixes to Documentation part - coding style fixes - pairing {map/unmap}_dmabuf in vb2-core - fixing variable types and semantic of arguments in videobufb2-dma-contig.c v3: - rebased on mainline 3.4-rc1 - split 'code refactor' patch to multiple smaller patches - squashed fixes to Sumit's patches - patchset is no longer dependant on 'DMA mapping redesign' - separated path for handling IO and non-IO mappings - add documentation for DMABUF importing to V4L - removed all DMABUF exporter related code - removed usage of dma_get_pages extension v2: - extended VIDIOC_EXPBUF argument from integer memoffset to struct v4l2_exportbuffer - added patch that breaks DMABUF spec on (un)map_atachment callcacks but allows to work with existing implementation of DMABUF prime in DRM - all dma-contig code refactoring patches were squashed - bugfixes 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… [4] http://thread.gmane.org/gmane.linux.kernel.cross-arch/12819 [5] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/47983 Laurent Pinchart (2): v4l: vb2-dma-contig: Shorten vb2_dma_contig prefix to vb2_dc v4l: vb2-dma-contig: Reorder functions Marek Szyprowski (2): v4l: vb2: add prepare/finish callbacks to allocators v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator Sumit Semwal (4): v4l: Add DMABUF as a memory type v4l: vb2: add support for shared buffer (dma_buf) v4l: vb: remove warnings about MEMORY_DMABUF v4l: vb2-dma-contig: add support for dma_buf importing Tomasz Stanislawski (7): Documentation: media: description of DMABUF importing in V4L2 v4l: vb2-dma-contig: remove reference of alloc_ctx from a buffer v4l: vb2-dma-contig: add support for scatterlist in userptr mode v4l: vb2-vmalloc: add support for dmabuf importing v4l: vivi: support for dmabuf importing v4l: s5p-tv: mixer: support for dmabuf importing v4l: s5p-fimc: support for dmabuf importing Documentation/DocBook/media/v4l/compat.xml | 4 + Documentation/DocBook/media/v4l/io.xml | 179 ++++++++ .../DocBook/media/v4l/vidioc-create-bufs.xml | 3 +- Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 15 + Documentation/DocBook/media/v4l/vidioc-reqbufs.xml | 47 +- drivers/media/video/Kconfig | 1 + drivers/media/video/s5p-fimc/Kconfig | 1 + drivers/media/video/s5p-fimc/fimc-capture.c | 2 +- drivers/media/video/s5p-tv/Kconfig | 1 + drivers/media/video/s5p-tv/mixer_video.c | 2 +- drivers/media/video/v4l2-compat-ioctl32.c | 16 + drivers/media/video/v4l2-ioctl.c | 1 + drivers/media/video/videobuf-core.c | 4 + drivers/media/video/videobuf2-core.c | 207 ++++++++- drivers/media/video/videobuf2-dma-contig.c | 470 +++++++++++++++++--- drivers/media/video/videobuf2-vmalloc.c | 56 +++ drivers/media/video/vivi.c | 2 +- include/linux/videodev2.h | 7 + include/media/videobuf2-core.h | 34 ++ 19 files changed, 963 insertions(+), 89 deletions(-) -- 1.7.9.5

12 years, 4 months

[PATCHv2 0/9] Support for dmabuf exporting for videobuf2

by Tomasz Stanislawski

Hello everyone, The patches adds support for DMABUF exporting to V4L2 stack. The latest support for DMABUF importing was posted in [1]. The exporter part is dependant on DMA mapping redesign [2] which is expected to be merged into the mainline. Therefore it is posted as a separate patchset. Moreover some patches depends on vmap extension for DMABUF by Dave Airlie [3] and sg_alloc_table_from_pages function [4]. The last patch 'v4l: vb2-dma-contig: use dma_get_sgtable' depends on dma_get_sgtable extension to DMA api [5]. The tree with all the patches and extensions is available at: repo: git://git.infradead.org/users/kmpark/linux-2.6-samsung branch: media-for3.5-vb2-dmabuf-v7 Changelog: v2: - add documentation for DMABUF exporting - squashed 'let mmap method to use dma_mmap_coherent call' with 'remove vb2_mmap_pfn_range function' - move setup of scatterlist for MMAP buffers from alloc to DMABUF export code - use locking to serialize map/unmap of DMABUF attachments - squash vmap/kmap, setup of sg lists, allocation in attachments into dma-contig exporter patch - fix occasional failure of follow_pfn trick by using init_mm in artificial VMA - add support for exporting in s5p-mfc driver - drop all code that duplicates sg_alloc_table_from_pages - introduce usage of dma_get_sgtable as generic solution to follow_pfn trick v1: - updated setup of VIDIOC_EXPBUF ioctl - doc updates - introduced workaround to avoid using dma_get_pages, - removed caching of exported dmabuf to avoid existence of circular reference between dmabuf and vb2_dc_buf or resource leakage - removed all 'change behaviour' patches - inital support for exporting in s5p-mfs driver - removal of vb2_mmap_pfn_range that is no longer used - use sg_alloc_table_from_pages instead of creating sglist in vb2_dc code - move attachment allocation to exporter's attach callback v0: RFC - initial version [1] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/49438 [2] http://thread.gmane.org/gmane.linux.kernel.cross-arch/14098 [3] http://permalink.gmane.org/gmane.comp.video.dri.devel/69302 [4] This patchset is rebased on 3.4-rc1 plus the following patchsets: [5] http://www.spinics.net/lists/linux-arch/msg18282.html Marek Szyprowski (1): v4l: vb2-dma-contig: let mmap method to use dma_mmap_coherent call Tomasz Stanislawski (8): Documentation: media: description of DMABUF exporting in V4L2 v4l: add buffer exporting via dmabuf v4l: vb2: add buffer exporting via dmabuf v4l: vb2-dma-contig: add support for DMABUF exporting v4l: s5p-fimc: support for dmabuf exporting v4l: s5p-tv: mixer: support for dmabuf exporting v4l: s5p-mfc: support for dmabuf exporting v4l: vb2-dma-contig: use dma_get_sgtable Documentation/DocBook/media/v4l/compat.xml | 3 + Documentation/DocBook/media/v4l/io.xml | 3 + Documentation/DocBook/media/v4l/v4l2.xml | 1 + Documentation/DocBook/media/v4l/vidioc-expbuf.xml | 223 ++++++++++++++++++++ drivers/media/video/s5p-fimc/fimc-capture.c | 9 + drivers/media/video/s5p-mfc/s5p_mfc_dec.c | 18 ++ drivers/media/video/s5p-mfc/s5p_mfc_enc.c | 18 ++ drivers/media/video/s5p-tv/mixer_video.c | 10 + drivers/media/video/v4l2-compat-ioctl32.c | 1 + drivers/media/video/v4l2-dev.c | 1 + drivers/media/video/v4l2-ioctl.c | 6 + drivers/media/video/videobuf2-core.c | 67 ++++++ drivers/media/video/videobuf2-dma-contig.c | 224 ++++++++++++++++++++- drivers/media/video/videobuf2-memops.c | 40 ---- include/linux/videodev2.h | 26 +++ include/media/v4l2-ioctl.h | 2 + include/media/videobuf2-core.h | 2 + include/media/videobuf2-memops.h | 5 - 18 files changed, 612 insertions(+), 47 deletions(-) create mode 100644 Documentation/DocBook/media/v4l/vidioc-expbuf.xml -- 1.7.9.5

12 years, 4 months

[PATCH 0/2] dma-parms and helpers for dma-buf

by Rob Clark

From: Rob Clark <rob(a)ti.com> Re-sending first patch, with a wider audience. Apparently I didn't spam enough inboxes the first time. And, at Daniel Vetter's suggestion, adding some helper functions in dma-buf to get the most restrictive parameters of all the attached devices. Rob Clark (2): device: add dma_params->max_segment_count dma-buf: add helpers for attacher dma-parms drivers/base/dma-buf.c | 63 +++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 1 + include/linux/dma-buf.h | 19 +++++++++++++ include/linux/dma-mapping.h | 16 +++++++++++ 4 files changed, 99 insertions(+) -- 1.7.9.5

12 years, 4 months

[RFC PATCH 1/3] dma-fence: dma-buf synchronization (v5)

by Maarten Lankhorst

A dma-fence can be attached to a buffer which is being filled or consumed by hw, to allow userspace to pass the buffer without waiting to another device. For example, userspace can call page_flip ioctl to display the next frame of graphics after kicking the GPU but while the GPU is still rendering. The display device sharing the buffer with the GPU would attach a callback to get notified when the GPU's rendering-complete IRQ fires, to update the scan-out address of the display, without having to wake up userspace. A dma-fence is transient, one-shot deal. It is allocated and attached to one or more dma-buf's. When the one that attached it is done, with the pending operation, it can signal the fence. + dma_fence_signal() The dma-buf-mgr handles tracking, and waiting on, the fences associated with a dma-buf. TODO maybe need some helper fxn for simple devices, like a display- only drm/kms device which simply wants to wait for exclusive fence to be signaled, and then attach a non-exclusive fence while scanout is in progress. The one pending on the fence can add an async callback (and optionally cancel it.. for example, to recover from GPU hangs): + dma_fence_add_callback() + dma_fence_cancel_callback() Or wait synchronously (optionally with timeout or from atomic context): + dma_fence_wait() A default software-only implementation is provided, which can be used by drivers attaching a fence to a buffer when they have no other means for hw sync. But a memory backed fence is also envisioned, because it is common that GPU's can write to, or poll on some memory location for synchronization. For example: fence = dma_buf_get_fence(dmabuf); if (fence->ops == &bikeshed_fence_ops) { dma_buf *fence_buf; dma_bikeshed_fence_get_buf(fence, &fence_buf, &offset); ... tell the hw the memory location to wait on ... } else { /* fall-back to sw sync * / dma_fence_add_callback(fence, my_cb); } On SoC platforms, if some other hw mechanism is provided for synchronizing between IP blocks, it could be supported as an alternate implementation with it's own fence ops in a similar way. To facilitate other non-sw implementations, the enable_signaling callback can be used to keep track if a device not supporting hw sync is waiting on the fence, and in this case should arrange to call dma_fence_signal() at some point after the condition has changed, to notify other devices waiting on the fence. If there are no sw waiters, this can be skipped to avoid waking the CPU unnecessarily. The intention is to provide a userspace interface (presumably via eventfd) later, to be used in conjunction with dma-buf's mmap support for sw access to buffers (or for userspace apps that would prefer to do their own synchronization). v1: Original v2: After discussion w/ danvet and mlankhorst on #dri-devel, we decided that dma-fence didn't need to care about the sw->hw signaling path (it can be handled same as sw->sw case), and therefore the fence->ops can be simplified and more handled in the core. So remove the signal, add_callback, cancel_callback, and wait ops, and replace with a simple enable_signaling() op which can be used to inform a fence supporting hw->hw signaling that one or more devices which do not support hw signaling are waiting (and therefore it should enable an irq or do whatever is necessary in order that the CPU is notified when the fence is passed). v3: Fix locking fail in attach_fence() and get_fence() v4: Remove tie-in w/ dma-buf.. after discussion w/ danvet and mlankorst we decided that we need to be able to attach one fence to N dma-buf's, so using the list_head in dma-fence struct would be problematic. v5: [ Maarten Lankhorst ] Updated for dma-bikeshed-fence and dma-buf-manager. --- drivers/base/Makefile | 2 drivers/base/dma-fence.c | 317 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-fence.h | 123 +++++++++++++++++ 3 files changed, 441 insertions(+), 1 deletion(-) create mode 100644 drivers/base/dma-fence.c create mode 100644 include/linux/dma-fence.h diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 5aa2d70..6e9f217 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -10,7 +10,7 @@ obj-$(CONFIG_CMA) += dma-contiguous.o obj-y += power/ obj-$(CONFIG_HAS_DMA) += dma-mapping.o obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o -obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf.o +obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf.o dma-fence.o obj-$(CONFIG_ISA) += isa.o obj-$(CONFIG_FW_LOADER) += firmware_class.o obj-$(CONFIG_NUMA) += node.o diff --git a/drivers/base/dma-fence.c b/drivers/base/dma-fence.c new file mode 100644 index 0000000..6798dc4 --- /dev/null +++ b/drivers/base/dma-fence.c @@ -0,0 +1,317 @@ +/* + * Fence mechanism for dma-buf to allow for asynchronous dma access + * + * Copyright (C) 2012 Texas Instruments + * Author: Rob Clark <rob.clark(a)linaro.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/export.h> +#include <linux/dma-fence.h> + +/** + * dma_fence_signal - Signal a fence. + * + * @fence: The fence to signal + * + * All registered callbacks will be called directly (synchronously) and + * all blocked waters will be awoken. + * + * TODO: any value in adding a dma_fence_cancel(), for example to recov + * from hung gpu? It would behave like dma_fence_signal() but return + * an error to waiters and cb's to let them know that the condition they + * are waiting for will never happen. + */ +int dma_fence_signal(struct dma_fence *fence) +{ + unsigned long flags; + int ret = -EINVAL; + + if (WARN_ON(!fence)) + return -EINVAL; + + spin_lock_irqsave(&fence->event_queue.lock, flags); + if (!fence->signaled) { + fence->signaled = true; + wake_up_all_locked(&fence->event_queue); + ret = 0; + } else WARN(1, "Already signaled"); + spin_unlock_irqrestore(&fence->event_queue.lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_fence_signal); + +static void release_fence(struct kref *kref) +{ + struct dma_fence *fence = + container_of(kref, struct dma_fence, refcount); + + WARN_ON(waitqueue_active(&fence->event_queue)); + if (fence->ops->release) + fence->ops->release(fence); + + kfree(fence); +} + +/** + * dma_fence_put - Release a reference to the fence. + */ +void dma_fence_put(struct dma_fence *fence) +{ + WARN_ON(!fence); + kref_put(&fence->refcount, release_fence); +} +EXPORT_SYMBOL_GPL(dma_fence_put); + +/** + * dma_fence_get - Take a reference to the fence. + * + * In most cases this is used only internally by dma-fence. + */ +void dma_fence_get(struct dma_fence *fence) +{ + WARN_ON(!fence); + kref_get(&fence->refcount); +} +EXPORT_SYMBOL_GPL(dma_fence_get); + +static int check_signaling(struct dma_fence *fence) +{ + bool enable_signaling = false, signaled; + unsigned long flags; + + spin_lock_irqsave(&fence->event_queue.lock, flags); + if (!fence->needs_sw_signal) + enable_signaling = fence->needs_sw_signal = true; + signaled = fence->signaled; + spin_unlock_irqrestore(&fence->event_queue.lock, flags); + + if (enable_signaling) { + int ret; + + /* At this point, if enable_signaling returns any error + * a wakeup has to be performanced regardless. + * -ENOENT signals fence was already signaled. Any other error + * inidicates a catastrophic hardware error. + * + * If any hardware error occurs, nothing can be done against + * it, so it's treated like the fence was already signaled. + * No synchronization can be performed, so we have to assume + * the fence was already signaled. + */ + ret = fence->ops->enable_signaling(fence); + if (ret) { + signaled = true; + dma_fence_signal(fence); + } + } + + if (!signaled) + return 0; + else + return -ENOENT; +} + +/** + * dma_fence_add_callback - Add a callback to be called when the fence + * is signaled. + * + * @fence: The fence to wait on + * @cb: The callback to register + * + * Any number of callbacks can be registered to a fence, but a callback + * can only be registered to once fence at a time. + * + * Note that the callback can be called from an atomic context. If + * fence is already signaled, this function will return -ENOENT (and + * *not* call the callback) + */ +int dma_fence_add_callback(struct dma_fence *fence, + struct dma_fence_cb *cb) +{ + unsigned long flags; + int ret; + + if (WARN_ON(!fence || !cb)) + return -EINVAL; + + ret = check_signaling(fence); + + spin_lock_irqsave(&fence->event_queue.lock, flags); + if (!ret && !fence->signaled) { + cb->fence = fence; + __add_wait_queue(&fence->event_queue, &cb->base); + ret = 0; + } else if (!ret) + ret = -ENOENT; + spin_unlock_irqrestore(&fence->event_queue.lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_fence_add_callback); + +/** + * dma_fence_cancel_callback - Remove a previously registered callback. + * + * @cb: The callback to unregister + * + * The callback will not be called after this function returns, but could + * be called before this function returns. + */ +int dma_fence_cancel_callback(struct dma_fence_cb *cb) +{ + struct dma_fence *fence; + unsigned long flags; + int ret = -EINVAL; + + if (WARN_ON(!cb)) + return -EINVAL; + + fence = cb->fence; + + spin_lock_irqsave(&fence->event_queue.lock, flags); + if (fence) { + __remove_wait_queue(&fence->event_queue, &cb->base); + cb->fence = NULL; + ret = 0; + } + spin_unlock_irqrestore(&fence->event_queue.lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_fence_cancel_callback); + +/** + * dma_fence_wait - Wait for a fence to be signaled. + * + * @fence: The fence to wait on + * @interruptible: if true, do an interruptible wait + * @timeout: absolute time for timeout, in jiffies. + * + * Returns 0 on success, -EBUSY if a timeout occured, + * -ERESTARTSYS if the wait was interrupted by a signal. + */ +int dma_fence_wait(struct dma_fence *fence, bool interruptible, unsigned long timeout) +{ + unsigned long cur; + int ret; + + if (WARN_ON(!fence)) + return -EINVAL; + + cur = jiffies; + if (time_after_eq(cur, timeout)) + return -EBUSY; + + timeout -= cur; + + ret = check_signaling(fence); + if (ret == -ENOENT) + return 0; + else if (ret) + return ret; + + if (interruptible) + ret = wait_event_interruptible_timeout(fence->event_queue, + fence->signaled, + timeout); + else + ret = wait_event_timeout(fence->event_queue, + fence->signaled, timeout); + + WARN(1, "wait_event_timeout(%u) returns %i", interruptible, ret); + if (ret > 0) + return 0; + else if (!ret) + return -EBUSY; + else + return ret; +} +EXPORT_SYMBOL_GPL(dma_fence_wait); + +int __dma_fence_wake_func(wait_queue_t *wait, unsigned mode, + int flags, void *key) +{ + struct dma_fence_cb *cb = + container_of(wait, struct dma_fence_cb, base); + struct dma_fence *fence = cb->fence; + int ret; + + ret = cb->func(cb, fence); + cb->fence = NULL; + + return ret; +} +EXPORT_SYMBOL_GPL(__dma_fence_wake_func); + +/* + * Helpers intended to be used by the ops of the dma_fence implementation: + * + * NOTE: helpers and fxns intended to be used by other dma-fence + * implementations are not exported.. I'm not really sure if it makes + * sense to have a dma-fence implementation that is itself a module. + */ + +void __dma_fence_init(struct dma_fence *fence, struct dma_fence_ops *ops, void *priv) +{ + WARN_ON(!ops || !ops->enable_signaling); + + kref_init(&fence->refcount); + fence->ops = ops; + fence->priv = priv; + init_waitqueue_head(&fence->event_queue); +} +EXPORT_SYMBOL_GPL(__dma_fence_init); + +/* + * Pure sw implementation for dma-fence. The CPU always gets involved. + */ + +static int sw_enable_signaling(struct dma_fence *fence) +{ + /* + * pure sw, no irq's to enable, because the fence creator will + * always call dma_fence_signal() + */ + return 0; +} + +static struct dma_fence_ops sw_fence_ops = { + .enable_signaling = sw_enable_signaling, +}; + +/** + * dma_fence_create - Create a simple sw-only fence. + * + * This fence only supports signaling from/to CPU. Other implementations + * of dma-fence can be used to support hardware to hardware signaling, if + * supported by the hardware, and use the dma_fence_helper_* functions for + * compatibility with other devices that only support sw signaling. + */ +struct dma_fence *dma_fence_create(void) +{ + struct dma_fence *fence; + + fence = kzalloc(sizeof(struct dma_fence), GFP_KERNEL); + if (!fence) + return ERR_PTR(-ENOMEM); + + __dma_fence_init(fence, &sw_fence_ops, 0); + + return fence; +} +EXPORT_SYMBOL_GPL(dma_fence_create); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h new file mode 100644 index 0000000..648f136 --- /dev/null +++ b/include/linux/dma-fence.h @@ -0,0 +1,123 @@ +/* + * Fence mechanism for dma-buf to allow for asynchronous dma access + * + * Copyright (C) 2012 Texas Instruments + * Author: Rob Clark <rob.clark(a)linaro.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __DMA_FENCE_H__ +#define __DMA_FENCE_H__ + +#include <linux/err.h> +#include <linux/list.h> +#include <linux/wait.h> +#include <linux/list.h> +#include <linux/dma-buf.h> + +struct dma_fence; +struct dma_fence_ops; +struct dma_fence_cb; + +struct dma_fence { + struct kref refcount; + struct dma_fence_ops *ops; + wait_queue_head_t event_queue; + void *priv; + + /* has this fence been signaled yet? */ + bool signaled : 1; + + /* do we have one or more waiters or callbacks? */ + bool needs_sw_signal : 1; +}; + +typedef int (*dma_fence_func_t)(struct dma_fence_cb *cb, + struct dma_fence *fence); + +struct dma_fence_cb { + wait_queue_t base; + dma_fence_func_t func; + + /* + * This is initialized when the cb is added, and NULL'd when it + * is canceled or expired, so can be used to for error checking + * if the cb is already pending. A dma_fence_cb can be pending + * on at most one fence at a time. + */ + struct dma_fence *fence; +}; + +struct dma_fence_ops { + /** + * For fence implementations that have the capability for hw->hw + * signaling, they can implement this op to enable the necessary + * irqs, or insert commands into cmdstream, etc. This is called + * in the first wait() or add_callback() path to let the fence + * implementation know that there is another driver waiting on + * the signal (ie. hw->sw case). + * + * A return value of -ENOENT will indicate that the fence has + * already passed. + */ + int (*enable_signaling)(struct dma_fence *fence); + void (*release)(struct dma_fence *fence); +}; + +int __dma_fence_wake_func(wait_queue_t *wait, unsigned mode, + int flags, void *key); + +#define DMA_FENCE_CB_INITIALIZER(cb_func) { \ + .base = { .func = __dma_fence_wake_func }, \ + .func = (cb_func), \ + } + +#define DECLARE_DMA_FENCE_CB(name, cb_func) \ + struct dma_fence_cb name = DMA_FENCE_CB_INITIALIZER(cb_func) + + +/* + * TODO does it make sense to be able to enable dma-fence without dma-buf, + * or visa versa? + */ +#ifdef CONFIG_DMA_SHARED_BUFFER + +/* create a basic (pure sw) fence: */ +struct dma_fence *dma_fence_create(void); + +/* intended to be used by other dma_fence implementations: */ +void __dma_fence_init(struct dma_fence *fence, struct dma_fence_ops *ops, void *priv); + +void dma_fence_get(struct dma_fence *fence); +void dma_fence_put(struct dma_fence *fence); +int dma_fence_signal(struct dma_fence *fence); + +int dma_fence_add_callback(struct dma_fence *fence, + struct dma_fence_cb *cb); +int dma_fence_cancel_callback(struct dma_fence_cb *cb); +int dma_fence_wait(struct dma_fence *fence, bool interruptible, unsigned long timeout); + +/* helpers intended to be used by the ops of the dma_fence implementation: */ +int dma_fence_helper_signal(struct dma_fence *fence); +int dma_fence_helper_add_callback(struct dma_fence *fence, + struct dma_fence_cb *cb); +int dma_fence_helper_cancel_callback(struct dma_fence_cb *cb); +int dma_fence_helper_wait(struct dma_fence *fence, bool interruptible, + long timeout); + +#else +// TODO +#endif /* CONFIG_DMA_SHARED_BUFFER */ + +#endif /* __DMA_FENCE_H__ */

12 years, 4 months

[GIT PULL] DMA-mapping updates for v3.6

by Marek Szyprowski

Hi Linus, I would like to ask for pulling another set of DMA-mapping framework updates for v3.6. The following changes since commit 28a33cbc24e4256c143dce96c7d93bf423229f92: Linux 3.5 (2012-07-21 13:58:29 -0700) with the top-most commit 97ef952a20853fad72087a53fa556fbec45edd8f ARM: dma-mapping: add support for DMA_ATTR_SKIP_CPU_SYNC attribute are available in the git repository at: git://git.linaro.org/people/mszyprowski/linux-dma-mapping.git for-linus-for-3.6-rc1 Those patches are continuation of my earlier works merged in commits 58bca4a8fa90 and d484864dd96e1. They contains extensions to DMA-mapping framework to remove limitation of the current ARM implementation (like limited total size of DMA coherent/write combine buffers), improve performance of buffer sharing between devices (attributes to skip cpu cache operations or creation of additional kernel mapping for some specific use cases) as well as some unification of the common code for dma_mmap_attrs()/dma_mmap_coherent() functions. All extensions have been implemented and tested for ARM architecture. Thanks! Best regards Marek Szyprowski Samsung Poland R&D Center Patch summary: Marek Szyprowski (11): mm: vmalloc: use const void * for caller argument ARM: dma-mapping: remove custom consistent dma region ARM: dma-mapping: add more sanity checks in arm_dma_mmap() ARM: dma-mapping: fix error path for memory allocation failure common: dma-mapping: add support for generic dma_mmap_* calls common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute ARM: dma-mapping: add support for DMA_ATTR_NO_KERNEL_MAPPING attribute common: dma-mapping: introduce dma_get_sgtable() function ARM: dma-mapping: add support for dma_get_sgtable() common: DMA-mapping: add DMA_ATTR_SKIP_CPU_SYNC attribute ARM: dma-mapping: add support for DMA_ATTR_SKIP_CPU_SYNC attribute Tomasz Stanislawski (1): scatterlist: add sg_alloc_table_from_pages function Documentation/DMA-attributes.txt | 42 +++ Documentation/kernel-parameters.txt | 2 +- arch/arm/common/dmabounce.c | 1 + arch/arm/include/asm/dma-mapping.h | 24 +- arch/arm/mm/dma-mapping.c | 561 ++++++++++++------------------ arch/arm/mm/mm.h | 3 + arch/powerpc/include/asm/dma-mapping.h | 8 +- arch/powerpc/kernel/dma-iommu.c | 1 + arch/powerpc/kernel/dma-swiotlb.c | 1 + arch/powerpc/kernel/dma.c | 36 +- arch/powerpc/kernel/vio.c | 1 + drivers/base/dma-mapping.c | 49 +++ include/asm-generic/dma-coherent.h | 1 + include/asm-generic/dma-mapping-common.h | 55 +++ include/linux/dma-attrs.h | 2 + include/linux/dma-mapping.h | 3 + include/linux/scatterlist.h | 4 + include/linux/vmalloc.h | 9 +- lib/scatterlist.c | 64 ++++ mm/vmalloc.c | 28 +- 20 files changed, 505 insertions(+), 390 deletions(-)

12 years, 4 months

[PATCH] ARM: dma-mapping: add more sanity checks in arm_dma_mmap()

by Marek Szyprowski

Add some sanity checks and forbid mmaping of buffers into vma areas larger than allocated dma buffer. Signed-off-by: Marek Szyprowski <m.szyprowski(a)samsung.com> --- arch/arm/mm/dma-mapping.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f906d5f..a2881c9 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -611,16 +611,22 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, { int ret = -ENXIO; #ifdef CONFIG_MMU + unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long pfn = dma_to_pfn(dev, dma_addr); + unsigned long off = vma->vm_pgoff; + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) return ret; - ret = remap_pfn_range(vma, vma->vm_start, - pfn + vma->vm_pgoff, - vma->vm_end - vma->vm_start, - vma->vm_page_prot); + if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); + } #endif /* CONFIG_MMU */ return ret; -- 1.7.1.569.g6f426

12 years, 4 months

[PATCHv5 0/2] ARM: replace custom consistent dma region with vmalloc

by Marek Szyprowski

Hello! This is yet another quick update on the patchset which replaces custom consistent dma regions usage in dma-mapping framework in favour of generic vmalloc areas created on demand for each allocation. The main purpose for this patchset is to remove 2MiB limit of dma coherent/writecombine allocations. This version addresses a few minor issues pointed by Minchan Kim. This patch is based on vanilla v3.5 release. Best regards Marek Szyprowski Samsung Poland R&D Center Changelog: v5: - fixed another minor issues pointed by Minchan Kim: added more comments here and there, changed pr_err() + stack_dump() to WARN(), added a fix for no-MMU systems v4: http://thread.gmane.org/gmane.linux.kernel.mm/80906 - replaced arch-independent VM_DMA flag with ARM-specific VM_ARM_DMA_CONSISTENT flag v3: http://thread.gmane.org/gmane.linux.kernel.mm/80028 - rebased onto v3.4-rc2: added support for IOMMU-aware implementation of dma-mapping calls, unified with CMA coherent dma pool - implemented changes requested by Minchan Kim: added more checks for vmarea->flags & VM_DMA, renamed some variables, removed obsole locks, squashed find_vm_area() exporting patch into the main redesign patch v2: http://thread.gmane.org/gmane.linux.kernel.mm/78563 - added support for atomic allocations (served from preallocated pool) - minor cleanup here and there - rebased onto v3.4-rc7 v1: http://thread.gmane.org/gmane.linux.kernel.mm/76703 - initial version Patch summary: Marek Szyprowski (2): mm: vmalloc: use const void * for caller argument ARM: dma-mapping: remove custom consistent dma region Documentation/kernel-parameters.txt | 2 +- arch/arm/include/asm/dma-mapping.h | 2 +- arch/arm/mm/dma-mapping.c | 511 +++++++++++++---------------------- arch/arm/mm/mm.h | 3 + include/linux/vmalloc.h | 9 +- mm/vmalloc.c | 28 ++- 6 files changed, 210 insertions(+), 345 deletions(-) -- 1.7.1.569.g6f426

12 years, 4 months

[PATCH] ARM: DMA-mapping: fix error path for memory allocation failure

by Marek Szyprowski

This patch fixes incorrect check in error path. When the allocation of first page fails, the kernel ops appears due to accessing -1 element of the pages array. Reported-by: Sylwester Nawrocki <s.nawrocki(a)samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski(a)samsung.com> --- arch/arm/mm/dma-mapping.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 7a1d224..3096ed2 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -977,7 +977,7 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t return pages; error: - while (--i) + while (i--) if (pages[i]) __free_pages(pages[i], 0); if (array_size <= PAGE_SIZE) -- 1.7.1.569.g6f426

12 years, 5 months

[RFc] Map CMA pages as cached

by Laura Abbott

Current APIs only support allocating CMA pages as either coherent or writecombine. This seems to miss support for cached pages completely. The following patch seems to be the first obvious solution. More generally though, what should be the strategy for remapping with other memory types? Add a new function call each time? Thanks, Laura

12 years, 5 months

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Linaro-mm-sig July 2012