Linaro-mm-sig

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11 participants
2530 discussions

[PATCH] dma-buf: add meta data attachment

by Bin Wang

we found there'd be varied specific data connected to a dmabuf, like the iommu mapping of buffer, the dma descriptors (that can be shared between several components). Though these info might be able to be generated every time before dma operations, for performance sake, it's better to be kept before really invalid. Change-Id: I89d43dc3fe1ee3da91c42074da5df71b968e6d3c Signed-off-by: Bin Wang <binw(a)marvell.com> --- drivers/base/dma-buf.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 22 ++++++++++ 2 files changed, 122 insertions(+), 0 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 08fe897..5c82e60 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -50,6 +50,7 @@ static int dma_buf_release(struct inode *inode, struct file *file) BUG_ON(dmabuf->vmapping_counter); + dma_buf_meta_release(dmabuf); dmabuf->ops->release(dmabuf); mutex_lock(&db_list.lock); @@ -138,6 +139,7 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, mutex_init(&dmabuf->lock); INIT_LIST_HEAD(&dmabuf->attachments); + INIT_LIST_HEAD(&dmabuf->metas); mutex_lock(&db_list.lock); list_add(&dmabuf->list_node, &db_list.head); @@ -570,6 +572,104 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) } EXPORT_SYMBOL_GPL(dma_buf_vunmap); +/** + * dma_buf_meta_attach - Attach additional meta data to the dmabuf + * @dmabuf: [in] the dmabuf to attach to + * @id: [in] the id of the meta data + * @pdata: [in] the raw data to be attached + * @release: [in] the callback to release the meta data + */ +int dma_buf_meta_attach(struct dma_buf *dmabuf, int id, void *pdata, + int (*release)(void *)) +{ + struct dma_buf_meta *pmeta; + + pmeta = kmalloc(sizeof(struct dma_buf_meta), GFP_KERNEL); + if (pmeta == NULL) + return -ENOMEM; + + pmeta->id = id; + pmeta->pdata = pdata; + pmeta->release = release; + + mutex_lock(&dmabuf->lock); + list_add(&pmeta->node, &dmabuf->metas); + mutex_unlock(&dmabuf->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(dma_buf_meta_attach); + +/** + * dma_buf_meta_dettach - Dettach the meta data from dmabuf by id + * @dmabuf: [in] the dmabuf including the meta data + * @id: [in] the id of the meta data + */ +int dma_buf_meta_dettach(struct dma_buf *dmabuf, int id) +{ + struct dma_buf_meta *pmeta, *tmp; + int ret = -ENOENT; + + mutex_lock(&dmabuf->lock); + list_for_each_entry_safe(pmeta, tmp, &dmabuf->metas, node) { + if (pmeta->id == id) { + if (pmeta->release) + pmeta->release(pmeta->pdata); + list_del(&pmeta->node); + kfree(pmeta); + ret = 0; + break; + } + } + mutex_unlock(&dmabuf->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_buf_meta_dettach); + +/** + * dma_buf_meta_fetch - Get the meta data from dmabuf by id + * @dmabuf: [in] the dmabuf including the meta data + * @id: [in] the id of the meta data + */ +void *dma_buf_meta_fetch(struct dma_buf *dmabuf, int id) +{ + struct dma_buf_meta *pmeta; + void *pdata = NULL; + + mutex_lock(&dmabuf->lock); + list_for_each_entry(pmeta, &dmabuf->metas, node) { + if (pmeta->id == id) { + pdata = pmeta->pdata; + break; + } + } + mutex_unlock(&dmabuf->lock); + + return pdata; +} +EXPORT_SYMBOL_GPL(dma_buf_meta_fetch); + +/** + * dma_buf_meta_release - Release all the meta data attached to the dmabuf + * @dmabuf: [in] the dmabuf including the meta data + */ +void dma_buf_meta_release(struct dma_buf *dmabuf) +{ + struct dma_buf_meta *pmeta, *tmp; + + mutex_lock(&dmabuf->lock); + list_for_each_entry_safe(pmeta, tmp, &dmabuf->metas, node) { + if (pmeta->release) + pmeta->release(pmeta->pdata); + list_del(&pmeta->node); + kfree(pmeta); + } + mutex_unlock(&dmabuf->lock); + + return; +} + #ifdef CONFIG_DEBUG_FS static int dma_buf_describe(struct seq_file *s) { diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index dfac5ed..369d032 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -120,6 +120,7 @@ struct dma_buf { size_t size; struct file *file; struct list_head attachments; + struct list_head metas; const struct dma_buf_ops *ops; /* mutex to serialize list manipulation, attach/detach and vmap/unmap */ struct mutex lock; @@ -149,6 +150,20 @@ struct dma_buf_attachment { }; /** + * struct dma_buf_meta - holds varied meta data attached to the buffer + * @id: the identification of the meta data + * @dmabuf: buffer for this attachment. + * @node: list of dma_buf_meta. + * @pdata: specific meta data. + */ +struct dma_buf_meta { + int id; + struct list_head node; + int (*release)(void *pdata); + void *pdata; +}; + +/** * get_dma_buf - convenience wrapper for get_file. * @dmabuf: [in] pointer to dma_buf * @@ -194,6 +209,13 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *, unsigned long); void *dma_buf_vmap(struct dma_buf *); void dma_buf_vunmap(struct dma_buf *, void *vaddr); + +int dma_buf_meta_attach(struct dma_buf *dmabuf, int id, void *pdata, + int (*release)(void *)); +int dma_buf_meta_dettach(struct dma_buf *dmabuf, int id); +void *dma_buf_meta_fetch(struct dma_buf *dmabuf, int id); +void dma_buf_meta_release(struct dma_buf *dmabuf); + int dma_buf_debugfs_create_file(const char *name, int (*write)(struct seq_file *)); #endif /* __DMA_BUF_H__ */ -- 1.7.0.4

10 years, 9 months

Re: [Linaro-mm-sig] [PATCH v5 09/11] arm: add support for reserved memory defined by device tree

by Grant Likely

On Thu, 13 Mar 2014 14:51:56 -0700, Kevin Hilman <khilman(a)linaro.org> wrote: > Josh Cartwright <joshc(a)codeaurora.org> writes: > > > On Thu, Mar 13, 2014 at 01:46:50PM -0700, Kevin Hilman wrote: > >> On Fri, Feb 21, 2014 at 4:25 AM, Marek Szyprowski > >> <m.szyprowski(a)samsung.com> wrote: > >> > Enable reserved memory initialization from device tree. > >> > > >> > Signed-off-by: Marek Szyprowski <m.szyprowski(a)samsung.com> > >> > >> This patch has hit -next and several legacy (non-DT) boot failures > >> were detected and bisected down to this patch. A quick scan looks > >> like there needs to be some sanity checking whether a DT is even > >> present. > > > > Hmm. Yes, the code unconditionally calls of_flat_dt_scan(), which will > > gladly touch initial_boot_params, even though it may be uninitialized. > > The below patch should allow these boards to boot... > > > > However, I'm wondering if there is a good reason why we don't parse the > > /reserved-memory nodes at the right after we parse the /memory nodes as > > part of early_init_dt_scan()... > > > > Thanks, > > Josh > > > > --8<-- > > Subject: [PATCH] drivers: of: only scan for reserved mem when fdt present > > > > Reported-by: Kevin Hilman <khilman(a)linaro.org> > > Signed-off-by: Josh Cartwright <joshc(a)codeaurora.org> > > This gets legacy boot working again. Thanks. > > Tested-by: Kevin Hilman <khilman(a)linaro.org> Applied and confirmed on non-DT qemu boot. Thanks. It will be pushed out shortly. g.

10 years, 9 months

[RFC][PATCH 1/1] ion: support multiple address space map

by Hiroshi Doyu

Hi, Our H/Ws(inc. GPU) can accept a dmabuf fd which is originally allocated via ION. GPU tries to map this buffer into GPU address space via ION dmabuf backend(.map_dma_buf). Our Tegra IOMMU supports multiple address space in IOMMU. Basically each device has its own address space assigned by IOMMU. Usually DMA API hides the existance of IOMMU from driver code. To support this multiple IOMMU address space, I think that at least "ion_map_dma_buf" needs to create IOMMU mapping *per* device(address space). And I made the following patch *experimentally*. Is this the right solution to solve this multiple IOMMU address space? Any comment would be really appreciated. ---8<------8<------8<------8<------8<------8<------8<------8<--- From: Hiroshi Doyu <hdoyu(a)nvidia.com> Ion doesn't support multiple address space. The recent IOMMU usually provide multiple address spaces, where a mapping depends on an address space. An address space is bind to a device pointer passed from attachment. Those info needs to be stored in a buffer info. If the same buffer needs to be mapped into the same AS, the same mapping info needs to be passed back. Signed-off-by: Hiroshi Doyu <hdoyu(a)nvidia.com> --- drivers/staging/android/ion/ion.c | 96 +++++++++++++++++++++++++++++++++- drivers/staging/android/ion/ion_priv.h | 10 ++++ 2 files changed, 104 insertions(+), 2 deletions(-) diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 0836717..e260434 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -872,17 +872,109 @@ static void ion_buffer_sync_for_device(struct ion_buffer *buffer, static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direction) { + int err, i, empty = -1; + struct dma_iommu_mapping *iommu_map; struct dma_buf *dmabuf = attachment->dmabuf; struct ion_buffer *buffer = dmabuf->priv; + unsigned int nents = buffer->sg_table->nents; + struct ion_mapping *map_ptr; + struct scatterlist *sg; + + iommu_map = to_dma_iommu_mapping(attachment->dev); + if (!iommu_map) { + ion_buffer_sync_for_device(buffer, attachment->dev, direction); + return buffer->sg_table; + } + + mutex_lock(&buffer->lock); + for (i = 0; i < ARRAY_SIZE(buffer->mapping); i++) { + map_ptr = &buffer->mapping[i]; + if (!map_ptr->dev) { + empty = i; + continue; + } + + if (to_dma_iommu_mapping(map_ptr->dev) == iommu_map) { + kref_get(&map_ptr->kref); + mutex_unlock(&buffer->lock); + return &map_ptr->sgt; + } + } - ion_buffer_sync_for_device(buffer, attachment->dev, direction); - return buffer->sg_table; + if (!empty) { + err = -ENOMEM; + goto err_no_space; + } + + map_ptr = &buffer->mapping[empty]; + err = sg_alloc_table(&map_ptr->sgt, nents, GFP_KERNEL); + if (err) + goto err_sg_alloc_table; + + for_each_sg(buffer->sg_table->sgl, sg, nents, i) + memcpy(map_ptr->sgt.sgl + i, sg, sizeof(*sg)); + + nents = dma_map_sg(attachment->dev, map_ptr->sgt.sgl, nents, direction); + if (!nents) { + err = -EINVAL; + goto err_dma_map_sg; + } + + kref_init(&map_ptr->kref); + map_ptr->dev = attachment->dev; + mutex_unlock(&buffer->lock); + return &map_ptr->sgt; + +err_dma_map_sg: + sg_free_table(&map_ptr->sgt); +err_sg_alloc_table: +err_no_space: + mutex_unlock(&buffer->lock); + return ERR_PTR(err); +} + +static void __ion_unmap_dma_buf(struct kref *kref) +{ + struct ion_mapping *map_ptr; + + map_ptr = container_of(kref, struct ion_mapping, kref); + dma_unmap_sg(map_ptr->dev, map_ptr->sgt.sgl, map_ptr->sgt.nents, + DMA_BIDIRECTIONAL); + sg_free_table(&map_ptr->sgt); + memset(map_ptr, 0, sizeof(*map_ptr)); } static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table, enum dma_data_direction direction) { + int i; + struct dma_iommu_mapping *iommu_map; + struct dma_buf *dmabuf = attachment->dmabuf; + struct ion_buffer *buffer = dmabuf->priv; + struct ion_mapping *map_ptr; + + iommu_map = to_dma_iommu_mapping(attachment->dev); + if (!iommu_map) + return; + + mutex_lock(&buffer->lock); + for (i = 0; i < ARRAY_SIZE(buffer->mapping); i++) { + map_ptr = &buffer->mapping[i]; + if (!map_ptr->dev) + continue; + + if (to_dma_iommu_mapping(map_ptr->dev) == iommu_map) { + kref_put(&map_ptr->kref, __ion_unmap_dma_buf); + mutex_unlock(&buffer->lock); + return; + } + } + + dev_warn(attachment->dev, "Not found a map(%p)\n", + to_dma_iommu_mapping(attachment->dev)); + + mutex_unlock(&buffer->lock); } void ion_pages_sync_for_device(struct device *dev, struct page *page, diff --git a/drivers/staging/android/ion/ion_priv.h b/drivers/staging/android/ion/ion_priv.h index 1eba3f2..441c251 100644 --- a/drivers/staging/android/ion/ion_priv.h +++ b/drivers/staging/android/ion/ion_priv.h @@ -26,11 +26,19 @@ #include <linux/sched.h> #include <linux/shrinker.h> #include <linux/types.h> +#include <linux/scatterlist.h> #include "ion.h" struct ion_buffer *ion_handle_buffer(struct ion_handle *handle); +struct ion_mapping { + struct device *dev; /* to get a map and dma_ops */ + struct sg_table sgt; + struct kref kref; +}; +#define NUM_ION_MAPPING 5 /* FIXME: dynamically allocate more than this */ + /** * struct ion_buffer - metadata for a particular buffer * @ref: refernce count @@ -84,6 +92,8 @@ struct ion_buffer { int handle_count; char task_comm[TASK_COMM_LEN]; pid_t pid; + + struct ion_mapping mapping[NUM_ION_MAPPING]; }; void ion_buffer_destroy(struct ion_buffer *buffer); -- 1.8.1.5

10 years, 9 months

Re: [Linaro-mm-sig] [PATCH v5 09/11] arm: add support for reserved memory defined by device tree

by Josh Cartwright

On Thu, Mar 13, 2014 at 01:46:50PM -0700, Kevin Hilman wrote: > On Fri, Feb 21, 2014 at 4:25 AM, Marek Szyprowski > <m.szyprowski(a)samsung.com> wrote: > > Enable reserved memory initialization from device tree. > > > > Signed-off-by: Marek Szyprowski <m.szyprowski(a)samsung.com> > > This patch has hit -next and several legacy (non-DT) boot failures > were detected and bisected down to this patch. A quick scan looks > like there needs to be some sanity checking whether a DT is even > present. Hmm. Yes, the code unconditionally calls of_flat_dt_scan(), which will gladly touch initial_boot_params, even though it may be uninitialized. The below patch should allow these boards to boot... However, I'm wondering if there is a good reason why we don't parse the /reserved-memory nodes at the right after we parse the /memory nodes as part of early_init_dt_scan()... Thanks, Josh --8<-- Subject: [PATCH] drivers: of: only scan for reserved mem when fdt present Reported-by: Kevin Hilman <khilman(a)linaro.org> Signed-off-by: Josh Cartwright <joshc(a)codeaurora.org> --- drivers/of/fdt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 510c0d8..501bc83 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -557,6 +557,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, */ void __init early_init_fdt_scan_reserved_mem(void) { + if (!initial_boot_params) + return; + of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); fdt_init_reserved_mem(); } -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

10 years, 9 months

[PATCH v6 00/11] reserved-memory regions/CMA in devicetree, again

by Marek Szyprowski

Hello again! Here is another update of the support for reserved memory regions in device tree. I've fixes a few more minor issues pointed by Grant. See changelog for more details. The initial code for this feature were posted here [1], merged as commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add initialization code for dma reserved memory") and later reverted by commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information, see [2]. Finally a new bindings has been proposed [3] and Josh Cartwright a few days ago prepared some code which implements those bindings [4]. This finally pushed me again to find some time to finish this task and review the code. Josh agreed to give me the ownership of this series to continue preparing them for mainline inclusion. For more information please refer to the changlelog and links below. [1]: http://lkml.kernel.org/g/1377527959-5080-1-git-send-email-m.szyprowski@sams… [2]: http://lkml.kernel.org/g/1381476448-14548-1-git-send-email-m.szyprowski@sam… [3]: http://lkml.kernel.org/g/20131030134702.19B57C402A0@trevor.secretlab.ca [4]: http://thread.gmane.org/gmane.linux.documentation/19579 Changelog: v6: - removed the need for "#memory-region-cells" property - fixed compilation issues on some systems - some other minor code cleanups v5: https://lkml.org/lkml/2014/2/21/147 - sliced main patch into several smaller patches on Grant's request - fixed coding style issues pointed by Grant - use node->phandle value directly instead of parsing properties manually v4: https://lkml.org/lkml/2014/2/20/150 - dynamic allocations are processed after all static reservations has been done - moved code for handling static reservations to drivers/of/fdt.c - removed node matching by string comparison, now phandle values are used directly - moved code for DMA and CMA handling directly to drivers/base/dma-{coherent,contiguous}.c - added checks for proper #size-cells, #address-cells, ranges properties in /reserved-memory node - even more code cleanup - added init code for ARM64 and PowerPC v3: http://article.gmane.org/gmane.linux.documentation/20169/ - refactored memory reservation code, created common code to parse reg, size, align, alloc-ranges properties - added support for multiple tuples in 'reg' property - memory is reserved regardless of presence of the driver for its compatible - prepared arch specific hooks for memory reservation (defaults use memblock calls) - removed node matching by string during device initialization - CMA init code: added checks for required region alignment - more code cleanup here and there v2: http://thread.gmane.org/gmane.linux.documentation/19870/ - removed copying of the node name - split shared-dma-pool handling into separate files (one for CMA and one for dma_declare_coherent based implementations) for making the code easier to understand - added support for AMBA devices, changed prototypes to use struct decice instead of struct platform_device - renamed some functions to better match other names used in drivers/of/ - restructured the rest of the code a bit for better readability - added 'reusable' property to exmaple linux,cma node in documentation - exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool' regions without 'reusable' property and CMA is used only for handling 'shared-dma-pool' regions with 'reusable' property. v1: http://thread.gmane.org/gmane.linux.documentation/19579 - initial version prepared by Josh Cartwright Summary: Grant Likely (1): of: document bindings for reserved-memory nodes Marek Szyprowski (10): drivers: of: add initialization code for static reserved memory drivers: of: add initialization code for dynamic reserved memory drivers: of: add support for custom reserved memory drivers drivers: of: add automated assignment of reserved regions to client devices drivers: of: initialize and assign reserved memory to newly created devices drivers: dma-coherent: add initialization from device tree drivers: dma-contiguous: add initialization from device tree arm: add support for reserved memory defined by device tree arm64: add support for reserved memory defined by device tree powerpc: add support for reserved memory defined by device tree .../bindings/reserved-memory/reserved-memory.txt | 136 ++++++++++ arch/arm/Kconfig | 1 + arch/arm/mm/init.c | 2 + arch/arm64/Kconfig | 1 + arch/arm64/mm/init.c | 1 + arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/prom.c | 3 + drivers/base/dma-coherent.c | 40 +++ drivers/base/dma-contiguous.c | 129 +++++++-- drivers/of/Kconfig | 6 + drivers/of/Makefile | 1 + drivers/of/fdt.c | 140 ++++++++++ drivers/of/of_reserved_mem.c | 287 ++++++++++++++++++++ drivers/of/platform.c | 7 + include/asm-generic/vmlinux.lds.h | 11 + include/linux/of_fdt.h | 3 + include/linux/of_reserved_mem.h | 60 ++++ 17 files changed, 807 insertions(+), 22 deletions(-) create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt create mode 100644 drivers/of/of_reserved_mem.c create mode 100644 include/linux/of_reserved_mem.h -- 1.7.9.5

10 years, 9 months

[PATCH 0/6] dma-buf synchronization patches

by Maarten Lankhorst

The following series implements fence and converts dma-buf and android sync to use it. Patch 6 and 7 add support for polling to dma-buf, blocking until all fences are signaled. I've dropped the extra patch to copy an export from the core, and instead use the public version of it. I've had to fix some fallout from the rebase, hopefully everything's clean now, and ready for -next. --- Maarten Lankhorst (6): fence: dma-buf cross-device synchronization (v17) seqno-fence: Hardware dma-buf implementation of fencing (v4) dma-buf: use reservation objects android: convert sync to fence api, v3 reservation: add support for fences to enable cross-device synchronisation dma-buf: add poll support, v2 Documentation/DocBook/device-drivers.tmpl | 3 drivers/base/Kconfig | 9 drivers/base/Makefile | 2 drivers/base/dma-buf.c | 123 +++ drivers/base/fence.c | 465 +++++++++++++ drivers/gpu/drm/drm_prime.c | 8 drivers/gpu/drm/exynos/exynos_drm_dmabuf.c | 2 drivers/gpu/drm/i915/i915_gem_dmabuf.c | 2 drivers/gpu/drm/nouveau/nouveau_drm.c | 1 drivers/gpu/drm/nouveau/nouveau_gem.h | 1 drivers/gpu/drm/nouveau/nouveau_prime.c | 7 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 2 drivers/gpu/drm/radeon/radeon_drv.c | 2 drivers/gpu/drm/radeon/radeon_prime.c | 8 drivers/gpu/drm/ttm/ttm_object.c | 2 drivers/media/v4l2-core/videobuf2-dma-contig.c | 2 drivers/staging/android/Kconfig | 1 drivers/staging/android/Makefile | 2 drivers/staging/android/sw_sync.c | 4 drivers/staging/android/sync.c | 892 ++++++++---------------- drivers/staging/android/sync.h | 80 +- drivers/staging/android/sync_debug.c | 245 +++++++ drivers/staging/android/trace/sync.h | 12 include/drm/drmP.h | 2 include/linux/dma-buf.h | 21 - include/linux/fence.h | 329 +++++++++ include/linux/reservation.h | 18 include/linux/seqno-fence.h | 109 +++ include/trace/events/fence.h | 125 +++ 29 files changed, 1822 insertions(+), 657 deletions(-) create mode 100644 drivers/base/fence.c create mode 100644 drivers/staging/android/sync_debug.c create mode 100644 include/linux/fence.h create mode 100644 include/linux/seqno-fence.h create mode 100644 include/trace/events/fence.h -- Signature

10 years, 9 months

Re: [Linaro-mm-sig] [PATCH 2/6] seqno-fence: Hardware dma-buf implementation of fencing (v4)

by Maarten Lankhorst

op 17-02-14 19:41, Christian König schreef: > Am 17.02.2014 19:24, schrieb Rob Clark: >> On Mon, Feb 17, 2014 at 12:36 PM, Christian König >> <deathsimple(a)vodafone.de> wrote: >>> Am 17.02.2014 18:27, schrieb Rob Clark: >>> >>>> On Mon, Feb 17, 2014 at 11:56 AM, Christian König >>>> <deathsimple(a)vodafone.de> wrote: >>>>> Am 17.02.2014 16:56, schrieb Maarten Lankhorst: >>>>> >>>>>> This type of fence can be used with hardware synchronization for simple >>>>>> hardware that can block execution until the condition >>>>>> (dma_buf[offset] - value) >= 0 has been met. >>>>> >>>>> Can't we make that just "dma_buf[offset] != 0" instead? As far as I know >>>>> this way it would match the definition M$ uses in their WDDM >>>>> specification >>>>> and so make it much more likely that hardware supports it. >>>> well 'buf[offset] >= value' at least means the same slot can be used >>>> for multiple operations (with increasing values of 'value').. not sure >>>> if that is something people care about. >>>> >>>>> =value seems to be possible with adreno and radeon. I'm not really sure >>>>> about others (although I presume it as least supported for nv desktop >>>>> stuff). For hw that cannot do >=value, we can either have a different fence >>>>> implementation which uses the !=0 approach. Or change seqno-fence >>>>> implementation later if needed. But if someone has hw that can do !=0 but >>>>> not >=value, speak up now ;-) >>> >>> Here! Radeon can only do >=value on the DMA and 3D engine, but not with UVD >>> or VCE. And for the 3D engine it means draining the pipe, which isn't really >>> a good idea. >> hmm, ok.. forgot you have a few extra rings compared to me. Is UVD >> re-ordering from decode-order to display-order for you in hw? If not, >> I guess you need sw intervention anyways when a frame is done for >> frame re-ordering, so maybe hw->hw sync doesn't really matter as much >> as compared to gpu/3d->display. For dma<->3d interactions, seems like >> you would care more about hw<->hw sync, but I guess you aren't likely >> to use GPU A to do a resolve blit for GPU B.. > > No UVD isn't reordering, but since frame reordering is predictable you usually end up with pipelining everything to the hardware. E.g. you send the decode commands in decode order to the UVD block and if you have overlay active one of the frames are going to be the first to display and then you want to wait for it on the display side. > >> For 3D ring, I assume you probably want a CP_WAIT_FOR_IDLE before a >> CP_MEM_WRITE to update fence value in memory (for the one signalling >> the fence). But why would you need that before a CP_WAIT_REG_MEM (for >> the one waiting for the fence)? I don't exactly have documentation >> for adreno version of CP_WAIT_REG_{MEM,EQ,GTE}.. but PFP and ME >> appear to be same instruction set as r600, so I'm pretty sure they >> should have similar capabilities.. CP_WAIT_REG_MEM appears to be same >> but with 32bit gpu addresses vs 64b. > > You shouldn't use any of the CP commands for engine synchronization (neither for wait nor for signal). The PFP and ME are just the top of a quite deep pipeline and when you use any of the CP_WAIT functions you block them for something and that's draining the pipeline. > > With the semaphore and fence commands the values are just attached as prerequisite to the draw command, e.g. the CP setups the draw environment and issues the command, but the actual execution of it is delayed until the "!= 0" condition hits. And in the meantime the CP already prepares the next draw operation. > > But at least for compute queues wait semaphore aren't the perfect solution either. What you need then is a GPU scheduler that uses a kernel task for setting up the command submission for you when all prerequisites are meet. nouveau has sort of a scheduler in hardware. It can yield when waiting on a semaphore. And each process gets their own context and the timeslices can be adjusted. ;-) But I don't mind changing this patch when an actual user pops up. Nouveau can do a wait for (*sema & mask) != 0 only on nvc0 and newer, where mask can be chosen. But it can do == somevalue and >= somevalue on older relevant optimus hardware, so if we know that it was zero before and we know the sign of the new value that could work too. Adding ops and a separate mask later on when users pop up is fine with me, the original design here was chosen so I could map the intel status page read-only into the process specific nvidia vm. ~Maarten

10 years, 10 months

How to manage cached dmabuf importer private data?

by Hiroshi Doyu

Hi, We have a problem about how to manage cached dmabuf importer private data, where to keep, how to reuse and how to clean up. We want to keep some data in dmabuf importer side until an buffer is free'ed actually since a buffer can be reused again later in that importer subsystem so that that cache data doesn't have to be regenerated. This can be considered as some kind of caching this data. The scenario is: (1) Exporter passes a dmabuf to Importer. (2) Importer attaches a dev to a dmabuf. (3) Importer generates some data for a buffer for its own use. (4) Importer finishes its use of a buffer. (5) Importer detaches a dev from a dmabuf. (6) Again, Exporter passes a dmabuf fd to the same Importer. (7) Again, Importer attaches a dev to a dmabuf. (8) Importer wants to use the previously cached data from (2) without regenerating. (9) Again, Importer detaches a dev from a dmabuf. (10) Exporter free's a buffer along with a cached data from (2)/(8). At first I considered to use attachmenet private data, but apparently a life time of the attachment isn't equal to one of a buffer. A buffer lives longer than an attachment. Also Neither private data from dmabuf nor from attachment are for /Importer/. They are for Exporter's use from the comment in the header file. /** * struct dma_buf - shared buffer object .... * @priv: exporter specific private data for this buffer object. */ /** * struct dma_buf_attachment - holds device-buffer attachment data ... * @priv: exporter specific attachment data. ... */ This leads to the following 2 questions: One question is how to clean up the cached data at (10) since there's no way for Importer to trigger clean up at that time. I am considering to embed an /notifier/ in dmabuf when it's called at dmabuf release. Importer could register any callback in that notifier. At least this requires a dmabuf to have an notifier to be called at release. Does this sound acceptable? Or can we do the same outside of dmabuf framework? If there's more appropriate way, please let me know since I'm not so familier with drm side yet. Another question is where to keep that cached data. Usually that data is only valid within Impoter subsystem. So Imoporter could keep the list of that data in it as a global list along with a dmabuf pointer. When a dmabuf is imported, Importer can look up a global list if it's already cached. This list needs to be kept till a buffer is free'ed. Those can be implemented in the dmabuf exporter backend but we want to allow multiple allocators/exporters to do the same, and I want to avoid having something related to importer in exporter side. Any comment would be really appreciated.

10 years, 10 months

[PATCH v5 00/11] reserved-memory regions/CMA in devicetree, again

by Marek Szyprowski

Hi all! Ok, I hope that this is the last update of the patches which add basic support for dynamic allocation of memory reserved regions defined in device tree. This time I've mainly sliced the main patch into several smaller pieces to make the changes easier to understand and fixes some minor coding style issues. The initial code for this feature were posted here [1], merged as commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add initialization code for dma reserved memory") and later reverted by commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information, see [2]. Finally a new bindings has been proposed [3] and Josh Cartwright a few days ago prepared some code which implements those bindings [4]. This finally pushed me again to find some time to finish this task and review the code. Josh agreed to give me the ownership of this series to continue preparing them for mainline inclusion. For more information please refer to the changlelog and links below. [1]: http://lkml.kernel.org/g/1377527959-5080-1-git-send-email-m.szyprowski@sams… [2]: http://lkml.kernel.org/g/1381476448-14548-1-git-send-email-m.szyprowski@sam… [3]: http://lkml.kernel.org/g/20131030134702.19B57C402A0@trevor.secretlab.ca [4]: http://thread.gmane.org/gmane.linux.documentation/19579 Changelog: v5: - sliced main patch into several smaller patches on Grant's request - fixed coding style issues pointed by Grant - use node->phandle value directly instead of parsing properties manually v4: https://lkml.org/lkml/2014/2/20/150 - dynamic allocations are processed after all static reservations has been done - moved code for handling static reservations to drivers/of/fdt.c - removed node matching by string comparison, now phandle values are used directly - moved code for DMA and CMA handling directly to drivers/base/dma-{coherent,contiguous}.c - added checks for proper #size-cells, #address-cells, ranges properties in /reserved-memory node - even more code cleanup - added init code for ARM64 and PowerPC v3: http://article.gmane.org/gmane.linux.documentation/20169/ - refactored memory reservation code, created common code to parse reg, size, align, alloc-ranges properties - added support for multiple tuples in 'reg' property - memory is reserved regardless of presence of the driver for its compatible - prepared arch specific hooks for memory reservation (defaults use memblock calls) - removed node matching by string during device initialization - CMA init code: added checks for required region alignment - more code cleanup here and there v2: http://thread.gmane.org/gmane.linux.documentation/19870/ - removed copying of the node name - split shared-dma-pool handling into separate files (one for CMA and one for dma_declare_coherent based implementations) for making the code easier to understand - added support for AMBA devices, changed prototypes to use struct decice instead of struct platform_device - renamed some functions to better match other names used in drivers/of/ - restructured the rest of the code a bit for better readability - added 'reusable' property to exmaple linux,cma node in documentation - exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool' regions without 'reusable' property and CMA is used only for handling 'shared-dma-pool' regions with 'reusable' property. v1: http://thread.gmane.org/gmane.linux.documentation/19579 - initial version prepared by Josh Cartwright Summary: Grant Likely (1): of: document bindings for reserved-memory nodes Marek Szyprowski (10): drivers: of: add initialization code for static reserved memory drivers: of: add initialization code for dynamic reserved memory drivers: of: add support for custom reserved memory drivers drivers: of: add automated assignment of reserved regions to client devices drivers: of: initialize and assign reserved memory to newly created devices drivers: dma-coherent: add initialization from device tree drivers: dma-contiguous: add initialization from device tree arm: add support for reserved memory defined by device tree arm64: add support for reserved memory defined by device tree powerpc: add support for reserved memory defined by device tree .../bindings/reserved-memory/reserved-memory.txt | 138 ++++++++++ arch/arm/Kconfig | 1 + arch/arm/mm/init.c | 2 + arch/arm64/Kconfig | 1 + arch/arm64/mm/init.c | 1 + arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/prom.c | 3 + drivers/base/dma-coherent.c | 41 +++ drivers/base/dma-contiguous.c | 130 +++++++-- drivers/of/Kconfig | 6 + drivers/of/Makefile | 1 + drivers/of/fdt.c | 134 +++++++++ drivers/of/of_reserved_mem.c | 291 ++++++++++++++++++++ drivers/of/platform.c | 7 + include/asm-generic/vmlinux.lds.h | 11 + include/linux/of_fdt.h | 3 + include/linux/of_reserved_mem.h | 61 ++++ 17 files changed, 810 insertions(+), 22 deletions(-) create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt create mode 100644 drivers/of/of_reserved_mem.c create mode 100644 include/linux/of_reserved_mem.h -- 1.7.9.5

10 years, 10 months

Use of dma_buf_unmap_attachment in interrupt context?

by Hans Verkuil

A quick question: can dma_buf_unmap_attachment be called from interrupt context? It is the dmabuf equivalent to e.g. dma_sync_sg_for_cpu or dma_unmap_sg, and those can be called from interrupt context. I cannot see anything specific about this in the sources or dma-buf-sharing.txt. If it turns out that dma_buf_unmap_attachment can be called from atomic context, then that should be documented, I think. Regards, Hans

10 years, 10 months

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