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drm/omap: gem: Implement dma_buf import 

OMAP GEM objects backed by dma_buf reuse the current OMAP GEM object
support as much as possible. If the imported buffer is physically
contiguous its physical address will be used directly, reusing the
OMAP_BO_MEM_DMA_API code paths. Otherwise it will be mapped through the
TILER using a pages list created from the scatterlist instead of the
shmem backing storage.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
hifive-unleashed-5.1
Laurent Pinchart 2015-12-14 22:39:44 +02:00 committed by Tomi Valkeinen
parent 9cba3b9945
commit b22e6690a3
3 changed files with 162 additions and 37 deletions
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2
drivers/gpu/drm/omapdrm/omap_drv.h
View File

@ -195,6 +195,8 @@ void omap_gem_deinit(struct drm_device *dev);
struct drm_gem_object *omap_gem_new(struct drm_device *dev,
union omap_gem_size gsize, uint32_t flags);
struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
struct sg_table *sgt);
int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file,
union omap_gem_size gsize, uint32_t flags, uint32_t *handle);
void omap_gem_free_object(struct drm_gem_object *obj);

138
drivers/gpu/drm/omapdrm/omap_gem.c
View File

@ -34,6 +34,7 @@
#define OMAP_BO_MEM_DMA_API 0x01000000 /* memory allocated with the dma_alloc_* API */
#define OMAP_BO_MEM_SHMEM 0x02000000 /* memory allocated through shmem backing */
#define OMAP_BO_MEM_EXT 0x04000000 /* memory allocated externally */
#define OMAP_BO_MEM_DMABUF 0x08000000 /* memory imported from a dmabuf */
#define OMAP_BO_EXT_SYNC 0x10000000 /* externally allocated sync object */
struct omap_gem_object {
@ -50,17 +51,25 @@ struct omap_gem_object {
uint32_t roll;
/**
* If buffer is allocated physically contiguous, the OMAP_BO_MEM_DMA_API
* flag is set and the paddr is valid. Also if the buffer is remapped
* in TILER and paddr_cnt > 0, then paddr is valid. But if you are using
* the physical address and OMAP_BO_MEM_DMA_API is not set, then you
* should be going thru omap_gem_{get,put}_paddr() to ensure the mapping
* is not removed from under your feet.
* paddr contains the buffer DMA address. It is valid for
*
* Note that OMAP_BO_SCANOUT is a hint from userspace that DMA capable
* buffer is requested, but doesn't mean that it is. Use the
* OMAP_BO_MEM_DMA_API flag to determine if the buffer has a DMA capable
* physical address.
* - buffers allocated through the DMA mapping API (with the
* OMAP_BO_MEM_DMA_API flag set)
*
* - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set)
* if they are physically contiguous (when sgt->orig_nents == 1)
*
* - buffers mapped through the TILER when paddr_cnt is not zero, in
* which case the DMA address points to the TILER aperture
*
* Physically contiguous buffers have their DMA address equal to the
* physical address as we don't remap those buffers through the TILER.
*
* Buffers mapped to the TILER have their DMA address pointing to the
* TILER aperture. As TILER mappings are refcounted (through paddr_cnt)
* the DMA address must be accessed through omap_get_get_paddr() to
* ensure that the mapping won't disappear unexpectedly. References must
* be released with omap_gem_put_paddr().
*/
dma_addr_t paddr;
@ -69,6 +78,12 @@ struct omap_gem_object {
*/
uint32_t paddr_cnt;
/**
* If the buffer has been imported from a dmabuf the OMAP_DB_DMABUF flag
* is set and the sgt field is valid.
*/
struct sg_table *sgt;
/**
* tiler block used when buffer is remapped in DMM/TILER.
*/
@ -167,6 +182,17 @@ static uint64_t mmap_offset(struct drm_gem_object *obj)
return drm_vma_node_offset_addr(&obj->vma_node);
}
static bool is_contiguous(struct omap_gem_object *omap_obj)
{
if (omap_obj->flags & OMAP_BO_MEM_DMA_API)
return true;
if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && omap_obj->sgt->nents == 1)
return true;
return false;
}
/* -----------------------------------------------------------------------------
* Eviction
*/
@ -400,7 +426,7 @@ static int fault_1d(struct drm_gem_object *obj,
omap_gem_cpu_sync(obj, pgoff);
pfn = page_to_pfn(omap_obj->pages[pgoff]);
} else {
BUG_ON(!(omap_obj->flags & OMAP_BO_MEM_DMA_API));
BUG_ON(!is_contiguous(omap_obj));
pfn = (omap_obj->paddr >> PAGE_SHIFT) + pgoff;
}
@ -803,8 +829,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj,
mutex_lock(&obj->dev->struct_mutex);
if (!(omap_obj->flags & OMAP_BO_MEM_DMA_API) &&
remap && priv->has_dmm) {
if (!is_contiguous(omap_obj) && remap && priv->has_dmm) {
if (omap_obj->paddr_cnt == 0) {
struct page **pages;
uint32_t npages = obj->size >> PAGE_SHIFT;
@ -851,7 +876,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj,
omap_obj->paddr_cnt++;
*paddr = omap_obj->paddr;
} else if (omap_obj->flags & OMAP_BO_MEM_DMA_API) {
} else if (is_contiguous(omap_obj)) {
*paddr = omap_obj->paddr;
} else {
ret = -EINVAL;
@ -1319,9 +1344,6 @@ unlock:
* Constructor & Destructor
*/
/* don't call directly.. called from GEM core when it is time to actually
* free the object..
*/
void omap_gem_free_object(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
@ -1343,14 +1365,20 @@ void omap_gem_free_object(struct drm_gem_object *obj)
/* don't free externally allocated backing memory */
if (!(omap_obj->flags & OMAP_BO_MEM_EXT)) {
if (omap_obj->pages)
omap_gem_detach_pages(obj);
if (omap_obj->pages) {
if (omap_obj->flags & OMAP_BO_MEM_DMABUF)
kfree(omap_obj->pages);
else
omap_gem_detach_pages(obj);
}
if (omap_obj->flags & OMAP_BO_MEM_DMA_API) {
dma_free_writecombine(dev->dev, obj->size,
omap_obj->vaddr, omap_obj->paddr);
} else if (omap_obj->vaddr) {
vunmap(omap_obj->vaddr);
} else if (obj->import_attach) {
drm_prime_gem_destroy(obj, omap_obj->sgt);
}
}
@ -1396,14 +1424,15 @@ struct drm_gem_object *omap_gem_new(struct drm_device *dev,
flags |= tiler_get_cpu_cache_flags();
} else if ((flags & OMAP_BO_SCANOUT) && !priv->has_dmm) {
/*
* Use contiguous memory if we don't have DMM to remap
* discontiguous buffers.
* OMAP_BO_SCANOUT hints that the buffer doesn't need to be
* tiled. However, to lower the pressure on memory allocation,
* use contiguous memory only if no TILER is available.
*/
flags |= OMAP_BO_MEM_DMA_API;
} else if (!(flags & OMAP_BO_MEM_EXT)) {
} else if (!(flags & (OMAP_BO_MEM_EXT | OMAP_BO_MEM_DMABUF))) {
/*
* All other buffers not backed with external memory are
* shmem-backed.
* All other buffers not backed by external memory or dma_buf
* are shmem-backed.
*/
flags |= OMAP_BO_MEM_SHMEM;
}
@ -1465,6 +1494,67 @@ fail:
return NULL;
}
struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
struct sg_table *sgt)
{
struct omap_drm_private *priv = dev->dev_private;
struct omap_gem_object *omap_obj;
struct drm_gem_object *obj;
union omap_gem_size gsize;
/* Without a DMM only physically contiguous buffers can be supported. */
if (sgt->orig_nents != 1 && !priv->has_dmm)
return ERR_PTR(-EINVAL);
mutex_lock(&dev->struct_mutex);
gsize.bytes = PAGE_ALIGN(size);
obj = omap_gem_new(dev, gsize, OMAP_BO_MEM_DMABUF | OMAP_BO_WC);
if (!obj) {
obj = ERR_PTR(-ENOMEM);
goto done;
}
omap_obj = to_omap_bo(obj);
omap_obj->sgt = sgt;
if (sgt->orig_nents == 1) {
omap_obj->paddr = sg_dma_address(sgt->sgl);
} else {
/* Create pages list from sgt */
struct sg_page_iter iter;
struct page **pages;
unsigned int npages;
unsigned int i = 0;
npages = DIV_ROUND_UP(size, PAGE_SIZE);
pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
if (!pages) {
omap_gem_free_object(obj);
obj = ERR_PTR(-ENOMEM);
goto done;
}
omap_obj->pages = pages;
for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
pages[i++] = sg_page_iter_page(&iter);
if (i > npages)
break;
}
if (WARN_ON(i != npages)) {
omap_gem_free_object(obj);
obj = ERR_PTR(-ENOMEM);
goto done;
}
}
done:
mutex_unlock(&dev->struct_mutex);
return obj;
}
/* convenience method to construct a GEM buffer object, and userspace handle */
int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file,
union omap_gem_size gsize, uint32_t flags, uint32_t *handle)

59
drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
View File

@ -21,6 +21,10 @@
#include "omap_drv.h"
/* -----------------------------------------------------------------------------
* DMABUF Export
*/
static struct sg_table *omap_gem_map_dma_buf(
struct dma_buf_attachment *attachment,
enum dma_data_direction dir)
@ -178,15 +182,20 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
return dma_buf_export(&exp_info);
}
struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
struct dma_buf *buffer)
{
struct drm_gem_object *obj;
/* -----------------------------------------------------------------------------
* DMABUF Import
*/
/* is this one of own objects? */
if (buffer->ops == &omap_dmabuf_ops) {
obj = buffer->priv;
/* is it from our device? */
struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
struct dma_buf *dma_buf)
{
struct dma_buf_attachment *attach;
struct drm_gem_object *obj;
struct sg_table *sgt;
int ret;
if (dma_buf->ops == &omap_dmabuf_ops) {
obj = dma_buf->priv;
if (obj->dev == dev) {
/*
* Importing dmabuf exported from out own gem increases
@ -197,9 +206,33 @@ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
}
}
/*
* TODO add support for importing buffers from other devices..
* for now we don't need this but would be nice to add eventually
*/
return ERR_PTR(-EINVAL);
attach = dma_buf_attach(dma_buf, dev->dev);
if (IS_ERR(attach))
return ERR_CAST(attach);
get_dma_buf(dma_buf);
sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
if (IS_ERR(sgt)) {
ret = PTR_ERR(sgt);
goto fail_detach;
}
obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
if (IS_ERR(obj)) {
ret = PTR_ERR(obj);
goto fail_unmap;
}
obj->import_attach = attach;
return obj;
fail_unmap:
dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
fail_detach:
dma_buf_detach(dma_buf, attach);
dma_buf_put(dma_buf);
return ERR_PTR(ret);
}