Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-09-20 06:53:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

drm/i915/gem: Calculate object page offset for partial memory mapping

Browse Source 
To enable partial memory mapping of GPU virtual memory, it's
necessary to introduce an offset to the object's memory
(obj->mm.pages) scatterlist. This adjustment compensates for
instances when userspace mappings do not start from the beginning
of the object.

Based on a patch by Chris Wilson.

Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Chris Wilson <chris.p.wilson@linux.intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240807100521.478266-3-andi.shyti@linux.intel.com
This commit is contained in:
Andi Shyti 2024-08-07 11:05:21 +01:00
parent 609d8b1c42
commit 255fc1703e
3 changed files with 16 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/gpu/drm/i915/gem/i915_gem_mman.c
View File

@ -252,6 +252,7 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf)
struct vm_area_struct *area = vmf->vma;
struct i915_mmap_offset *mmo = area->vm_private_data;
struct drm_i915_gem_object *obj = mmo->obj;
unsigned long obj_offset;
resource_size_t iomap;
int err;
@ -273,10 +274,11 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf)
iomap -= obj->mm.region->region.start;
}
obj_offset = area->vm_pgoff - drm_vma_node_start(&mmo->vma_node);
/* PTEs are revoked in obj->ops->put_pages() */
err = remap_io_sg(area,
area->vm_start, area->vm_end - area->vm_start,
obj->mm.pages->sgl, iomap);
obj->mm.pages->sgl, obj_offset, iomap);
if (area->vm_flags & VM_WRITE) {
GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));

12
drivers/gpu/drm/i915/i915_mm.c
View File

@ -122,13 +122,15 @@ int remap_io_mapping(struct vm_area_struct *vma,
* @addr: target user address to start at
* @size: size of map area
* @sgl: Start sg entry
* @offset: offset from the start of the page
* @iobase: Use stored dma address offset by this address or pfn if -1
*
* Note: this is only safe if the mm semaphore is held when called.
*/
int remap_io_sg(struct vm_area_struct *vma,
unsigned long addr, unsigned long size,
struct scatterlist *sgl, resource_size_t iobase)
struct scatterlist *sgl, unsigned long offset,
resource_size_t iobase)
{
struct remap_pfn r = {
.mm = vma->vm_mm,
@ -141,6 +143,14 @@ int remap_io_sg(struct vm_area_struct *vma,
/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
while (offset >= sg_dma_len(r.sgt.sgp) >> PAGE_SHIFT) {
offset -= sg_dma_len(r.sgt.sgp) >> PAGE_SHIFT;
r.sgt = __sgt_iter(__sg_next(r.sgt.sgp), use_dma(iobase));
if (!r.sgt.sgp)
return -EINVAL;
}
r.sgt.curr = offset << PAGE_SHIFT;
if (!use_dma(iobase))
flush_cache_range(vma, addr, size);

3
drivers/gpu/drm/i915/i915_mm.h
View File

@ -30,6 +30,7 @@ int remap_io_mapping(struct vm_area_struct *vma,
int remap_io_sg(struct vm_area_struct *vma,
unsigned long addr, unsigned long size,
struct scatterlist *sgl, resource_size_t iobase);
struct scatterlist *sgl, unsigned long offset,
resource_size_t iobase);
#endif /* __I915_MM_H__ */