github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-31 11:37:06 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm/i915/gem: Improve pfn calculation readability in vm_fault_gtt()

Browse Source 
By moving the pfn calculation to the set_address_limits()
function we improve code readability. This way,
set_address_limits() is responsible for calculating all memory
mapping paramenters: "start", "end" and "pfn".

This suggestion from Jonathan was made during the review of
commit 8bdd9ef7e9 ("drm/i915/gem: Fix Virtual Memory mapping
boundaries calculation"), which I liked, but it got lost on the
way.

Suggested-by: Jonathan Cavitt <Jonathan.cavitt@intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Krzysztof Niemiec <krzysztof.niemiec@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240807104553.481763-1-andi.shyti@linux.intel.com
This commit is contained in:
Andi Shyti 2024-08-07 11:45:53 +01:00
parent 0829b5bcdd
commit cecab0bb73
1 changed files with 14 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/gpu/drm/i915/gem/i915_gem_mman.c
View File

@ -293,8 +293,10 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf)
static void set_address_limits(struct vm_area_struct *area,
struct i915_vma *vma,
unsigned long obj_offset,
resource_size_t gmadr_start,
unsigned long *start_vaddr,
unsigned long *end_vaddr)
unsigned long *end_vaddr,
unsigned long *pfn)
{
unsigned long vm_start, vm_end, vma_size; /* user's memory parameters */
long start, end; /* memory boundaries */
@ -323,6 +325,10 @@ static void set_address_limits(struct vm_area_struct *area,
/* Let's move back into the "<< PAGE_SHIFT" domain */
*start_vaddr = (unsigned long)start << PAGE_SHIFT;
*end_vaddr = (unsigned long)end << PAGE_SHIFT;
*pfn = (gmadr_start + i915_ggtt_offset(vma)) >> PAGE_SHIFT;
*pfn += (*start_vaddr - area->vm_start) >> PAGE_SHIFT;
*pfn += obj_offset - vma->gtt_view.partial.offset;
}
static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
@ -441,11 +447,13 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
if (ret)
goto err_unpin;
set_address_limits(area, vma, obj_offset, &start, &end);
pfn = (ggtt->gmadr.start + i915_ggtt_offset(vma)) >> PAGE_SHIFT;
pfn += (start - area->vm_start) >> PAGE_SHIFT;
pfn += obj_offset - vma->gtt_view.partial.offset;
/*
* Dump all the necessary parameters in this function to perform the
* arithmetic calculation for the virtual address start and end and
* the PFN (Page Frame Number).
*/
set_address_limits(area, vma, obj_offset, ggtt->gmadr.start,
&start, &end, &pfn);
/* Finally, remap it using the new GTT offset */
ret = remap_io_mapping(area, start, pfn, end - start, &ggtt->iomap);