From: Matthew Auld matthew.auld@intel.com
On some platforms we have alignment restrictions when accessing LMEM from the GTT. In the next patch few patches we need to be able to modify the page-tables directly via the GTT itself.
Suggested-by: Ramalingam C ramalingam.c@intel.com Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Ramalingam C ramalingam.c@intel.com --- drivers/gpu/drm/i915/gt/intel_gtt.h | 10 +++++++++- drivers/gpu/drm/i915/gt/intel_ppgtt.c | 16 ++++++++++++---- 2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h index 01e9a98846fb..5ca5caa667b8 100644 --- a/drivers/gpu/drm/i915/gt/intel_gtt.h +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h @@ -199,6 +199,14 @@ void *__px_vaddr(struct drm_i915_gem_object *p); struct i915_vm_pt_stash { /* preallocated chains of page tables/directories */ struct i915_page_table *pt[2]; + /* + * Optionally override the alignment/size of the physical page that + * contains each PT. If not set defaults back to the usual + * I915_GTT_PAGE_SIZE_4K. This does not influence the other paging + * structures. MUST be a power-of-two. ONLY applicable on discrete + * platforms. + */ + int pt_sz; };
struct i915_vma_ops { @@ -586,7 +594,7 @@ void free_scratch(struct i915_address_space *vm);
struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz); struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz); -struct i915_page_table *alloc_pt(struct i915_address_space *vm); +struct i915_page_table *alloc_pt(struct i915_address_space *vm, int sz); struct i915_page_directory *alloc_pd(struct i915_address_space *vm); struct i915_page_directory *__alloc_pd(int npde);
diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c index b8238f5bc8b1..3c90aea25072 100644 --- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c +++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c @@ -12,7 +12,7 @@ #include "gen6_ppgtt.h" #include "gen8_ppgtt.h"
-struct i915_page_table *alloc_pt(struct i915_address_space *vm) +struct i915_page_table *alloc_pt(struct i915_address_space *vm, int sz) { struct i915_page_table *pt;
@@ -20,7 +20,7 @@ struct i915_page_table *alloc_pt(struct i915_address_space *vm) if (unlikely(!pt)) return ERR_PTR(-ENOMEM);
- pt->base = vm->alloc_pt_dma(vm, I915_GTT_PAGE_SIZE_4K); + pt->base = vm->alloc_pt_dma(vm, sz); if (IS_ERR(pt->base)) { kfree(pt); return ERR_PTR(-ENOMEM); @@ -219,17 +219,25 @@ int i915_vm_alloc_pt_stash(struct i915_address_space *vm, u64 size) { unsigned long count; - int shift, n; + int shift, n, pt_sz;
shift = vm->pd_shift; if (!shift) return 0;
+ pt_sz = stash->pt_sz; + if (!pt_sz) + pt_sz = I915_GTT_PAGE_SIZE_4K; + else + GEM_BUG_ON(!IS_DGFX(vm->i915)); + + GEM_BUG_ON(!is_power_of_2(pt_sz)); + count = pd_count(size, shift); while (count--) { struct i915_page_table *pt;
- pt = alloc_pt(vm); + pt = alloc_pt(vm, pt_sz); if (IS_ERR(pt)) { i915_vm_free_pt_stash(vm, stash); return PTR_ERR(pt);