drm/i915: Preallocate stashes for vma page-directories

[linux-2.6-microblaze.git] / drivers / gpu / drm / i915 / gt / gen8_ppgtt.c

diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
index 6991259..08cb65b 100644 (file)
--- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
@@ -269,14 +269,12 @@ static void gen8_ppgtt_clear(struct i915_address_space *vm,
                           start, start + length, vm->top);
 }
 
-static int __gen8_ppgtt_alloc(struct i915_address_space * const vm,
-                             struct i915_page_directory * const pd,
-                             u64 * const start, const u64 end, int lvl)
+static void __gen8_ppgtt_alloc(struct i915_address_space * const vm,
+                              struct i915_vm_pt_stash *stash,
+                              struct i915_page_directory * const pd,
+                              u64 * const start, const u64 end, int lvl)
 {
-       const struct i915_page_scratch * const scratch = &vm->scratch[lvl];
-       struct i915_page_table *alloc = NULL;
        unsigned int idx, len;
-       int ret = 0;
 
        GEM_BUG_ON(end > vm->total >> GEN8_PTE_SHIFT);
 
@@ -297,49 +295,30 @@ static int __gen8_ppgtt_alloc(struct i915_address_space * const vm,
                        DBG("%s(%p):{ lvl:%d, idx:%d } allocating new tree\n",
                            __func__, vm, lvl + 1, idx);
 
-                       pt = fetch_and_zero(&alloc);
-                       if (lvl) {
-                               if (!pt) {
-                                       pt = &alloc_pd(vm)->pt;
-                                       if (IS_ERR(pt)) {
-                                               ret = PTR_ERR(pt);
-                                               goto out;
-                                       }
-                               }
+                       pt = stash->pt[!!lvl];
+                       GEM_BUG_ON(!pt);
 
+                       if (lvl ||
+                           gen8_pt_count(*start, end) < I915_PDES ||
+                           intel_vgpu_active(vm->i915))
                                fill_px(pt, vm->scratch[lvl].encode);
-                       } else {
-                               if (!pt) {
-                                       pt = alloc_pt(vm);
-                                       if (IS_ERR(pt)) {
-                                               ret = PTR_ERR(pt);
-                                               goto out;
-                                       }
-                               }
-
-                               if (intel_vgpu_active(vm->i915) ||
-                                   gen8_pt_count(*start, end) < I915_PDES)
-                                       fill_px(pt, vm->scratch[lvl].encode);
-                       }
 
                        spin_lock(&pd->lock);
-                       if (likely(!pd->entry[idx]))
+                       if (likely(!pd->entry[idx])) {
+                               stash->pt[!!lvl] = pt->stash;
+                               atomic_set(&pt->used, 0);
                                set_pd_entry(pd, idx, pt);
-                       else
-                               alloc = pt, pt = pd->entry[idx];
+                       } else {
+                               pt = pd->entry[idx];
+                       }
                }
 
                if (lvl) {
                        atomic_inc(&pt->used);
                        spin_unlock(&pd->lock);
 
-                       ret = __gen8_ppgtt_alloc(vm, as_pd(pt),
-                                                start, end, lvl);
-                       if (unlikely(ret)) {
-                               if (release_pd_entry(pd, idx, pt, scratch))
-                                       free_px(vm, pt);
-                               goto out;
-                       }
+                       __gen8_ppgtt_alloc(vm, stash,
+                                          as_pd(pt), start, end, lvl);
 
                        spin_lock(&pd->lock);
                        atomic_dec(&pt->used);
@@ -359,18 +338,12 @@ static int __gen8_ppgtt_alloc(struct i915_address_space * const vm,
                }
        } while (idx++, --len);
        spin_unlock(&pd->lock);
-out:
-       if (alloc)
-               free_px(vm, alloc);
-       return ret;
 }
 
-static int gen8_ppgtt_alloc(struct i915_address_space *vm,
-                           u64 start, u64 length)
+static void gen8_ppgtt_alloc(struct i915_address_space *vm,
+                            struct i915_vm_pt_stash *stash,
+                            u64 start, u64 length)
 {
-       u64 from;
-       int err;
-
        GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
        GEM_BUG_ON(!IS_ALIGNED(length, BIT_ULL(GEN8_PTE_SHIFT)));
        GEM_BUG_ON(range_overflows(start, length, vm->total));
@@ -378,15 +351,9 @@ static int gen8_ppgtt_alloc(struct i915_address_space *vm,
        start >>= GEN8_PTE_SHIFT;
        length >>= GEN8_PTE_SHIFT;
        GEM_BUG_ON(length == 0);
-       from = start;
-
-       err = __gen8_ppgtt_alloc(vm, i915_vm_to_ppgtt(vm)->pd,
-                                &start, start + length, vm->top);
-       if (unlikely(err && from != start))
-               __gen8_ppgtt_clear(vm, i915_vm_to_ppgtt(vm)->pd,
-                                  from, start, vm->top);
 
-       return err;
+       __gen8_ppgtt_alloc(vm, stash, i915_vm_to_ppgtt(vm)->pd,
+                          &start, start + length, vm->top);
 }
 
 static __always_inline void
@@ -703,6 +670,7 @@ struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt)
 
        ppgtt_init(ppgtt, gt);
        ppgtt->vm.top = i915_vm_is_4lvl(&ppgtt->vm) ? 3 : 2;
+       ppgtt->vm.pd_shift = ilog2(SZ_4K * SZ_4K / sizeof(gen8_pte_t));
 
        /*
         * From bdw, there is hw support for read-only pages in the PPGTT.