drm/i915/gtt: Recursive ppgtt alloc for gen8

Refactor the separate allocation routines into a single recursive
function.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712112725.2892-4-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 1e3ccdf..49de6d3 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1007,199 +1007,119 @@ static void gen8_ppgtt_clear(struct i915_address_space *vm,
                           start, start + length, vm->top);
 }
 
-static void gen8_ppgtt_clear_pd(struct i915_address_space *vm,
-                               struct i915_page_directory *pd,
-                               u64 start, u64 length)
-{
-       GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
-       GEM_BUG_ON(!IS_ALIGNED(length, BIT_ULL(GEN8_PTE_SHIFT)));
-
-       start >>= GEN8_PTE_SHIFT;
-       length >>= GEN8_PTE_SHIFT;
-
-       __gen8_ppgtt_clear(vm, pd, start, start + length, 1);
-}
-
-static void gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
-                                struct i915_page_directory * const pdp,
-                                u64 start, u64 length)
-{
-       GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
-       GEM_BUG_ON(!IS_ALIGNED(length, BIT_ULL(GEN8_PTE_SHIFT)));
-
-       start >>= GEN8_PTE_SHIFT;
-       length >>= GEN8_PTE_SHIFT;
-
-       __gen8_ppgtt_clear(vm, pdp, start, start + length, 2);
-}
-
-static int gen8_ppgtt_alloc_pd(struct i915_address_space *vm,
-                              struct i915_page_directory *pd,
-                              u64 start, u64 length)
+static int __gen8_ppgtt_alloc(struct i915_address_space * const vm,
+                             struct i915_page_directory * const pd,
+                             u64 * const start, u64 end, int lvl)
 {
-       struct i915_page_table *pt, *alloc = NULL;
-       u64 from = start;
-       unsigned int pde;
+       const struct i915_page_scratch * const scratch = &vm->scratch[lvl];
+       struct i915_page_table *alloc = NULL;
+       unsigned int idx, len;
        int ret = 0;
 
+       len = gen8_pd_range(*start, end, lvl--, &idx);
+       DBG("%s(%p):{lvl:%d, start:%llx, end:%llx, idx:%d, len:%d, used:%d}\n",
+           __func__, vm, lvl + 1, *start, end,
+           idx, len, atomic_read(px_used(pd)));
+       GEM_BUG_ON(!len || (idx + len - 1) >> gen8_pd_shift(1));
+
        spin_lock(&pd->lock);
-       gen8_for_each_pde(pt, pd, start, length, pde) {
-               const int count = gen8_pte_count(start, length);
+       GEM_BUG_ON(!atomic_read(px_used(pd))); /* Must be pinned! */
+       do {
+               struct i915_page_table *pt = pd->entry[idx];
 
                if (!pt) {
                        spin_unlock(&pd->lock);
 
-                       pt = fetch_and_zero(&alloc);
-                       if (!pt)
-                               pt = alloc_pt(vm);
-                       if (IS_ERR(pt)) {
-                               ret = PTR_ERR(pt);
-                               goto unwind;
-                       }
+                       DBG("%s(%p):{ lvl:%d, idx:%d } allocating new tree\n",
+                           __func__, vm, lvl + 1, idx);
 
-                       if (count < GEN8_PTES || intel_vgpu_active(vm->i915))
-                               fill_px(pt, vm->scratch[0].encode);
+                       pt = fetch_and_zero(&alloc);
+                       if (lvl) {
+                               if (!pt) {
+                                       pt = &alloc_pd(vm)->pt;
+                                       if (IS_ERR(pt)) {
+                                               ret = PTR_ERR(pt);
+                                               goto out;
+                                       }
+                               }
 
-                       spin_lock(&pd->lock);
-                       if (!pd->entry[pde]) {
-                               set_pd_entry(pd, pde, pt);
+                               fill_px(pt, vm->scratch[lvl].encode);
                        } else {
-                               alloc = pt;
-                               pt = pd->entry[pde];
-                       }
-               }
-
-               atomic_add(count, &pt->used);
-       }
-       spin_unlock(&pd->lock);
-       goto out;
-
-unwind:
-       gen8_ppgtt_clear_pd(vm, pd, from, start - from);
-out:
-       if (alloc)
-               free_px(vm, alloc);
-       return ret;
-}
-
-static int gen8_ppgtt_alloc_pdp(struct i915_address_space *vm,
-                               struct i915_page_directory *pdp,
-                               u64 start, u64 length)
-{
-       struct i915_page_directory *pd, *alloc = NULL;
-       u64 from = start;
-       unsigned int pdpe;
-       int ret = 0;
+                               if (!pt) {
+                                       pt = alloc_pt(vm);
+                                       if (IS_ERR(pt)) {
+                                               ret = PTR_ERR(pt);
+                                               goto out;
+                                       }
+                               }
 
-       spin_lock(&pdp->lock);
-       gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
-               if (!pd) {
-                       spin_unlock(&pdp->lock);
-
-                       pd = fetch_and_zero(&alloc);
-                       if (!pd)
-                               pd = alloc_pd(vm);
-                       if (IS_ERR(pd)) {
-                               ret = PTR_ERR(pd);
-                               goto unwind;
+                               if (intel_vgpu_active(vm->i915) ||
+                                   gen8_pt_count(*start, end) < I915_PDES)
+                                       fill_px(pt, vm->scratch[lvl].encode);
                        }
 
-                       fill_px(pd, vm->scratch[1].encode);
+                       spin_lock(&pd->lock);
+                       if (likely(!pd->entry[idx]))
+                               set_pd_entry(pd, idx, pt);
+                       else
+                               alloc = pt, pt = pd->entry[idx];
+               }
 
-                       spin_lock(&pdp->lock);
-                       if (!pdp->entry[pdpe]) {
-                               set_pd_entry(pdp, pdpe, pd);
-                       } else {
-                               alloc = pd;
-                               pd = pdp->entry[pdpe];
+               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;
                        }
-               }
-               atomic_inc(px_used(pd));
-               spin_unlock(&pdp->lock);
 
-               ret = gen8_ppgtt_alloc_pd(vm, pd, start, length);
-               if (unlikely(ret))
-                       goto unwind_pd;
+                       spin_lock(&pd->lock);
+                       atomic_dec(&pt->used);
+                       GEM_BUG_ON(!atomic_read(&pt->used));
+               } else {
+                       unsigned int count = gen8_pt_count(*start, end);
 
-               spin_lock(&pdp->lock);
-               atomic_dec(px_used(pd));
-       }
-       spin_unlock(&pdp->lock);
-       goto out;
+                       DBG("%s(%p):{lvl:%d, start:%llx, end:%llx, idx:%d, len:%d, used:%d} inserting pte\n",
+                           __func__, vm, lvl, *start, end,
+                           gen8_pd_index(*start, 0), count,
+                           atomic_read(&pt->used));
 
-unwind_pd:
-       if (release_pd_entry(pdp, pdpe, &pd->pt, &vm->scratch[2]))
-               free_px(vm, pd);
-unwind:
-       gen8_ppgtt_clear_pdp(vm, pdp, from, start - from);
+                       atomic_add(count, &pt->used);
+                       GEM_BUG_ON(atomic_read(&pt->used) > I915_PDES);
+                       *start += count;
+               }
+       } while (idx++, --len);
+       spin_unlock(&pd->lock);
 out:
        if (alloc)
                free_px(vm, alloc);
        return ret;
 }
 
-static int gen8_ppgtt_alloc_3lvl(struct i915_address_space *vm,
-                                u64 start, u64 length)
-{
-       return gen8_ppgtt_alloc_pdp(vm,
-                                   i915_vm_to_ppgtt(vm)->pd, start, length);
-}
-
-static int gen8_ppgtt_alloc_4lvl(struct i915_address_space *vm,
-                                u64 start, u64 length)
+static int gen8_ppgtt_alloc(struct i915_address_space *vm,
+                           u64 start, u64 length)
 {
-       struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
-       struct i915_page_directory * const pml4 = ppgtt->pd;
-       struct i915_page_directory *pdp, *alloc = NULL;
        u64 from = start;
-       int ret = 0;
-       u32 pml4e;
-
-       spin_lock(&pml4->lock);
-       gen8_for_each_pml4e(pdp, pml4, start, length, pml4e) {
-               if (!pdp) {
-                       spin_unlock(&pml4->lock);
-
-                       pdp = fetch_and_zero(&alloc);
-                       if (!pdp)
-                               pdp = alloc_pd(vm);
-                       if (IS_ERR(pdp)) {
-                               ret = PTR_ERR(pdp);
-                               goto unwind;
-                       }
-
-                       fill_px(pdp, vm->scratch[2].encode);
+       int err;
 
-                       spin_lock(&pml4->lock);
-                       if (!pml4->entry[pml4e]) {
-                               set_pd_entry(pml4, pml4e, pdp);
-                       } else {
-                               alloc = pdp;
-                               pdp = pml4->entry[pml4e];
-                       }
-               }
-               atomic_inc(px_used(pdp));
-               spin_unlock(&pml4->lock);
+       GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
+       GEM_BUG_ON(!IS_ALIGNED(length, BIT_ULL(GEN8_PTE_SHIFT)));
 
-               ret = gen8_ppgtt_alloc_pdp(vm, pdp, start, length);
-               if (unlikely(ret))
-                       goto unwind_pdp;
+       start >>= GEN8_PTE_SHIFT;
+       length >>= GEN8_PTE_SHIFT;
+       GEM_BUG_ON(length == 0);
 
-               spin_lock(&pml4->lock);
-               atomic_dec(px_used(pdp));
-       }
-       spin_unlock(&pml4->lock);
-       goto out;
+       err = __gen8_ppgtt_alloc(vm, i915_vm_to_ppgtt(vm)->pd,
+                                &start, start + length, vm->top);
+       if (unlikely(err))
+               __gen8_ppgtt_clear(vm, i915_vm_to_ppgtt(vm)->pd,
+                                  from, start, vm->top);
 
-unwind_pdp:
-       if (release_pd_entry(pml4, pml4e, &pdp->pt, &vm->scratch[3]))
-               free_px(vm, pdp);
-unwind:
-       gen8_ppgtt_clear(vm, from, start - from);
-out:
-       if (alloc)
-               free_px(vm, alloc);
-       return ret;
+       return err;
 }
 
 static inline struct sgt_dma {
@@ -1496,19 +1416,22 @@ free_scratch:
 static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt)
 {
        struct i915_address_space *vm = &ppgtt->vm;
-       struct i915_page_directory *pdp = ppgtt->pd;
-       struct i915_page_directory *pd;
-       u64 start = 0, length = ppgtt->vm.total;
-       unsigned int pdpe;
+       struct i915_page_directory *pd = ppgtt->pd;
+       unsigned int idx;
+
+       GEM_BUG_ON(vm->top != 2);
+       GEM_BUG_ON((vm->total >> __gen8_pte_shift(2)) != GEN8_3LVL_PDPES);
+
+       for (idx = 0; idx < GEN8_3LVL_PDPES; idx++) {
+               struct i915_page_directory *pde;
 
-       gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
-               pd = alloc_pd(vm);
-               if (IS_ERR(pd))
-                       return PTR_ERR(pd);
+               pde = alloc_pd(vm);
+               if (IS_ERR(pde))
+                       return PTR_ERR(pde);
 
-               fill_px(pd, vm->scratch[1].encode);
-               set_pd_entry(pdp, pdpe, pd);
-               atomic_inc(px_used(pd)); /* keep pinned */
+               fill_px(pde, vm->scratch[1].encode);
+               set_pd_entry(pd, idx, pde);
+               atomic_inc(px_used(pde)); /* keep pinned */
        }
 
        return 0;
@@ -1597,7 +1520,6 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
        }
 
        if (i915_vm_is_4lvl(&ppgtt->vm)) {
-               ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc_4lvl;
                ppgtt->vm.insert_entries = gen8_ppgtt_insert_4lvl;
        } else {
                if (intel_vgpu_active(i915)) {
@@ -1606,10 +1528,10 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
                                goto err_free_pd;
                }
 
-               ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc_3lvl;
                ppgtt->vm.insert_entries = gen8_ppgtt_insert_3lvl;
        }
 
+       ppgtt->vm.allocate_va_range = gen8_ppgtt_alloc;
        ppgtt->vm.clear_range = gen8_ppgtt_clear;
 
        if (intel_vgpu_active(i915))