drm/i915/gtt: Recursive cleanup for gen8

With an explicit level, we can refactor the separate cleanup functions
as a simple recursive function. We take the opportunity to pass down the
size of each level so that we can deal with the different sizes of
top-level and avoid over allocating for 32/36-bit vm.

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/20190712112725.2892-2-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 7352b9e..3a156f0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -713,11 +713,11 @@ static struct i915_page_table *alloc_pt(struct i915_address_space *vm)
        return pt;
 }
 
-static struct i915_page_directory *__alloc_pd(void)
+static struct i915_page_directory *__alloc_pd(size_t sz)
 {
        struct i915_page_directory *pd;
 
-       pd = kzalloc(sizeof(*pd), I915_GFP_ALLOW_FAIL);
+       pd = kzalloc(sz, I915_GFP_ALLOW_FAIL);
        if (unlikely(!pd))
                return NULL;
 
@@ -729,7 +729,7 @@ static struct i915_page_directory *alloc_pd(struct i915_address_space *vm)
 {
        struct i915_page_directory *pd;
 
-       pd = __alloc_pd();
+       pd = __alloc_pd(sizeof(*pd));
        if (unlikely(!pd))
                return ERR_PTR(-ENOMEM);
 
@@ -766,7 +766,7 @@ __set_pd_entry(struct i915_page_directory * const pd,
               struct i915_page_dma * const to,
               u64 (*encode)(const dma_addr_t, const enum i915_cache_level))
 {
-       GEM_BUG_ON(atomic_read(px_used(pd)) > 512);
+       GEM_BUG_ON(atomic_read(px_used(pd)) > ARRAY_SIZE(pd->entry));
 
        atomic_inc(px_used(pd));
        pd->entry[idx] = to;
@@ -896,64 +896,34 @@ static inline unsigned int gen8_pt_count(u64 start, u64 end)
                return end - start;
 }
 
-static void gen8_free_page_tables(struct i915_address_space *vm,
-                                 struct i915_page_directory *pd)
+static void __gen8_ppgtt_cleanup(struct i915_address_space *vm,
+                                struct i915_page_directory *pd,
+                                int count, int lvl)
 {
-       int i;
-
-       for (i = 0; i < I915_PDES; i++) {
-               if (pd->entry[i])
-                       free_pd(vm, pd->entry[i]);
-       }
-}
-
-static void gen8_ppgtt_cleanup_3lvl(struct i915_address_space *vm,
-                                   struct i915_page_directory *pdp)
-{
-       const unsigned int pdpes = i915_pdpes_per_pdp(vm);
-       int i;
-
-       for (i = 0; i < pdpes; i++) {
-               if (!pdp->entry[i])
-                       continue;
-
-               gen8_free_page_tables(vm, pdp->entry[i]);
-               free_pd(vm, pdp->entry[i]);
-       }
-
-       free_px(vm, pdp);
-}
-
-static void gen8_ppgtt_cleanup_4lvl(struct i915_ppgtt *ppgtt)
-{
-       struct i915_page_directory * const pml4 = ppgtt->pd;
-       int i;
-
-       for (i = 0; i < GEN8_PML4ES_PER_PML4; i++) {
-               struct i915_page_directory *pdp = i915_pdp_entry(pml4, i);
+       if (lvl) {
+               void **pde = pd->entry;
 
-               if (!pdp)
-                       continue;
+               do {
+                       if (!*pde)
+                               continue;
 
-               gen8_ppgtt_cleanup_3lvl(&ppgtt->vm, pdp);
+                       __gen8_ppgtt_cleanup(vm, *pde, GEN8_PDES, lvl - 1);
+               } while (pde++, --count);
        }
 
-       free_px(&ppgtt->vm, pml4);
+       free_px(vm, pd);
 }
 
 static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
 {
-       struct drm_i915_private *i915 = vm->i915;
        struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 
-       if (intel_vgpu_active(i915))
+       if (intel_vgpu_active(vm->i915))
                gen8_ppgtt_notify_vgt(ppgtt, false);
 
-       if (i915_vm_is_4lvl(vm))
-               gen8_ppgtt_cleanup_4lvl(ppgtt);
-       else
-               gen8_ppgtt_cleanup_3lvl(&ppgtt->vm, ppgtt->pd);
-
+       __gen8_ppgtt_cleanup(vm, ppgtt->pd,
+                            vm->total >> __gen8_pte_shift(vm->top),
+                            vm->top);
        free_scratch(vm);
 }
 
@@ -1505,24 +1475,18 @@ static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt)
        struct i915_page_directory *pdp = ppgtt->pd;
        struct i915_page_directory *pd;
        u64 start = 0, length = ppgtt->vm.total;
-       u64 from = start;
        unsigned int pdpe;
 
        gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
                pd = alloc_pd(vm);
                if (IS_ERR(pd))
-                       goto unwind;
+                       return PTR_ERR(pd);
 
                fill_px(pd, vm->scratch[1].encode);
                set_pd_entry(pdp, pdpe, pd);
        }
 
        return 0;
-
-unwind:
-       gen8_ppgtt_clear_pdp(vm, pdp, from, start - from);
-       atomic_set(px_used(pdp), 0);
-       return -ENOMEM;
 }
 
 static void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt)
@@ -1550,9 +1514,14 @@ gen8_alloc_top_pd(struct i915_address_space *vm)
 
        GEM_BUG_ON(count > ARRAY_SIZE(pd->entry));
 
-       pd = alloc_pd(vm);
-       if (IS_ERR(pd))
-               return pd;
+       pd = __alloc_pd(offsetof(typeof(*pd), entry[count]));
+       if (unlikely(!pd))
+               return ERR_PTR(-ENOMEM);
+
+       if (unlikely(setup_page_dma(vm, px_base(pd)))) {
+               kfree(pd);
+               return ERR_PTR(-ENOMEM);
+       }
 
        fill_page_dma(px_base(pd), vm->scratch[vm->top].encode, count);
        return pd;
@@ -1625,7 +1594,9 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
        return ppgtt;
 
 err_free_pd:
-       free_px(&ppgtt->vm, ppgtt->pd);
+       __gen8_ppgtt_cleanup(&ppgtt->vm, ppgtt->pd,
+                            ppgtt->vm.total >> __gen8_pte_shift(ppgtt->vm.top),
+                            ppgtt->vm.top);
 err_free_scratch:
        free_scratch(&ppgtt->vm);
 err_free:
@@ -2071,7 +2042,7 @@ static struct i915_ppgtt *gen6_ppgtt_create(struct drm_i915_private *i915)
 
        ppgtt->base.vm.pte_encode = ggtt->vm.pte_encode;
 
-       ppgtt->base.pd = __alloc_pd();
+       ppgtt->base.pd = __alloc_pd(sizeof(*ppgtt->base.pd));
        if (!ppgtt->base.pd) {
                err = -ENOMEM;
                goto err_free;