drm/i915: Remove bitmap tracking for used-pdes
authorChris Wilson <chris@chris-wilson.co.uk>
Wed, 15 Feb 2017 08:43:47 +0000 (08:43 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Wed, 15 Feb 2017 10:07:26 +0000 (10:07 +0000)
We only operate on known extents (both for alloc/clear) and so we can use
both the knowledge of the bind/unbind range along with the knowledge of
the existing pagetable to avoid having to allocate temporary and
auxiliary bitmaps.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170215084357.19977-13-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_gem_gtt.c
drivers/gpu/drm/i915/i915_gem_gtt.h

index ae2ff36..f3171d5 100644 (file)
@@ -494,39 +494,25 @@ static void gen6_initialize_pt(struct i915_address_space *vm,
 static struct i915_page_directory *alloc_pd(struct i915_address_space *vm)
 {
        struct i915_page_directory *pd;
-       int ret = -ENOMEM;
 
-       pd = kzalloc(sizeof(*pd), GFP_KERNEL);
-       if (!pd)
+       pd = kzalloc(sizeof(*pd), GFP_KERNEL | __GFP_NOWARN);
+       if (unlikely(!pd))
                return ERR_PTR(-ENOMEM);
 
-       pd->used_pdes = kcalloc(BITS_TO_LONGS(I915_PDES),
-                               sizeof(*pd->used_pdes), GFP_KERNEL);
-       if (!pd->used_pdes)
-               goto fail_bitmap;
-
-       ret = setup_px(vm, pd);
-       if (ret)
-               goto fail_page_m;
+       if (unlikely(setup_px(vm, pd))) {
+               kfree(pd);
+               return ERR_PTR(-ENOMEM);
+       }
 
+       pd->used_pdes = 0;
        return pd;
-
-fail_page_m:
-       kfree(pd->used_pdes);
-fail_bitmap:
-       kfree(pd);
-
-       return ERR_PTR(ret);
 }
 
 static void free_pd(struct i915_address_space *vm,
                    struct i915_page_directory *pd)
 {
-       if (px_page(pd)) {
-               cleanup_px(vm, pd);
-               kfree(pd->used_pdes);
-               kfree(pd);
-       }
+       cleanup_px(vm, pd);
+       kfree(pd);
 }
 
 static void gen8_initialize_pd(struct i915_address_space *vm,
@@ -540,10 +526,11 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
                pd->page_table[i] = vm->scratch_pt;
 }
 
-static int __pdp_init(struct drm_i915_private *dev_priv,
+static int __pdp_init(struct i915_address_space *vm,
                      struct i915_page_directory_pointer *pdp)
 {
-       size_t pdpes = I915_PDPES_PER_PDP(dev_priv);
+       size_t pdpes = I915_PDPES_PER_PDP(vm->i915);
+       int i;
 
        pdp->used_pdpes = kcalloc(BITS_TO_LONGS(pdpes),
                                  sizeof(unsigned long),
@@ -551,8 +538,8 @@ static int __pdp_init(struct drm_i915_private *dev_priv,
        if (!pdp->used_pdpes)
                return -ENOMEM;
 
-       pdp->page_directory = kcalloc(pdpes, sizeof(*pdp->page_directory),
-                                     GFP_KERNEL);
+       pdp->page_directory = kmalloc_array(pdpes, sizeof(*pdp->page_directory),
+                                           GFP_KERNEL);
        if (!pdp->page_directory) {
                kfree(pdp->used_pdpes);
                /* the PDP might be the statically allocated top level. Keep it
@@ -561,6 +548,9 @@ static int __pdp_init(struct drm_i915_private *dev_priv,
                return -ENOMEM;
        }
 
+       for (i = 0; i < pdpes; i++)
+               pdp->page_directory[i] = vm->scratch_pd;
+
        return 0;
 }
 
@@ -583,7 +573,7 @@ alloc_pdp(struct i915_address_space *vm)
        if (!pdp)
                return ERR_PTR(-ENOMEM);
 
-       ret = __pdp_init(vm->i915, pdp);
+       ret = __pdp_init(vm, pdp);
        if (ret)
                goto fail_bitmap;
 
@@ -633,25 +623,9 @@ static void gen8_initialize_pml4(struct i915_address_space *vm,
 }
 
 static void
-gen8_setup_pdpe(struct i915_hw_ppgtt *ppgtt,
-               struct i915_page_directory_pointer *pdp,
-               struct i915_page_directory *pd,
-               int index)
-{
-       gen8_ppgtt_pdpe_t *page_directorypo;
-
-       if (!USES_FULL_48BIT_PPGTT(to_i915(ppgtt->base.dev)))
-               return;
-
-       page_directorypo = kmap_atomic_px(pdp);
-       page_directorypo[index] = gen8_pdpe_encode(px_dma(pd), I915_CACHE_LLC);
-       kunmap_atomic(page_directorypo);
-}
-
-static void
-gen8_setup_pml4e(struct i915_pml4 *pml4,
-                struct i915_page_directory_pointer *pdp,
-                int index)
+gen8_ppgtt_set_pml4e(struct i915_pml4 *pml4,
+                    struct i915_page_directory_pointer *pdp,
+                    int index)
 {
        gen8_ppgtt_pml4e_t *pagemap = kmap_atomic_px(pml4);
 
@@ -758,9 +732,6 @@ static void gen8_ppgtt_set_pde(struct i915_address_space *vm,
        kunmap_atomic(vaddr);
 }
 
-/* Removes entries from a single page dir, releasing it if it's empty.
- * Caller can use the return value to update higher-level entries
- */
 static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
                                struct i915_page_directory *pd,
                                u64 start, u64 length)
@@ -773,15 +744,28 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
                        continue;
 
                gen8_ppgtt_set_pde(vm, pd, vm->scratch_pt, pde);
-               __clear_bit(pde, pd->used_pdes);
+               pd->used_pdes--;
 
                free_pt(vm, pt);
        }
 
-       if (bitmap_empty(pd->used_pdes, I915_PDES))
-               return true;
+       return !pd->used_pdes;
+}
 
-       return false;
+static void gen8_ppgtt_set_pdpe(struct i915_address_space *vm,
+                               struct i915_page_directory_pointer *pdp,
+                               struct i915_page_directory *pd,
+                               unsigned int pdpe)
+{
+       gen8_ppgtt_pdpe_t *vaddr;
+
+       pdp->page_directory[pdpe] = pd;
+       if (!USES_FULL_48BIT_PPGTT(vm->i915))
+               return;
+
+       vaddr = kmap_atomic_px(pdp);
+       vaddr[pdpe] = gen8_pdpe_encode(px_dma(pd), I915_CACHE_LLC);
+       kunmap_atomic(vaddr);
 }
 
 /* Removes entries from a single page dir pointer, releasing it if it's empty.
@@ -789,25 +773,20 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
  */
 static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
                                 struct i915_page_directory_pointer *pdp,
-                                uint64_t start,
-                                uint64_t length)
+                                u64 start, u64 length)
 {
-       struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
        struct i915_page_directory *pd;
-       uint64_t pdpe;
+       unsigned int pdpe;
 
        gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
-               if (WARN_ON(!pdp->page_directory[pdpe]))
-                       break;
+               if (!gen8_ppgtt_clear_pd(vm, pd, start, length))
+                       continue;
 
-               if (gen8_ppgtt_clear_pd(vm, pd, start, length)) {
-                       __clear_bit(pdpe, pdp->used_pdpes);
-                       gen8_setup_pdpe(ppgtt, pdp, vm->scratch_pd, pdpe);
-                       free_pd(vm, pd);
-               }
-       }
+               gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
+               __clear_bit(pdpe, pdp->used_pdpes);
 
-       mark_tlbs_dirty(ppgtt);
+               free_pd(vm, pd);
+       }
 
        if (bitmap_empty(pdp->used_pdpes, I915_PDPES_PER_PDP(dev_priv)))
                return true;
@@ -815,15 +794,21 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
        return false;
 }
 
+static void gen8_ppgtt_clear_3lvl(struct i915_address_space *vm,
+                                 u64 start, u64 length)
+{
+       gen8_ppgtt_clear_pdp(vm, &i915_vm_to_ppgtt(vm)->pdp, start, length);
+}
+
 /* Removes entries from a single pml4.
  * This is the top-level structure in 4-level page tables used on gen8+.
  * Empty entries are always scratch pml4e.
  */
-static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm,
-                                 struct i915_pml4 *pml4,
-                                 uint64_t start,
-                                 uint64_t length)
+static void gen8_ppgtt_clear_4lvl(struct i915_address_space *vm,
+                                 u64 start, u64 length)
 {
+       struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
+       struct i915_pml4 *pml4 = &ppgtt->pml4;
        struct i915_page_directory_pointer *pdp;
        uint64_t pml4e;
 
@@ -835,23 +820,12 @@ static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm,
 
                if (gen8_ppgtt_clear_pdp(vm, pdp, start, length)) {
                        __clear_bit(pml4e, pml4->used_pml4es);
-                       gen8_setup_pml4e(pml4, vm->scratch_pdp, pml4e);
+                       gen8_ppgtt_set_pml4e(pml4, vm->scratch_pdp, pml4e);
                        free_pdp(vm, pdp);
                }
        }
 }
 
-static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
-                                  uint64_t start, uint64_t length)
-{
-       struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
-
-       if (USES_FULL_48BIT_PPGTT(vm->i915))
-               gen8_ppgtt_clear_pml4(vm, &ppgtt->pml4, start, length);
-       else
-               gen8_ppgtt_clear_pdp(vm, &ppgtt->pdp, start, length);
-}
-
 struct sgt_dma {
        struct scatterlist *sg;
        dma_addr_t dma, max;
@@ -956,12 +930,9 @@ static void gen8_free_page_tables(struct i915_address_space *vm,
        if (!px_page(pd))
                return;
 
-       for_each_set_bit(i, pd->used_pdes, I915_PDES) {
-               if (WARN_ON(!pd->page_table[i]))
-                       continue;
-
-               free_pt(vm, pd->page_table[i]);
-               pd->page_table[i] = NULL;
+       for (i = 0; i < I915_PDES; i++) {
+               if (pd->page_table[i] != vm->scratch_pt)
+                       free_pt(vm, pd->page_table[i]);
        }
 }
 
@@ -1056,7 +1027,7 @@ static void gen8_ppgtt_cleanup_3lvl(struct i915_address_space *vm,
        int i;
 
        for_each_set_bit(i, pdp->used_pdpes, I915_PDPES_PER_PDP(vm->i915)) {
-               if (WARN_ON(!pdp->page_directory[i]))
+               if (pdp->page_directory[i] == vm->scratch_pd)
                        continue;
 
                gen8_free_page_tables(vm, pdp->page_directory[i]);
@@ -1096,44 +1067,28 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
        gen8_free_scratch(vm);
 }
 
-/**
- * gen8_ppgtt_alloc_pagetabs() - Allocate page tables for VA range.
- * @vm:        Master vm structure.
- * @pd:        Page directory for this address range.
- * @start:     Starting virtual address to begin allocations.
- * @length:    Size of the allocations.
- *
- * Allocate the required number of page tables. Extremely similar to
- * gen8_ppgtt_alloc_page_directories(). The main difference is here we are limited by
- * the page directory boundary (instead of the page directory pointer). That
- * boundary is 1GB virtual. Therefore, unlike gen8_ppgtt_alloc_page_directories(), it is
- * possible, and likely that the caller will need to use multiple calls of this
- * function to achieve the appropriate allocation.
- *
- * Return: 0 if success; negative error code otherwise.
- */
-static int gen8_ppgtt_alloc_pagetabs(struct i915_address_space *vm,
-                                    struct i915_page_directory *pd,
-                                    u64 start, u64 length)
+static int gen8_ppgtt_alloc_pd(struct i915_address_space *vm,
+                              struct i915_page_directory *pd,
+                              u64 start, u64 length)
 {
        struct i915_page_table *pt;
        u64 from = start;
-       uint32_t pde;
+       unsigned int pde;
 
        gen8_for_each_pde(pt, pd, start, length, pde) {
-               /* Don't reallocate page tables */
-               if (!test_bit(pde, pd->used_pdes)) {
+               if (pt == vm->scratch_pt) {
                        pt = alloc_pt(vm);
                        if (IS_ERR(pt))
                                goto unwind;
 
                        gen8_initialize_pt(vm, pt);
-                       pd->page_table[pde] = pt;
+
+                       gen8_ppgtt_set_pde(vm, pd, pt, pde);
+                       pd->used_pdes++;
                }
+
                pt->used_ptes += gen8_pte_count(start, length);
-               trace_i915_page_table_entry_alloc(vm, pde, start, GEN8_PDE_SHIFT);
        }
-
        return 0;
 
 unwind:
@@ -1210,7 +1165,7 @@ unwind_out:
  *             caller to free on error.
  *
  * Allocate the required number of page directory pointers. Extremely similar to
- * gen8_ppgtt_alloc_page_directories() and gen8_ppgtt_alloc_pagetabs().
+ * gen8_ppgtt_alloc_page_directories() and gen8_ppgtt_alloc_pd().
  * The main difference is here we are limited by the pml4 boundary (instead of
  * the page directory pointer).
  *
@@ -1262,9 +1217,8 @@ free_gen8_temp_bitmaps(unsigned long *new_pds)
 /* Fills in the page directory bitmap, and the array of page tables bitmap. Both
  * of these are based on the number of PDPEs in the system.
  */
-static
-int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds,
-                                        uint32_t pdpes)
+static int __must_check
+alloc_gen8_temp_bitmaps(unsigned long **new_pds, uint32_t pdpes)
 {
        unsigned long *pds;
 
@@ -1284,8 +1238,6 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
        struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
        unsigned long *new_page_dirs;
        struct i915_page_directory *pd;
-       const uint64_t orig_start = start;
-       const uint64_t orig_length = length;
        uint32_t pdpe;
        uint32_t pdpes = I915_PDPES_PER_PDP(dev_priv);
        int ret;
@@ -1304,51 +1256,16 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
 
        /* For every page directory referenced, allocate page tables */
        gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
-               ret = gen8_ppgtt_alloc_pagetabs(vm, pd, start, length);
+               ret = gen8_ppgtt_alloc_pd(vm, pd, start, length);
                if (ret)
                        goto err_out;
-       }
 
-       start = orig_start;
-       length = orig_length;
+               if (test_and_set_bit(pdpe, pdp->used_pdpes))
+                       gen8_ppgtt_set_pdpe(vm, pdp, pd, pdpe);
+       }
 
        /* Allocations have completed successfully, so set the bitmaps, and do
         * the mappings. */
-       gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
-               gen8_pde_t *const page_directory = kmap_atomic_px(pd);
-               struct i915_page_table *pt;
-               uint64_t pd_len = length;
-               uint64_t pd_start = start;
-               uint32_t pde;
-
-               /* Every pd should be allocated, we just did that above. */
-               WARN_ON(!pd);
-
-               gen8_for_each_pde(pt, pd, pd_start, pd_len, pde) {
-                       /* Same reasoning as pd */
-                       WARN_ON(!pt);
-                       WARN_ON(!pd_len);
-                       WARN_ON(!gen8_pte_count(pd_start, pd_len));
-
-                       /* Our pde is now pointing to the pagetable, pt */
-                       __set_bit(pde, pd->used_pdes);
-
-                       /* Map the PDE to the page table */
-                       page_directory[pde] = gen8_pde_encode(px_dma(pt),
-                                                             I915_CACHE_LLC);
-                       trace_i915_page_table_entry_map(&ppgtt->base, pde, pt,
-                                                       gen8_pte_index(start),
-                                                       gen8_pte_count(start, length));
-
-                       /* NB: We haven't yet mapped ptes to pages. At this
-                        * point we're still relying on insert_entries() */
-               }
-
-               kunmap_atomic(page_directory);
-               __set_bit(pdpe, pdp->used_pdpes);
-               gen8_setup_pdpe(ppgtt, pdp, pd, pdpe);
-       }
-
        free_gen8_temp_bitmaps(new_page_dirs);
        mark_tlbs_dirty(ppgtt);
        return 0;
@@ -1391,7 +1308,7 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
                if (ret)
                        goto err_out;
 
-               gen8_setup_pml4e(pml4, pdp, pml4e);
+               gen8_ppgtt_set_pml4e(pml4, pdp, pml4e);
        }
 
        bitmap_or(pml4->used_pml4es, new_pdps, pml4->used_pml4es,
@@ -1440,7 +1357,7 @@ static void gen8_dump_pdp(struct i915_hw_ppgtt *ppgtt,
                        uint32_t  pte;
                        gen8_pte_t *pt_vaddr;
 
-                       if (!test_bit(pde, pd->used_pdes))
+                       if (pd->page_table[pde] == ppgtt->base.scratch_pt)
                                continue;
 
                        pt_vaddr = kmap_atomic_px(pt);
@@ -1543,7 +1460,6 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
        ppgtt->base.start = 0;
        ppgtt->base.cleanup = gen8_ppgtt_cleanup;
        ppgtt->base.allocate_va_range = gen8_alloc_va_range;
-       ppgtt->base.clear_range = gen8_ppgtt_clear_range;
        ppgtt->base.unbind_vma = ppgtt_unbind_vma;
        ppgtt->base.bind_vma = ppgtt_bind_vma;
        ppgtt->debug_dump = gen8_dump_ppgtt;
@@ -1565,8 +1481,9 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
                ppgtt->switch_mm = gen8_48b_mm_switch;
 
                ppgtt->base.insert_entries = gen8_ppgtt_insert_4lvl;
+               ppgtt->base.clear_range = gen8_ppgtt_clear_4lvl;
        } else {
-               ret = __pdp_init(dev_priv, &ppgtt->pdp);
+               ret = __pdp_init(&ppgtt->base, &ppgtt->pdp);
                if (ret)
                        goto free_scratch;
 
@@ -1583,6 +1500,7 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
                }
 
                ppgtt->base.insert_entries = gen8_ppgtt_insert_3lvl;
+               ppgtt->base.clear_range = gen8_ppgtt_clear_3lvl;
        }
 
        if (intel_vgpu_active(dev_priv))
index 5ad5b59..a62b0ef 100644 (file)
@@ -226,8 +226,8 @@ struct i915_page_table {
 struct i915_page_directory {
        struct i915_page_dma base;
 
-       unsigned long *used_pdes;
        struct i915_page_table *page_table[I915_PDES]; /* PDEs */
+       unsigned int used_pdes;
 };
 
 struct i915_page_directory_pointer {
@@ -520,9 +520,7 @@ static inline size_t gen8_pte_count(uint64_t address, uint64_t length)
 static inline dma_addr_t
 i915_page_dir_dma_addr(const struct i915_hw_ppgtt *ppgtt, const unsigned n)
 {
-       return test_bit(n, ppgtt->pdp.used_pdpes) ?
-               px_dma(ppgtt->pdp.page_directory[n]) :
-               px_dma(ppgtt->base.scratch_pd);
+       return px_dma(ppgtt->pdp.page_directory[n]);
 }
 
 static inline struct i915_ggtt *