On 2 February 2017 at 15:02, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_gem_gtt.c | 275 +++++++++++-------------------------
> drivers/gpu/drm/i915/i915_gem_gtt.h | 3 +-
> 2 files changed, 84 insertions(+), 194 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 15e95904931f..99319461f86c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -526,24 +526,13 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
> static int __pdp_init(struct i915_address_space *vm,
> struct i915_page_directory_pointer *pdp)
> {
> - size_t pdpes = I915_PDPES_PER_PDP(vm->i915);
> - int i;
> -
> - pdp->used_pdpes = kcalloc(BITS_TO_LONGS(pdpes),
> - sizeof(unsigned long),
> - GFP_KERNEL);
> - if (!pdp->used_pdpes)
> - return -ENOMEM;
> + const unsigned int pdpes = I915_PDPES_PER_PDP(vm->i915);
> + unsigned int i;
>
> 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
> - * as clean as possible */
> - pdp->used_pdpes = NULL;
> + GFP_KERNEL | __GFP_NOWARN);
> + if (unlikely(!pdp->page_directory))
> return -ENOMEM;
> - }
>
> for (i = 0; i < pdpes; i++)
> pdp->page_directory[i] = vm->scratch_pd;
> @@ -553,7 +542,6 @@ static int __pdp_init(struct i915_address_space *vm,
>
> static void __pdp_fini(struct i915_page_directory_pointer *pdp)
> {
> - kfree(pdp->used_pdpes);
> kfree(pdp->page_directory);
> pdp->page_directory = NULL;
> }
> @@ -611,23 +599,12 @@ static void gen8_initialize_pdp(struct i915_address_space *vm,
> static void gen8_initialize_pml4(struct i915_address_space *vm,
> struct i915_pml4 *pml4)
> {
> - gen8_ppgtt_pml4e_t scratch_pml4e;
> -
> - scratch_pml4e = gen8_pml4e_encode(px_dma(vm->scratch_pdp),
> - I915_CACHE_LLC);
> -
> - fill_px(vm, pml4, scratch_pml4e);
> -}
> -
> -static void
> -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);
> + unsigned int i;
>
> - pagemap[index] = gen8_pml4e_encode(px_dma(pdp), I915_CACHE_LLC);
> - kunmap_atomic(pagemap);
> + fill_px(vm, pml4,
> + gen8_pml4e_encode(px_dma(vm->scratch_pdp), I915_CACHE_LLC));
> + for (i = 0; i < GEN8_PML4ES_PER_PML4; i++)
> + pml4->pdps[i] = vm->scratch_pdp;
> }
>
> /* Broadwell Page Directory Pointer Descriptors */
> @@ -781,15 +758,12 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
> continue;
>
> gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
> - __clear_bit(pdpe, pdp->used_pdpes);
> + pdp->used_pdpes--;
>
> free_pd(vm, pd);
> }
>
> - if (bitmap_empty(pdp->used_pdpes, I915_PDPES_PER_PDP(dev_priv)))
> - return true;
> -
> - return false;
> + return !pdp->used_pdpes;
> }
>
> static void gen8_ppgtt_clear_3lvl(struct i915_address_space *vm,
> @@ -798,6 +772,19 @@ static void gen8_ppgtt_clear_3lvl(struct i915_address_space *vm,
> gen8_ppgtt_clear_pdp(vm, &i915_vm_to_ppgtt(vm)->pdp, start, length);
> }
>
> +static void gen8_ppgtt_set_pml4e(struct i915_pml4 *pml4,
> + struct i915_page_directory_pointer *pdp,
> + unsigned int pml4e)
> +{
> + gen8_ppgtt_pml4e_t *vaddr;
> +
> + pml4->pdps[pml4e] = pdp;
> +
> + vaddr = kmap_atomic_px(pml4);
> + vaddr[pml4e] = gen8_pml4e_encode(px_dma(pdp), I915_CACHE_LLC);
> + kunmap_atomic(vaddr);
> +}
> +
> /* 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.
> @@ -808,19 +795,18 @@ static void gen8_ppgtt_clear_4lvl(struct i915_address_space *vm,
> 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;
> + unsigned int pml4e;
>
> GEM_BUG_ON(!USES_FULL_48BIT_PPGTT(vm->i915));
>
> gen8_for_each_pml4e(pdp, pml4, start, length, pml4e) {
> - if (WARN_ON(!pml4->pdps[pml4e]))
> - break;
> + if (!gen8_ppgtt_clear_pdp(vm, pdp, start, length))
> + continue;
>
> - if (gen8_ppgtt_clear_pdp(vm, pdp, start, length)) {
> - __clear_bit(pml4e, pml4->used_pml4es);
> - gen8_ppgtt_set_pml4e(pml4, vm->scratch_pdp, pml4e);
> - free_pdp(vm, pdp);
> - }
> + gen8_ppgtt_set_pml4e(pml4, vm->scratch_pdp, pml4e);
> + __clear_bit(pml4e, pml4->used_pml4es);
> +
> + free_pdp(vm, pdp);
> }
> }
>
> @@ -1017,7 +1003,7 @@ 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)) {
> + for (i = 0; i < I915_PDPES_PER_PDP(vm->i915); i++) {
> if (pdp->page_directory[i] == vm->scratch_pd)
> continue;
>
> @@ -1088,65 +1074,6 @@ static int gen8_ppgtt_alloc_pd(struct i915_address_space *vm,
> }
>
> /**
> - * gen8_ppgtt_alloc_page_directories() - Allocate page directories for VA range.
> - * @vm: Master vm structure.
> - * @pdp: Page directory pointer for this address range.
> - * @start: Starting virtual address to begin allocations.
> - * @length: Size of the allocations.
> - * @new_pds: Bitmap set by function with new allocations. Likely used by the
> - * caller to free on error.
> - *
> - * Allocate the required number of page directories starting at the pde index of
> - * @start, and ending at the pde index @start + @length. This function will skip
> - * over already allocated page directories within the range, and only allocate
> - * new ones, setting the appropriate pointer within the pdp as well as the
> - * correct position in the bitmap @new_pds.
> - *
> - * The function will only allocate the pages within the range for a give page
> - * directory pointer. In other words, if @start + @length straddles a virtually
> - * addressed PDP boundary (512GB for 4k pages), there will be more allocations
> - * required by the caller, This is not currently possible, and the BUG in the
> - * code will prevent it.
> - *
> - * Return: 0 if success; negative error code otherwise.
> - */
> -static int
> -gen8_ppgtt_alloc_page_directories(struct i915_address_space *vm,
> - struct i915_page_directory_pointer *pdp,
> - uint64_t start,
> - uint64_t length,
> - unsigned long *new_pds)
> -{
> - struct i915_page_directory *pd;
> - uint32_t pdpe;
> - uint32_t pdpes = I915_PDPES_PER_PDP(dev_priv);
> -
> - WARN_ON(!bitmap_empty(new_pds, pdpes));
> -
> - gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
> - if (test_bit(pdpe, pdp->used_pdpes))
> - continue;
> -
> - pd = alloc_pd(vm);
> - if (IS_ERR(pd))
> - goto unwind_out;
> -
> - gen8_initialize_pd(vm, pd);
> - pdp->page_directory[pdpe] = pd;
> - __set_bit(pdpe, new_pds);
> - trace_i915_page_directory_entry_alloc(vm, pdpe, start, GEN8_PDPE_SHIFT);
> - }
> -
> - return 0;
> -
> -unwind_out:
> - for_each_set_bit(pdpe, new_pds, pdpes)
> - free_pd(vm, pdp->page_directory[pdpe]);
> -
> - return -ENOMEM;
> -}
> -
> -/**
> * gen8_ppgtt_alloc_page_dirpointers() - Allocate pdps for VA range.
> * @vm: Master vm structure.
> * @pml4: Page map level 4 for this address range.
> @@ -1166,23 +1093,19 @@ static int
> gen8_ppgtt_alloc_page_dirpointers(struct i915_address_space *vm,
> struct i915_pml4 *pml4,
> uint64_t start,
> - uint64_t length,
> - unsigned long *new_pdps)
> + uint64_t length)
> {
> struct i915_page_directory_pointer *pdp;
> uint32_t pml4e;
>
> - WARN_ON(!bitmap_empty(new_pdps, GEN8_PML4ES_PER_PML4));
> -
> gen8_for_each_pml4e(pdp, pml4, start, length, pml4e) {
> if (!test_bit(pml4e, pml4->used_pml4es)) {
> pdp = alloc_pdp(vm);
> if (IS_ERR(pdp))
> - goto unwind_out;
> + return PTR_ERR(pdp);
>
> gen8_initialize_pdp(vm, pdp);
> pml4->pdps[pml4e] = pdp;
> - __set_bit(pml4e, new_pdps);
> trace_i915_page_directory_pointer_entry_alloc(vm,
> pml4e,
> start,
> @@ -1191,34 +1114,6 @@ gen8_ppgtt_alloc_page_dirpointers(struct i915_address_space *vm,
> }
>
> return 0;
> -
> -unwind_out:
> - for_each_set_bit(pml4e, new_pdps, GEN8_PML4ES_PER_PML4)
> - free_pdp(vm, pml4->pdps[pml4e]);
> -
> - return -ENOMEM;
> -}
> -
> -static void
> -free_gen8_temp_bitmaps(unsigned long *new_pds)
> -{
> - kfree(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)
> -{
> - unsigned long *pds;
> -
> - pds = kcalloc(BITS_TO_LONGS(pdpes), sizeof(unsigned long), GFP_TEMPORARY);
> - if (!pds)
> - return -ENOMEM;
> -
> - *new_pds = pds;
> - return 0;
> }
>
> static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
> @@ -1227,47 +1122,37 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
> uint64_t length)
> {
> struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
> - unsigned long *new_page_dirs;
> struct i915_page_directory *pd;
> - uint32_t pdpe;
> - uint32_t pdpes = I915_PDPES_PER_PDP(dev_priv);
> + u64 from = start;
> + unsigned int pdpe;
> int ret;
>
> - ret = alloc_gen8_temp_bitmaps(&new_page_dirs, pdpes);
> - if (ret)
> - return ret;
> -
> - /* Do the allocations first so we can easily bail out */
> - ret = gen8_ppgtt_alloc_page_directories(vm, pdp, start, length,
> - new_page_dirs);
> - if (ret) {
> - free_gen8_temp_bitmaps(new_page_dirs);
> - return ret;
> - }
> -
> - /* For every page directory referenced, allocate page tables */
> gen8_for_each_pdpe(pd, pdp, start, length, pdpe) {
> - ret = gen8_ppgtt_alloc_pd(vm, pd, start, length);
> - if (ret)
> - goto err_out;
> + if (pd == vm->scratch_pd) {
> + pd = alloc_pd(vm);
> + if (IS_ERR(pd))
> + goto unwind;
>
> - if (test_and_set_bit(pdpe, pdp->used_pdpes))
> + gen8_initialize_pd(vm, pd);
> gen8_ppgtt_set_pdpe(vm, pdp, pd, pdpe);
> + pdp->used_pdpes++;
> + }
> +
> + ret = gen8_ppgtt_alloc_pd(vm, pd, start, length);
> + if (unlikely(ret)) {
> + gen8_ppgtt_set_pdpe(vm, pdp, vm->scratch_pd, pdpe);
> + pdp->used_pdpes--;
> + free_pd(vm, pd);
> + goto unwind;
> + }
> }
>
> - /* Allocations have completed successfully, so set the bitmaps, and do
> - * the mappings. */
> - free_gen8_temp_bitmaps(new_page_dirs);
> mark_tlbs_dirty(ppgtt);
> return 0;
>
> -err_out:
> - for_each_set_bit(pdpe, new_page_dirs, pdpes)
> - free_pd(vm, pdp->page_directory[pdpe]);
> -
> - free_gen8_temp_bitmaps(new_page_dirs);
> - mark_tlbs_dirty(ppgtt);
> - return ret;
> +unwind:
> + gen8_ppgtt_clear_pdp(vm, pdp, from, start - from);
> + return -ENOMEM;
> }
>
> static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
> @@ -1287,8 +1172,7 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
> /* The pagedirectory and pagetable allocations are done in the shared 3
> * and 4 level code. Just allocate the pdps.
> */
> - ret = gen8_ppgtt_alloc_page_dirpointers(vm, pml4, start, length,
> - new_pdps);
> + ret = gen8_ppgtt_alloc_page_dirpointers(vm, pml4, start, length);
> if (ret)
> return ret;
>
> @@ -1340,7 +1224,7 @@ static void gen8_dump_pdp(struct i915_hw_ppgtt *ppgtt,
> uint64_t pd_start = start;
> uint32_t pde;
>
> - if (!test_bit(pdpe, pdp->used_pdpes))
> + if (pdp->page_directory[pdpe] == ppgtt->base.scratch_pd)
> continue;
>
> seq_printf(m, "\tPDPE #%d\n", pdpe);
> @@ -1407,29 +1291,34 @@ static void gen8_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
>
> static int gen8_preallocate_top_level_pdps(struct i915_hw_ppgtt *ppgtt)
> {
s/gen8_preallocate_top_level_pdps/gen8_preallocate_top_level_pdp/ ?
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
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