[Intel-gfx] [PATCH v8 06/19] drm/i915/gen8: Add PML4 structure
Goel, Akash
akash.goel at intel.com
Fri Jul 31 10:35:02 PDT 2015
On 7/31/2015 5:42 PM, Michel Thierry wrote:
> Introduces the Page Map Level 4 (PML4), ie. the new top level structure
> of the page tables.
>
> To facilitate testing, 48b mode will be available on Broadwell and
> GEN9+, when i915.enable_ppgtt = 3.
>
> v2: Remove unnecessary CONFIG_X86_64 checks, ppgtt code is already
> 32/64-bit safe (Chris).
> v3: Add goto free_scratch in temp 48-bit mode init code (Akash).
> v4: kfree the pdp until the 4lvl alloc/free patch (Akash).
> v5: Postpone 48-bit code in sanitize_enable_ppgtt (Akash).
>
> Cc: Akash Goel <akash.goel at intel.com>
> Signed-off-by: Michel Thierry <michel.thierry at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 3 ++-
> drivers/gpu/drm/i915/i915_gem_gtt.c | 30 +++++++++++++++++-------------
> drivers/gpu/drm/i915/i915_gem_gtt.h | 26 +++++++++++++++++++++-----
> 3 files changed, 40 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 04aa34a..4729eaf 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2498,7 +2498,8 @@ struct drm_i915_cmd_table {
> #define HAS_HW_CONTEXTS(dev) (INTEL_INFO(dev)->gen >= 6)
> #define HAS_LOGICAL_RING_CONTEXTS(dev) (INTEL_INFO(dev)->gen >= 8)
> #define USES_PPGTT(dev) (i915.enable_ppgtt)
> -#define USES_FULL_PPGTT(dev) (i915.enable_ppgtt == 2)
> +#define USES_FULL_PPGTT(dev) (i915.enable_ppgtt >= 2)
> +#define USES_FULL_48BIT_PPGTT(dev) (i915.enable_ppgtt == 3)
>
> #define HAS_OVERLAY(dev) (INTEL_INFO(dev)->has_overlay)
> #define OVERLAY_NEEDS_PHYSICAL(dev) (INTEL_INFO(dev)->overlay_needs_physical)
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 7f71746..ba99b67 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -689,9 +689,6 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
> pt_vaddr = NULL;
>
> for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
> - if (WARN_ON(pdpe >= GEN8_LEGACY_PDPES))
> - break;
> -
Apologize for this eleventh hour comment.
Would this change be better off in the later patch "Add 4 level support
in insert_entries and clear_range".
Best regards
Akash
> if (pt_vaddr == NULL) {
> struct i915_page_directory *pd = pdp->page_directory[pdpe];
> struct i915_page_table *pt = pd->page_table[pde];
> @@ -1105,14 +1102,6 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
> return ret;
>
> ppgtt->base.start = 0;
> - ppgtt->base.total = 1ULL << 32;
> - if (IS_ENABLED(CONFIG_X86_32))
> - /* While we have a proliferation of size_t variables
> - * we cannot represent the full ppgtt size on 32bit,
> - * so limit it to the same size as the GGTT (currently
> - * 2GiB).
> - */
> - ppgtt->base.total = to_i915(ppgtt->base.dev)->gtt.base.total;
> ppgtt->base.cleanup = gen8_ppgtt_cleanup;
> ppgtt->base.allocate_va_range = gen8_alloc_va_range;
> ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
> @@ -1122,10 +1111,25 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
>
> ppgtt->switch_mm = gen8_mm_switch;
>
> - ret = __pdp_init(false, &ppgtt->pdp);
> + if (!USES_FULL_48BIT_PPGTT(ppgtt->base.dev)) {
> + ret = __pdp_init(false, &ppgtt->pdp);
>
> - if (ret)
> + if (ret)
> + goto free_scratch;
> +
> + ppgtt->base.total = 1ULL << 32;
> + if (IS_ENABLED(CONFIG_X86_32))
> + /* While we have a proliferation of size_t variables
> + * we cannot represent the full ppgtt size on 32bit,
> + * so limit it to the same size as the GGTT (currently
> + * 2GiB).
> + */
> + ppgtt->base.total = to_i915(ppgtt->base.dev)->gtt.base.total;
> + } else {
> + ppgtt->base.total = 1ULL << 48;
> + ret = -EPERM; /* Not yet implemented */
> goto free_scratch;
> + }
>
> return 0;
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
> index 87e389c..04bc66f 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
> @@ -88,9 +88,17 @@ typedef uint64_t gen8_pde_t;
> * PDPE | PDE | PTE | offset
> * The difference as compared to normal x86 3 level page table is the PDPEs are
> * programmed via register.
> + *
> + * GEN8 48b legacy style address is defined as a 4 level page table:
> + * 47:39 | 38:30 | 29:21 | 20:12 | 11:0
> + * PML4E | PDPE | PDE | PTE | offset
> */
> +#define GEN8_PML4ES_PER_PML4 512
> +#define GEN8_PML4E_SHIFT 39
> #define GEN8_PDPE_SHIFT 30
> -#define GEN8_PDPE_MASK 0x3
> +/* NB: GEN8_PDPE_MASK is untrue for 32b platforms, but it has no impact on 32b page
> + * tables */
> +#define GEN8_PDPE_MASK 0x1ff
> #define GEN8_PDE_SHIFT 21
> #define GEN8_PDE_MASK 0x1ff
> #define GEN8_PTE_SHIFT 12
> @@ -98,8 +106,8 @@ typedef uint64_t gen8_pde_t;
> #define GEN8_LEGACY_PDPES 4
> #define GEN8_PTES I915_PTES(sizeof(gen8_pte_t))
>
> -/* FIXME: Next patch will use dev */
> -#define I915_PDPES_PER_PDP(dev) GEN8_LEGACY_PDPES
> +#define I915_PDPES_PER_PDP(dev) (USES_FULL_48BIT_PPGTT(dev) ?\
> + GEN8_PML4ES_PER_PML4 : GEN8_LEGACY_PDPES)
>
> #define PPAT_UNCACHED_INDEX (_PAGE_PWT | _PAGE_PCD)
> #define PPAT_CACHED_PDE_INDEX 0 /* WB LLC */
> @@ -250,6 +258,13 @@ struct i915_page_directory_pointer {
> struct i915_page_directory **page_directory;
> };
>
> +struct i915_pml4 {
> + struct i915_page_dma base;
> +
> + DECLARE_BITMAP(used_pml4es, GEN8_PML4ES_PER_PML4);
> + struct i915_page_directory_pointer *pdps[GEN8_PML4ES_PER_PML4];
> +};
> +
> struct i915_address_space {
> struct drm_mm mm;
> struct drm_device *dev;
> @@ -345,8 +360,9 @@ struct i915_hw_ppgtt {
> struct drm_mm_node node;
> unsigned long pd_dirty_rings;
> union {
> - struct i915_page_directory_pointer pdp;
> - struct i915_page_directory pd;
> + struct i915_pml4 pml4; /* GEN8+ & 48b PPGTT */
> + struct i915_page_directory_pointer pdp; /* GEN8+ */
> + struct i915_page_directory pd; /* GEN6-7 */
> };
>
> struct drm_i915_file_private *file_priv;
>
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