Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 27763264 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gtt: Compute the radix for gen8 page table levels 



The radix levels of each page directory are easily determined so replace
the numerous hardcoded constants with precomputed derived constants.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712094327.24437-4-chris@chris-wilson.co.uk
parent 18c7962b

drivers/gpu/drm/i915/i915_gem_gtt.c

+42 −0
Original line number Diff line number Diff line
@@ -867,6 +867,48 @@ static int gen8_ppgtt_notify_vgt(struct i915_ppgtt *ppgtt, bool create) 
	return 0;

}



/* Index shifts into the pagetable are offset by GEN8_PTE_SHIFT [12] */

#define GEN8_PAGE_SIZE (SZ_4K) /* page and page-directory sizes are the same */

#define GEN8_PTE_SHIFT (ilog2(GEN8_PAGE_SIZE))

#define GEN8_PDES (GEN8_PAGE_SIZE / sizeof(u64))

#define gen8_pd_shift(lvl) ((lvl) * ilog2(GEN8_PDES))

#define gen8_pd_index(i, lvl) i915_pde_index((i), gen8_pd_shift(lvl))

#define __gen8_pte_shift(lvl) (GEN8_PTE_SHIFT + gen8_pd_shift(lvl))

#define __gen8_pte_index(a, lvl) i915_pde_index((a), __gen8_pte_shift(lvl))



static inline unsigned int

gen8_pd_range(u64 start, u64 end, int lvl, unsigned int *idx)

{

	const int shift = gen8_pd_shift(lvl);

	const u64 mask = ~0ull << gen8_pd_shift(lvl + 1);



	GEM_BUG_ON(start >= end);

	end += ~mask >> gen8_pd_shift(1);



	*idx = i915_pde_index(start, shift);

	if ((start ^ end) & mask)

		return GEN8_PDES - *idx;

	else

		return i915_pde_index(end, shift) - *idx;

}



static inline bool gen8_pd_contains(u64 start, u64 end, int lvl)

{

	const u64 mask = ~0ull << gen8_pd_shift(lvl + 1);



	GEM_BUG_ON(start >= end);

	return (start ^ end) & mask && (start & ~mask) == 0;

}



static inline unsigned int gen8_pt_count(u64 start, u64 end)

{

	GEM_BUG_ON(start >= end);

	if ((start ^ end) >> gen8_pd_shift(1))

		return GEN8_PDES - (start & (GEN8_PDES - 1));

	else

		return end - start;

}



static void gen8_free_page_tables(struct i915_address_space *vm,

				  struct i915_page_directory *pd)

{

drivers/gpu/drm/i915/i915_gem_gtt.h

+0 −1
Original line number Diff line number Diff line
@@ -124,7 +124,6 @@ typedef u64 gen8_pte_t; 
#define GEN8_3LVL_PDPES			4

#define GEN8_PDE_SHIFT			21

#define GEN8_PDE_MASK			0x1ff

#define GEN8_PTE_SHIFT			12

#define GEN8_PTE_MASK			0x1ff

#define GEN8_PTES			I915_PTES(sizeof(gen8_pte_t))