[RFC 2/8] drm/i915: Split PTE encode between Gen12 and Meteorlake

[Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>]

From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

No need to run extra instructions which will never trigger on platforms
before Meteorlake.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
 drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
index c8568e5d1147..862ac1d2de25 100644
--- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
@@ -63,6 +63,30 @@ static u64 gen12_pte_encode(dma_addr_t addr,
 {
 	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
 
+	if (unlikely(flags & PTE_READ_ONLY))
+		pte &= ~GEN8_PAGE_RW;
+
+	if (flags & PTE_LM)
+		pte |= GEN12_PPGTT_PTE_LM;
+
+	if (pat_index & BIT(0))
+		pte |= GEN12_PPGTT_PTE_PAT0;
+
+	if (pat_index & BIT(1))
+		pte |= GEN12_PPGTT_PTE_PAT1;
+
+	if (pat_index & BIT(2))
+		pte |= GEN12_PPGTT_PTE_PAT2;
+
+	return pte;
+}
+
+static u64 mtl_pte_encode(dma_addr_t addr,
+			  unsigned int pat_index,
+			  u32 flags)
+{
+	gen8_pte_t pte = addr | GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
+
 	if (unlikely(flags & PTE_READ_ONLY))
 		pte &= ~GEN8_PAGE_RW;
 
@@ -995,6 +1019,8 @@ struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
 	 */
 	ppgtt->vm.alloc_scratch_dma = alloc_pt_dma;
 
+	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
+		ppgtt->vm.pte_encode = mtl_pte_encode;
 	if (GRAPHICS_VER(gt->i915) >= 12)
 		ppgtt->vm.pte_encode = gen12_pte_encode;
 	else
-- 
2.39.2