[PATCH v3 1/4] drm/xe/xe_migrate: Align MEM_COPY pitch with destination address

[Jan Maslak <jan.maslak@intel.com>]

From: Christoph Manszewski <christoph.manszewski@intel.com>

MEM_COPY_CMD can corrupt memory when MATRIX_COPY mode uses a pitch that
is not aligned to the destination address.

Fix this by incorporating the destination address into the pitch
selection so the chosen pitch is aligned to both the copy length and the
destination address.

Signed-off-by: Christoph Manszewski <christoph.manszewski@intel.com>
Signed-off-by: Jan Maslak <jan.maslak@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 drivers/gpu/drm/xe/xe_migrate.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
index ff45c24d8889..2e5827aaf99d 100644
--- a/drivers/gpu/drm/xe/xe_migrate.c
+++ b/drivers/gpu/drm/xe/xe_migrate.c
@@ -2205,17 +2205,18 @@ static bool xe_migrate_vram_use_pde(struct drm_pagemap_addr *sram_addr,
 #define XE_CACHELINE_BYTES	64ull
 #define XE_CACHELINE_MASK	(XE_CACHELINE_BYTES - 1)
 
-static u32 xe_migrate_copy_pitch(struct xe_device *xe, u32 len)
+static u32 xe_migrate_copy_pitch(struct xe_device *xe, u32 len, u64 dst_addr)
 {
+	u64 align_check = len | dst_addr;
 	u32 pitch;
 
-	if (IS_ALIGNED(len, PAGE_SIZE))
+	if (IS_ALIGNED(align_check, PAGE_SIZE))
 		pitch = PAGE_SIZE;
-	else if (IS_ALIGNED(len, SZ_4K))
+	else if (IS_ALIGNED(align_check, SZ_4K))
 		pitch = SZ_4K;
-	else if (IS_ALIGNED(len, SZ_256))
+	else if (IS_ALIGNED(align_check, SZ_256))
 		pitch = SZ_256;
-	else if (IS_ALIGNED(len, 4))
+	else if (IS_ALIGNED(align_check, 4))
 		pitch = 4;
 	else
 		pitch = 1;
@@ -2242,16 +2243,11 @@ static struct dma_fence *xe_migrate_vram(struct xe_migrate *m,
 	struct xe_bb *bb;
 	u32 update_idx, pt_slot = 0;
 	unsigned long npages = DIV_ROUND_UP(len + sram_offset, PAGE_SIZE);
-	unsigned int pitch = xe_migrate_copy_pitch(xe, len);
+	unsigned int pitch;
 	int err;
 	unsigned long i, j;
 	bool use_pde = xe_migrate_vram_use_pde(sram_addr, len + sram_offset);
 
-	if (!xe->info.has_mem_copy_instr &&
-	    drm_WARN_ON(&xe->drm,
-			(!IS_ALIGNED(len, pitch)) || (sram_offset | vram_addr) & XE_CACHELINE_MASK))
-		return ERR_PTR(-EOPNOTSUPP);
-
 	xe_assert(xe, npages * PAGE_SIZE <= MAX_PREEMPTDISABLE_TRANSFER);
 
 	batch_size += pte_update_cmd_size(npages << PAGE_SHIFT);
@@ -2303,6 +2299,13 @@ static struct dma_fence *xe_migrate_vram(struct xe_migrate *m,
 			dst_L0_ofs = xe_migrate_vm_addr(pt_slot, 0) + sram_offset;
 	}
 
+	pitch = xe_migrate_copy_pitch(xe, len, dst_L0_ofs);
+	if (!xe->info.has_mem_copy_instr &&
+	    drm_WARN_ON(&xe->drm,
+			(!IS_ALIGNED(len, pitch)) ||
+			(sram_offset | vram_addr) & XE_CACHELINE_MASK))
+		return ERR_PTR(-EOPNOTSUPP);
+
 	bb->cs[bb->len++] = MI_BATCH_BUFFER_END;
 	update_idx = bb->len;
 
@@ -2555,7 +2558,9 @@ int xe_migrate_access_memory(struct xe_migrate *m, struct xe_bo *bo,
 		else
 			current_bytes = min_t(int, bytes_left, cursor.size);
 
-		pitch = xe_migrate_copy_pitch(xe, current_bytes);
+		pitch = xe_migrate_copy_pitch(xe, current_bytes,
+					      write ? vram_addr :
+					      (unsigned long)buf & ~PAGE_MASK);
 		if (xe->info.has_mem_copy_instr)
 			current_bytes = min_t(int, current_bytes, U16_MAX * pitch);
 		else
-- 
2.43.0