[PATCH v3 2/2] drm/imagination: Fix page count for page table for map() interface

[Brajesh Gupta <brajesh.gupta@imgtec.com>]

The GPU virtual start address wasn't included in the calculation for the
amount of page tables required for mapping a BO object in map() interface.
It resulted in map failure later due to not enough pages at L0/L1 level.
Update pvr_mmu_op_context_create() interface to pass device address as well
to allow correct calculation for page table memory.

Miscalculation of page table pages for mapping a BO starting at a device
address 0x8001b45000 of size 0x8ca000:
               old       new
L0 count       5          6
L1 count       1          1

Fixes: ff5f643de0bf ("drm/imagination: Add GEM and VM related code")
Signed-off-by: Brajesh Gupta <brajesh.gupta@imgtec.com>

Reviewed-by: Alexandru Dadu <alexandru.dadu@imgtec.com>
Reviewed-by: Alessio Belle <alessio.belle@imgtec.com>
---
 drivers/gpu/drm/imagination/pvr_mmu.c | 14 ++++++++------
 drivers/gpu/drm/imagination/pvr_mmu.h |  2 +-
 drivers/gpu/drm/imagination/pvr_vm.c  |  4 ++--
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
index 23261d9ad3fd..62eae7fcd5a2 100644
--- a/drivers/gpu/drm/imagination/pvr_mmu.c
+++ b/drivers/gpu/drm/imagination/pvr_mmu.c
@@ -2336,6 +2336,7 @@ void pvr_mmu_op_context_destroy(struct pvr_mmu_op_context *op_ctx)
  * pvr_mmu_op_context_create() - Create an MMU op context.
  * @ctx: MMU context associated with owning VM context.
  * @sgt: Scatter gather table containing pages pinned for use by this context.
+ * @device_addr: Virtual device address at the start of the requested mapping.
  * @sgt_offset: Start offset of the requested device-virtual memory mapping.
  * @size: Size in bytes of the requested device-virtual memory mapping. For an
  * unmapping, this should be zero so that no page tables are allocated.
@@ -2347,8 +2348,9 @@ void pvr_mmu_op_context_destroy(struct pvr_mmu_op_context *op_ctx)
  */
 struct pvr_mmu_op_context *
 pvr_mmu_op_context_create(struct pvr_mmu_context *ctx, struct sg_table *sgt,
-			  u64 sgt_offset, u64 size)
+			  u64 device_addr, u64 sgt_offset, u64 size)
 {
+	u64 start_addr = device_addr + sgt_offset;
 	int err;
 
 	struct pvr_mmu_op_context *op_ctx = kzalloc_obj(*op_ctx);
@@ -2364,16 +2366,16 @@ pvr_mmu_op_context_create(struct pvr_mmu_context *ctx, struct sg_table *sgt,
 	if (size) {
 		/*
 		 * The number of page table objects we need to prealloc is
-		 * indicated by the mapping size, start offset and the sizes
+		 * indicated by the mapping size, start address and the sizes
 		 * of the areas mapped per PT or PD. The range calculation is
 		 * identical to that for the index into a table for a device
 		 * address, so we reuse those functions here.
 		 */
-		const u32 l1_start_idx = pvr_page_table_l2_idx(sgt_offset);
-		const u32 l1_end_idx = pvr_page_table_l2_idx(sgt_offset + size);
+		const u32 l1_start_idx = pvr_page_table_l2_idx(start_addr);
+		const u32 l1_end_idx = pvr_page_table_l2_idx(start_addr + size);
 		const u32 l1_count = l1_end_idx - l1_start_idx + 1;
-		const u32 l0_start_idx = pvr_page_table_l1_idx(sgt_offset);
-		const u32 l0_end_idx = pvr_page_table_l1_idx(sgt_offset + size);
+		const u32 l0_start_idx = pvr_page_table_l1_idx(start_addr);
+		const u32 l0_end_idx = pvr_page_table_l1_idx(start_addr + size);
 		const u32 l0_count = l0_end_idx - l0_start_idx + 1;
 
 		/*
diff --git a/drivers/gpu/drm/imagination/pvr_mmu.h b/drivers/gpu/drm/imagination/pvr_mmu.h
index a8ecd460168d..2c02d61ba0a2 100644
--- a/drivers/gpu/drm/imagination/pvr_mmu.h
+++ b/drivers/gpu/drm/imagination/pvr_mmu.h
@@ -99,7 +99,7 @@ dma_addr_t pvr_mmu_get_root_table_dma_addr(struct pvr_mmu_context *ctx);
 void pvr_mmu_op_context_destroy(struct pvr_mmu_op_context *op_ctx);
 struct pvr_mmu_op_context *
 pvr_mmu_op_context_create(struct pvr_mmu_context *ctx,
-			  struct sg_table *sgt, u64 sgt_offset, u64 size);
+			  struct sg_table *sgt, u64 device_addr, u64 sgt_offset, u64 size);
 
 int pvr_mmu_map(struct pvr_mmu_op_context *op_ctx, u64 size, u64 flags,
 		u64 device_addr);
diff --git a/drivers/gpu/drm/imagination/pvr_vm.c b/drivers/gpu/drm/imagination/pvr_vm.c
index 396d349fb6ce..867a4a44958a 100644
--- a/drivers/gpu/drm/imagination/pvr_vm.c
+++ b/drivers/gpu/drm/imagination/pvr_vm.c
@@ -276,7 +276,7 @@ pvr_vm_bind_op_map_init(struct pvr_vm_bind_op *bind_op,
 		goto err_bind_op_fini;
 
 	bind_op->mmu_op_ctx =
-		pvr_mmu_op_context_create(vm_ctx->mmu_ctx, sgt, offset, size);
+		pvr_mmu_op_context_create(vm_ctx->mmu_ctx, sgt, device_addr, offset, size);
 	err = PTR_ERR_OR_ZERO(bind_op->mmu_op_ctx);
 	if (err) {
 		bind_op->mmu_op_ctx = NULL;
@@ -318,7 +318,7 @@ pvr_vm_bind_op_unmap_init(struct pvr_vm_bind_op *bind_op,
 	}
 
 	bind_op->mmu_op_ctx =
-		pvr_mmu_op_context_create(vm_ctx->mmu_ctx, NULL, 0, 0);
+		pvr_mmu_op_context_create(vm_ctx->mmu_ctx, NULL, device_addr, 0, 0);
 	err = PTR_ERR_OR_ZERO(bind_op->mmu_op_ctx);
 	if (err) {
 		bind_op->mmu_op_ctx = NULL;

-- 
2.43.0