habanalabs: partly skip cache flush when in PMMU map flow

The PCI MMU cache is two layered. The upper layer, memcache, uses cache
lines, the bottom layer doesn't.

Hence, after PMMU map operation we have to invalidate memcache, to avoid
the situation where the new entry is already in the cache due to its
cache line being fully in the cache.

However, we do not have to invalidate the lower cache, and here we can
optimize, since cache invalidation is time consuming.

Signed-off-by: Yuri Nudelman <ynudelman@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

diff --git a/drivers/misc/habanalabs/common/command_buffer.c b/drivers/misc/habanalabs/common/command_buffer.c
index fab499d252d4ac6c40471955e9bd9c726674c71c..71910f7809bd0bb397642b460d75f649b8a8562c 100644 (file)
--- a/drivers/misc/habanalabs/common/command_buffer.c
+++ b/drivers/misc/habanalabs/common/command_buffer.c
@@ -80,7 +80,8 @@ static int cb_map_mem(struct hl_ctx *ctx, struct hl_cb *cb)
                offset += va_block->size;
        }
 
-       hdev->asic_funcs->mmu_invalidate_cache(hdev, false, MMU_OP_USERPTR);
+       hdev->asic_funcs->mmu_invalidate_cache(hdev, false,
+               MMU_OP_USERPTR | MMU_OP_SKIP_LOW_CACHE_INV);
 
        mutex_unlock(&ctx->mmu_lock);
 

diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 202c7f7948f5ad3c7c26c33e24550c3097724bee..aac73c8d2e1dadf19b89e241adfb71443e557bd3 100644 (file)
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -356,10 +356,14 @@ enum vm_type {
  * enum mmu_op_flags - mmu operation relevant information.
  * @MMU_OP_USERPTR: operation on user memory (host resident).
  * @MMU_OP_PHYS_PACK: operation on DRAM (device resident).
+ * @MMU_OP_CLEAR_MEMCACHE: operation has to clear memcache.
+ * @MMU_OP_SKIP_LOW_CACHE_INV: operation is allowed to skip parts of cache invalidation.
  */
 enum mmu_op_flags {
        MMU_OP_USERPTR = 0x1,
-       MMU_OP_PHYS_PACK = 0x2
+       MMU_OP_PHYS_PACK = 0x2,
+       MMU_OP_CLEAR_MEMCACHE = 0x4,
+       MMU_OP_SKIP_LOW_CACHE_INV = 0x8,
 };
 
 

diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index 40f2197388fe1b23403166b72d384865ad5d65a7..cd3640617d0261688340d15f7c9e22a61a760d78 100644 (file)
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -1202,7 +1202,8 @@ static int map_device_va(struct hl_ctx *ctx, struct hl_mem_in *args,
        }
 
        rc = hdev->asic_funcs->mmu_invalidate_cache_range(hdev, false,
-               *vm_type, ctx->asid, ret_vaddr, phys_pg_pack->total_size);
+               *vm_type | MMU_OP_SKIP_LOW_CACHE_INV,
+               ctx->asid, ret_vaddr, phys_pg_pack->total_size);
 
        mutex_unlock(&ctx->mmu_lock);