habanalabs: do MMU prefetch as deferred work

When user requests to prefetch the MMU translations, the driver will
not block the user until prefetch is done.
Instead, the prefetch work will be delegated to a WQ which will do it
in the background.
This way, the prefetch may progress without blocking the user at all.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 24 insertions, 3 deletions

diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 8977ec67dba7..632037b29922 100644
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -1402,8 +1402,7 @@ struct hl_asic_funcs {
 					u32 flags);
 	int (*mmu_invalidate_cache_range)(struct hl_device *hdev, bool is_hard,
 				u32 flags, u32 asid, u64 va, u64 size);
-	int (*mmu_prefetch_cache_range)(struct hl_device *hdev, u32 flags, u32 asid, u64 va,
-				u64 size);
+	int (*mmu_prefetch_cache_range)(struct hl_ctx *ctx, u32 flags, u32 asid, u64 va, u64 size);
 	int (*send_heartbeat)(struct hl_device *hdev);
 	int (*debug_coresight)(struct hl_device *hdev, struct hl_ctx *ctx, void *data);
 	bool (*is_device_idle)(struct hl_device *hdev, u64 *mask_arr,
@@ -2476,6 +2475,24 @@ struct hl_mmu_funcs {
 };
 
 /**
+ * struct hl_prefetch_work - prefetch work structure handler
+ * @pf_work: actual work struct.
+ * @ctx: compute context.
+ * @va: virtual address to pre-fetch.
+ * @size: pre-fetch size.
+ * @flags: operation flags.
+ * @asid: ASID for maintenance operation.
+ */
+struct hl_prefetch_work {
+	struct work_struct	pf_work;
+	struct hl_ctx		*ctx;
+	u64			va;
+	u64			size;
+	u32			flags;
+	u32			asid;
+};
+
+/*
  * number of user contexts allowed to call wait_for_multi_cs ioctl in
  * parallel
  */
@@ -2648,6 +2665,7 @@ struct hl_reset_info {
  *         context.
  * @eq_wq: work queue of event queue for executing work in process context.
  * @ts_free_obj_wq: work queue for timestamp registration objects release.
+ * @pf_wq: work queue for MMU pre-fetch operations.
  * @kernel_ctx: Kernel driver context structure.
  * @kernel_queues: array of hl_hw_queue.
  * @cs_mirror_list: CS mirror list for TDR.
@@ -2760,6 +2778,7 @@ struct hl_reset_info {
  * @supports_wait_for_multi_cs: true if wait for multi CS is supported
  * @is_compute_ctx_active: Whether there is an active compute context executing.
  * @compute_ctx_in_release: true if the current compute context is being released.
+ * @supports_mmu_prefetch: true if prefetch is supported, otherwise false.
  */
 struct hl_device {
 	struct pci_dev			*pdev;
@@ -2781,6 +2800,7 @@ struct hl_device {
 	struct workqueue_struct		**cq_wq;
 	struct workqueue_struct		*eq_wq;
 	struct workqueue_struct		*ts_free_obj_wq;
+	struct workqueue_struct		*pf_wq;
 	struct hl_ctx			*kernel_ctx;
 	struct hl_hw_queue		*kernel_queues;
 	struct list_head		cs_mirror_list;
@@ -2882,6 +2902,7 @@ struct hl_device {
 	u8				stream_master_qid_arr_size;
 	u8				is_compute_ctx_active;
 	u8				compute_ctx_in_release;
+	u8				supports_mmu_prefetch;
 
 	/* Parameters for bring-up */
 	u64				nic_ports_mask;
@@ -3163,7 +3184,7 @@ int hl_mmu_unmap_contiguous(struct hl_ctx *ctx, u64 virt_addr, u32 size);
 int hl_mmu_invalidate_cache(struct hl_device *hdev, bool is_hard, u32 flags);
 int hl_mmu_invalidate_cache_range(struct hl_device *hdev, bool is_hard,
 					u32 flags, u32 asid, u64 va, u64 size);
-int hl_mmu_prefetch_cache_range(struct hl_device *hdev, u32 flags, u32 asid, u64 va, u64 size);
+int hl_mmu_prefetch_cache_range(struct hl_ctx *ctx, u32 flags, u32 asid, u64 va, u64 size);
 u64 hl_mmu_get_next_hop_addr(struct hl_ctx *ctx, u64 curr_pte);
 u64 hl_mmu_get_hop_pte_phys_addr(struct hl_ctx *ctx, struct hl_mmu_properties *mmu_prop,
 					u8 hop_idx, u64 hop_addr, u64 virt_addr);