habanalabs: change wait_for_interrupt implementation

Currently the cq counters are allocated in userspace memory,
and mapped by the driver to the device address space.

A new requirement that is part of new future API related to this one,
requires that cq counters will be allocated in kernel memory.

We leverage the existing cb_create API with KERNEL_MAPPED flag set to
allocate this memory.

That way we gain two things:
1. The memory cannot be freed while in use since it's protected
by refcount in driver.

2. No need to wake up the user thread upon each interrupt from CQ,
because the kernel has direct access to the counter. Therefore,
it can make comparison with the target value in the interrupt
handler and wake up the user thread only if the counter reaches the
target value. This is instead of waking the thread up to copy counter
value from user then go sleep again if target value wasn't reached.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

1 files changed, 44 insertions, 17 deletions

diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index 648850b954a3..371dfc4243b3 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -680,7 +680,10 @@ struct hl_info_args {
 #define HL_MAX_CB_SIZE		(0x200000 - 32)
 
 /* Indicates whether the command buffer should be mapped to the device's MMU */
-#define HL_CB_FLAGS_MAP		0x1
+#define HL_CB_FLAGS_MAP			0x1
+
+/* Used with HL_CB_OP_INFO opcode to get the device va address for kernel mapped CB */
+#define HL_CB_FLAGS_GET_DEVICE_VA	0x2
 
 struct hl_cb_in {
 	/* Handle of CB or 0 if we want to create one */
@@ -702,11 +705,16 @@ struct hl_cb_out {
 		/* Handle of CB */
 		__u64 cb_handle;
 
-		/* Information about CB */
-		struct {
-			/* Usage count of CB */
-			__u32 usage_cnt;
-			__u32 pad;
+		union {
+			/* Information about CB */
+			struct {
+				/* Usage count of CB */
+				__u32 usage_cnt;
+				__u32 pad;
+			};
+
+			/* CB mapped address to device MMU */
+			__u64 device_va;
 		};
 	};
 };
@@ -947,9 +955,10 @@ union hl_cs_args {
 	struct hl_cs_out out;
 };
 
-#define HL_WAIT_CS_FLAGS_INTERRUPT	0x2
-#define HL_WAIT_CS_FLAGS_INTERRUPT_MASK 0xFFF00000
-#define HL_WAIT_CS_FLAGS_MULTI_CS	0x4
+#define HL_WAIT_CS_FLAGS_INTERRUPT		0x2
+#define HL_WAIT_CS_FLAGS_INTERRUPT_MASK		0xFFF00000
+#define HL_WAIT_CS_FLAGS_MULTI_CS		0x4
+#define HL_WAIT_CS_FLAGS_INTERRUPT_KERNEL_CQ	0x10
 
 #define HL_WAIT_MULTI_CS_LIST_MAX_LEN	32
 
@@ -969,14 +978,23 @@ struct hl_wait_cs_in {
 		};
 
 		struct {
-			/* User address for completion comparison.
-			 * upon interrupt, driver will compare the value pointed
-			 * by this address with the supplied target value.
-			 * in order not to perform any comparison, set address
-			 * to all 1s.
-			 * Relevant only when HL_WAIT_CS_FLAGS_INTERRUPT is set
-			 */
-			__u64 addr;
+			union {
+				/* User address for completion comparison.
+				 * upon interrupt, driver will compare the value pointed
+				 * by this address with the supplied target value.
+				 * in order not to perform any comparison, set address
+				 * to all 1s.
+				 * Relevant only when HL_WAIT_CS_FLAGS_INTERRUPT is set
+				 */
+				__u64 addr;
+
+				/* cq_counters_handle to a kernel mapped cb which contains
+				 * cq counters.
+				 * Relevant only when HL_WAIT_CS_FLAGS_INTERRUPT_KERNEL_CQ is set
+				 */
+				__u64 cq_counters_handle;
+			};
+
 			/* Target value for completion comparison */
 			__u64 target;
 		};
@@ -1004,6 +1022,15 @@ struct hl_wait_cs_in {
 		 */
 		__u64 interrupt_timeout_us;
 	};
+
+	/*
+	 * cq counter offset inside the counters cb pointed by cq_counters_handle above.
+	 * upon interrupt, driver will compare the value pointed
+	 * by this address (cq_counters_handle + cq_counters_offset)
+	 * with the supplied target value.
+	 * relevant only when HL_WAIT_CS_FLAGS_INTERRUPT_KERNEL_CQ is set
+	 */
+	__u64 cq_counters_offset;
 };
 
 #define HL_WAIT_CS_STATUS_COMPLETED	0