drm/amdkfd: Add SMI add event helper

To remove duplicate code, unify event message format and simplify new
event add in the following patches.

Use KFD_SMI_EVENT_MSG_SIZE to define msg size, the same size will be
used in user space to alloc the msg receive buffer.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c

@@ -176,22 +176,28 @@ static void add_event_to_kfifo(struct kfd_dev *dev, unsigned int smi_event,
 	rcu_read_unlock();
 }
 
-void kfd_smi_event_update_gpu_reset(struct kfd_dev *dev, bool post_reset)
+static void kfd_smi_event_add(struct kfd_dev *dev, unsigned int event,
+			      char *fmt, ...)
 {
-	/*
-	 * GpuReset msg = Reset seq number (incremented for
-	 * every reset message sent before GPU reset).
-	 * 1 byte event + 1 byte space + 8 bytes seq num +
-	 * 1 byte \n + 1 byte \0 = 12
-	 */
-	char fifo_in[12];
+	char fifo_in[KFD_SMI_EVENT_MSG_SIZE];
 	int len;
-	unsigned int event;
+	va_list args;
 
 	if (list_empty(&dev->smi_clients))
 		return;
 
-	memset(fifo_in, 0x0, sizeof(fifo_in));
+	len = snprintf(fifo_in, sizeof(fifo_in), "%x ", event);
+
+	va_start(args, fmt);
+	len += vsnprintf(fifo_in + len, sizeof(fifo_in) - len, fmt, args);
+	va_end(args);
+
+	add_event_to_kfifo(dev, event, fifo_in, len);
+}
+
+void kfd_smi_event_update_gpu_reset(struct kfd_dev *dev, bool post_reset)
+{
+	unsigned int event;
 
 	if (post_reset) {
 		event = KFD_SMI_EVENT_GPU_POST_RESET;
@@ -199,48 +205,20 @@ void kfd_smi_event_update_gpu_reset(struct kfd_dev *dev, bool post_reset)
 		event = KFD_SMI_EVENT_GPU_PRE_RESET;
 		++(dev->reset_seq_num);
 	}
-
-	len = snprintf(fifo_in, sizeof(fifo_in), "%x %x\n", event,
-						dev->reset_seq_num);
-
-	add_event_to_kfifo(dev, event, fifo_in, len);
+	kfd_smi_event_add(dev, event, "%x\n", dev->reset_seq_num);
 }
 
 void kfd_smi_event_update_thermal_throttling(struct kfd_dev *dev,
 					     uint64_t throttle_bitmask)
 {
-	/*
-	 * ThermalThrottle msg = throttle_bitmask(8):
-	 * 			 thermal_interrupt_count(16):
-	 * 1 byte event + 1 byte space + 16 byte throttle_bitmask +
-	 * 1 byte : + 16 byte thermal_interupt_counter + 1 byte \n +
-	 * 1 byte \0 = 37
-	 */
-	char fifo_in[37];
-	int len;
-
-	if (list_empty(&dev->smi_clients))
-		return;
-
-	len = snprintf(fifo_in, sizeof(fifo_in), "%x %llx:%llx\n",
-		       KFD_SMI_EVENT_THERMAL_THROTTLE, throttle_bitmask,
-		       amdgpu_dpm_get_thermal_throttling_counter(dev->adev));
-
-	add_event_to_kfifo(dev, KFD_SMI_EVENT_THERMAL_THROTTLE,	fifo_in, len);
+	kfd_smi_event_add(dev, KFD_SMI_EVENT_THERMAL_THROTTLE, "%llx:%llx\n",
+			  throttle_bitmask,
+			  amdgpu_dpm_get_thermal_throttling_counter(dev->adev));
 }
 
 void kfd_smi_event_update_vmfault(struct kfd_dev *dev, uint16_t pasid)
 {
 	struct amdgpu_task_info task_info;
-	/* VmFault msg = (hex)uint32_pid(8) + :(1) + task name(16) = 25 */
-	/* 1 byte event + 1 byte space + 25 bytes msg + 1 byte \n +
-	 * 1 byte \0 = 29
-	 */
-	char fifo_in[29];
-	int len;
-
-	if (list_empty(&dev->smi_clients))
-		return;
 
 	memset(&task_info, 0, sizeof(struct amdgpu_task_info));
 	amdgpu_vm_get_task_info(dev->adev, pasid, &task_info);
@@ -248,10 +226,8 @@ void kfd_smi_event_update_vmfault(struct kfd_dev *dev, uint16_t pasid)
 	if (!task_info.pid)
 		return;
 
-	len = snprintf(fifo_in, sizeof(fifo_in), "%x %x:%s\n", KFD_SMI_EVENT_VMFAULT,
-		task_info.pid, task_info.task_name);
-
-	add_event_to_kfifo(dev, KFD_SMI_EVENT_VMFAULT, fifo_in, len);
+	kfd_smi_event_add(dev, KFD_SMI_EVENT_VMFAULT, "%x:%s\n",
+			  task_info.pid, task_info.task_name);
 }
 
 int kfd_smi_event_open(struct kfd_dev *dev, uint32_t *fd)

include/uapi/linux/kfd_ioctl.h

@@ -463,6 +463,7 @@ enum kfd_smi_event {
 };
 
 #define KFD_SMI_EVENT_MASK_FROM_INDEX(i) (1ULL << ((i) - 1))
+#define KFD_SMI_EVENT_MSG_SIZE	96
 
 struct kfd_ioctl_smi_events_args {
 	__u32 gpuid;	/* to KFD */