habanalabs: added open_stats info ioctl

In a system with multiple ASICs, there is a need to provide monitoring
tools with information on how long a device was opened and how many
times a device was opened.

Therefore, we add a new opcode to the INFO ioctl to provide that
information.

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

include/uapi/misc/habanalabs.h

@@ -313,6 +313,7 @@ enum hl_device_status {
  * HL_INFO_SYNC_MANAGER  - Retrieve sync manager info per dcore
  * HL_INFO_TOTAL_ENERGY  - Retrieve total energy consumption
  * HL_INFO_PLL_FREQUENCY - Retrieve PLL frequency
+ * HL_INFO_OPEN_STATS    - Retrieve info regarding recent device open calls
  */
 #define HL_INFO_HW_IP_INFO		0
 #define HL_INFO_HW_EVENTS		1
@@ -331,6 +332,7 @@ enum hl_device_status {
 #define HL_INFO_TOTAL_ENERGY		15
 #define HL_INFO_PLL_FREQUENCY		16
 #define HL_INFO_POWER			17
+#define HL_INFO_OPEN_STATS		18
 
 #define HL_INFO_VERSION_MAX_LEN	128
 #define HL_INFO_CARD_NAME_MAX_LEN	16
@@ -444,6 +446,16 @@ struct hl_pll_frequency_info {
 	__u16 output[HL_PLL_NUM_OUTPUTS];
 };
 
+/**
+ * struct hl_open_stats_info - device open statistics information
+ * @open_counter: ever growing counter, increased on each successful dev open
+ * @last_open_period_ms: duration (ms) device was open last time
+ */
+struct hl_open_stats_info {
+	__u64 open_counter;
+	__u64 last_open_period_ms;
+};
+
 /**
  * struct hl_power_info - power information
  * @power: power consumption