megaraid_sas: Dual queue depth support

1. For iMR controllers, firmware will report two queue depths:

   - Controller-wide queue depth
   - LDIO queue depth (240)

Controller-wide queue depth will be greater among the two. Using this
new feature, iMR can provide larger Queue depth(QD) for JBOD and limited
QD for Virtual Disk(VD).

2. megaraid_sas driver will throttle read/write LDIOs based on "LDIO
Queue Depth".

3. Dual queue depth can be enabled/disabled via module parameter. It is
enabled by default if the firmware supports it. Only specific firmware
builds will enable the feature.

4. Added sysfs parameter "ldio_outstanding" which permits querying the
number of outstanding LDIO requests at runtime.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 3b1ed2d86efe..2a2f49134491 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1353,6 +1353,12 @@ enum DCMD_TIMEOUT_ACTION {
 	KILL_ADAPTER = 1,
 	IGNORE_TIMEOUT = 2,
 };
+
+enum FW_BOOT_CONTEXT {
+	PROBE_CONTEXT = 0,
+	OCR_CONTEXT = 1,
+};
+
 /* Frame Type */
 #define IO_FRAME				0
 #define PTHRU_FRAME				1
@@ -2038,6 +2044,8 @@ struct megasas_instance {
 	u16 max_fw_cmds;
 	u16 max_mfi_cmds;
 	u16 max_scsi_cmds;
+	u16 ldio_threshold;
+	u16 cur_can_queue;
 	u32 max_sectors_per_req;
 	struct megasas_aen_event *ev;
 
@@ -2068,6 +2076,7 @@ struct megasas_instance {
 	u32 fw_support_ieee;
 
 	atomic_t fw_outstanding;
+	atomic_t ldio_outstanding;
 	atomic_t fw_reset_no_pci_access;
 
 	struct megasas_instance_template *instancet;