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[v2,09/15] megaraid_sas: Dual Queue depth support

Message ID 1453995276-24955-10-git-send-email-sumit.saxena@avagotech.com (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Sumit Saxena Jan. 28, 2016, 3:34 p.m. UTC
This patch will add support for Dual Queue depth reported by firmware.

Below are key points-

1. For iMR controllers, firmware will report two queue depths- 1. Controller wide Queue depth 2. LDIO Queue depth(240).
Ofcourse, Controller wide Queue depth will be greater among two. Using this new method, iMR can provide larger Queue depth(QD)
for JBOD and limited QD for Virtual Disk(VD). This feature gives benefit for iMR product which will be used for deployment
with large number of JBOD and limited number of VD on setup. 
2. megaraid_sas driver will throttle Read write LDIOs based when RW LDIOs reaches "LDIO Queue Depth".
3. This feature of dual queue depth can enabled/disabled via module parameter. Default behavior is: Dual Queue depth is enabled.
4. Added sysfs parameter "ldio_outstanding" for user to read LDIO outstanding at run time.
5. There are different flavors of firmware using same driver and for specific firmware this will be
turned on(by default) where it's really needed. For rest of firmware flavors, this will be switched off(not supported).

I have accomodated Tomas' comments provided on last time sent patch- use atomic_inc_return instead of using atomic_read() and
atomic_inc() separately inside function- megasas_build_and_issue_cmd_fusion(). 

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
---
 drivers/scsi/megaraid/megaraid_sas.h        |  9 +++
 drivers/scsi/megaraid/megaraid_sas_base.c   | 20 ++++++-
 drivers/scsi/megaraid/megaraid_sas_fusion.c | 88 ++++++++++++++++++++++++++---
 3 files changed, 107 insertions(+), 10 deletions(-)
diff mbox

Patch

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 3b1ed2d..2a2f491 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;
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index edf8911..961c024 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -96,6 +96,10 @@  int rdpq_enable = 1;
 module_param(rdpq_enable, int, S_IRUGO);
 MODULE_PARM_DESC(rdpq_enable, " Allocate reply queue in chunks for large queue depth enable/disable Default: disable(0)");
 
+unsigned int dual_qdepth_disable;
+module_param(dual_qdepth_disable, int, S_IRUGO);
+MODULE_PARM_DESC(dual_qdepth_disable, "Disable dual queue depth feature. Default: 0");
+
 MODULE_LICENSE("GPL");
 MODULE_VERSION(MEGASAS_VERSION);
 MODULE_AUTHOR("megaraidlinux.pdl@avagotech.com");
@@ -1976,7 +1980,7 @@  megasas_check_and_restore_queue_depth(struct megasas_instance *instance)
 		spin_lock_irqsave(instance->host->host_lock, flags);
 		instance->flag &= ~MEGASAS_FW_BUSY;
 
-		instance->host->can_queue = instance->max_scsi_cmds;
+		instance->host->can_queue = instance->cur_can_queue;
 		spin_unlock_irqrestore(instance->host->host_lock, flags);
 	}
 }
@@ -2941,6 +2945,16 @@  megasas_page_size_show(struct device *cdev,
 	return snprintf(buf, PAGE_SIZE, "%ld\n", (unsigned long)PAGE_SIZE - 1);
 }
 
+static ssize_t
+megasas_ldio_outstanding_show(struct device *cdev, struct device_attribute *attr,
+	char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(cdev);
+	struct megasas_instance *instance = (struct megasas_instance *)shost->hostdata;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&instance->ldio_outstanding));
+}
+
 static DEVICE_ATTR(fw_crash_buffer, S_IRUGO | S_IWUSR,
 	megasas_fw_crash_buffer_show, megasas_fw_crash_buffer_store);
 static DEVICE_ATTR(fw_crash_buffer_size, S_IRUGO,
@@ -2949,12 +2963,15 @@  static DEVICE_ATTR(fw_crash_state, S_IRUGO | S_IWUSR,
 	megasas_fw_crash_state_show, megasas_fw_crash_state_store);
 static DEVICE_ATTR(page_size, S_IRUGO,
 	megasas_page_size_show, NULL);
+static DEVICE_ATTR(ldio_outstanding, S_IRUGO,
+	megasas_ldio_outstanding_show, NULL);
 
 struct device_attribute *megaraid_host_attrs[] = {
 	&dev_attr_fw_crash_buffer_size,
 	&dev_attr_fw_crash_buffer,
 	&dev_attr_fw_crash_state,
 	&dev_attr_page_size,
+	&dev_attr_ldio_outstanding,
 	NULL,
 };
 
@@ -4749,6 +4766,7 @@  megasas_init_adapter_mfi(struct megasas_instance *instance)
 		sema_init(&instance->ioctl_sem, (MEGASAS_MFI_IOCTL_CMDS));
 	}
 
+	instance->cur_can_queue = instance->max_scsi_cmds;
 	/*
 	 * Create a pool of commands
 	 */
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index f553830..6b8547c 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -92,6 +92,7 @@  void megasas_start_timer(struct megasas_instance *instance,
 			 void *fn, unsigned long interval);
 extern struct megasas_mgmt_info megasas_mgmt_info;
 extern int resetwaittime;
+extern unsigned int dual_qdepth_disable;
 static void megasas_free_rdpq_fusion(struct megasas_instance *instance);
 static void megasas_free_reply_fusion(struct megasas_instance *instance);
 
@@ -208,6 +209,67 @@  megasas_fire_cmd_fusion(struct megasas_instance *instance,
 }
 
 /**
+ * megasas_fusion_update_can_queue -	Do all Adapter Queue depth related calculations here
+ * @instance:							Adapter soft state
+ * fw_boot_context:						Whether this function called during probe or after OCR
+ *
+ * This function is only for fusion controllers.
+ * Update host can queue, if firmware downgrade max supported firmware commands.
+ * Firmware upgrade case will be skiped because underlying firmware has
+ * more resource than exposed to the OS.
+ *
+ */
+static void
+megasas_fusion_update_can_queue(struct megasas_instance *instance, int fw_boot_context)
+{
+	u16 cur_max_fw_cmds = 0;
+	u16 ldio_threshold = 0;
+	struct megasas_register_set __iomem *reg_set;
+
+	reg_set = instance->reg_set;
+
+	cur_max_fw_cmds = readl(&instance->reg_set->outbound_scratch_pad_3) & 0x00FFFF;
+
+	if (dual_qdepth_disable || !cur_max_fw_cmds)
+		cur_max_fw_cmds = instance->instancet->read_fw_status_reg(reg_set) & 0x00FFFF;
+	else
+		ldio_threshold =
+			(instance->instancet->read_fw_status_reg(reg_set) & 0x00FFFF) - MEGASAS_FUSION_IOCTL_CMDS;
+
+	dev_info(&instance->pdev->dev,
+			"Current firmware maximum commands: %d\t LDIO threshold: %d\n",
+			cur_max_fw_cmds, ldio_threshold);
+
+	if (fw_boot_context == OCR_CONTEXT) {
+		cur_max_fw_cmds = cur_max_fw_cmds - 1;
+		if (cur_max_fw_cmds <= instance->max_fw_cmds) {
+			instance->cur_can_queue =
+				cur_max_fw_cmds - (MEGASAS_FUSION_INTERNAL_CMDS +
+						MEGASAS_FUSION_IOCTL_CMDS);
+			instance->host->can_queue = instance->cur_can_queue;
+			instance->ldio_threshold = ldio_threshold;
+		}
+	} else {
+		instance->max_fw_cmds = cur_max_fw_cmds;
+		instance->ldio_threshold = ldio_threshold;
+
+		if (!instance->is_rdpq)
+			instance->max_fw_cmds = min_t(u16, instance->max_fw_cmds, 1024);
+
+		/*
+		* Reduce the max supported cmds by 1. This is to ensure that the
+		* reply_q_sz (1 more than the max cmd that driver may send)
+		* does not exceed max cmds that the FW can support
+		*/
+		instance->max_fw_cmds = instance->max_fw_cmds-1;
+
+		instance->max_scsi_cmds = instance->max_fw_cmds -
+				(MEGASAS_FUSION_INTERNAL_CMDS +
+				MEGASAS_FUSION_IOCTL_CMDS);
+		instance->cur_can_queue = instance->max_scsi_cmds;
+	}
+}
+/**
  * megasas_free_cmds_fusion -	Free all the cmds in the free cmd pool
  * @instance:		Adapter soft state
  */
@@ -738,6 +800,8 @@  megasas_ioc_init_fusion(struct megasas_instance *instance)
 		drv_ops->mfi_capabilities.support_ext_io_size = 1;
 
 	drv_ops->mfi_capabilities.support_fp_rlbypass = 1;
+	if (!dual_qdepth_disable)
+		drv_ops->mfi_capabilities.support_ext_queue_depth = 1;
 
 	/* Convert capability to LE32 */
 	cpu_to_le32s((u32 *)&init_frame->driver_operations.mfi_capabilities);
@@ -1153,15 +1217,7 @@  megasas_init_adapter_fusion(struct megasas_instance *instance)
 
 	reg_set = instance->reg_set;
 
-	/*
-	 * Get various operational parameters from status register
-	 */
-	instance->max_fw_cmds =
-		instance->instancet->read_fw_status_reg(reg_set) & 0x00FFFF;
-	dev_info(&instance->pdev->dev,
-		"firmware support max fw cmd\t: (%d)\n", instance->max_fw_cmds);
-	if (!instance->is_rdpq)
-		instance->max_fw_cmds = min_t(u16, instance->max_fw_cmds, 1024);
+	megasas_fusion_update_can_queue(instance, PROBE_CONTEXT);
 
 	/*
 	 * Reduce the max supported cmds by 1. This is to ensure that the
@@ -2119,6 +2175,14 @@  megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
 
 	fusion = instance->ctrl_context;
 
+	if ((megasas_cmd_type(scmd) == READ_WRITE_LDIO) &&
+		instance->ldio_threshold &&
+		(atomic_inc_return(&instance->ldio_outstanding) >
+		instance->ldio_threshold)) {
+		atomic_dec(&instance->ldio_outstanding);
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
 	cmd = megasas_get_cmd_fusion(instance, scmd->request->tag);
 
 	index = cmd->index;
@@ -2249,6 +2313,8 @@  complete_cmd_fusion(struct megasas_instance *instance, u32 MSIxIndex)
 			map_cmd_status(cmd_fusion, status, extStatus);
 			scsi_io_req->RaidContext.status = 0;
 			scsi_io_req->RaidContext.exStatus = 0;
+			if (megasas_cmd_type(scmd_local) == READ_WRITE_LDIO)
+				atomic_dec(&instance->ldio_outstanding);
 			megasas_return_cmd_fusion(instance, cmd_fusion);
 			scsi_dma_unmap(scmd_local);
 			scmd_local->scsi_done(scmd_local);
@@ -3367,6 +3433,8 @@  int megasas_reset_fusion(struct Scsi_Host *shost, int reason)
 				scmd_local->result =
 					megasas_check_mpio_paths(instance,
 							scmd_local);
+				if (megasas_cmd_type(scmd_local) == READ_WRITE_LDIO)
+					atomic_dec(&instance->ldio_outstanding);
 				megasas_return_cmd_fusion(instance, cmd_fusion);
 				scsi_dma_unmap(scmd_local);
 				scmd_local->scsi_done(scmd_local);
@@ -3459,6 +3527,8 @@  int megasas_reset_fusion(struct Scsi_Host *shost, int reason)
 			}
 
 			megasas_reset_reply_desc(instance);
+			megasas_fusion_update_can_queue(instance, OCR_CONTEXT);
+
 			if (megasas_ioc_init_fusion(instance)) {
 				dev_warn(&instance->pdev->dev,
 				       "megasas_ioc_init_fusion() failed!"