[PATCH 3/4] scsi: megaraid_sas - add module param max_sectors,cmd_per_lun
From: linux-box
Date: Thu Sep 13 2007 - 13:16:39 EST
Adding module parameters to configure max sectors per request & # of cmds for each lun.
Signed-off-by: Bo Yang <bo.yang@xxxxxxx>
---
Re-submitting
drivers/scsi/megaraid/megaraid_sas.c | 93 ++++++++++++++++++++++++-
drivers/scsi/megaraid/megaraid_sas.h | 2
2 files changed, 93 insertions(+), 2 deletions(-)
diff -rupN linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c
--- linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.c 2007-08-14 21:47:00.517984856 -0400
+++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.c 2007-08-14 21:47:14.952790432 -0400
@@ -62,6 +62,23 @@ MODULE_PARM_DESC(fast_load,
"megasas: Faster loading of the driver, skips physical devices! \
(default = 0)");
+/*
+ * Number of sectors per IO command will be set in megasas_init_mfi
+ * if user does not provide
+ */
+static unsigned int max_sectors;
+module_param_named(max_sectors, max_sectors, int, 0);
+MODULE_PARM_DESC(max_sectors,
+ "Maximum number of sectors per IO command");
+
+/*
+ * Number of cmds per logical unit
+ */
+static unsigned int cmd_per_lun = MEGASAS_DEFAULT_CMD_PER_LUN;
+module_param_named(cmd_per_lun, cmd_per_lun, int, 0);
+MODULE_PARM_DESC(cmd_per_lun,
+ "Maximum number of commands per logical unit (default=128)");
+
MODULE_LICENSE("GPL");
MODULE_VERSION(MEGASAS_VERSION);
MODULE_AUTHOR("megaraidlinux@xxxxxxx");
@@ -2303,6 +2320,30 @@ static int megasas_start_aen(struct mega
class_locale.word);
}
+static ssize_t
+sysfs_max_sectors_read(struct kobject *kobj, char *buf,
+ loff_t off, size_t count)
+{
+ struct Scsi_Host *host = class_to_shost(container_of(kobj,
+ struct class_device, kobj));
+ struct megasas_instance *instance =
+ (struct megasas_instance *)host->hostdata;
+
+ count = sprintf(buf, "%u\n", instance->max_sectors_per_req);
+
+ return count+1;
+}
+
+static struct bin_attribute sysfs_max_sectors_attr = {
+ .attr = {
+ .name = "max_sectors",
+ .mode = S_IRUSR|S_IRGRP|S_IROTH,
+ .owner = THIS_MODULE,
+ },
+ .size = 7,
+ .read = sysfs_max_sectors_read,
+};
+
/**
* megasas_io_attach - Attaches this driver to SCSI mid-layer
* @instance: Adapter soft state
@@ -2310,17 +2351,48 @@ static int megasas_start_aen(struct mega
static int megasas_io_attach(struct megasas_instance *instance)
{
struct Scsi_Host *host = instance->host;
+ int error;
/*
- * Export parameters required by SCSI mid-layer
+ * Export host parameters required by SCSI
+ * mid-layer
*/
host->irq = instance->pdev->irq;
host->unique_id = instance->unique_id;
host->can_queue = instance->max_fw_cmds - MEGASAS_INT_CMDS;
host->this_id = instance->init_id;
host->sg_tablesize = instance->max_num_sge;
+
+ /*
+ * Check if the module parameter value for max_sectors can be used
+ */
+ if (max_sectors && max_sectors <= instance->max_sectors_per_req)
+ instance->max_sectors_per_req = max_sectors;
+ else {
+ if (max_sectors)
+ printk(KERN_INFO
+ "megasas: max_sectors should be > 0 and"
+ "<= %d\n",
+ instance->max_sectors_per_req);
+ }
+
host->max_sectors = instance->max_sectors_per_req;
- host->cmd_per_lun = 128;
+
+ /*
+ * Check if the module parameter value for cmd_per_lun can be used
+ */
+ instance->cmd_per_lun = MEGASAS_DEFAULT_CMD_PER_LUN;
+ if (cmd_per_lun && cmd_per_lun <= MEGASAS_DEFAULT_CMD_PER_LUN)
+ instance->cmd_per_lun = cmd_per_lun;
+ else
+ printk(KERN_INFO "megasas: cmd_per_lun should be > 0 and"
+ "<= %d\n", MEGASAS_DEFAULT_CMD_PER_LUN);
+
+ host->cmd_per_lun = instance->cmd_per_lun;
+
+ printk(KERN_DEBUG "megasas: max_sectors : 0x%x, cmd_per_lun : 0x%x\n",
+ instance->max_sectors_per_req, instance->cmd_per_lun);
+
host->max_channel = MEGASAS_MAX_CHANNELS - 1;
host->max_id = MEGASAS_MAX_DEV_PER_CHANNEL;
host->max_lun = MEGASAS_MAX_LUN;
@@ -2335,10 +2407,25 @@ static int megasas_io_attach(struct mega
}
/*
+ * Create sysfs entries for module paramaters
+ */
+ error = sysfs_create_bin_file(&instance->host->shost_classdev.kobj,
+ &sysfs_max_sectors_attr);
+ if (error) {
+ printk(KERN_INFO "megasas: Error in creating the sysfs entry"
+ " max_sectors.\n");
+ goto out_remove_host;
+ }
+
+ /*
* Trigger SCSI to scan our drives
*/
scsi_scan_host(host);
return 0;
+
+out_remove_host:
+ scsi_remove_host(host);
+ return error;
}
static int
@@ -2759,6 +2846,8 @@ static void megasas_detach_one(struct pc
instance = pci_get_drvdata(pdev);
host = instance->host;
+ sysfs_remove_bin_file(&host->shost_classdev.kobj,
+ &sysfs_max_sectors_attr);
scsi_remove_host(instance->host);
megasas_flush_cache(instance);
megasas_shutdown_controller(instance, MR_DCMD_CTRL_SHUTDOWN);
diff -rupN linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.h linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.h
--- linux-2.6.22_orig/drivers/scsi/megaraid/megaraid_sas.h 2007-07-23 23:18:15.000000000 -0400
+++ linux-2.6.22_new/drivers/scsi/megaraid/megaraid_sas.h 2007-07-01 22:25:59.000000000 -0400
@@ -537,6 +537,7 @@ struct megasas_ctrl_info {
#define MEGASAS_DEFAULT_INIT_ID -1
#define MEGASAS_MAX_LUN 8
#define MEGASAS_MAX_LD 64
+#define MEGASAS_DEFAULT_CMD_PER_LUN 128
#define MEGASAS_DBG_LVL 1
@@ -1080,6 +1081,7 @@ struct megasas_instance {
u16 max_num_sge;
u16 max_fw_cmds;
u32 max_sectors_per_req;
+ u32 cmd_per_lun;
struct megasas_cmd **cmd_list;
struct list_head cmd_pool;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/