[SCSI] ipr: Write caching state host attribute

Adds a scsi_host sysfs attribute and module parm to enable/disable
the write cache on an ipr adapter.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 8817ea06adbffd234dd70f63f8681ef59d763cfb..7149aada3f3ce92e466012cb1bd09fc0336d4474 100644 (file)
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -91,6 +91,7 @@ static unsigned int ipr_max_speed = 1;
 static int ipr_testmode = 0;
 static unsigned int ipr_fastfail = 0;
 static unsigned int ipr_transop_timeout = IPR_OPERATIONAL_TIMEOUT;
+static unsigned int ipr_enable_cache = 1;
 static DEFINE_SPINLOCK(ipr_driver_lock);
 
 /* This table describes the differences between DMA controller chips */
@@ -150,6 +151,8 @@ module_param_named(fastfail, ipr_fastfail, int, 0);
 MODULE_PARM_DESC(fastfail, "Reduce timeouts and retries");
 module_param_named(transop_timeout, ipr_transop_timeout, int, 0);
 MODULE_PARM_DESC(transop_timeout, "Time in seconds to wait for adapter to come operational (default: 300)");
+module_param_named(enable_cache, ipr_enable_cache, int, 0);
+MODULE_PARM_DESC(enable_cache, "Enable adapter's non-volatile write cache (default: 1)");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(IPR_DRIVER_VERSION);
 
@@ -1937,6 +1940,103 @@ static struct bin_attribute ipr_trace_attr = {
 };
 #endif
 
+static const struct {
+       enum ipr_cache_state state;
+       char *name;
+} cache_state [] = {
+       { CACHE_NONE, "none" },
+       { CACHE_DISABLED, "disabled" },
+       { CACHE_ENABLED, "enabled" }
+};
+
+/**
+ * ipr_show_write_caching - Show the write caching attribute
+ * @class_dev: class device struct
+ * @buf:               buffer
+ *
+ * Return value:
+ *     number of bytes printed to buffer
+ **/
+static ssize_t ipr_show_write_caching(struct class_device *class_dev, char *buf)
+{
+       struct Scsi_Host *shost = class_to_shost(class_dev);
+       struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;
+       unsigned long lock_flags = 0;
+       int i, len = 0;
+
+       spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+       for (i = 0; i < ARRAY_SIZE(cache_state); i++) {
+               if (cache_state[i].state == ioa_cfg->cache_state) {
+                       len = snprintf(buf, PAGE_SIZE, "%s\n", cache_state[i].name);
+                       break;
+               }
+       }
+       spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+       return len;
+}
+
+
+/**
+ * ipr_store_write_caching - Enable/disable adapter write cache
+ * @class_dev: class_device struct
+ * @buf:               buffer
+ * @count:             buffer size
+ *
+ * This function will enable/disable adapter write cache.
+ *
+ * Return value:
+ *     count on success / other on failure
+ **/
+static ssize_t ipr_store_write_caching(struct class_device *class_dev,
+                                       const char *buf, size_t count)
+{
+       struct Scsi_Host *shost = class_to_shost(class_dev);
+       struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;
+       unsigned long lock_flags = 0;
+       enum ipr_cache_state new_state = CACHE_INVALID;
+       int i;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+       if (ioa_cfg->cache_state == CACHE_NONE)
+               return -EINVAL;
+
+       for (i = 0; i < ARRAY_SIZE(cache_state); i++) {
+               if (!strncmp(cache_state[i].name, buf, strlen(cache_state[i].name))) {
+                       new_state = cache_state[i].state;
+                       break;
+               }
+       }
+
+       if (new_state != CACHE_DISABLED && new_state != CACHE_ENABLED)
+               return -EINVAL;
+
+       spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+       if (ioa_cfg->cache_state == new_state) {
+               spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+               return count;
+       }
+
+       ioa_cfg->cache_state = new_state;
+       dev_info(&ioa_cfg->pdev->dev, "%s adapter write cache.\n",
+                new_state == CACHE_ENABLED ? "Enabling" : "Disabling");
+       if (!ioa_cfg->in_reset_reload)
+               ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NORMAL);
+       spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+       wait_event(ioa_cfg->reset_wait_q, !ioa_cfg->in_reset_reload);
+
+       return count;
+}
+
+static struct class_device_attribute ipr_ioa_cache_attr = {
+       .attr = {
+               .name =         "write_cache",
+               .mode =         S_IRUGO | S_IWUSR,
+       },
+       .show = ipr_show_write_caching,
+       .store = ipr_store_write_caching
+};
+
 /**
  * ipr_show_fw_version - Show the firmware version
  * @class_dev: class device struct
@@ -2406,6 +2506,7 @@ static struct class_device_attribute *ipr_ioa_attrs[] = {
        &ipr_diagnostics_attr,
        &ipr_ioa_reset_attr,
        &ipr_update_fw_attr,
+       &ipr_ioa_cache_attr,
        NULL,
 };
 
@@ -4147,6 +4248,36 @@ static int ipr_set_supported_devs(struct ipr_cmnd *ipr_cmd)
        return IPR_RC_JOB_CONTINUE;
 }
 
+/**
+ * ipr_setup_write_cache - Disable write cache if needed
+ * @ipr_cmd:   ipr command struct
+ *
+ * This function sets up adapters write cache to desired setting
+ *
+ * Return value:
+ *     IPR_RC_JOB_CONTINUE / IPR_RC_JOB_RETURN
+ **/
+static int ipr_setup_write_cache(struct ipr_cmnd *ipr_cmd)
+{
+       struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+
+       ipr_cmd->job_step = ipr_set_supported_devs;
+       ipr_cmd->u.res = list_entry(ioa_cfg->used_res_q.next,
+                                   struct ipr_resource_entry, queue);
+
+       if (ioa_cfg->cache_state != CACHE_DISABLED)
+               return IPR_RC_JOB_CONTINUE;
+
+       ipr_cmd->ioarcb.res_handle = cpu_to_be32(IPR_IOA_RES_HANDLE);
+       ipr_cmd->ioarcb.cmd_pkt.request_type = IPR_RQTYPE_IOACMD;
+       ipr_cmd->ioarcb.cmd_pkt.cdb[0] = IPR_IOA_SHUTDOWN;
+       ipr_cmd->ioarcb.cmd_pkt.cdb[1] = IPR_SHUTDOWN_PREPARE_FOR_NORMAL;
+
+       ipr_do_req(ipr_cmd, ipr_reset_ioa_job, ipr_timeout, IPR_INTERNAL_TIMEOUT);
+
+       return IPR_RC_JOB_RETURN;
+}
+
 /**
  * ipr_get_mode_page - Locate specified mode page
  * @mode_pages:        mode page buffer
@@ -4358,10 +4489,7 @@ static int ipr_ioafp_mode_select_page28(struct ipr_cmnd *ipr_cmd)
                              ioa_cfg->vpd_cbs_dma + offsetof(struct ipr_misc_cbs, mode_pages),
                              length);
 
-       ipr_cmd->job_step = ipr_set_supported_devs;
-       ipr_cmd->u.res = list_entry(ioa_cfg->used_res_q.next,
-                                   struct ipr_resource_entry, queue);
-
+       ipr_cmd->job_step = ipr_setup_write_cache;
        ipr_do_req(ipr_cmd, ipr_reset_ioa_job, ipr_timeout, IPR_INTERNAL_TIMEOUT);
 
        LEAVE;
@@ -4580,6 +4708,27 @@ static void ipr_ioafp_inquiry(struct ipr_cmnd *ipr_cmd, u8 flags, u8 page,
        LEAVE;
 }
 
+/**
+ * ipr_inquiry_page_supported - Is the given inquiry page supported
+ * @page0:             inquiry page 0 buffer
+ * @page:              page code.
+ *
+ * This function determines if the specified inquiry page is supported.
+ *
+ * Return value:
+ *     1 if page is supported / 0 if not
+ **/
+static int ipr_inquiry_page_supported(struct ipr_inquiry_page0 *page0, u8 page)
+{
+       int i;
+
+       for (i = 0; i < min_t(u8, page0->len, IPR_INQUIRY_PAGE0_ENTRIES); i++)
+               if (page0->page[i] == page)
+                       return 1;
+
+       return 0;
+}
+
 /**
  * ipr_ioafp_page3_inquiry - Send a Page 3 Inquiry to the adapter.
  * @ipr_cmd:   ipr command struct
@@ -4591,6 +4740,36 @@ static void ipr_ioafp_inquiry(struct ipr_cmnd *ipr_cmd, u8 flags, u8 page,
  *     IPR_RC_JOB_CONTINUE / IPR_RC_JOB_RETURN
  **/
 static int ipr_ioafp_page3_inquiry(struct ipr_cmnd *ipr_cmd)
+{
+       struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+       struct ipr_inquiry_page0 *page0 = &ioa_cfg->vpd_cbs->page0_data;
+
+       ENTER;
+
+       if (!ipr_inquiry_page_supported(page0, 1))
+               ioa_cfg->cache_state = CACHE_NONE;
+
+       ipr_cmd->job_step = ipr_ioafp_query_ioa_cfg;
+
+       ipr_ioafp_inquiry(ipr_cmd, 1, 3,
+                         ioa_cfg->vpd_cbs_dma + offsetof(struct ipr_misc_cbs, page3_data),
+                         sizeof(struct ipr_inquiry_page3));
+
+       LEAVE;
+       return IPR_RC_JOB_RETURN;
+}
+
+/**
+ * ipr_ioafp_page0_inquiry - Send a Page 0 Inquiry to the adapter.
+ * @ipr_cmd:   ipr command struct
+ *
+ * This function sends a Page 0 inquiry to the adapter
+ * to retrieve supported inquiry pages.
+ *
+ * Return value:
+ *     IPR_RC_JOB_CONTINUE / IPR_RC_JOB_RETURN
+ **/
+static int ipr_ioafp_page0_inquiry(struct ipr_cmnd *ipr_cmd)
 {
        struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
        char type[5];
@@ -4602,11 +4781,11 @@ static int ipr_ioafp_page3_inquiry(struct ipr_cmnd *ipr_cmd)
        type[4] = '\0';
        ioa_cfg->type = simple_strtoul((char *)type, NULL, 16);
 
-       ipr_cmd->job_step = ipr_ioafp_query_ioa_cfg;
+       ipr_cmd->job_step = ipr_ioafp_page3_inquiry;
 
-       ipr_ioafp_inquiry(ipr_cmd, 1, 3,
-                         ioa_cfg->vpd_cbs_dma + offsetof(struct ipr_misc_cbs, page3_data),
-                         sizeof(struct ipr_inquiry_page3));
+       ipr_ioafp_inquiry(ipr_cmd, 1, 0,
+                         ioa_cfg->vpd_cbs_dma + offsetof(struct ipr_misc_cbs, page0_data),
+                         sizeof(struct ipr_inquiry_page0));
 
        LEAVE;
        return IPR_RC_JOB_RETURN;
@@ -4626,7 +4805,7 @@ static int ipr_ioafp_std_inquiry(struct ipr_cmnd *ipr_cmd)
        struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
 
        ENTER;
-       ipr_cmd->job_step = ipr_ioafp_page3_inquiry;
+       ipr_cmd->job_step = ipr_ioafp_page0_inquiry;
 
        ipr_ioafp_inquiry(ipr_cmd, 0, 0,
                          ioa_cfg->vpd_cbs_dma + offsetof(struct ipr_misc_cbs, ioa_vpd),
@@ -5629,6 +5808,10 @@ static void __devinit ipr_init_ioa_cfg(struct ipr_ioa_cfg *ioa_cfg,
        INIT_WORK(&ioa_cfg->work_q, ipr_worker_thread, ioa_cfg);
        init_waitqueue_head(&ioa_cfg->reset_wait_q);
        ioa_cfg->sdt_state = INACTIVE;
+       if (ipr_enable_cache)
+               ioa_cfg->cache_state = CACHE_ENABLED;
+       else
+               ioa_cfg->cache_state = CACHE_DISABLED;
 
        ipr_initialize_bus_attr(ioa_cfg);
 

diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
index b8c1603f99ebba04a3dd93debabcf55f5d0fe472..6d9aef001fe7292f187d2a547ab839a593ff800d 100644 (file)
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -541,6 +541,15 @@ struct ipr_inquiry_page3 {
        u8 patch_number[4];
 }__attribute__((packed));
 
+#define IPR_INQUIRY_PAGE0_ENTRIES 20
+struct ipr_inquiry_page0 {
+       u8 peri_qual_dev_type;
+       u8 page_code;
+       u8 reserved1;
+       u8 len;
+       u8 page[IPR_INQUIRY_PAGE0_ENTRIES];
+}__attribute__((packed));
+
 struct ipr_hostrcb_device_data_entry {
        struct ipr_vpd vpd;
        struct ipr_res_addr dev_res_addr;
@@ -731,6 +740,7 @@ struct ipr_resource_table {
 
 struct ipr_misc_cbs {
        struct ipr_ioa_vpd ioa_vpd;
+       struct ipr_inquiry_page0 page0_data;
        struct ipr_inquiry_page3 page3_data;
        struct ipr_mode_pages mode_pages;
        struct ipr_supported_device supp_dev;
@@ -813,6 +823,13 @@ enum ipr_sdt_state {
        DUMP_OBTAINED
 };
 
+enum ipr_cache_state {
+       CACHE_NONE,
+       CACHE_DISABLED,
+       CACHE_ENABLED,
+       CACHE_INVALID
+};
+
 /* Per-controller data */
 struct ipr_ioa_cfg {
        char eye_catcher[8];
@@ -829,6 +846,7 @@ struct ipr_ioa_cfg {
        u8 allow_cmds:1;
        u8 allow_ml_add_del:1;
 
+       enum ipr_cache_state cache_state;
        u16 type; /* CCIN of the card */
 
        u8 log_level;