+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
+};
+