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-rw-r--r--drivers/scsi/scsi_dh.c373
1 files changed, 373 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
new file mode 100644
index 000000000..6f41e4b5a
--- /dev/null
+++ b/drivers/scsi/scsi_dh.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SCSI device handler infrastruture.
+ *
+ * Copyright IBM Corporation, 2007
+ * Authors:
+ * Chandra Seetharaman <sekharan@us.ibm.com>
+ * Mike Anderson <andmike@linux.vnet.ibm.com>
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <scsi/scsi_dh.h>
+#include "scsi_priv.h"
+
+static DEFINE_SPINLOCK(list_lock);
+static LIST_HEAD(scsi_dh_list);
+
+struct scsi_dh_blist {
+ const char *vendor;
+ const char *model;
+ const char *driver;
+};
+
+static const struct scsi_dh_blist scsi_dh_blist[] = {
+ {"DGC", "RAID", "emc" },
+ {"DGC", "DISK", "emc" },
+ {"DGC", "VRAID", "emc" },
+
+ {"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
+ {"COMPAQ", "HSV110", "hp_sw" },
+ {"HP", "HSV100", "hp_sw"},
+ {"DEC", "HSG80", "hp_sw"},
+
+ {"IBM", "1722", "rdac", },
+ {"IBM", "1724", "rdac", },
+ {"IBM", "1726", "rdac", },
+ {"IBM", "1742", "rdac", },
+ {"IBM", "1745", "rdac", },
+ {"IBM", "1746", "rdac", },
+ {"IBM", "1813", "rdac", },
+ {"IBM", "1814", "rdac", },
+ {"IBM", "1815", "rdac", },
+ {"IBM", "1818", "rdac", },
+ {"IBM", "3526", "rdac", },
+ {"IBM", "3542", "rdac", },
+ {"IBM", "3552", "rdac", },
+ {"SGI", "TP9300", "rdac", },
+ {"SGI", "TP9400", "rdac", },
+ {"SGI", "TP9500", "rdac", },
+ {"SGI", "TP9700", "rdac", },
+ {"SGI", "IS", "rdac", },
+ {"STK", "OPENstorage", "rdac", },
+ {"STK", "FLEXLINE 380", "rdac", },
+ {"STK", "BladeCtlr", "rdac", },
+ {"SUN", "CSM", "rdac", },
+ {"SUN", "LCSM100", "rdac", },
+ {"SUN", "STK6580_6780", "rdac", },
+ {"SUN", "SUN_6180", "rdac", },
+ {"SUN", "ArrayStorage", "rdac", },
+ {"DELL", "MD3", "rdac", },
+ {"NETAPP", "INF-01-00", "rdac", },
+ {"LSI", "INF-01-00", "rdac", },
+ {"ENGENIO", "INF-01-00", "rdac", },
+ {"LENOVO", "DE_Series", "rdac", },
+ {"FUJITSU", "ETERNUS_AHB", "rdac", },
+ {NULL, NULL, NULL },
+};
+
+static const char *
+scsi_dh_find_driver(struct scsi_device *sdev)
+{
+ const struct scsi_dh_blist *b;
+
+ if (scsi_device_tpgs(sdev))
+ return "alua";
+
+ for (b = scsi_dh_blist; b->vendor; b++) {
+ if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
+ !strncmp(sdev->model, b->model, strlen(b->model))) {
+ return b->driver;
+ }
+ }
+ return NULL;
+}
+
+
+static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
+{
+ struct scsi_device_handler *tmp, *found = NULL;
+
+ spin_lock(&list_lock);
+ list_for_each_entry(tmp, &scsi_dh_list, list) {
+ if (!strncmp(tmp->name, name, strlen(tmp->name))) {
+ found = tmp;
+ break;
+ }
+ }
+ spin_unlock(&list_lock);
+ return found;
+}
+
+static struct scsi_device_handler *scsi_dh_lookup(const char *name)
+{
+ struct scsi_device_handler *dh;
+
+ if (!name || strlen(name) == 0)
+ return NULL;
+
+ dh = __scsi_dh_lookup(name);
+ if (!dh) {
+ request_module("scsi_dh_%s", name);
+ dh = __scsi_dh_lookup(name);
+ }
+
+ return dh;
+}
+
+/*
+ * scsi_dh_handler_attach - Attach a device handler to a device
+ * @sdev - SCSI device the device handler should attach to
+ * @scsi_dh - The device handler to attach
+ */
+static int scsi_dh_handler_attach(struct scsi_device *sdev,
+ struct scsi_device_handler *scsi_dh)
+{
+ int error, ret = 0;
+
+ if (!try_module_get(scsi_dh->module))
+ return -EINVAL;
+
+ error = scsi_dh->attach(sdev);
+ if (error != SCSI_DH_OK) {
+ switch (error) {
+ case SCSI_DH_NOMEM:
+ ret = -ENOMEM;
+ break;
+ case SCSI_DH_RES_TEMP_UNAVAIL:
+ ret = -EAGAIN;
+ break;
+ case SCSI_DH_DEV_UNSUPP:
+ case SCSI_DH_NOSYS:
+ ret = -ENODEV;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ if (ret != -ENODEV)
+ sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
+ scsi_dh->name, error);
+ module_put(scsi_dh->module);
+ } else
+ sdev->handler = scsi_dh;
+
+ return ret;
+}
+
+/*
+ * scsi_dh_handler_detach - Detach a device handler from a device
+ * @sdev - SCSI device the device handler should be detached from
+ */
+static void scsi_dh_handler_detach(struct scsi_device *sdev)
+{
+ sdev->handler->detach(sdev);
+ sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
+ module_put(sdev->handler->module);
+}
+
+void scsi_dh_add_device(struct scsi_device *sdev)
+{
+ struct scsi_device_handler *devinfo = NULL;
+ const char *drv;
+
+ drv = scsi_dh_find_driver(sdev);
+ if (drv)
+ devinfo = __scsi_dh_lookup(drv);
+ /*
+ * device_handler is optional, so ignore errors
+ * from scsi_dh_handler_attach()
+ */
+ if (devinfo)
+ (void)scsi_dh_handler_attach(sdev, devinfo);
+}
+
+void scsi_dh_release_device(struct scsi_device *sdev)
+{
+ if (sdev->handler)
+ scsi_dh_handler_detach(sdev);
+}
+
+/*
+ * scsi_register_device_handler - register a device handler personality
+ * module.
+ * @scsi_dh - device handler to be registered.
+ *
+ * Returns 0 on success, -EBUSY if handler already registered.
+ */
+int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
+{
+ if (__scsi_dh_lookup(scsi_dh->name))
+ return -EBUSY;
+
+ if (!scsi_dh->attach || !scsi_dh->detach)
+ return -EINVAL;
+
+ spin_lock(&list_lock);
+ list_add(&scsi_dh->list, &scsi_dh_list);
+ spin_unlock(&list_lock);
+
+ printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
+
+ return SCSI_DH_OK;
+}
+EXPORT_SYMBOL_GPL(scsi_register_device_handler);
+
+/*
+ * scsi_unregister_device_handler - register a device handler personality
+ * module.
+ * @scsi_dh - device handler to be unregistered.
+ *
+ * Returns 0 on success, -ENODEV if handler not registered.
+ */
+int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
+{
+ if (!__scsi_dh_lookup(scsi_dh->name))
+ return -ENODEV;
+
+ spin_lock(&list_lock);
+ list_del(&scsi_dh->list);
+ spin_unlock(&list_lock);
+ printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
+
+ return SCSI_DH_OK;
+}
+EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
+
+/*
+ * scsi_dh_activate - activate the path associated with the scsi_device
+ * corresponding to the given request queue.
+ * Returns immediately without waiting for activation to be completed.
+ * @q - Request queue that is associated with the scsi_device to be
+ * activated.
+ * @fn - Function to be called upon completion of the activation.
+ * Function fn is called with data (below) and the error code.
+ * Function fn may be called from the same calling context. So,
+ * do not hold the lock in the caller which may be needed in fn.
+ * @data - data passed to the function fn upon completion.
+ *
+ */
+int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
+{
+ struct scsi_device *sdev;
+ int err = SCSI_DH_NOSYS;
+
+ sdev = scsi_device_from_queue(q);
+ if (!sdev) {
+ if (fn)
+ fn(data, err);
+ return err;
+ }
+
+ if (!sdev->handler)
+ goto out_fn;
+ err = SCSI_DH_NOTCONN;
+ if (sdev->sdev_state == SDEV_CANCEL ||
+ sdev->sdev_state == SDEV_DEL)
+ goto out_fn;
+
+ err = SCSI_DH_DEV_OFFLINED;
+ if (sdev->sdev_state == SDEV_OFFLINE)
+ goto out_fn;
+
+ if (sdev->handler->activate)
+ err = sdev->handler->activate(sdev, fn, data);
+
+out_put_device:
+ put_device(&sdev->sdev_gendev);
+ return err;
+
+out_fn:
+ if (fn)
+ fn(data, err);
+ goto out_put_device;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_activate);
+
+/*
+ * scsi_dh_set_params - set the parameters for the device as per the
+ * string specified in params.
+ * @q - Request queue that is associated with the scsi_device for
+ * which the parameters to be set.
+ * @params - parameters in the following format
+ * "no_of_params\0param1\0param2\0param3\0...\0"
+ * for example, string for 2 parameters with value 10 and 21
+ * is specified as "2\010\021\0".
+ */
+int scsi_dh_set_params(struct request_queue *q, const char *params)
+{
+ struct scsi_device *sdev;
+ int err = -SCSI_DH_NOSYS;
+
+ sdev = scsi_device_from_queue(q);
+ if (!sdev)
+ return err;
+
+ if (sdev->handler && sdev->handler->set_params)
+ err = sdev->handler->set_params(sdev, params);
+ put_device(&sdev->sdev_gendev);
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_set_params);
+
+/*
+ * scsi_dh_attach - Attach device handler
+ * @q - Request queue that is associated with the scsi_device
+ * the handler should be attached to
+ * @name - name of the handler to attach
+ */
+int scsi_dh_attach(struct request_queue *q, const char *name)
+{
+ struct scsi_device *sdev;
+ struct scsi_device_handler *scsi_dh;
+ int err = 0;
+
+ sdev = scsi_device_from_queue(q);
+ if (!sdev)
+ return -ENODEV;
+
+ scsi_dh = scsi_dh_lookup(name);
+ if (!scsi_dh) {
+ err = -EINVAL;
+ goto out_put_device;
+ }
+
+ if (sdev->handler) {
+ if (sdev->handler != scsi_dh)
+ err = -EBUSY;
+ goto out_put_device;
+ }
+
+ err = scsi_dh_handler_attach(sdev, scsi_dh);
+
+out_put_device:
+ put_device(&sdev->sdev_gendev);
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_attach);
+
+/*
+ * scsi_dh_attached_handler_name - Get attached device handler's name
+ * @q - Request queue that is associated with the scsi_device
+ * that may have a device handler attached
+ * @gfp - the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Returns name of attached handler, NULL if no handler is attached.
+ * Caller must take care to free the returned string.
+ */
+const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
+{
+ struct scsi_device *sdev;
+ const char *handler_name = NULL;
+
+ sdev = scsi_device_from_queue(q);
+ if (!sdev)
+ return NULL;
+
+ if (sdev->handler)
+ handler_name = kstrdup(sdev->handler->name, gfp);
+ put_device(&sdev->sdev_gendev);
+ return handler_name;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
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