nfit, libnvdimm: allow an ARS scrub to be triggered on demand
[cascardo/linux.git] / drivers / acpi / nfit.c
index 54a4ee0..19d0dfd 100644 (file)
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/ndctl.h>
+#include <linux/sysfs.h>
 #include <linux/delay.h>
 #include <linux/list.h>
 #include <linux/acpi.h>
@@ -874,14 +875,87 @@ static ssize_t revision_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(revision);
 
+/*
+ * This shows the number of full Address Range Scrubs that have been
+ * completed since driver load time. Userspace can wait on this using
+ * select/poll etc. A '+' at the end indicates an ARS is in progress
+ */
+static ssize_t scrub_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nvdimm_bus_descriptor *nd_desc;
+       ssize_t rc = -ENXIO;
+
+       device_lock(dev);
+       nd_desc = dev_get_drvdata(dev);
+       if (nd_desc) {
+               struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+
+               rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,
+                               (work_busy(&acpi_desc->work)) ? "+\n" : "\n");
+       }
+       device_unlock(dev);
+       return rc;
+}
+
+static int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc);
+
+static ssize_t scrub_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t size)
+{
+       struct nvdimm_bus_descriptor *nd_desc;
+       ssize_t rc;
+       long val;
+
+       rc = kstrtol(buf, 0, &val);
+       if (rc)
+               return rc;
+       if (val != 1)
+               return -EINVAL;
+
+       device_lock(dev);
+       nd_desc = dev_get_drvdata(dev);
+       if (nd_desc) {
+               struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+
+               rc = acpi_nfit_ars_rescan(acpi_desc);
+       }
+       device_unlock(dev);
+       if (rc)
+               return rc;
+       return size;
+}
+static DEVICE_ATTR_RW(scrub);
+
+static bool ars_supported(struct nvdimm_bus *nvdimm_bus)
+{
+       struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
+       const unsigned long mask = 1 << ND_CMD_ARS_CAP | 1 << ND_CMD_ARS_START
+               | 1 << ND_CMD_ARS_STATUS;
+
+       return (nd_desc->cmd_mask & mask) == mask;
+}
+
+static umode_t nfit_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+
+       if (a == &dev_attr_scrub.attr && !ars_supported(nvdimm_bus))
+               return 0;
+       return a->mode;
+}
+
 static struct attribute *acpi_nfit_attributes[] = {
        &dev_attr_revision.attr,
+       &dev_attr_scrub.attr,
        NULL,
 };
 
 static struct attribute_group acpi_nfit_attribute_group = {
        .name = "nfit",
        .attrs = acpi_nfit_attributes,
+       .is_visible = nfit_visible,
 };
 
 static const struct attribute_group *acpi_nfit_attribute_groups[] = {
@@ -2054,7 +2128,7 @@ static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc,
        unsigned int tmo = scrub_timeout;
        int rc;
 
-       if (nfit_spa->ars_done || !nfit_spa->nd_region)
+       if (!nfit_spa->ars_required || !nfit_spa->nd_region)
                return;
 
        rc = ars_start(acpi_desc, nfit_spa);
@@ -2143,7 +2217,9 @@ static void acpi_nfit_scrub(struct work_struct *work)
         * firmware initiated scrubs to complete and then we go search for the
         * affected spa regions to mark them scanned.  In the second phase we
         * initiate a directed scrub for every range that was not scrubbed in
-        * phase 1.
+        * phase 1. If we're called for a 'rescan', we harmlessly pass through
+        * the first phase, but really only care about running phase 2, where
+        * regions can be notified of new poison.
         */
 
        /* process platform firmware initiated scrubs */
@@ -2246,14 +2322,17 @@ static void acpi_nfit_scrub(struct work_struct *work)
                 * Flag all the ranges that still need scrubbing, but
                 * register them now to make data available.
                 */
-               if (nfit_spa->nd_region)
-                       nfit_spa->ars_done = 1;
-               else
+               if (!nfit_spa->nd_region) {
+                       nfit_spa->ars_required = 1;
                        acpi_nfit_register_region(acpi_desc, nfit_spa);
+               }
        }
 
        list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
                acpi_nfit_async_scrub(acpi_desc, nfit_spa);
+       acpi_desc->scrub_count++;
+       if (acpi_desc->scrub_count_state)
+               sysfs_notify_dirent(acpi_desc->scrub_count_state);
        mutex_unlock(&acpi_desc->init_mutex);
 }
 
@@ -2291,14 +2370,77 @@ static int acpi_nfit_check_deletions(struct acpi_nfit_desc *acpi_desc,
        return 0;
 }
 
-int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
+static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc)
+{
+       struct device *dev = acpi_desc->dev;
+       struct kernfs_node *nfit;
+       struct device *bus_dev;
+
+       if (!ars_supported(acpi_desc->nvdimm_bus))
+               return 0;
+
+       bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
+       nfit = sysfs_get_dirent(bus_dev->kobj.sd, "nfit");
+       if (!nfit) {
+               dev_err(dev, "sysfs_get_dirent 'nfit' failed\n");
+               return -ENODEV;
+       }
+       acpi_desc->scrub_count_state = sysfs_get_dirent(nfit, "scrub");
+       sysfs_put(nfit);
+       if (!acpi_desc->scrub_count_state) {
+               dev_err(dev, "sysfs_get_dirent 'scrub' failed\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static void acpi_nfit_destruct(void *data)
+{
+       struct acpi_nfit_desc *acpi_desc = data;
+       struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
+
+       acpi_desc->cancel = 1;
+       /*
+        * Bounce the nvdimm bus lock to make sure any in-flight
+        * acpi_nfit_ars_rescan() submissions have had a chance to
+        * either submit or see ->cancel set.
+        */
+       device_lock(bus_dev);
+       device_unlock(bus_dev);
+
+       flush_workqueue(nfit_wq);
+       if (acpi_desc->scrub_count_state)
+               sysfs_put(acpi_desc->scrub_count_state);
+       nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
+       acpi_desc->nvdimm_bus = NULL;
+}
+
+int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz)
 {
        struct device *dev = acpi_desc->dev;
        struct nfit_table_prev prev;
        const void *end;
-       u8 *data;
        int rc;
 
+       if (!acpi_desc->nvdimm_bus) {
+               acpi_nfit_init_dsms(acpi_desc);
+
+               acpi_desc->nvdimm_bus = nvdimm_bus_register(dev,
+                               &acpi_desc->nd_desc);
+               if (!acpi_desc->nvdimm_bus)
+                       return -ENOMEM;
+
+               rc = devm_add_action_or_reset(dev, acpi_nfit_destruct,
+                               acpi_desc);
+               if (rc)
+                       return rc;
+
+               rc = acpi_nfit_desc_init_scrub_attr(acpi_desc);
+               if (rc)
+                       return rc;
+       }
+
        mutex_lock(&acpi_desc->init_mutex);
 
        INIT_LIST_HEAD(&prev.spas);
@@ -2321,7 +2463,6 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
        list_cut_position(&prev.flushes, &acpi_desc->flushes,
                                acpi_desc->flushes.prev);
 
-       data = (u8 *) acpi_desc->nfit;
        end = data + sz;
        while (!IS_ERR_OR_NULL(data))
                data = add_table(acpi_desc, &prev, data, end);
@@ -2341,8 +2482,6 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
        if (rc)
                goto out_unlock;
 
-       acpi_nfit_init_dsms(acpi_desc);
-
        rc = acpi_nfit_register_dimms(acpi_desc);
        if (rc)
                goto out_unlock;
@@ -2410,6 +2549,33 @@ static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
        return 0;
 }
 
+static int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc)
+{
+       struct device *dev = acpi_desc->dev;
+       struct nfit_spa *nfit_spa;
+
+       if (work_busy(&acpi_desc->work))
+               return -EBUSY;
+
+       if (acpi_desc->cancel)
+               return 0;
+
+       mutex_lock(&acpi_desc->init_mutex);
+       list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
+               struct acpi_nfit_system_address *spa = nfit_spa->spa;
+
+               if (nfit_spa_type(spa) != NFIT_SPA_PM)
+                       continue;
+
+               nfit_spa->ars_required = 1;
+       }
+       queue_work(nfit_wq, &acpi_desc->work);
+       dev_dbg(dev, "%s: ars_scan triggered\n", __func__);
+       mutex_unlock(&acpi_desc->init_mutex);
+
+       return 0;
+}
+
 void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
 {
        struct nvdimm_bus_descriptor *nd_desc;
@@ -2419,6 +2585,7 @@ void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
        acpi_desc->blk_do_io = acpi_nfit_blk_region_do_io;
        nd_desc = &acpi_desc->nd_desc;
        nd_desc->provider_name = "ACPI.NFIT";
+       nd_desc->module = THIS_MODULE;
        nd_desc->ndctl = acpi_nfit_ctl;
        nd_desc->flush_probe = acpi_nfit_flush_probe;
        nd_desc->clear_to_send = acpi_nfit_clear_to_send;
@@ -2457,53 +2624,33 @@ static int acpi_nfit_add(struct acpi_device *adev)
        if (!acpi_desc)
                return -ENOMEM;
        acpi_nfit_desc_init(acpi_desc, &adev->dev);
-       acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, &acpi_desc->nd_desc);
-       if (!acpi_desc->nvdimm_bus)
-               return -ENOMEM;
 
-       /*
-        * Save the acpi header for later and then skip it,
-        * making nfit point to the first nfit table header.
-        */
+       /* Save the acpi header for exporting the revision via sysfs */
        acpi_desc->acpi_header = *tbl;
-       acpi_desc->nfit = (void *) tbl + sizeof(struct acpi_table_nfit);
-       sz -= sizeof(struct acpi_table_nfit);
 
        /* Evaluate _FIT and override with that if present */
        status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
        if (ACPI_SUCCESS(status) && buf.length > 0) {
-               union acpi_object *obj;
-               /*
-                * Adjust for the acpi_object header of the _FIT
-                */
-               obj = buf.pointer;
-               if (obj->type == ACPI_TYPE_BUFFER) {
-                       acpi_desc->nfit =
-                               (struct acpi_nfit_header *)obj->buffer.pointer;
-                       sz = obj->buffer.length;
-                       rc = acpi_nfit_init(acpi_desc, sz);
-               } else
+               union acpi_object *obj = buf.pointer;
+
+               if (obj->type == ACPI_TYPE_BUFFER)
+                       rc = acpi_nfit_init(acpi_desc, obj->buffer.pointer,
+                                       obj->buffer.length);
+               else
                        dev_dbg(dev, "%s invalid type %d, ignoring _FIT\n",
                                 __func__, (int) obj->type);
-               acpi_desc->nfit = NULL;
                kfree(buf.pointer);
        } else
-               rc = acpi_nfit_init(acpi_desc, sz);
-
-       if (rc) {
-               nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
-               return rc;
-       }
-       return 0;
+               /* skip over the lead-in header table */
+               rc = acpi_nfit_init(acpi_desc, (void *) tbl
+                               + sizeof(struct acpi_table_nfit),
+                               sz - sizeof(struct acpi_table_nfit));
+       return rc;
 }
 
 static int acpi_nfit_remove(struct acpi_device *adev)
 {
-       struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(&adev->dev);
-
-       acpi_desc->cancel = 1;
-       flush_workqueue(nfit_wq);
-       nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
+       /* see acpi_nfit_destruct */
        return 0;
 }
 
@@ -2511,8 +2658,8 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 {
        struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(&adev->dev);
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
-       union acpi_object *obj;
        struct device *dev = &adev->dev;
+       union acpi_object *obj;
        acpi_status status;
        int ret;
 
@@ -2530,9 +2677,6 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
                if (!acpi_desc)
                        goto out_unlock;
                acpi_nfit_desc_init(acpi_desc, &adev->dev);
-               acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, &acpi_desc->nd_desc);
-               if (!acpi_desc->nvdimm_bus)
-                       goto out_unlock;
        } else {
                /*
                 * Finish previous registration before considering new
@@ -2550,14 +2694,12 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 
        obj = buf.pointer;
        if (obj->type == ACPI_TYPE_BUFFER) {
-               acpi_desc->nfit =
-                       (struct acpi_nfit_header *)obj->buffer.pointer;
-               ret = acpi_nfit_init(acpi_desc, obj->buffer.length);
+               ret = acpi_nfit_init(acpi_desc, obj->buffer.pointer,
+                               obj->buffer.length);
                if (ret)
                        dev_err(dev, "failed to merge updated NFIT\n");
        } else
                dev_err(dev, "Invalid _FIT\n");
-       acpi_desc->nfit = NULL;
        kfree(buf.pointer);
 
  out_unlock: