1 files changed, 242 insertions, 56 deletions

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 6e26761a27da..f7dab53b352a 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -33,6 +33,15 @@ static bool force_enable_dimms;
 module_param(force_enable_dimms, bool, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(force_enable_dimms, "Ignore _STA (ACPI DIMM device) status");
 
+struct nfit_table_prev {
+        struct list_head spas;
+        struct list_head memdevs;
+        struct list_head dcrs;
+        struct list_head bdws;
+        struct list_head idts;
+        struct list_head flushes;
+};
+
 static u8 nfit_uuid[NFIT_UUID_MAX][16];
 
 const u8 *to_nfit_uuid(enum nfit_uuids id)
@@ -221,12 +230,20 @@ static int nfit_spa_type(struct acpi_nfit_system_address *spa)
 }
 
 static bool add_spa(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_system_address *spa)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_spa *nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa),
-                        GFP_KERNEL);
+        struct nfit_spa *nfit_spa;
+
+        list_for_each_entry(nfit_spa, &prev->spas, list) {
+                if (memcmp(nfit_spa->spa, spa, sizeof(*spa)) == 0) {
+                        list_move_tail(&nfit_spa->list, &acpi_desc->spas);
+                        return true;
+                }
+        }
 
+        nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa), GFP_KERNEL);
         if (!nfit_spa)
                 return false;
         INIT_LIST_HEAD(&nfit_spa->list);
@@ -239,12 +256,19 @@ static bool add_spa(struct acpi_nfit_desc *acpi_desc,
 }
 
 static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_memory_map *memdev)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_memdev *nfit_memdev = devm_kzalloc(dev,
-                        sizeof(*nfit_memdev), GFP_KERNEL);
+        struct nfit_memdev *nfit_memdev;
 
+        list_for_each_entry(nfit_memdev, &prev->memdevs, list)
+                if (memcmp(nfit_memdev->memdev, memdev, sizeof(*memdev)) == 0) {
+                        list_move_tail(&nfit_memdev->list, &acpi_desc->memdevs);
+                        return true;
+                }
+
+        nfit_memdev = devm_kzalloc(dev, sizeof(*nfit_memdev), GFP_KERNEL);
         if (!nfit_memdev)
                 return false;
         INIT_LIST_HEAD(&nfit_memdev->list);
@@ -257,12 +281,19 @@ static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
 }
 
 static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_control_region *dcr)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_dcr *nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr),
-                        GFP_KERNEL);
+        struct nfit_dcr *nfit_dcr;
+
+        list_for_each_entry(nfit_dcr, &prev->dcrs, list)
+                if (memcmp(nfit_dcr->dcr, dcr, sizeof(*dcr)) == 0) {
+                        list_move_tail(&nfit_dcr->list, &acpi_desc->dcrs);
+                        return true;
+                }
 
+        nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr), GFP_KERNEL);
         if (!nfit_dcr)
                 return false;
         INIT_LIST_HEAD(&nfit_dcr->list);
@@ -274,12 +305,19 @@ static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
 }
 
 static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_data_region *bdw)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_bdw *nfit_bdw = devm_kzalloc(dev, sizeof(*nfit_bdw),
-                        GFP_KERNEL);
+        struct nfit_bdw *nfit_bdw;
+
+        list_for_each_entry(nfit_bdw, &prev->bdws, list)
+                if (memcmp(nfit_bdw->bdw, bdw, sizeof(*bdw)) == 0) {
+                        list_move_tail(&nfit_bdw->list, &acpi_desc->bdws);
+                        return true;
+                }
 
+        nfit_bdw = devm_kzalloc(dev, sizeof(*nfit_bdw), GFP_KERNEL);
         if (!nfit_bdw)
                 return false;
         INIT_LIST_HEAD(&nfit_bdw->list);
@@ -291,12 +329,19 @@ static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
 }
 
 static bool add_idt(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_interleave *idt)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_idt *nfit_idt = devm_kzalloc(dev, sizeof(*nfit_idt),
-                        GFP_KERNEL);
+        struct nfit_idt *nfit_idt;
+
+        list_for_each_entry(nfit_idt, &prev->idts, list)
+                if (memcmp(nfit_idt->idt, idt, sizeof(*idt)) == 0) {
+                        list_move_tail(&nfit_idt->list, &acpi_desc->idts);
+                        return true;
+                }
 
+        nfit_idt = devm_kzalloc(dev, sizeof(*nfit_idt), GFP_KERNEL);
         if (!nfit_idt)
                 return false;
         INIT_LIST_HEAD(&nfit_idt->list);
@@ -308,12 +353,19 @@ static bool add_idt(struct acpi_nfit_desc *acpi_desc,
 }
 
 static bool add_flush(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev,
                 struct acpi_nfit_flush_address *flush)
 {
         struct device *dev = acpi_desc->dev;
-        struct nfit_flush *nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush),
-                        GFP_KERNEL);
+        struct nfit_flush *nfit_flush;
 
+        list_for_each_entry(nfit_flush, &prev->flushes, list)
+                if (memcmp(nfit_flush->flush, flush, sizeof(*flush)) == 0) {
+                        list_move_tail(&nfit_flush->list, &acpi_desc->flushes);
+                        return true;
+                }
+
+        nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush), GFP_KERNEL);
         if (!nfit_flush)
                 return false;
         INIT_LIST_HEAD(&nfit_flush->list);
@@ -324,8 +376,8 @@ static bool add_flush(struct acpi_nfit_desc *acpi_desc,
         return true;
 }
 
-static void *add_table(struct acpi_nfit_desc *acpi_desc, void *table,
-                const void *end)
+static void *add_table(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev, void *table, const void *end)
 {
         struct device *dev = acpi_desc->dev;
         struct acpi_nfit_header *hdr;
@@ -335,29 +387,35 @@ static void *add_table(struct acpi_nfit_desc *acpi_desc, void *table,
                 return NULL;
 
         hdr = table;
+        if (!hdr->length) {
+                dev_warn(dev, "found a zero length table '%d' parsing nfit\n",
+                        hdr->type);
+                return NULL;
+        }
+
         switch (hdr->type) {
         case ACPI_NFIT_TYPE_SYSTEM_ADDRESS:
-                if (!add_spa(acpi_desc, table))
+                if (!add_spa(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_MEMORY_MAP:
-                if (!add_memdev(acpi_desc, table))
+                if (!add_memdev(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_CONTROL_REGION:
-                if (!add_dcr(acpi_desc, table))
+                if (!add_dcr(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_DATA_REGION:
-                if (!add_bdw(acpi_desc, table))
+                if (!add_bdw(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_INTERLEAVE:
-                if (!add_idt(acpi_desc, table))
+                if (!add_idt(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_FLUSH_ADDRESS:
-                if (!add_flush(acpi_desc, table))
+                if (!add_flush(acpi_desc, prev, table))
                         return err;
                 break;
         case ACPI_NFIT_TYPE_SMBIOS:
@@ -802,12 +860,7 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
                 device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
                 nvdimm = acpi_nfit_dimm_by_handle(acpi_desc, device_handle);
                 if (nvdimm) {
-                        /*
-                         * If for some reason we find multiple DCRs the
-                         * first one wins
-                         */
-                        dev_err(acpi_desc->dev, "duplicate DCR detected: %s\n",
-                                        nvdimm_name(nvdimm));
+                        dimm_count++;
                         continue;
                 }
 
@@ -1476,6 +1529,9 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
         struct resource res;
         int count = 0, rc;
 
+        if (nfit_spa->is_registered)
+                return 0;
+
         if (spa->range_index == 0) {
                 dev_dbg(acpi_desc->dev, "%s: detected invalid spa index\n",
                                 __func__);
@@ -1529,6 +1585,8 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
                 if (!nvdimm_volatile_region_create(nvdimm_bus, ndr_desc))
                         return -ENOMEM;
         }
+
+        nfit_spa->is_registered = 1;
         return 0;
 }
 
@@ -1545,71 +1603,101 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
         return 0;
 }
 
+static int acpi_nfit_check_deletions(struct acpi_nfit_desc *acpi_desc,
+                struct nfit_table_prev *prev)
+{
+        struct device *dev = acpi_desc->dev;
+
+        if (!list_empty(&prev->spas) ||
+                        !list_empty(&prev->memdevs) ||
+                        !list_empty(&prev->dcrs) ||
+                        !list_empty(&prev->bdws) ||
+                        !list_empty(&prev->idts) ||
+                        !list_empty(&prev->flushes)) {
+                dev_err(dev, "new nfit deletes entries (unsupported)\n");
+                return -ENXIO;
+        }
+        return 0;
+}
+
 int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
 {
         struct device *dev = acpi_desc->dev;
+        struct nfit_table_prev prev;
         const void *end;
         u8 *data;
         int rc;
 
-        INIT_LIST_HEAD(&acpi_desc->spa_maps);
-        INIT_LIST_HEAD(&acpi_desc->spas);
-        INIT_LIST_HEAD(&acpi_desc->dcrs);
-        INIT_LIST_HEAD(&acpi_desc->bdws);
-        INIT_LIST_HEAD(&acpi_desc->idts);
-        INIT_LIST_HEAD(&acpi_desc->flushes);
-        INIT_LIST_HEAD(&acpi_desc->memdevs);
-        INIT_LIST_HEAD(&acpi_desc->dimms);
-        mutex_init(&acpi_desc->spa_map_mutex);
+        mutex_lock(&acpi_desc->init_mutex);
+
+        INIT_LIST_HEAD(&prev.spas);
+        INIT_LIST_HEAD(&prev.memdevs);
+        INIT_LIST_HEAD(&prev.dcrs);
+        INIT_LIST_HEAD(&prev.bdws);
+        INIT_LIST_HEAD(&prev.idts);
+        INIT_LIST_HEAD(&prev.flushes);
+
+        list_cut_position(&prev.spas, &acpi_desc->spas,
+                                acpi_desc->spas.prev);
+        list_cut_position(&prev.memdevs, &acpi_desc->memdevs,
+                                acpi_desc->memdevs.prev);
+        list_cut_position(&prev.dcrs, &acpi_desc->dcrs,
+                                acpi_desc->dcrs.prev);
+        list_cut_position(&prev.bdws, &acpi_desc->bdws,
+                                acpi_desc->bdws.prev);
+        list_cut_position(&prev.idts, &acpi_desc->idts,
+                                acpi_desc->idts.prev);
+        list_cut_position(&prev.flushes, &acpi_desc->flushes,
+                                acpi_desc->flushes.prev);
 
         data = (u8 *) acpi_desc->nfit;
         end = data + sz;
         data += sizeof(struct acpi_table_nfit);
         while (!IS_ERR_OR_NULL(data))
-                data = add_table(acpi_desc, data, end);
+                data = add_table(acpi_desc, &prev, data, end);
 
         if (IS_ERR(data)) {
                 dev_dbg(dev, "%s: nfit table parsing error: %ld\n", __func__,
                                 PTR_ERR(data));
-                return PTR_ERR(data);
+                rc = PTR_ERR(data);
+                goto out_unlock;
         }
 
-        if (nfit_mem_init(acpi_desc) != 0)
-                return -ENOMEM;
+        rc = acpi_nfit_check_deletions(acpi_desc, &prev);
+        if (rc)
+                goto out_unlock;
+
+        if (nfit_mem_init(acpi_desc) != 0) {
+                rc = -ENOMEM;
+                goto out_unlock;
+        }
 
         acpi_nfit_init_dsms(acpi_desc);
 
         rc = acpi_nfit_register_dimms(acpi_desc);
         if (rc)
-                return rc;
+                goto out_unlock;
+
+        rc = acpi_nfit_register_regions(acpi_desc);
 
-        return acpi_nfit_register_regions(acpi_desc);
+ out_unlock:
+        mutex_unlock(&acpi_desc->init_mutex);
+        return rc;
 }
 EXPORT_SYMBOL_GPL(acpi_nfit_init);
 
-static int acpi_nfit_add(struct acpi_device *adev)
+static struct acpi_nfit_desc *acpi_nfit_desc_init(struct acpi_device *adev)
 {
         struct nvdimm_bus_descriptor *nd_desc;
         struct acpi_nfit_desc *acpi_desc;
         struct device *dev = &adev->dev;
-        struct acpi_table_header *tbl;
-        acpi_status status = AE_OK;
-        acpi_size sz;
-        int rc;
-
-        status = acpi_get_table_with_size("NFIT", 0, &tbl, &sz);
-        if (ACPI_FAILURE(status)) {
-                dev_err(dev, "failed to find NFIT\n");
-                return -ENXIO;
-        }
 
         acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
         if (!acpi_desc)
-                return -ENOMEM;
+                return ERR_PTR(-ENOMEM);
 
         dev_set_drvdata(dev, acpi_desc);
         acpi_desc->dev = dev;
-        acpi_desc->nfit = (struct acpi_table_nfit *) tbl;
         acpi_desc->blk_do_io = acpi_nfit_blk_region_do_io;
         nd_desc = &acpi_desc->nd_desc;
         nd_desc->provider_name = "ACPI.NFIT";
@@ -1617,8 +1705,57 @@ static int acpi_nfit_add(struct acpi_device *adev)
         nd_desc->attr_groups = acpi_nfit_attribute_groups;
 
         acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, nd_desc);
-        if (!acpi_desc->nvdimm_bus)
-                return -ENXIO;
+        if (!acpi_desc->nvdimm_bus) {
+                devm_kfree(dev, acpi_desc);
+                return ERR_PTR(-ENXIO);
+        }
+
+        INIT_LIST_HEAD(&acpi_desc->spa_maps);
+        INIT_LIST_HEAD(&acpi_desc->spas);
+        INIT_LIST_HEAD(&acpi_desc->dcrs);
+        INIT_LIST_HEAD(&acpi_desc->bdws);
+        INIT_LIST_HEAD(&acpi_desc->idts);
+        INIT_LIST_HEAD(&acpi_desc->flushes);
+        INIT_LIST_HEAD(&acpi_desc->memdevs);
+        INIT_LIST_HEAD(&acpi_desc->dimms);
+        mutex_init(&acpi_desc->spa_map_mutex);
+        mutex_init(&acpi_desc->init_mutex);
+
+        return acpi_desc;
+}
+
+static int acpi_nfit_add(struct acpi_device *adev)
+{
+        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+        struct acpi_nfit_desc *acpi_desc;
+        struct device *dev = &adev->dev;
+        struct acpi_table_header *tbl;
+        acpi_status status = AE_OK;
+        acpi_size sz;
+        int rc;
+
+        status = acpi_get_table_with_size("NFIT", 0, &tbl, &sz);
+        if (ACPI_FAILURE(status)) {
+                /* This is ok, we could have an nvdimm hotplugged later */
+                dev_dbg(dev, "failed to find NFIT at startup\n");
+                return 0;
+        }
+
+        acpi_desc = acpi_nfit_desc_init(adev);
+        if (IS_ERR(acpi_desc)) {
+                dev_err(dev, "%s: error initializing acpi_desc: %ld\n",
+                                __func__, PTR_ERR(acpi_desc));
+                return PTR_ERR(acpi_desc);
+        }
+
+        acpi_desc->nfit = (struct acpi_table_nfit *) tbl;
+
+        /* Evaluate _FIT and override with that if present */
+        status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
+        if (ACPI_SUCCESS(status) && buf.length > 0) {
+                acpi_desc->nfit = (struct acpi_table_nfit *)buf.pointer;
+                sz = buf.length;
+        }
 
         rc = acpi_nfit_init(acpi_desc, sz);
         if (rc) {
@@ -1636,6 +1773,54 @@ static int acpi_nfit_remove(struct acpi_device *adev)
         return 0;
 }
 
+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 };
+        struct acpi_table_nfit *nfit_saved;
+        struct device *dev = &adev->dev;
+        acpi_status status;
+        int ret;
+
+        dev_dbg(dev, "%s: event: %d\n", __func__, event);
+
+        device_lock(dev);
+        if (!dev->driver) {
+                /* dev->driver may be null if we're being removed */
+                dev_dbg(dev, "%s: no driver found for dev\n", __func__);
+                return;
+        }
+
+        if (!acpi_desc) {
+                acpi_desc = acpi_nfit_desc_init(adev);
+                if (IS_ERR(acpi_desc)) {
+                        dev_err(dev, "%s: error initializing acpi_desc: %ld\n",
+                                __func__, PTR_ERR(acpi_desc));
+                        goto out_unlock;
+                }
+        }
+
+        /* Evaluate _FIT */
+        status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
+        if (ACPI_FAILURE(status)) {
+                dev_err(dev, "failed to evaluate _FIT\n");
+                goto out_unlock;
+        }
+
+        nfit_saved = acpi_desc->nfit;
+        acpi_desc->nfit = (struct acpi_table_nfit *)buf.pointer;
+        ret = acpi_nfit_init(acpi_desc, buf.length);
+        if (!ret) {
+                /* Merge failed, restore old nfit, and exit */
+                acpi_desc->nfit = nfit_saved;
+                dev_err(dev, "failed to merge updated NFIT\n");
+        }
+        kfree(buf.pointer);
+
+ out_unlock:
+        device_unlock(dev);
+}
+
 static const struct acpi_device_id acpi_nfit_ids[] = {
         { "ACPI0012", 0 },
         { "", 0 },
@@ -1648,6 +1833,7 @@ static struct acpi_driver acpi_nfit_driver = {
         .ops = {
                 .add = acpi_nfit_add,
                 .remove = acpi_nfit_remove,
+                .notify = acpi_nfit_notify,
         },
 };