[PATCH 3/3] acpi: nfit: Add support for hotplug

[Vishal Verma <vishal.l.verma@intel.com>]

Add a .notify callback to the acpi_nfit_driver that gets called on a
hotplug event. From this, evaluate the _FIT ACPI method which returns
the updated NFIT with handles for the hot-plugged NVDIMM.

Iterate over the new NFIT, and add any new tables found, and
register/enable the corresponding regions.

In the nfit test framework, after normal initialization, update the NFIT
with a new hot-plugged NVDIMM, and directly call into the driver to
update its view of the available regions.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: <linux-acpi@vger.kernel.org>
Cc: <linux-nvdimm@lists.01.org>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 drivers/acpi/nfit.c              | 136 ++++++++++++++++++++++++++++++++----
 drivers/acpi/nfit.h              |   2 +
 tools/testing/nvdimm/test/nfit.c | 144 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 267 insertions(+), 15 deletions(-)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index ed599d1..2c24466 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -224,9 +224,13 @@ static bool add_spa(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->spas, list)
+		if (memcmp(nfit_spa->spa, spa, sizeof(*spa)) == 0)
+			return true;
 
+	nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa), GFP_KERNEL);
 	if (!nfit_spa)
 		return false;
 	INIT_LIST_HEAD(&nfit_spa->list);
@@ -242,9 +246,13 @@ static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->memdevs, list)
+		if (memcmp(nfit_memdev->memdev, memdev, sizeof(*memdev)) == 0)
+			return true;
 
+	nfit_memdev = devm_kzalloc(dev, sizeof(*nfit_memdev), GFP_KERNEL);
 	if (!nfit_memdev)
 		return false;
 	INIT_LIST_HEAD(&nfit_memdev->list);
@@ -260,9 +268,13 @@ static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->dcrs, list)
+		if (memcmp(nfit_dcr->dcr, dcr, sizeof(*dcr)) == 0)
+			return true;
+
+	nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr), GFP_KERNEL);
 	if (!nfit_dcr)
 		return false;
 	INIT_LIST_HEAD(&nfit_dcr->list);
@@ -277,9 +289,13 @@ static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->bdws, list)
+		if (memcmp(nfit_bdw->bdw, bdw, sizeof(*bdw)) == 0)
+			return true;
+
+	nfit_bdw = devm_kzalloc(dev, sizeof(*nfit_bdw), GFP_KERNEL);
 	if (!nfit_bdw)
 		return false;
 	INIT_LIST_HEAD(&nfit_bdw->list);
@@ -294,9 +310,13 @@ static bool add_idt(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->idts, list)
+		if (memcmp(nfit_idt->idt, idt, sizeof(*idt)) == 0)
+			return true;
+
+	nfit_idt = devm_kzalloc(dev, sizeof(*nfit_idt), GFP_KERNEL);
 	if (!nfit_idt)
 		return false;
 	INIT_LIST_HEAD(&nfit_idt->list);
@@ -311,9 +331,13 @@ static bool add_flush(struct acpi_nfit_desc *acpi_desc,
 		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, &acpi_desc->flushes, list)
+		if (memcmp(nfit_flush->flush, flush, sizeof(*flush)) == 0)
+			return true;
+
+	nfit_flush = devm_kzalloc(dev, sizeof(*nfit_flush), GFP_KERNEL);
 	if (!nfit_flush)
 		return false;
 	INIT_LIST_HEAD(&nfit_flush->list);
@@ -811,6 +835,8 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 			 */
 			dev_err(acpi_desc->dev, "duplicate DCR detected: %s\n",
 					nvdimm_name(nvdimm));
+			/* TODO Do we need the warning? */
+			dimm_count++;
 			continue;
 		}
 
@@ -1532,6 +1558,8 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 		if (!nvdimm_volatile_region_create(nvdimm_bus, ndr_desc))
 			return -ENOMEM;
 	}
+
+	acpi_desc->last_init_spa = nfit_spa;
 	return 0;
 }
 
@@ -1539,7 +1567,15 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
 {
 	struct nfit_spa *nfit_spa;
 
-	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
+	if (acpi_desc->last_init_spa) {
+		nfit_spa = acpi_desc->last_init_spa;
+		nfit_spa = list_next_entry(nfit_spa, list);
+
+	} else
+		nfit_spa = list_first_entry(&acpi_desc->spas,
+				typeof(*nfit_spa), list);
+
+	list_for_each_entry_from(nfit_spa, &acpi_desc->spas, list) {
 		int rc = acpi_nfit_register_region(acpi_desc, nfit_spa);
 
 		if (rc)
@@ -1590,6 +1626,52 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
 }
 EXPORT_SYMBOL_GPL(acpi_nfit_init);
 
+int acpi_nfit_merge(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
+{
+	struct device *dev = acpi_desc->dev;
+	const void *end;
+	u8 *data;
+	int rc;
+
+	/*
+	 * TODO Can we get here with an uninitialized acpi_desc?
+	 * In the case where the only nvdimm in the system is hotplugged?
+	 */
+	if (!acpi_desc) {
+		dev_err(dev, "%s: acpi_desc uninitialized\n", __func__);
+		return -ENXIO;
+	}
+
+	/*
+	 * At this point, acpi_desc->nfit will have the updated nfit table,
+	 * but the various lists in acpi_dev correspond to the old table.
+	 */
+	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);
+
+	if (IS_ERR(data)) {
+		dev_dbg(dev, "%s: nfit table parsing error: %ld\n", __func__,
+				PTR_ERR(data));
+		return PTR_ERR(data);
+	}
+
+	if (nfit_mem_init(acpi_desc) != 0)
+		return -ENOMEM;
+
+	acpi_nfit_init_dsms(acpi_desc);
+
+	rc = acpi_nfit_register_dimms(acpi_desc);
+	if (rc)
+		return rc;
+
+	rc = acpi_nfit_register_regions(acpi_desc);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(acpi_nfit_merge);
+
 static int acpi_nfit_add(struct acpi_device *adev)
 {
 	struct nvdimm_bus_descriptor *nd_desc;
@@ -1639,6 +1721,33 @@ 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_table_nfit *nfit_saved;
+	struct device *dev = &adev->dev;
+	struct acpi_buffer *buf;
+	acpi_status status;
+	int ret;
+
+	dev_dbg(dev, "%s: event: %d\n", __func__, event);
+
+	/* Evaluate _FIT */
+	status = acpi_evaluate_fit(adev->handle, &buf);
+	if (ACPI_FAILURE(status))
+		dev_err(dev, "failed to evaluate _FIT\n");
+
+	nfit_saved = acpi_desc->nfit;
+	acpi_desc->nfit = (struct acpi_table_nfit *)buf;
+	ret = acpi_nfit_merge(acpi_desc, buf->length);
+	if (!ret) {
+		/* Merge failed, restore old nfit buf, and exit */
+		acpi_desc->nfit = nfit_saved;
+		dev_err(dev, "failed to merge updated NFIT\n");
+	}
+	kfree(buf->pointer);
+}
+
 static const struct acpi_device_id acpi_nfit_ids[] = {
 	{ "ACPI0012", 0 },
 	{ "", 0 },
@@ -1651,6 +1760,7 @@ static struct acpi_driver acpi_nfit_driver = {
 	.ops = {
 		.add = acpi_nfit_add,
 		.remove = acpi_nfit_remove,
+		.notify = acpi_nfit_notify,
 	},
 };
 
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index 7e74015..9f4758f 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -105,6 +105,7 @@ struct acpi_nfit_desc {
 	struct list_head dcrs;
 	struct list_head bdws;
 	struct list_head idts;
+	struct nfit_spa *last_init_spa;
 	struct nvdimm_bus *nvdimm_bus;
 	struct device *dev;
 	unsigned long dimm_dsm_force_en;
@@ -179,5 +180,6 @@ static inline struct acpi_nfit_desc *to_acpi_desc(
 
 const u8 *to_nfit_uuid(enum nfit_uuids id);
 int acpi_nfit_init(struct acpi_nfit_desc *nfit, acpi_size sz);
+int acpi_nfit_merge(struct acpi_nfit_desc *acpi_desc, acpi_size sz);
 extern const struct attribute_group *acpi_nfit_attribute_groups[];
 #endif /* __NFIT_H__ */
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index 021e6f9..3a7b691 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -44,6 +44,15 @@
  * +------+  |                 blk5.0             |  pm1.0  |    3      region5
  *           +-------------------------+----------+-+-------+
  *
+ * +--+---+
+ * | cpu1 |
+ * +--+---+                   (Hotplug DIMM)
+ *    |      +----------------------------------------------+
+ * +--+---+  |                 blk6.0/pm7.0                 |    4      region6
+ * | imc0 +--+----------------------------------------------+
+ * +------+
+ *
+ *
  * *) In this layout we have four dimms and two memory controllers in one
  *    socket.  Each unique interface (BLK or PMEM) to DPA space
  *    is identified by a region device with a dynamically assigned id.
@@ -85,8 +94,8 @@
  *    reference an NVDIMM.
  */
 enum {
-	NUM_PM  = 2,
-	NUM_DCR = 4,
+	NUM_PM  = 3,
+	NUM_DCR = 5,
 	NUM_BDW = NUM_DCR,
 	NUM_SPA = NUM_PM + NUM_DCR + NUM_BDW,
 	NUM_MEM = NUM_DCR + NUM_BDW + 2 /* spa0 iset */ + 4 /* spa1 iset */,
@@ -115,6 +124,7 @@ static u32 handle[NUM_DCR] = {
 	[1] = NFIT_DIMM_HANDLE(0, 0, 0, 0, 1),
 	[2] = NFIT_DIMM_HANDLE(0, 0, 1, 0, 0),
 	[3] = NFIT_DIMM_HANDLE(0, 0, 1, 0, 1),
+	[4] = NFIT_DIMM_HANDLE(0, 1, 0, 0, 0),
 };
 
 struct nfit_test {
@@ -138,6 +148,7 @@ struct nfit_test {
 	dma_addr_t *dcr_dma;
 	int (*alloc)(struct nfit_test *t);
 	void (*setup)(struct nfit_test *t);
+	int setup_hotplug;
 };
 
 static struct nfit_test *to_nfit_test(struct device *dev)
@@ -428,6 +439,10 @@ static int nfit_test0_alloc(struct nfit_test *t)
 	if (!t->spa_set[1])
 		return -ENOMEM;
 
+	t->spa_set[2] = test_alloc_coherent(t, SPA0_SIZE, &t->spa_set_dma[2]);
+	if (!t->spa_set[2])
+		return -ENOMEM;
+
 	for (i = 0; i < NUM_DCR; i++) {
 		t->dimm[i] = test_alloc(t, DIMM_SIZE, &t->dimm_dma[i]);
 		if (!t->dimm[i])
@@ -950,6 +965,119 @@ static void nfit_test0_setup(struct nfit_test *t)
 	flush->hint_count = 1;
 	flush->hint_address[0] = t->flush_dma[3];
 
+
+	if (t->setup_hotplug) {
+		offset = offset + sizeof(struct acpi_nfit_flush_address) * 4;
+		/* dcr-descriptor4 */
+		dcr = nfit_buf + offset;
+		dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+		dcr->header.length = sizeof(struct acpi_nfit_control_region);
+		dcr->region_index = 4+1;
+		dcr->vendor_id = 0xabcd;
+		dcr->device_id = 0;
+		dcr->revision_id = 1;
+		dcr->serial_number = ~handle[4];
+		dcr->windows = 0;
+		dcr->window_size = 0;
+		dcr->command_offset = 0;
+		dcr->command_size = 0;
+		dcr->status_offset = 0;
+		dcr->status_size = 0;
+
+		offset = offset + sizeof(struct acpi_nfit_control_region);
+		/* bdw4 (spa/dcr4, dimm4) */
+		bdw = nfit_buf + offset;
+		bdw->header.type = ACPI_NFIT_TYPE_DATA_REGION;
+		bdw->header.length = sizeof(struct acpi_nfit_data_region);
+		bdw->region_index = 4+1;
+		bdw->windows = 1;
+		bdw->offset = 0;
+		bdw->size = BDW_SIZE;
+		bdw->capacity = DIMM_SIZE;
+		bdw->start_address = 0;
+
+		offset = offset + sizeof(struct acpi_nfit_data_region);
+		/* spa10 (dcr4) dimm4 */
+		spa = nfit_buf + offset;
+		spa->header.type = ACPI_NFIT_TYPE_SYSTEM_ADDRESS;
+		spa->header.length = sizeof(*spa);
+		memcpy(spa->range_guid, to_nfit_uuid(NFIT_SPA_DCR), 16);
+		spa->range_index = 10+1;
+		spa->address = t->dcr_dma[4];
+		spa->length = DCR_SIZE;
+
+		/*
+		 * spa11 (single-dimm interleave for hotplug, note storage
+		 * does not actually alias the related block-data-window
+		 * regions)
+		 */
+		spa = nfit_buf + offset + sizeof(*spa);
+		spa->header.type = ACPI_NFIT_TYPE_SYSTEM_ADDRESS;
+		spa->header.length = sizeof(*spa);
+		memcpy(spa->range_guid, to_nfit_uuid(NFIT_SPA_PM), 16);
+		spa->range_index = 11+1;
+		spa->address = t->spa_set_dma[2];
+		spa->length = SPA0_SIZE;
+
+		/* spa12 (bdw for dcr4) dimm4 */
+		spa = nfit_buf + offset + sizeof(*spa) * 2;
+		spa->header.type = ACPI_NFIT_TYPE_SYSTEM_ADDRESS;
+		spa->header.length = sizeof(*spa);
+		memcpy(spa->range_guid, to_nfit_uuid(NFIT_SPA_BDW), 16);
+		spa->range_index = 12+1;
+		spa->address = t->dimm_dma[4];
+		spa->length = DIMM_SIZE;
+
+		offset = offset + sizeof(*spa) * 3;
+		/* mem-region14 (spa/dcr4, dimm4) */
+		memdev = nfit_buf + offset;
+		memdev->header.type = ACPI_NFIT_TYPE_MEMORY_MAP;
+		memdev->header.length = sizeof(*memdev);
+		memdev->device_handle = handle[4];
+		memdev->physical_id = 4;
+		memdev->region_id = 0;
+		memdev->range_index = 10+1;
+		memdev->region_index = 4+1;
+		memdev->region_size = 0;
+		memdev->region_offset = 0;
+		memdev->address = 0;
+		memdev->interleave_index = 0;
+		memdev->interleave_ways = 1;
+
+		/* mem-region15 (spa0, dimm4) */
+		memdev = nfit_buf + offset +
+				sizeof(struct acpi_nfit_memory_map);
+		memdev->header.type = ACPI_NFIT_TYPE_MEMORY_MAP;
+		memdev->header.length = sizeof(*memdev);
+		memdev->device_handle = handle[4];
+		memdev->physical_id = 4;
+		memdev->region_id = 0;
+		memdev->range_index = 11+1;
+		memdev->region_index = 4+1;
+		memdev->region_size = SPA0_SIZE;
+		memdev->region_offset = t->spa_set_dma[2];
+		memdev->address = 0;
+		memdev->interleave_index = 0;
+		memdev->interleave_ways = 1;
+
+		/* mem-region16 (spa/dcr4, dimm4) */
+		memdev = nfit_buf + offset +
+				sizeof(struct acpi_nfit_memory_map) * 2;
+		memdev->header.type = ACPI_NFIT_TYPE_MEMORY_MAP;
+		memdev->header.length = sizeof(*memdev);
+		memdev->device_handle = handle[4];
+		memdev->physical_id = 4;
+		memdev->region_id = 0;
+		memdev->range_index = 12+1;
+		memdev->region_index = 4+1;
+		memdev->region_size = 0;
+		memdev->region_offset = 0;
+		memdev->address = 0;
+		memdev->interleave_index = 0;
+		memdev->interleave_ways = 1;
+
+	}
+
 	acpi_desc = &t->acpi_desc;
 	set_bit(ND_CMD_GET_CONFIG_SIZE, &acpi_desc->dimm_dsm_force_en);
 	set_bit(ND_CMD_GET_CONFIG_DATA, &acpi_desc->dimm_dsm_force_en);
@@ -1114,6 +1242,18 @@ static int nfit_test_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	if (nfit_test->setup != nfit_test0_setup)
+		return 0;
+
+	nfit_test->setup_hotplug = 1;
+	nfit_test->setup(nfit_test);
+
+	rc = acpi_nfit_merge(acpi_desc, nfit_test->nfit_size);
+	if (rc) {
+		nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
+		return rc;
+	}
+
 	return 0;
 }
 
-- 
2.4.3