[PATCH 0/3] acpi, nfit: nvdimm notification support + tests

[PATCH 0/3] acpi, nfit: nvdimm notification support + tests

[Dan Williams]

ACPI 6.1 added an "NFIT Health Event Notification" for nvdimm devices.
When this fires, system software is expected to issue a DSM to retrieve
the latest health values.  For the NFIT driver this notification
arrives as an event on the sysfs 'flags' attribute for an nfit/nvdimm
device.  The 'flags' attribute reflects the "NVDIMM State Flags" of the
"5.2.25.3 NVDIMM Region Mapping Structure", and when read indicates if
the platform supports sending health events.

---

Dan Williams (3):
      tools/testing/nvdimm: unit test for acpi_nfit_notify()
      acpi, nfit: add dimm device notification support
      tools/testing/nvdimm: unit test for acpi_nvdimm_notify()


 drivers/acpi/nfit/core.c          |  112 ++++++++++++++++++++++++++++++++-----
 drivers/acpi/nfit/nfit.h          |    7 ++
 drivers/nvdimm/dimm_devs.c        |    6 ++
 include/linux/libnvdimm.h         |    1 
 tools/testing/nvdimm/Kbuild       |    1 
 tools/testing/nvdimm/test/iomap.c |   17 ++++++
 tools/testing/nvdimm/test/nfit.c  |   64 +++++++++++++++++++--
 7 files changed, 188 insertions(+), 20 deletions(-)

[PATCH 1/3] tools/testing/nvdimm: unit test for acpi_nfit_notify()

[Dan Williams]

We have had a couple bugs in this implementation in the past and before
we add another ->notify() implementation for nvdimm devices, lets allow
this routine to be exercised via nfit_test.

Rewrite acpi_nfit_notify() in terms of a generic struct device and
acpi_handle parameter, and then implement a mock acpi_evaluate_object()
that returns a _FIT payload.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/nfit/core.c          |   25 ++++++++++++++-----------
 drivers/acpi/nfit/nfit.h          |    1 +
 tools/testing/nvdimm/Kbuild       |    1 +
 tools/testing/nvdimm/test/iomap.c |   17 +++++++++++++++++
 tools/testing/nvdimm/test/nfit.c  |   21 +++++++++++++++------
 5 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 4a363bed89b3..8120e8218f93 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2670,11 +2670,10 @@ static int acpi_nfit_remove(struct acpi_device *adev)
 	return 0;
 }
 
-static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
+void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event)
 {
-	struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(&adev->dev);
+	struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(dev);
 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
-	struct device *dev = &adev->dev;
 	union acpi_object *obj;
 	acpi_status status;
 	int ret;
@@ -2684,18 +2683,17 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 	if (event != NFIT_NOTIFY_UPDATE)
 		return;
 
-	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__);
-		goto out_unlock;
+		return;
 	}
 
 	if (!acpi_desc) {
 		acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
 		if (!acpi_desc)
-			goto out_unlock;
-		acpi_nfit_desc_init(acpi_desc, &adev->dev);
+			return;
+		acpi_nfit_desc_init(acpi_desc, dev);
 	} else {
 		/*
 		 * Finish previous registration before considering new
@@ -2705,10 +2703,10 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 	}
 
 	/* Evaluate _FIT */
-	status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
+	status = acpi_evaluate_object(handle, "_FIT", NULL, &buf);
 	if (ACPI_FAILURE(status)) {
 		dev_err(dev, "failed to evaluate _FIT\n");
-		goto out_unlock;
+		return;
 	}
 
 	obj = buf.pointer;
@@ -2720,9 +2718,14 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 	} else
 		dev_err(dev, "Invalid _FIT\n");
 	kfree(buf.pointer);
+}
+EXPORT_SYMBOL_GPL(__acpi_nfit_notify);
 
- out_unlock:
-	device_unlock(dev);
+static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
+{
+	device_lock(&adev->dev);
+	__acpi_nfit_notify(&adev->dev, adev->handle, event);
+	device_unlock(&adev->dev);
 }
 
 static const struct acpi_device_id acpi_nfit_ids[] = {
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 51d23f130d86..52370347fb0e 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -227,5 +227,6 @@ 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 *acpi_desc, void *nfit, acpi_size sz);
+void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event);
 void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev);
 #endif /* __NFIT_H__ */
diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild
index ad6dd0543019..582db95127ed 100644
--- a/tools/testing/nvdimm/Kbuild
+++ b/tools/testing/nvdimm/Kbuild
@@ -13,6 +13,7 @@ ldflags-y += --wrap=__release_region
 ldflags-y += --wrap=devm_memremap_pages
 ldflags-y += --wrap=insert_resource
 ldflags-y += --wrap=remove_resource
+ldflags-y += --wrap=acpi_evaluate_object
 
 DRIVERS := ../../../drivers
 NVDIMM_SRC := $(DRIVERS)/nvdimm
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index c29f8dca9e67..dae5b9b6d186 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/pfn_t.h>
+#include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/mm.h>
 #include "nfit_test.h"
@@ -276,4 +277,20 @@ void __wrap___devm_release_region(struct device *dev, struct resource *parent,
 }
 EXPORT_SYMBOL(__wrap___devm_release_region);
 
+acpi_status __wrap_acpi_evaluate_object(acpi_handle handle, acpi_string path,
+		struct acpi_object_list *p, struct acpi_buffer *buf)
+{
+	struct nfit_test_resource *nfit_res = get_nfit_res((long) handle);
+	union acpi_object **obj;
+
+	if (!nfit_res || strcmp(path, "_FIT") || !buf)
+		return acpi_evaluate_object(handle, path, p, buf);
+
+	obj = nfit_res->buf;
+	buf->length = sizeof(union acpi_object);
+	buf->pointer = *obj;
+	return AE_OK;
+}
+EXPORT_SYMBOL(__wrap_acpi_evaluate_object);
+
 MODULE_LICENSE("GPL v2");
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index dd48f421844c..8d79c75d3cae 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -154,6 +154,8 @@ struct nfit_test {
 	int (*alloc)(struct nfit_test *t);
 	void (*setup)(struct nfit_test *t);
 	int setup_hotplug;
+	union acpi_object **_fit;
+	dma_addr_t _fit_dma;
 	struct ars_state {
 		struct nd_cmd_ars_status *ars_status;
 		unsigned long deadline;
@@ -615,6 +617,10 @@ static int nfit_test0_alloc(struct nfit_test *t)
 			return -ENOMEM;
 	}
 
+	t->_fit = test_alloc(t, sizeof(union acpi_object **), &t->_fit_dma);
+	if (!t->_fit)
+		return -ENOMEM;
+
 	return ars_state_init(&t->pdev.dev, &t->ars_state);
 }
 
@@ -1408,6 +1414,7 @@ static int nfit_test_probe(struct platform_device *pdev)
 	struct acpi_nfit_desc *acpi_desc;
 	struct device *dev = &pdev->dev;
 	struct nfit_test *nfit_test;
+	union acpi_object *obj;
 	int rc;
 
 	nfit_test = to_nfit_test(&pdev->dev);
@@ -1475,15 +1482,17 @@ static int nfit_test_probe(struct platform_device *pdev)
 	if (nfit_test->setup != nfit_test0_setup)
 		return 0;
 
-	flush_work(&acpi_desc->work);
 	nfit_test->setup_hotplug = 1;
 	nfit_test->setup(nfit_test);
 
-	rc = acpi_nfit_init(acpi_desc, nfit_test->nfit_buf,
-			nfit_test->nfit_size);
-	if (rc)
-		return rc;
-
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+	obj->type = ACPI_TYPE_BUFFER;
+	obj->buffer.length = nfit_test->nfit_size;
+	obj->buffer.pointer = nfit_test->nfit_buf;
+	*(nfit_test->_fit) = obj;
+	__acpi_nfit_notify(&pdev->dev, nfit_test, 0x80);
 	return 0;
 }
 

[PATCH 2/3] acpi, nfit: add dimm device notification support

[Dan Williams]

Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the ACPI0012
NVDIMM Root device, can receive health event notifications.

Given that these devices are precluded from registering a notification
handler via acpi_driver.acpi_device_ops (due to no _HID), we use
acpi_install_notify_handler() directly.  The registered handler,
acpi_nvdimm_notify(), triggers a poll(2) event on the nmemX/nfit/flags
sysfs attribute when a health event notification is received.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/nfit/core.c   |   83 ++++++++++++++++++++++++++++++++++++++++++--
 drivers/acpi/nfit/nfit.h   |    5 +++
 drivers/nvdimm/dimm_devs.c |    6 +++
 include/linux/libnvdimm.h  |    1 +
 4 files changed, 91 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 8120e8218f93..65f155db4283 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1248,6 +1248,43 @@ static struct nvdimm *acpi_nfit_dimm_by_handle(struct acpi_nfit_desc *acpi_desc,
 	return NULL;
 }
 
+static void __acpi_nvdimm_notify(struct device *dev, u32 event)
+{
+	struct nfit_mem *nfit_mem;
+	struct acpi_nfit_desc *acpi_desc;
+
+	dev_dbg(dev->parent, "%s: %s: event: %d\n", dev_name(dev), __func__,
+			event);
+
+	if (event != NFIT_NOTIFY_DIMM_HEALTH) {
+		dev_dbg(dev->parent, "%s: unknown event: %d\n", dev_name(dev),
+				event);
+		return;
+	}
+
+	acpi_desc = dev_get_drvdata(dev->parent);
+	if (!acpi_desc)
+		return;
+
+	/*
+	 * If we successfully retrieved acpi_desc, then we know nfit_mem data
+	 * is still valid.
+	 */
+	nfit_mem = dev_get_drvdata(dev);
+	if (nfit_mem && nfit_mem->flags_attr)
+		sysfs_notify_dirent(nfit_mem->flags_attr);
+}
+
+static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_device *adev = data;
+	struct device *dev = &adev->dev;
+
+	device_lock(dev->parent);
+	__acpi_nvdimm_notify(dev, event);
+	device_unlock(dev->parent);
+}
+
 static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 		struct nfit_mem *nfit_mem, u32 device_handle)
 {
@@ -1272,6 +1309,13 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 		return force_enable_dimms ? 0 : -ENODEV;
 	}
 
+	if (ACPI_FAILURE(acpi_install_notify_handler(adev_dimm->handle,
+		ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify, adev_dimm))) {
+		dev_err(dev, "%s: notification registration failed\n",
+				dev_name(&adev_dimm->dev));
+		return -ENXIO;
+	}
+
 	/*
 	 * Until standardization materializes we need to consider 4
 	 * different command sets.  Note, that checking for function0 (bit0)
@@ -1313,15 +1357,14 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 {
 	struct nfit_mem *nfit_mem;
-	int dimm_count = 0;
+	int dimm_count = 0, rc;
+	struct nvdimm *nvdimm;
 
 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
 		struct acpi_nfit_flush_address *flush;
 		unsigned long flags = 0, cmd_mask;
-		struct nvdimm *nvdimm;
 		u32 device_handle;
 		u16 mem_flags;
-		int rc;
 
 		device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
 		nvdimm = acpi_nfit_dimm_by_handle(acpi_desc, device_handle);
@@ -1374,7 +1417,28 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 
 	}
 
-	return nvdimm_bus_check_dimm_count(acpi_desc->nvdimm_bus, dimm_count);
+	rc = nvdimm_bus_check_dimm_count(acpi_desc->nvdimm_bus, dimm_count);
+	if (rc)
+		return rc;
+
+	/*
+	 * Now that dimms are successfully registered, and async registration
+	 * is flushed, attempt to enable event notification.
+	 */
+	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+		struct kernfs_node *nfit_kernfs;
+
+		nvdimm = nfit_mem->nvdimm;
+		nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
+		if (nfit_kernfs)
+			nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,
+					"flags");
+		sysfs_put(nfit_kernfs);
+		if (!nfit_mem->flags_attr)
+			dev_warn(acpi_desc->dev, "%s: notifications disabled\n",
+					nvdimm_name(nvdimm));
+	}
+	return 0;
 }
 
 static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
@@ -2400,6 +2464,7 @@ static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc)
 
 static void acpi_nfit_destruct(void *data)
 {
+	struct nfit_mem *nfit_mem;
 	struct acpi_nfit_desc *acpi_desc = data;
 	struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
 
@@ -2415,6 +2480,16 @@ static void acpi_nfit_destruct(void *data)
 	 * either submit or see ->cancel set.
 	 */
 	device_lock(bus_dev);
+	/*
+	 * Clear out the nfit_mem->flags_attr and shut down dimm event
+	 * notifications.
+	 */
+	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+		sysfs_put(nfit_mem->flags_attr);
+		nfit_mem->flags_attr = NULL;
+		acpi_remove_notify_handler(nfit_mem->adev->handle,
+				ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify);
+	}
 	device_unlock(bus_dev);
 
 	flush_workqueue(nfit_wq);
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 52370347fb0e..13195824778c 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -82,6 +82,10 @@ enum nfit_root_notifiers {
 	NFIT_NOTIFY_UPDATE = 0x80,
 };
 
+enum nfit_dimm_notifiers {
+	NFIT_NOTIFY_DIMM_HEALTH = 0x81,
+};
+
 struct nfit_spa {
 	struct list_head list;
 	struct nd_region *nd_region;
@@ -128,6 +132,7 @@ struct nfit_mem {
 	struct acpi_nfit_system_address *spa_bdw;
 	struct acpi_nfit_interleave *idt_dcr;
 	struct acpi_nfit_interleave *idt_bdw;
+	struct kernfs_node *flags_attr;
 	struct nfit_flush *nfit_flush;
 	struct list_head list;
 	struct acpi_device *adev;
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index d9bba5edd8dc..ce75cc3f41fb 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -263,6 +263,12 @@ const char *nvdimm_name(struct nvdimm *nvdimm)
 }
 EXPORT_SYMBOL_GPL(nvdimm_name);
 
+struct kobject *nvdimm_kobj(struct nvdimm *nvdimm)
+{
+	return &nvdimm->dev.kobj;
+}
+EXPORT_SYMBOL_GPL(nvdimm_kobj);
+
 unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
 {
 	return nvdimm->cmd_mask;
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index b519e137b9b7..ad18d0531b6e 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -139,6 +139,7 @@ struct nd_blk_region *to_nd_blk_region(struct device *dev);
 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);
 struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus);
 const char *nvdimm_name(struct nvdimm *nvdimm);
+struct kobject *nvdimm_kobj(struct nvdimm *nvdimm);
 unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm);
 void *nvdimm_provider_data(struct nvdimm *nvdimm);
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,

[PATCH 3/3] tools/testing/nvdimm: unit test for acpi_nvdimm_notify()

[Dan Williams]

Trigger an nmemX/nfit/flags attribute to fire an event whenever a
smart-threshold DSM is received.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/acpi/nfit/core.c         |   10 ++++++--
 drivers/acpi/nfit/nfit.h         |    1 +
 tools/testing/nvdimm/test/nfit.c |   45 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 65f155db4283..91ed148784c3 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1248,7 +1248,7 @@ static struct nvdimm *acpi_nfit_dimm_by_handle(struct acpi_nfit_desc *acpi_desc,
 	return NULL;
 }
 
-static void __acpi_nvdimm_notify(struct device *dev, u32 event)
+void __acpi_nvdimm_notify(struct device *dev, u32 event)
 {
 	struct nfit_mem *nfit_mem;
 	struct acpi_nfit_desc *acpi_desc;
@@ -1274,6 +1274,7 @@ static void __acpi_nvdimm_notify(struct device *dev, u32 event)
 	if (nfit_mem && nfit_mem->flags_attr)
 		sysfs_notify_dirent(nfit_mem->flags_attr);
 }
+EXPORT_SYMBOL_GPL(__acpi_nvdimm_notify);
 
 static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
 {
@@ -2485,10 +2486,13 @@ static void acpi_nfit_destruct(void *data)
 	 * notifications.
 	 */
 	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+		struct acpi_device *adev_dimm = nfit_mem->adev;
+
 		sysfs_put(nfit_mem->flags_attr);
 		nfit_mem->flags_attr = NULL;
-		acpi_remove_notify_handler(nfit_mem->adev->handle,
-				ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify);
+		if (adev_dimm)
+			acpi_remove_notify_handler(adev_dimm->handle,
+					ACPI_DEVICE_NOTIFY, acpi_nvdimm_notify);
 	}
 	device_unlock(bus_dev);
 
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 13195824778c..bb101170cd0b 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -233,5 +233,6 @@ 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 *acpi_desc, void *nfit, acpi_size sz);
 void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event);
+void __acpi_nvdimm_notify(struct device *dev, u32 event);
 void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev);
 #endif /* __NFIT_H__ */
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index 8d79c75d3cae..99ea68674f0a 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -161,6 +161,7 @@ struct nfit_test {
 		unsigned long deadline;
 		spinlock_t lock;
 	} ars_state;
+	struct device *dimm_dev[NUM_DCR];
 };
 
 static struct nfit_test *to_nfit_test(struct device *dev)
@@ -430,6 +431,9 @@ static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
 			break;
 		case ND_CMD_SMART_THRESHOLD:
 			rc = nfit_test_cmd_smart_threshold(buf, buf_len);
+			device_lock(&t->pdev.dev);
+			__acpi_nvdimm_notify(t->dimm_dev[i], 0x81);
+			device_unlock(&t->pdev.dev);
 			break;
 		default:
 			return -ENOTTY;
@@ -566,6 +570,18 @@ static int ars_state_init(struct device *dev, struct ars_state *ars_state)
 	return 0;
 }
 
+static void put_dimms(void *data)
+{
+	struct device **dimm_dev = data;
+	int i;
+
+	for (i = 0; i < NUM_DCR; i++)
+		if (dimm_dev[i])
+			device_unregister(dimm_dev[i]);
+}
+
+static struct class *nfit_test_dimm;
+
 static int nfit_test0_alloc(struct nfit_test *t)
 {
 	size_t nfit_size = sizeof(struct acpi_nfit_system_address) * NUM_SPA
@@ -621,6 +637,15 @@ static int nfit_test0_alloc(struct nfit_test *t)
 	if (!t->_fit)
 		return -ENOMEM;
 
+	if (devm_add_action_or_reset(&t->pdev.dev, put_dimms, t->dimm_dev))
+		return -ENOMEM;
+	for (i = 0; i < NUM_DCR; i++) {
+		t->dimm_dev[i] = device_create(nfit_test_dimm, &t->pdev.dev, 0,
+				NULL, "test_dimm%d", i);
+		if (!t->dimm_dev[i])
+			return -ENOMEM;
+	}
+
 	return ars_state_init(&t->pdev.dev, &t->ars_state);
 }
 
@@ -1414,6 +1439,7 @@ static int nfit_test_probe(struct platform_device *pdev)
 	struct acpi_nfit_desc *acpi_desc;
 	struct device *dev = &pdev->dev;
 	struct nfit_test *nfit_test;
+	struct nfit_mem *nfit_mem;
 	union acpi_object *obj;
 	int rc;
 
@@ -1493,6 +1519,20 @@ static int nfit_test_probe(struct platform_device *pdev)
 	obj->buffer.pointer = nfit_test->nfit_buf;
 	*(nfit_test->_fit) = obj;
 	__acpi_nfit_notify(&pdev->dev, nfit_test, 0x80);
+
+	/* associate dimm devices with nfit_mem data for notification testing */
+	mutex_lock(&acpi_desc->init_mutex);
+	list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+		u32 nfit_handle = __to_nfit_memdev(nfit_mem)->device_handle;
+		int i;
+
+		for (i = 0; i < NUM_DCR; i++)
+			if (nfit_handle == handle[i])
+				dev_set_drvdata(nfit_test->dimm_dev[i],
+						nfit_mem);
+	}
+	mutex_unlock(&acpi_desc->init_mutex);
+
 	return 0;
 }
 
@@ -1526,6 +1566,10 @@ static __init int nfit_test_init(void)
 {
 	int rc, i;
 
+	nfit_test_dimm = class_create(THIS_MODULE, "nfit_test_dimm");
+	if (IS_ERR(nfit_test_dimm))
+		return PTR_ERR(nfit_test_dimm);
+
 	nfit_test_setup(nfit_test_lookup);
 
 	for (i = 0; i < NUM_NFITS; i++) {
@@ -1592,6 +1636,7 @@ static __exit void nfit_test_exit(void)
 	for (i = 0; i < NUM_NFITS; i++)
 		platform_device_unregister(&instances[i]->pdev);
 	nfit_test_teardown();
+	class_destroy(nfit_test_dimm);
 }
 
 module_init(nfit_test_init);

Re: [PATCH 0/3] acpi, nfit: nvdimm notification support + tests

[Vishal Verma]

On 08/23, Dan Williams wrote:
> ACPI 6.1 added an "NFIT Health Event Notification" for nvdimm devices.
> When this fires, system software is expected to issue a DSM to retrieve
> the latest health values.  For the NFIT driver this notification
> arrives as an event on the sysfs 'flags' attribute for an nfit/nvdimm
> device.  The 'flags' attribute reflects the "NVDIMM State Flags" of the
> "5.2.25.3 NVDIMM Region Mapping Structure", and when read indicates if
> the platform supports sending health events.
> 
> ---
> 
> Dan Williams (3):
>       tools/testing/nvdimm: unit test for acpi_nfit_notify()
>       acpi, nfit: add dimm device notification support
>       tools/testing/nvdimm: unit test for acpi_nvdimm_notify()
> 
> 
>  drivers/acpi/nfit/core.c          |  112 ++++++++++++++++++++++++++++++++-----
>  drivers/acpi/nfit/nfit.h          |    7 ++
>  drivers/nvdimm/dimm_devs.c        |    6 ++
>  include/linux/libnvdimm.h         |    1 
>  tools/testing/nvdimm/Kbuild       |    1 
>  tools/testing/nvdimm/test/iomap.c |   17 ++++++
>  tools/testing/nvdimm/test/nfit.c  |   64 +++++++++++++++++++--
>  7 files changed, 188 insertions(+), 20 deletions(-)

Looks good to me. For the series,

Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>

Re: [PATCH 2/3] acpi, nfit: add dimm device notification support

[Kani, Toshimitsu]

On Tue, 2016-08-23 at 14:54 -0700, Dan Williams wrote:
> Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the
> ACPI0012 NVDIMM Root device, can receive health event notifications.
> 
> Given that these devices are precluded from registering a
> notification handler via acpi_driver.acpi_device_ops (due to no
> _HID), we use acpi_install_notify_handler() directly.  

I've confirmed that this ACPI notify handler is called properly.

> The registered handler, acpi_nvdimm_notify(), triggers a poll(2)
> event on the nmemX/nfit/flags sysfs attribute when a health event
> notification is received.

This sounds good idea, but should we document that the value of sysfs
'flags' itself does not get updated?  User space program will then need
to call its _DSM to get health status.

Thanks,
-Toshi

Re: [PATCH 2/3] acpi, nfit: add dimm device notification support

[Dan Williams]

On Fri, Aug 26, 2016 at 11:26 AM, Kani, Toshimitsu <toshi.kani@hpe.com> wrote:
> On Tue, 2016-08-23 at 14:54 -0700, Dan Williams wrote:
>> Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the
>> ACPI0012 NVDIMM Root device, can receive health event notifications.
>>
>> Given that these devices are precluded from registering a
>> notification handler via acpi_driver.acpi_device_ops (due to no
>> _HID), we use acpi_install_notify_handler() directly.
>
> I've confirmed that this ACPI notify handler is called properly.
>
>> The registered handler, acpi_nvdimm_notify(), triggers a poll(2)
>> event on the nmemX/nfit/flags sysfs attribute when a health event
>> notification is received.
>
> This sounds good idea, but should we document that the value of sysfs
> 'flags' itself does not get updated?  User space program will then need
> to call its _DSM to get health status.

Yes, this plus the new scrub attribute behavior need documentation.
I'll prepare a refresh for Documentation/nvdimm/nvdimm.txt.

The need to call a _DSM after a notification event is documented in
the ACPI spec, but you're right, we do need to connect that language
to the Linux specific mechanism.

Re: [PATCH 0/3] acpi, nfit: nvdimm notification support + tests

[Rafael J. Wysocki]

On Tue, Aug 23, 2016 at 11:54 PM, Dan Williams <dan.j.williams@intel.com> wrote:
> ACPI 6.1 added an "NFIT Health Event Notification" for nvdimm devices.
> When this fires, system software is expected to issue a DSM to retrieve
> the latest health values.  For the NFIT driver this notification
> arrives as an event on the sysfs 'flags' attribute for an nfit/nvdimm
> device.  The 'flags' attribute reflects the "NVDIMM State Flags" of the
> "5.2.25.3 NVDIMM Region Mapping Structure", and when read indicates if
> the platform supports sending health events.
>
> ---
>
> Dan Williams (3):
>       tools/testing/nvdimm: unit test for acpi_nfit_notify()
>       acpi, nfit: add dimm device notification support
>       tools/testing/nvdimm: unit test for acpi_nvdimm_notify()

ACK for the series from the ACPI core perspective.

Thanks,
Rafael

Re: [PATCH 2/3] acpi, nfit: add dimm device notification support

[Kani, Toshimitsu]

On Fri, 2016-08-26 at 11:39 -0700, Dan Williams wrote:
> On Fri, Aug 26, 2016 at 11:26 AM, Kani, Toshimitsu <toshi.kani@hpe.co
> m> wrote:
> > 
> > On Tue, 2016-08-23 at 14:54 -0700, Dan Williams wrote:
> > > 
> > > Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the
> > > ACPI0012 NVDIMM Root device, can receive health event
> > > notifications.
> > > 
> > > Given that these devices are precluded from registering a
> > > notification handler via acpi_driver.acpi_device_ops (due to no
> > > _HID), we use acpi_install_notify_handler() directly.
> > 
> > I've confirmed that this ACPI notify handler is called properly.
> > 
> > > 
> > > The registered handler, acpi_nvdimm_notify(), triggers a poll(2)
> > > event on the nmemX/nfit/flags sysfs attribute when a health event
> > > notification is received.
> > 
> > This sounds good idea, but should we document that the value of
> > sysfs 'flags' itself does not get updated?  User space program will
> > then need to call its _DSM to get health status.
> 
> Yes, this plus the new scrub attribute behavior need documentation.
> I'll prepare a refresh for Documentation/nvdimm/nvdimm.txt.
>
> The need to call a _DSM after a notification event is documented in
> the ACPI spec, but you're right, we do need to connect that language
> to the Linux specific mechanism.

Sounds great.  With that:

Reviewed-by: Toshi Kani <toshi.kani@hpe.com>

Thanks!
-Toshi

Re: [PATCH 2/3] acpi, nfit: add dimm device notification support

[Dan Williams]

On Tue, Aug 23, 2016 at 2:54 PM, Dan Williams <dan.j.williams@intel.com> wrote:
> Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the ACPI0012
> NVDIMM Root device, can receive health event notifications.
>
> Given that these devices are precluded from registering a notification
> handler via acpi_driver.acpi_device_ops (due to no _HID), we use
> acpi_install_notify_handler() directly.  The registered handler,
> acpi_nvdimm_notify(), triggers a poll(2) event on the nmemX/nfit/flags
> sysfs attribute when a health event notification is received.
>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Cc: Toshi Kani <toshi.kani@hpe.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/acpi/nfit/core.c   |   83 ++++++++++++++++++++++++++++++++++++++++++--
>  drivers/acpi/nfit/nfit.h   |    5 +++
>  drivers/nvdimm/dimm_devs.c |    6 +++
>  include/linux/libnvdimm.h  |    1 +
>  4 files changed, 91 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> index 8120e8218f93..65f155db4283 100644
> --- a/drivers/acpi/nfit/core.c
> +++ b/drivers/acpi/nfit/core.c
[..]
> @@ -2400,6 +2464,7 @@ static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc)
>
>  static void acpi_nfit_destruct(void *data)
>  {
> +       struct nfit_mem *nfit_mem;
>         struct acpi_nfit_desc *acpi_desc = data;
>         struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);
>
> @@ -2415,6 +2480,16 @@ static void acpi_nfit_destruct(void *data)
>          * either submit or see ->cancel set.
>          */
>         device_lock(bus_dev);
> +       /*
> +        * Clear out the nfit_mem->flags_attr and shut down dimm event
> +        * notifications.
> +        */
> +       list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
> +               sysfs_put(nfit_mem->flags_attr);
> +               nfit_mem->flags_attr = NULL;

We need to check if flags_attr is NULL here in the case when the DIMM
failed to initialize.  I believe the crash I am hitting is fixed by
Toshi's patch https://patchwork.kernel.org/patch/9284427/, but I'll
still fix this up for other cases.