nvdimm: Read NVDIMM namespace labels

When attaching to NVDIMM devices, read and verify the namespace
labels from the special namespace label storage area. A later
change will expose NVDIMM namespaces derived from this label data.

Submitted by:	D Scott Phillips <d.scott.phillips@intel.com>
Discussed with:	kib
MFC after:	1 week
Sponsored by:	Intel Corporation
Differential Revision:	https://reviews.freebsd.org/D18735

sys/dev/nvdimm/nvdimm.c

@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/bio.h>
+#include <sys/bitstring.h>
 #include <sys/bus.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
@@ -51,10 +52,240 @@ __FBSDID("$FreeBSD$");
 #define _COMPONENT	ACPI_OEM
 ACPI_MODULE_NAME("NVDIMM")
 
+static struct uuid intel_nvdimm_dsm_uuid =
+    {0x4309AC30,0x0D11,0x11E4,0x91,0x91,{0x08,0x00,0x20,0x0C,0x9A,0x66}};
+#define INTEL_NVDIMM_DSM_REV 1
+#define INTEL_NVDIMM_DSM_GET_LABEL_SIZE 4
+#define INTEL_NVDIMM_DSM_GET_LABEL_DATA 5
+
 static devclass_t nvdimm_devclass;
 static devclass_t nvdimm_root_devclass;
 MALLOC_DEFINE(M_NVDIMM, "nvdimm", "NVDIMM driver memory");
 
+static int
+read_label_area_size(struct nvdimm_dev *nv)
+{
+	ACPI_OBJECT *result_buffer;
+	ACPI_HANDLE handle;
+	ACPI_STATUS status;
+	ACPI_BUFFER result;
+	uint32_t *out;
+	int error;
+
+	handle = nvdimm_root_get_acpi_handle(nv->nv_dev);
+	if (handle == NULL)
+		return (ENODEV);
+	result.Length = ACPI_ALLOCATE_BUFFER;
+	result.Pointer = NULL;
+	status = acpi_EvaluateDSM(handle, (uint8_t *)&intel_nvdimm_dsm_uuid,
+	    INTEL_NVDIMM_DSM_REV, INTEL_NVDIMM_DSM_GET_LABEL_SIZE, NULL,
+	    &result);
+	error = ENXIO;
+	if (ACPI_SUCCESS(status) && result.Pointer != NULL &&
+	    result.Length >= sizeof(ACPI_OBJECT)) {
+		result_buffer = result.Pointer;
+		if (result_buffer->Type == ACPI_TYPE_BUFFER &&
+		    result_buffer->Buffer.Length >= 12) {
+			out = (uint32_t *)result_buffer->Buffer.Pointer;
+			nv->label_area_size = out[1];
+			nv->max_label_xfer = out[2];
+			error = 0;
+		}
+	}
+	if (result.Pointer != NULL)
+		AcpiOsFree(result.Pointer);
+	return (error);
+}
+
+static int
+read_label_area(struct nvdimm_dev *nv, uint8_t *dest, off_t offset,
+    off_t length)
+{
+	ACPI_BUFFER result;
+	ACPI_HANDLE handle;
+	ACPI_OBJECT params_pkg, params_buf, *result_buf;
+	ACPI_STATUS status;
+	uint32_t params[2];
+	off_t to_read;
+	int error;
+
+	error = 0;
+	handle = nvdimm_root_get_acpi_handle(nv->nv_dev);
+	if (offset < 0 || length <= 0 ||
+	    offset + length > nv->label_area_size ||
+	    handle == NULL)
+		return (ENODEV);
+	params_pkg.Type = ACPI_TYPE_PACKAGE;
+	params_pkg.Package.Count = 1;
+	params_pkg.Package.Elements = &params_buf;
+	params_buf.Type = ACPI_TYPE_BUFFER;
+	params_buf.Buffer.Length = sizeof(params);
+	params_buf.Buffer.Pointer = (UINT8 *)params;
+	while (length > 0) {
+		to_read = MIN(length, nv->max_label_xfer);
+		params[0] = offset;
+		params[1] = to_read;
+		result.Length = ACPI_ALLOCATE_BUFFER;
+		result.Pointer = NULL;
+		status = acpi_EvaluateDSM(handle,
+		    (uint8_t *)&intel_nvdimm_dsm_uuid, INTEL_NVDIMM_DSM_REV,
+		    INTEL_NVDIMM_DSM_GET_LABEL_DATA, &params_pkg, &result);
+		if (ACPI_FAILURE(status) ||
+		    result.Length < sizeof(ACPI_OBJECT) ||
+		    result.Pointer == NULL) {
+			error = ENXIO;
+			break;
+		}
+		result_buf = (ACPI_OBJECT *)result.Pointer;
+		if (result_buf->Type != ACPI_TYPE_BUFFER ||
+		    result_buf->Buffer.Pointer == NULL ||
+		    result_buf->Buffer.Length != 4 + to_read ||
+		    ((uint16_t *)result_buf->Buffer.Pointer)[0] != 0) {
+			error = ENXIO;
+			break;
+		}
+		bcopy(result_buf->Buffer.Pointer + 4, dest, to_read);
+		dest += to_read;
+		offset += to_read;
+		length -= to_read;
+		if (result.Pointer != NULL) {
+			AcpiOsFree(result.Pointer);
+			result.Pointer = NULL;
+		}
+	}
+	if (result.Pointer != NULL)
+		AcpiOsFree(result.Pointer);
+	return (error);
+}
+
+static uint64_t
+fletcher64(const void *data, size_t length)
+{
+	size_t i;
+	uint32_t a, b;
+	const uint32_t *d;
+
+	a = 0;
+	b = 0;
+	d = (const uint32_t *)data;
+	length = length / sizeof(uint32_t);
+	for (i = 0; i < length; i++) {
+		a += d[i];
+		b += a;
+	}
+	return ((uint64_t)b << 32 | a);
+}
+
+static bool
+label_index_is_valid(struct nvdimm_label_index *index, uint32_t max_labels,
+    size_t size, size_t offset)
+{
+	uint64_t checksum;
+
+	index = (struct nvdimm_label_index *)((uint8_t *)index + offset);
+	if (strcmp(index->signature, NVDIMM_INDEX_BLOCK_SIGNATURE) != 0)
+		return false;
+	checksum = index->checksum;
+	index->checksum = 0;
+	if (checksum != fletcher64(index, size) ||
+	    index->this_offset != size * offset || index->this_size != size ||
+	    index->other_offset != size * (offset == 0 ? 1 : 0) ||
+	    index->seq == 0 || index->seq > 3 || index->slot_cnt > max_labels ||
+	    index->label_size != 1)
+		return false;
+	return true;
+}
+
+static int
+read_label(struct nvdimm_dev *nv, int num)
+{
+	struct nvdimm_label_entry *entry, *i, *next;
+	uint64_t checksum;
+	off_t offset;
+	int error;
+
+	offset = nv->label_index->label_offset +
+	    num * (128 << nv->label_index->label_size);
+	entry = malloc(sizeof(*entry), M_NVDIMM, M_WAITOK);
+	error = read_label_area(nv, (uint8_t *)&entry->label, offset,
+	    sizeof(struct nvdimm_label));
+	if (error != 0) {
+		free(entry, M_NVDIMM);
+		return (error);
+	}
+	checksum = entry->label.checksum;
+	entry->label.checksum = 0;
+	if (checksum != fletcher64(&entry->label, sizeof(entry->label)) ||
+	    entry->label.slot != num) {
+		free(entry, M_NVDIMM);
+		return (ENXIO);
+	}
+
+	/* Insertion ordered by dimm_phys_addr */
+	if (SLIST_EMPTY(&nv->labels) ||
+	    entry->label.dimm_phys_addr <=
+	    SLIST_FIRST(&nv->labels)->label.dimm_phys_addr) {
+		SLIST_INSERT_HEAD(&nv->labels, entry, link);
+		return (0);
+	}
+	SLIST_FOREACH_SAFE(i, &nv->labels, link, next) {
+		if (next == NULL ||
+		    entry->label.dimm_phys_addr <= next->label.dimm_phys_addr) {
+			SLIST_INSERT_AFTER(i, entry, link);
+			return (0);
+		}
+	}
+	__unreachable();
+}
+
+static int
+read_labels(struct nvdimm_dev *nv)
+{
+	struct nvdimm_label_index *indices;
+	size_t bitfield_size, index_size, num_labels;
+	int error, n;
+	bool index_0_valid, index_1_valid;
+
+	for (index_size = 256; ; index_size += 256) {
+		num_labels = 8 * (index_size -
+		    sizeof(struct nvdimm_label_index));
+		if (index_size + num_labels * sizeof(struct nvdimm_label) >=
+		    nv->label_area_size)
+			break;
+	}
+	num_labels = (nv->label_area_size - index_size) /
+	    sizeof(struct nvdimm_label);
+	bitfield_size = roundup2(num_labels, 8) / 8;
+	indices = malloc(2 * index_size, M_NVDIMM, M_WAITOK);
+	error = read_label_area(nv, (void *)indices, 0, 2 * index_size);
+	if (error != 0) {
+		free(indices, M_NVDIMM);
+		return (error);
+	}
+	index_0_valid = label_index_is_valid(indices, num_labels, index_size,
+	    0);
+	index_1_valid = label_index_is_valid(indices, num_labels, index_size,
+	    1);
+	if (!index_0_valid && !index_1_valid) {
+		free(indices, M_NVDIMM);
+		return (ENXIO);
+	}
+	if (index_0_valid && index_1_valid &&
+	    (indices[1].seq > indices[0].seq ||
+	    (indices[1].seq == 1 && indices[0].seq == 3)))
+		index_0_valid = false;
+	nv->label_index = malloc(index_size, M_NVDIMM, M_WAITOK);
+	bcopy(indices + (index_0_valid ? 0 : 1), nv->label_index, index_size);
+	free(indices, M_NVDIMM);
+	for (bit_ffc_at((bitstr_t *)nv->label_index->free, 0, num_labels, &n);
+	     n >= 0;
+	     bit_ffc_at((bitstr_t *)nv->label_index->free, n + 1, num_labels,
+	     &n)) {
+		read_label(nv, n);
+	}
+	return (0);
+}
+
 struct nvdimm_dev *
 nvdimm_find_by_handle(nfit_handle_t nv_handle)
 {
@@ -90,6 +321,7 @@ nvdimm_attach(device_t dev)
 	ACPI_TABLE_NFIT *nfitbl;
 	ACPI_HANDLE handle;
 	ACPI_STATUS status;
+	int error;
 
 	nv = device_get_softc(dev);
 	handle = nvdimm_root_get_acpi_handle(dev);
@@ -107,6 +339,14 @@ nvdimm_attach(device_t dev)
 	acpi_nfit_get_flush_addrs(nfitbl, nv->nv_handle, &nv->nv_flush_addr,
 	    &nv->nv_flush_addr_cnt);
 	AcpiPutTable(&nfitbl->Header);
+	error = read_label_area_size(nv);
+	if (error == 0) {
+		/*
+		 * Ignoring errors reading labels. Not all NVDIMMs
+		 * support labels and namespaces.
+		 */
+		read_labels(nv);
+	}
 	return (0);
 }
 
@@ -114,9 +354,15 @@ static int
 nvdimm_detach(device_t dev)
 {
 	struct nvdimm_dev *nv;
+	struct nvdimm_label_entry *label, *next;
 
 	nv = device_get_softc(dev);
 	free(nv->nv_flush_addr, M_NVDIMM);
+	free(nv->label_index, M_NVDIMM);
+	SLIST_FOREACH_SAFE(label, &nv->labels, link, next) {
+		SLIST_REMOVE_HEAD(&nv->labels, link);
+		free(label, M_NVDIMM);
+	}
 	return (0);
 }
 

sys/dev/nvdimm/nvdimm_var.h

@@ -33,6 +33,51 @@
 #ifndef __DEV_NVDIMM_VAR_H__
 #define	__DEV_NVDIMM_VAR_H__
 
+#define NVDIMM_INDEX_BLOCK_SIGNATURE "NAMESPACE_INDEX"
+
+struct nvdimm_label_index {
+	char		signature[16];
+	uint8_t		flags[3];
+	uint8_t		label_size;
+	uint32_t	seq;
+	uint64_t	this_offset;
+	uint64_t	this_size;
+	uint64_t	other_offset;
+	uint64_t	label_offset;
+	uint32_t	slot_cnt;
+	uint16_t	rev_major;
+	uint16_t	rev_minor;
+	uint64_t	checksum;
+	uint8_t		free[0];
+};
+
+struct nvdimm_label {
+	struct uuid	uuid;
+	char		name[64];
+	uint32_t	flags;
+	uint16_t	nlabel;
+	uint16_t	position;
+	uint64_t	set_cookie;
+	uint64_t	lba_size;
+	uint64_t	dimm_phys_addr;
+	uint64_t	raw_size;
+	uint32_t	slot;
+	uint8_t		alignment;
+	uint8_t		reserved[3];
+	struct uuid	type_guid;
+	struct uuid	address_abstraction_guid;
+	uint8_t		reserved1[88];
+	uint64_t	checksum;
+};
+
+struct nvdimm_label_entry {
+	SLIST_ENTRY(nvdimm_label_entry) link;
+	struct nvdimm_label	label;
+};
+
+_Static_assert(sizeof(struct nvdimm_label_index) == 72, "Incorrect layout");
+_Static_assert(sizeof(struct nvdimm_label) == 256, "Incorrect layout");
+
 typedef uint32_t nfit_handle_t;
 
 enum nvdimm_root_ivar {
@@ -53,6 +98,10 @@ struct nvdimm_dev {
 	nfit_handle_t	nv_handle;
 	uint64_t	**nv_flush_addr;
 	int		nv_flush_addr_cnt;
+	uint32_t	label_area_size;
+	uint32_t	max_label_xfer;
+	struct nvdimm_label_index *label_index;
+	SLIST_HEAD(, nvdimm_label_entry) labels;
 };
 
 enum SPA_mapping_type {