acpi, nfit: add support for the _LSI, _LSR, and _LSW label methods

ACPI 6.2 adds support for named methods to access the label storage area
of an NVDIMM. We prefer these new methods if available and otherwise
fallback to the NVDIMM_FAMILY_INTEL _DSMs. The kernel ioctls,
ND_IOCTL_{GET,SET}_CONFIG_{SIZE,DATA}, remain generic and the driver
translates the 'package' payloads into the NVDIMM_FAMILY_INTEL 'buffer'
format to maintain compatibility with existing userspace and keep the
output buffer parsing code in the driver common.

The output payloads are mostly compatible save for the 'label area
locked' status that moves from the 'config_size' (_LSI) command to the
'config_read' (_LSR) command status.

Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 212 insertions, 4 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 3369bb8fd9ba..ebe0857ac346 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -183,13 +183,33 @@ static int xlat_bus_status(void *buf, unsigned int cmd, u32 status)
 	return 0;
 }
 
-static int xlat_nvdimm_status(void *buf, unsigned int cmd, u32 status)
+#define ACPI_LABELS_LOCKED 3
+
+static int xlat_nvdimm_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd,
+		u32 status)
 {
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+
 	switch (cmd) {
 	case ND_CMD_GET_CONFIG_SIZE:
+		/*
+		 * In the _LSI, _LSR, _LSW case the locked status is
+		 * communicated via the read/write commands
+		 */
+		if (nfit_mem->has_lsi)
+			break;
+
 		if (status >> 16 & ND_CONFIG_LOCKED)
 			return -EACCES;
 		break;
+	case ND_CMD_GET_CONFIG_DATA:
+		if (nfit_mem->has_lsr && status == ACPI_LABELS_LOCKED)
+			return -EACCES;
+		break;
+	case ND_CMD_SET_CONFIG_DATA:
+		if (nfit_mem->has_lsw && status == ACPI_LABELS_LOCKED)
+			return -EACCES;
+		break;
 	default:
 		break;
 	}
@@ -205,13 +225,156 @@ static int xlat_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd,
 {
 	if (!nvdimm)
 		return xlat_bus_status(buf, cmd, status);
-	return xlat_nvdimm_status(buf, cmd, status);
+	return xlat_nvdimm_status(nvdimm, buf, cmd, status);
+}
+
+/* convert _LS{I,R} packages to the buffer object acpi_nfit_ctl expects */
+static union acpi_object *pkg_to_buf(union acpi_object *pkg)
+{
+	int i;
+	void *dst;
+	size_t size = 0;
+	union acpi_object *buf = NULL;
+
+	if (pkg->type != ACPI_TYPE_PACKAGE) {
+		WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
+				pkg->type);
+		goto err;
+	}
+
+	for (i = 0; i < pkg->package.count; i++) {
+		union acpi_object *obj = &pkg->package.elements[i];
+
+		if (obj->type == ACPI_TYPE_INTEGER)
+			size += 4;
+		else if (obj->type == ACPI_TYPE_BUFFER)
+			size += obj->buffer.length;
+		else {
+			WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
+					obj->type);
+			goto err;
+		}
+	}
+
+	buf = ACPI_ALLOCATE(sizeof(*buf) + size);
+	if (!buf)
+		goto err;
+
+	dst = buf + 1;
+	buf->type = ACPI_TYPE_BUFFER;
+	buf->buffer.length = size;
+	buf->buffer.pointer = dst;
+	for (i = 0; i < pkg->package.count; i++) {
+		union acpi_object *obj = &pkg->package.elements[i];
+
+		if (obj->type == ACPI_TYPE_INTEGER) {
+			memcpy(dst, &obj->integer.value, 4);
+			dst += 4;
+		} else if (obj->type == ACPI_TYPE_BUFFER) {
+			memcpy(dst, obj->buffer.pointer, obj->buffer.length);
+			dst += obj->buffer.length;
+		}
+	}
+err:
+	ACPI_FREE(pkg);
+	return buf;
+}
+
+static union acpi_object *int_to_buf(union acpi_object *integer)
+{
+	union acpi_object *buf = ACPI_ALLOCATE(sizeof(*buf) + 4);
+	void *dst = NULL;
+
+	if (!buf)
+		goto err;
+
+	if (integer->type != ACPI_TYPE_INTEGER) {
+		WARN_ONCE(1, "BIOS bug, unexpected element type: %d\n",
+				integer->type);
+		goto err;
+	}
+
+	dst = buf + 1;
+	buf->type = ACPI_TYPE_BUFFER;
+	buf->buffer.length = 4;
+	buf->buffer.pointer = dst;
+	memcpy(dst, &integer->integer.value, 4);
+err:
+	ACPI_FREE(integer);
+	return buf;
+}
+
+static union acpi_object *acpi_label_write(acpi_handle handle, u32 offset,
+		u32 len, void *data)
+{
+	acpi_status rc;
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_object_list input = {
+		.count = 3,
+		.pointer = (union acpi_object []) {
+			[0] = {
+				.integer.type = ACPI_TYPE_INTEGER,
+				.integer.value = offset,
+			},
+			[1] = {
+				.integer.type = ACPI_TYPE_INTEGER,
+				.integer.value = len,
+			},
+			[2] = {
+				.buffer.type = ACPI_TYPE_BUFFER,
+				.buffer.pointer = data,
+				.buffer.length = len,
+			},
+		},
+	};
+
+	rc = acpi_evaluate_object(handle, "_LSW", &input, &buf);
+	if (ACPI_FAILURE(rc))
+		return NULL;
+	return int_to_buf(buf.pointer);
+}
+
+static union acpi_object *acpi_label_read(acpi_handle handle, u32 offset,
+		u32 len)
+{
+	acpi_status rc;
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_object_list input = {
+		.count = 2,
+		.pointer = (union acpi_object []) {
+			[0] = {
+				.integer.type = ACPI_TYPE_INTEGER,
+				.integer.value = offset,
+			},
+			[1] = {
+				.integer.type = ACPI_TYPE_INTEGER,
+				.integer.value = len,
+			},
+		},
+	};
+
+	rc = acpi_evaluate_object(handle, "_LSR", &input, &buf);
+	if (ACPI_FAILURE(rc))
+		return NULL;
+	return pkg_to_buf(buf.pointer);
+}
+
+static union acpi_object *acpi_label_info(acpi_handle handle)
+{
+	acpi_status rc;
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	rc = acpi_evaluate_object(handle, "_LSI", NULL, &buf);
+	if (ACPI_FAILURE(rc))
+		return NULL;
+	return pkg_to_buf(buf.pointer);
 }
 
 int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
 {
 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
 	union acpi_object in_obj, in_buf, *out_obj;
 	const struct nd_cmd_desc *desc = NULL;
 	struct device *dev = acpi_desc->dev;
@@ -235,7 +398,6 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	}
 
 	if (nvdimm) {
-		struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
 		struct acpi_device *adev = nfit_mem->adev;
 
 		if (!adev)
@@ -294,7 +456,21 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 			in_buf.buffer.pointer,
 			min_t(u32, 256, in_buf.buffer.length), true);
 
-	out_obj = acpi_evaluate_dsm(handle, guid, 1, func, &in_obj);
+	/* call the BIOS, prefer the named methods over _DSM if available */
+	if (cmd == ND_CMD_GET_CONFIG_SIZE && nfit_mem->has_lsi)
+		out_obj = acpi_label_info(handle);
+	else if (cmd == ND_CMD_GET_CONFIG_DATA && nfit_mem->has_lsr) {
+		struct nd_cmd_get_config_data_hdr *p = buf;
+
+		out_obj = acpi_label_read(handle, p->in_offset, p->in_length);
+	} else if (cmd == ND_CMD_SET_CONFIG_DATA && nfit_mem->has_lsw) {
+		struct nd_cmd_set_config_hdr *p = buf;
+
+		out_obj = acpi_label_write(handle, p->in_offset, p->in_length,
+				p->in_buf);
+	} else
+		out_obj = acpi_evaluate_dsm(handle, guid, 1, func, &in_obj);
+
 	if (!out_obj) {
 		dev_dbg(dev, "%s:%s _DSM failed cmd: %s\n", __func__, dimm_name,
 				cmd_name);
@@ -1431,6 +1607,7 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 {
 	struct acpi_device *adev, *adev_dimm;
 	struct device *dev = acpi_desc->dev;
+	union acpi_object *obj;
 	unsigned long dsm_mask;
 	const guid_t *guid;
 	int i;
@@ -1496,6 +1673,27 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 		if (acpi_check_dsm(adev_dimm->handle, guid, 1, 1ULL << i))
 			set_bit(i, &nfit_mem->dsm_mask);
 
+	obj = acpi_label_info(adev_dimm->handle);
+	if (obj) {
+		ACPI_FREE(obj);
+		nfit_mem->has_lsi = 1;
+		dev_dbg(dev, "%s: has _LSI\n", dev_name(&adev_dimm->dev));
+	}
+
+	obj = acpi_label_read(adev_dimm->handle, 0, 0);
+	if (obj) {
+		ACPI_FREE(obj);
+		nfit_mem->has_lsr = 1;
+		dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev));
+	}
+
+	obj = acpi_label_write(adev_dimm->handle, 0, 0, NULL);
+	if (obj) {
+		ACPI_FREE(obj);
+		nfit_mem->has_lsw = 1;
+		dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev));
+	}
+
 	return 0;
 }
 
@@ -1574,6 +1772,13 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
 			cmd_mask |= nfit_mem->dsm_mask;
 
+		if (nfit_mem->has_lsi)
+			set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
+		if (nfit_mem->has_lsr)
+			set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
+		if (nfit_mem->has_lsw)
+			set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);
+
 		flush = nfit_mem->nfit_flush ? nfit_mem->nfit_flush->flush
 			: NULL;
 		nvdimm = nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index f2c6380bdbb2..3976d649f27c 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -140,6 +140,9 @@ struct nfit_mem {
 	struct resource *flush_wpq;
 	unsigned long dsm_mask;
 	int family;
+	u32 has_lsi:1;
+	u32 has_lsr:1;
+	u32 has_lsw:1;
 };
 
 struct acpi_nfit_desc {