From cafe4b2d4970b0d7f2193abb9cb32f58c03cbe3b Mon Sep 17 00:00:00 2001

From: Vishal Verma <vishal.l.verma@intel.com>

Date: Mon, 15 Aug 2022 13:22:09 -0600

Subject: [PATCH 194/217] libcxl: add low level APIs for region creation

Add libcxl APIs to create a region under a given root decoder, and to

set different attributes for the new region. These allow setting the

size, interleave_ways, interleave_granularity, uuid, and the target

devices for the newly minted cxl_region object.

Link: https://lore.kernel.org/r/20220815192214.545800-7-vishal.l.verma@intel.com

Cc: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

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

---

 Documentation/cxl/lib/libcxl.txt |  69 ++++++

 cxl/lib/libcxl.c                 | 381 ++++++++++++++++++++++++++++++-

 cxl/lib/libcxl.sym               |  16 ++

 cxl/lib/private.h                |   2 +

 cxl/libcxl.h                     |  23 +-

 5 files changed, 488 insertions(+), 3 deletions(-)

diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt

index 7a38ce4..50b0c9c 100644

--- a/Documentation/cxl/lib/libcxl.txt

+++ b/Documentation/cxl/lib/libcxl.txt

@@ -508,6 +508,75 @@ device to represent the root of a PCI device hierarchy. The

 cxl_target_get_physical_node() helper returns the device name of that

 companion object in the PCI hierarchy.

+==== REGIONS

+A CXL region is composed of one or more slices of CXL memdevs, with configurable

+interleave settings - both the number of interleave ways, and the interleave

+granularity. In terms of hierarchy, it is the child of a CXL root decoder. A root

+decoder (recall that this corresponds to an ACPI CEDT.CFMWS 'window'), may have

+multiple child regions, but a region is strictly tied to one root decoder.

+

+The slices that compose a region are called mappings. A mapping is a

+tuple of 'memdev', 'endpoint decoder', and the 'position'.

+

+===== REGION: Enumeration

+----

+struct cxl_region *cxl_region_get_first(struct cxl_decoder *decoder);

+struct cxl_region *cxl_region_get_next(struct cxl_region *region);

+

+#define cxl_region_foreach(decoder, region)                                    \

+	for (region = cxl_region_get_first(decoder); region != NULL;           \

+	     region = cxl_region_get_next(region))

+

+#define cxl_region_foreach_safe(decoder, region, _region)                      \

+	for (region = cxl_region_get_first(decoder),                           \

+	     _region = region ? cxl_region_get_next(region) : NULL;            \

+	     region != NULL;                                                   \

+	     region = _region,                                                 \

+	     _region = _region ? cxl_region_get_next(_region) : NULL)

+----

+

+===== REGION: Attributes

+----

+int cxl_region_get_id(struct cxl_region *region);

+const char *cxl_region_get_devname(struct cxl_region *region);

+void cxl_region_get_uuid(struct cxl_region *region, uuid_t uu);

+unsigned long long cxl_region_get_size(struct cxl_region *region);

+unsigned long long cxl_region_get_resource(struct cxl_region *region);

+unsigned int cxl_region_get_interleave_ways(struct cxl_region *region);

+unsigned int cxl_region_get_interleave_granularity(struct cxl_region *region);

+struct cxl_decoder *cxl_region_get_target_decoder(struct cxl_region *region,

+						  int position);

+int cxl_region_set_size(struct cxl_region *region, unsigned long long size);

+int cxl_region_set_uuid(struct cxl_region *region, uuid_t uu);

+int cxl_region_set_interleave_ways(struct cxl_region *region,

+				   unsigned int ways);

+int cxl_region_set_interleave_granularity(struct cxl_region *region,

+					  unsigned int granularity);

+int cxl_region_set_target(struct cxl_region *region, int position,

+			  struct cxl_decoder *decoder);

+int cxl_region_clear_target(struct cxl_region *region, int position);

+int cxl_region_clear_all_targets(struct cxl_region *region);

+int cxl_region_decode_commit(struct cxl_region *region);

+int cxl_region_decode_reset(struct cxl_region *region);

+----

+

+A region's resource attribute is the Host Physical Address at which the region's

+address space starts. The region's address space is a subset of the parent root

+decoder's address space.

+

+The interleave ways is the number of component memdevs participating in the

+region.

+

+The interleave granularity depends on the root decoder's granularity, and must

+follow the interleave math rules defined in the CXL spec.

+

+Regions have a list of targets 0..N, which are programmed with the name of an

+endpoint decoder under each participating memdev.

+

+The 'decode_commit' and 'decode_reset' attributes reserve and free DPA space

+on a given memdev by allocating an endpoint decoder, and programming it based

+on the region's interleave geometry.

+

 include::../../copyright.txt[]

 SEE ALSO

diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c

index ad98188..fd2ea4f 100644

--- a/cxl/lib/libcxl.c

+++ b/cxl/lib/libcxl.c

@@ -17,6 +17,7 @@

 #include <ccan/minmax/minmax.h>

 #include <ccan/array_size/array_size.h>

 #include <ccan/short_types/short_types.h>

+#include <ccan/container_of/container_of.h>

 #include <util/log.h>

 #include <util/list.h>

@@ -420,6 +421,40 @@ CXL_EXPORT int cxl_region_enable(struct cxl_region *region)

 	return 0;

 }

+static int cxl_region_delete_name(struct cxl_decoder *decoder,

+				  const char *devname)

+{

+	struct cxl_ctx *ctx = cxl_decoder_get_ctx(decoder);

+	char *path = decoder->dev_buf;

+	int rc;

+

+	sprintf(path, "%s/delete_region", decoder->dev_path);

+	rc = sysfs_write_attr(ctx, path, devname);

+	if (rc != 0) {

+		err(ctx, "error deleting region: %s\n", strerror(-rc));

+		return rc;

+	}

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_delete(struct cxl_region *region)

+{

+	struct cxl_decoder *decoder = cxl_region_get_decoder(region);

+	const char *devname = cxl_region_get_devname(region);

+	int rc;

+

+	if (cxl_region_is_enabled(region))

+		return -EBUSY;

+

+	rc = cxl_region_delete_name(decoder, devname);

+	if (rc != 0)

+		return rc;

+

+	decoder->regions_init = 0;

+	free_region(region, &decoder->regions);

+	return 0;

+}

+

 static void *add_cxl_region(void *parent, int id, const char *cxlregion_base)

 {

 	const char *devname = devpath_to_devname(cxlregion_base);

@@ -599,6 +634,258 @@ cxl_region_get_interleave_granularity(struct cxl_region *region)

 	return region->interleave_granularity;

 }

+CXL_EXPORT struct cxl_decoder *

+cxl_region_get_target_decoder(struct cxl_region *region, int position)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	struct cxl_decoder *decoder;

+	char buf[SYSFS_ATTR_SIZE];

+

+	if (snprintf(path, len, "%s/target%d", region->dev_path, position) >=

+	    len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return NULL;

+	}

+

+	rc = sysfs_read_attr(ctx, path, buf);

+	if (rc < 0) {

+		err(ctx, "%s: error reading target%d: %s\n", devname,

+		    position, strerror(-rc));

+		return NULL;

+	}

+

+	decoder = cxl_decoder_get_by_name(ctx, buf);

+	if (!decoder) {

+		err(ctx, "%s: error locating decoder for target%d\n", devname,

+		    position);

+		return NULL;

+	}

+	return decoder;

+}

+

+CXL_EXPORT int cxl_region_set_size(struct cxl_region *region,

+				   unsigned long long size)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	char buf[SYSFS_ATTR_SIZE];

+

+	if (size == 0) {

+		dbg(ctx, "%s: cannot use %s to delete a region\n", __func__,

+		    devname);

+		return -EINVAL;

+	}

+

+	if (snprintf(path, len, "%s/size", region->dev_path) >= len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	sprintf(buf, "%#llx\n", size);

+	rc = sysfs_write_attr(ctx, path, buf);

+	if (rc < 0)

+		return rc;

+

+	region->size = size;

+

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_set_uuid(struct cxl_region *region, uuid_t uu)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	char uuid[SYSFS_ATTR_SIZE];

+

+	if (snprintf(path, len, "%s/uuid", region->dev_path) >= len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	uuid_unparse(uu, uuid);

+	rc = sysfs_write_attr(ctx, path, uuid);

+	if (rc != 0)

+		return rc;

+	memcpy(region->uuid, uu, sizeof(uuid_t));

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_set_interleave_ways(struct cxl_region *region,

+					      unsigned int ways)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	char buf[SYSFS_ATTR_SIZE];

+

+	if (snprintf(path, len, "%s/interleave_ways",

+		     region->dev_path) >= len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	sprintf(buf, "%u\n", ways);

+	rc = sysfs_write_attr(ctx, path, buf);

+	if (rc < 0)

+		return rc;

+

+	region->interleave_ways = ways;

+

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_set_interleave_granularity(struct cxl_region *region,

+						     unsigned int granularity)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	char buf[SYSFS_ATTR_SIZE];

+

+	if (snprintf(path, len, "%s/interleave_granularity",

+		     region->dev_path) >= len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	sprintf(buf, "%u\n", granularity);

+	rc = sysfs_write_attr(ctx, path, buf);

+	if (rc < 0)

+		return rc;

+

+	region->interleave_granularity = granularity;

+

+	return 0;

+}

+

+static int region_write_target(struct cxl_region *region, int position,

+			       struct cxl_decoder *decoder)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	const char *dec_name = "";

+

+	if (decoder)

+		dec_name = cxl_decoder_get_devname(decoder);

+

+	if (snprintf(path, len, "%s/target%d", region->dev_path, position) >=

+	    len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	rc = sysfs_write_attr(ctx, path, dec_name);

+	if (rc < 0)

+		return rc;

+

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_set_target(struct cxl_region *region, int position,

+				     struct cxl_decoder *decoder)

+{

+	if (!decoder)

+		return -ENXIO;

+

+	return region_write_target(region, position, decoder);

+}

+

+CXL_EXPORT int cxl_region_clear_target(struct cxl_region *region, int position)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int rc;

+

+	if (cxl_region_is_enabled(region)) {

+		err(ctx, "%s: can't clear targets on an active region\n",

+		    devname);

+		return -EBUSY;

+	}

+

+	rc = region_write_target(region, position, NULL);

+	if (rc) {

+		err(ctx, "%s: error clearing target%d: %s\n",

+		    devname, position, strerror(-rc));

+		return rc;

+	}

+

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_clear_all_targets(struct cxl_region *region)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	unsigned int ways, i;

+	int rc;

+

+	if (cxl_region_is_enabled(region)) {

+		err(ctx, "%s: can't clear targets on an active region\n",

+		    devname);

+		return -EBUSY;

+	}

+

+	ways = cxl_region_get_interleave_ways(region);

+	if (ways == 0 || ways == UINT_MAX)

+		return -ENXIO;

+

+	for (i = 0; i < ways; i++) {

+		rc = region_write_target(region, i, NULL);

+		if (rc) {

+			err(ctx, "%s: error clearing target%d: %s\n",

+			    devname, i, strerror(-rc));

+			return rc;

+		}

+	}

+

+	return 0;

+}

+

+static int set_region_decode(struct cxl_region *region,

+			     enum cxl_decode_state decode_state)

+{

+	const char *devname = cxl_region_get_devname(region);

+	struct cxl_ctx *ctx = cxl_region_get_ctx(region);

+	int len = region->buf_len, rc;

+	char *path = region->dev_buf;

+	char buf[SYSFS_ATTR_SIZE];

+

+	if (snprintf(path, len, "%s/commit", region->dev_path) >= len) {

+		err(ctx, "%s: buffer too small!\n", devname);

+		return -ENXIO;

+	}

+

+	sprintf(buf, "%d\n", decode_state);

+	rc = sysfs_write_attr(ctx, path, buf);

+	if (rc < 0)

+		return rc;

+

+	region->decode_state = decode_state;

+

+	return 0;

+}

+

+CXL_EXPORT int cxl_region_decode_commit(struct cxl_region *region)

+{

+	return set_region_decode(region, CXL_DECODE_COMMIT);

+}

+

+CXL_EXPORT int cxl_region_decode_reset(struct cxl_region *region)

+{

+	return set_region_decode(region, CXL_DECODE_RESET);

+}

+

 static struct cxl_decoder *__cxl_port_match_decoder(struct cxl_port *port,

 						    const char *ident)

 {

@@ -633,8 +920,8 @@ static struct cxl_decoder *cxl_port_find_decoder(struct cxl_port *port,

 	return NULL;

 }

-static struct cxl_decoder *cxl_decoder_get_by_name(struct cxl_ctx *ctx,

-						   const char *ident)

+CXL_EXPORT struct cxl_decoder *cxl_decoder_get_by_name(struct cxl_ctx *ctx,

+						       const char *ident)

 {

 	struct cxl_bus *bus;

@@ -1399,6 +1686,18 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)

 	} else

 		decoder->mode = CXL_DECODER_MODE_NONE;

+	sprintf(path, "%s/interleave_granularity", cxldecoder_base);

+	if (sysfs_read_attr(ctx, path, buf) < 0)

+		decoder->interleave_granularity = UINT_MAX;

+	else

+		decoder->interleave_granularity = strtoul(buf, NULL, 0);

+

+	sprintf(path, "%s/interleave_ways", cxldecoder_base);

+	if (sysfs_read_attr(ctx, path, buf) < 0)

+		decoder->interleave_ways = UINT_MAX;

+	else

+		decoder->interleave_ways = strtoul(buf, NULL, 0);

+

 	switch (port->type) {

 	case CXL_PORT_ENDPOINT:

 		sprintf(path, "%s/dpa_resource", cxldecoder_base);

@@ -1731,6 +2030,66 @@ CXL_EXPORT bool cxl_decoder_is_locked(struct cxl_decoder *decoder)

 	return decoder->locked;

 }

+CXL_EXPORT unsigned int

+cxl_decoder_get_interleave_granularity(struct cxl_decoder *decoder)

+{

+	return decoder->interleave_granularity;

+}

+

+CXL_EXPORT unsigned int

+cxl_decoder_get_interleave_ways(struct cxl_decoder *decoder)

+{

+	return decoder->interleave_ways;

+}

+

+CXL_EXPORT struct cxl_region *

+cxl_decoder_create_pmem_region(struct cxl_decoder *decoder)

+{

+	struct cxl_ctx *ctx = cxl_decoder_get_ctx(decoder);

+	char *path = decoder->dev_buf;

+	char buf[SYSFS_ATTR_SIZE];

+	struct cxl_region *region;

+	int rc;

+

+	sprintf(path, "%s/create_pmem_region", decoder->dev_path);

+	rc = sysfs_read_attr(ctx, path, buf);

+	if (rc < 0) {

+		err(ctx, "failed to read new region name: %s\n",

+		    strerror(-rc));

+		return NULL;

+	}

+

+	rc = sysfs_write_attr(ctx, path, buf);

+	if (rc < 0) {

+		err(ctx, "failed to write new region name: %s\n",

+		    strerror(-rc));

+		return NULL;

+	}

+

+	/* Force a re-init of regions so that the new one can be discovered */

+	decoder->regions_init = 0;

+

+	/* create_region was successful, walk to the new region */

+	cxl_region_foreach(decoder, region) {

+		const char *devname = cxl_region_get_devname(region);

+

+		if (strcmp(devname, buf) == 0)

+			goto found;

+	}

+

+	/*

+	 * If walking to the region we just created failed, something has gone

+	 * very wrong. Attempt to delete it to avoid leaving a dangling region

+	 * id behind.

+	 */

+	err(ctx, "failed to add new region to libcxl\n");

+	cxl_region_delete_name(decoder, buf);

+	return NULL;

+

+ found:

+	return region;

+}

+

 CXL_EXPORT int cxl_decoder_get_nr_targets(struct cxl_decoder *decoder)

 {

 	return decoder->nr_targets;

@@ -1741,6 +2100,24 @@ CXL_EXPORT const char *cxl_decoder_get_devname(struct cxl_decoder *decoder)

 	return devpath_to_devname(decoder->dev_path);

 }

+CXL_EXPORT struct cxl_memdev *

+cxl_decoder_get_memdev(struct cxl_decoder *decoder)

+{

+	struct cxl_port *port = cxl_decoder_get_port(decoder);

+	struct cxl_endpoint *ep;

+

+	if (!port)

+		return NULL;

+	if (!cxl_port_is_endpoint(port))

+		return NULL;

+

+	ep = container_of(port, struct cxl_endpoint, port);

+	if (!ep)

+		return NULL;

+

+	return cxl_endpoint_get_memdev(ep);

+}

+

 CXL_EXPORT struct cxl_target *cxl_target_get_first(struct cxl_decoder *decoder)

 {

 	return list_top(&decoder->targets, struct cxl_target, list);

diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym

index e410298..cb23a0b 100644

--- a/cxl/lib/libcxl.sym

+++ b/cxl/lib/libcxl.sym

@@ -140,6 +140,7 @@ global:

 	cxl_decoder_is_mem_capable;

 	cxl_decoder_is_accelmem_capable;

 	cxl_decoder_is_locked;

+	cxl_decoder_create_pmem_region;

 	cxl_target_get_first;

 	cxl_target_get_next;

 	cxl_target_get_decoder;

@@ -183,6 +184,7 @@ global:

 	cxl_region_is_enabled;

 	cxl_region_disable;

 	cxl_region_enable;

+	cxl_region_delete;

 	cxl_region_get_ctx;

 	cxl_region_get_decoder;

 	cxl_region_get_id;

@@ -192,9 +194,23 @@ global:

 	cxl_region_get_resource;

 	cxl_region_get_interleave_ways;

 	cxl_region_get_interleave_granularity;

+	cxl_region_get_target_decoder;

+	cxl_region_set_size;

+	cxl_region_set_uuid;

+	cxl_region_set_interleave_ways;

+	cxl_region_set_interleave_granularity;

+	cxl_region_set_target;

+	cxl_region_clear_target;

+	cxl_region_clear_all_targets;

+	cxl_region_decode_commit;

+	cxl_region_decode_reset;

 	cxl_mapping_get_first;

 	cxl_mapping_get_next;

 	cxl_mapping_get_decoder;

 	cxl_mapping_get_region;

 	cxl_mapping_get_position;

+	cxl_decoder_get_by_name;

+	cxl_decoder_get_memdev;

+	cxl_decoder_get_interleave_granularity;

+	cxl_decoder_get_interleave_ways;

 } LIBCXL_2;

diff --git a/cxl/lib/private.h b/cxl/lib/private.h

index 5e2fdd5..8bc9620 100644

--- a/cxl/lib/private.h

+++ b/cxl/lib/private.h

@@ -110,6 +110,8 @@ struct cxl_decoder {

 	int nr_targets;

 	int id;

 	enum cxl_decoder_mode mode;

+	unsigned int interleave_ways;

+	unsigned int interleave_granularity;

 	bool pmem_capable;

 	bool volatile_capable;

 	bool mem_capable;

diff --git a/cxl/libcxl.h b/cxl/libcxl.h

index 19d94e4..69d9c09 100644

--- a/cxl/libcxl.h

+++ b/cxl/libcxl.h

@@ -195,7 +195,13 @@ bool cxl_decoder_is_volatile_capable(struct cxl_decoder *decoder);

 bool cxl_decoder_is_mem_capable(struct cxl_decoder *decoder);

 bool cxl_decoder_is_accelmem_capable(struct cxl_decoder *decoder);

 bool cxl_decoder_is_locked(struct cxl_decoder *decoder);

-

+unsigned int

+cxl_decoder_get_interleave_granularity(struct cxl_decoder *decoder);

+unsigned int cxl_decoder_get_interleave_ways(struct cxl_decoder *decoder);

+struct cxl_region *cxl_decoder_create_pmem_region(struct cxl_decoder *decoder);

+struct cxl_decoder *cxl_decoder_get_by_name(struct cxl_ctx *ctx,

+					    const char *ident);

+struct cxl_memdev *cxl_decoder_get_memdev(struct cxl_decoder *decoder);

 #define cxl_decoder_foreach(port, decoder)                                     \

 	for (decoder = cxl_decoder_get_first(port); decoder != NULL;           \

 	     decoder = cxl_decoder_get_next(decoder))

@@ -244,6 +250,7 @@ int cxl_region_decode_is_committed(struct cxl_region *region);

 int cxl_region_is_enabled(struct cxl_region *region);

 int cxl_region_disable(struct cxl_region *region);

 int cxl_region_enable(struct cxl_region *region);

+int cxl_region_delete(struct cxl_region *region);

 struct cxl_ctx *cxl_region_get_ctx(struct cxl_region *region);

 struct cxl_decoder *cxl_region_get_decoder(struct cxl_region *region);

 int cxl_region_get_id(struct cxl_region *region);

@@ -253,6 +260,20 @@ unsigned long long cxl_region_get_size(struct cxl_region *region);

 unsigned long long cxl_region_get_resource(struct cxl_region *region);

 unsigned int cxl_region_get_interleave_ways(struct cxl_region *region);

 unsigned int cxl_region_get_interleave_granularity(struct cxl_region *region);

+struct cxl_decoder *cxl_region_get_target_decoder(struct cxl_region *region,

+						  int position);

+int cxl_region_set_size(struct cxl_region *region, unsigned long long size);

+int cxl_region_set_uuid(struct cxl_region *region, uuid_t uu);

+int cxl_region_set_interleave_ways(struct cxl_region *region,

+				   unsigned int ways);

+int cxl_region_set_interleave_granularity(struct cxl_region *region,

+					  unsigned int granularity);

+int cxl_region_set_target(struct cxl_region *region, int position,

+			  struct cxl_decoder *decoder);

+int cxl_region_clear_target(struct cxl_region *region, int position);

+int cxl_region_clear_all_targets(struct cxl_region *region);

+int cxl_region_decode_commit(struct cxl_region *region);

+int cxl_region_decode_reset(struct cxl_region *region);

 #define cxl_region_foreach(decoder, region)                                    \

 	for (region = cxl_region_get_first(decoder); region != NULL;           \

-- 

2.27.0