On 5/23/26 2:50 AM, Anisa Su wrote: > From: Ira Weiny <[email protected]> > > DCD regions have 0 or more extents. The ability to list those and their > properties is useful to end users. > > Add extent scanning and reporting functionality to libcxl. > > Signed-off-by: Ira Weiny <[email protected]> Missing Anisa sign-off > > --- > Changes: > [alison: s/tag/uuid/ for extents] > --- > Documentation/cxl/lib/libcxl.txt | 27 ++++++ > cxl/lib/libcxl.c | 138 +++++++++++++++++++++++++++++++ > cxl/lib/libcxl.sym | 5 ++ > cxl/lib/private.h | 11 +++ > cxl/libcxl.h | 11 +++ > 5 files changed, 192 insertions(+) > > diff --git a/Documentation/cxl/lib/libcxl.txt > b/Documentation/cxl/lib/libcxl.txt > index 9921ac1..0ad294c 100644 > --- a/Documentation/cxl/lib/libcxl.txt > +++ b/Documentation/cxl/lib/libcxl.txt > @@ -635,6 +635,33 @@ where its properties can be interrogated by daxctl. The > helper > cxl_region_get_daxctl_region() returns an 'struct daxctl_region *' that > can be used with other libdaxctl APIs. > > +EXTENTS > +------- > + > +=== EXTENT: Enumeration > +---- > +struct cxl_region_extent; > +struct cxl_region_extent *cxl_extent_get_first(struct cxl_region *region); > +struct cxl_region_extent *cxl_extent_get_next(struct cxl_region_extent > *extent); > +#define cxl_extent_foreach(region, extent) \ > + for (extent = cxl_extent_get_first(region); \ > + extent != NULL; \ > + extent = cxl_extent_get_next(extent)) > + > +---- > + > +=== EXTENT: Attributes > +---- > +unsigned long long cxl_extent_get_offset(struct cxl_region_extent *extent); > +unsigned long long cxl_extent_get_length(struct cxl_region_extent *extent); > +void cxl_extent_get_uuid(struct cxl_region_extent *extent, uuid_t uuid); > +---- > + > +Extents represent available memory within a dynamic capacity region. Extent > +objects are available for informational purposes to aid in allocation of > +memory. > + > + > include::../../copyright.txt[] > > SEE ALSO > diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c > index be0bc03..c096666 100644 > --- a/cxl/lib/libcxl.c > +++ b/cxl/lib/libcxl.c > @@ -635,6 +635,7 @@ static void *add_cxl_region(void *parent, int id, const > char *cxlregion_base) > region->ctx = ctx; > region->decoder = decoder; > list_head_init(®ion->mappings); > + list_head_init(®ion->extents); > > region->dev_path = strdup(cxlregion_base); > if (!region->dev_path) > @@ -1257,6 +1258,143 @@ cxl_mapping_get_next(struct cxl_memdev_mapping > *mapping) > return list_next(®ion->mappings, mapping, list); > } > > +static void cxl_extents_init(struct cxl_region *region) > +{ > + const char *devname = cxl_region_get_devname(region); > + struct cxl_ctx *ctx = cxl_region_get_ctx(region); > + char *extent_path, *dax_region_path; > + struct dirent *de; > + DIR *dir = NULL; > + > + if (region->extents_init) > + return; > + region->extents_init = 1; > + > + dax_region_path = calloc(1, strlen(region->dev_path) + 64); > + if (!dax_region_path) { > + err(ctx, "%s: allocation failure\n", devname); > + return; > + } > + > + extent_path = calloc(1, strlen(region->dev_path) + 100); > + if (!extent_path) { > + err(ctx, "%s: allocation failure\n", devname); > + free(dax_region_path); > + return; > + } > + > + sprintf(dax_region_path, "%s/dax_region%d", > + region->dev_path, region->id); > + dir = opendir(dax_region_path); > + if (!dir) { > + err(ctx, "no extents found (%s): %s\n", > + strerror(errno), dax_region_path); > + free(extent_path); > + free(dax_region_path); > + return; > + } > + > + while ((de = readdir(dir)) != NULL) { > + struct cxl_region_extent *extent; > + char buf[SYSFS_ATTR_SIZE]; > + u64 offset, length; > + int id, region_id; > + > + if (sscanf(de->d_name, "extent%d.%d", ®ion_id, &id) != 2) > + continue; > + > + sprintf(extent_path, "%s/extent%d.%d/offset", > + dax_region_path, region_id, id); > + if (sysfs_read_attr(ctx, extent_path, buf) < 0) { > + err(ctx, "%s: failed to read extent%d.%d/offset\n", > + devname, region_id, id); > + continue; > + } > + > + offset = strtoull(buf, NULL, 0); > + if (offset == ULLONG_MAX) { > + err(ctx, "%s extent%d.%d: failed to read offset\n", > + devname, region_id, id); > + continue; > + } > + > + sprintf(extent_path, "%s/extent%d.%d/length", > + dax_region_path, region_id, id); > + if (sysfs_read_attr(ctx, extent_path, buf) < 0) { > + err(ctx, "%s: failed to read extent%d.%d/length\n", > + devname, region_id, id); > + continue; > + } > + > + length = strtoull(buf, NULL, 0); > + if (length == ULLONG_MAX) { > + err(ctx, "%s extent%d.%d: failed to read length\n", > + devname, region_id, id); > + continue; > + } > + > + sprintf(extent_path, "%s/extent%d.%d/tag", > + dax_region_path, region_id, id); > + buf[0] = '\0'; > + if (sysfs_read_attr(ctx, extent_path, buf) != 0) > + dbg(ctx, "%s extent%d.%d: failed to read uuid\n", > + devname, region_id, id); > + > + extent = calloc(1, sizeof(*extent)); > + if (!extent) { > + err(ctx, "%s extent%d.%d: allocation failure\n", > + devname, region_id, id); > + continue; > + } > + if (strlen(buf) && uuid_parse(buf, extent->uuid) < 0) > + err(ctx, "%s:%s\n", extent_path, buf); > + extent->region = region; > + extent->offset = offset; > + extent->length = length; > + > + list_node_init(&extent->list); > + list_add(®ion->extents, &extent->list); free_region() never frees any of the extents allocated and added here and thus leak the memory when region is freed. > + dbg(ctx, "%s added extent%d.%d\n", devname, region_id, id); > + } > + free(dax_region_path); > + free(extent_path); > + closedir(dir); > +} > + > +CXL_EXPORT struct cxl_region_extent * > +cxl_extent_get_first(struct cxl_region *region) > +{ > + cxl_extents_init(region); > + > + return list_top(®ion->extents, struct cxl_region_extent, list); > +} > + > +CXL_EXPORT struct cxl_region_extent * > +cxl_extent_get_next(struct cxl_region_extent *extent) > +{ > + struct cxl_region *region = extent->region; > + > + return list_next(®ion->extents, extent, list); > +} > + > +CXL_EXPORT unsigned long long > +cxl_extent_get_offset(struct cxl_region_extent *extent) > +{ > + return extent->offset; > +} > + > +CXL_EXPORT unsigned long long > +cxl_extent_get_length(struct cxl_region_extent *extent) > +{ > + return extent->length; > +} > + > +CXL_EXPORT void > +cxl_extent_get_uuid(struct cxl_region_extent *extent, uuid_t uuid) > +{ > + memcpy(uuid, extent->uuid, sizeof(uuid_t)); > +} > + > CXL_EXPORT struct cxl_decoder * > cxl_mapping_get_decoder(struct cxl_memdev_mapping *mapping) > { > diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym > index 258bdd3..dcfe242 100644 > --- a/cxl/lib/libcxl.sym > +++ b/cxl/lib/libcxl.sym > @@ -298,6 +298,11 @@ global: > cxl_memdev_get_dynamic_ram_a_qos_class; > cxl_decoder_is_dynamic_ram_a_capable; > cxl_decoder_create_dynamic_ram_a_region; > + cxl_extent_get_first; > + cxl_extent_get_next; > + cxl_extent_get_offset; > + cxl_extent_get_length; > + cxl_extent_get_uuid; > } LIBECXL_8; > > LIBCXL_10 { > diff --git a/cxl/lib/private.h b/cxl/lib/private.h > index 37b7b06..c5f3bed 100644 > --- a/cxl/lib/private.h > +++ b/cxl/lib/private.h > @@ -183,6 +183,7 @@ struct cxl_region { > struct cxl_decoder *decoder; > struct list_node list; > int mappings_init; > + int extents_init; > struct cxl_ctx *ctx; > void *dev_buf; > size_t buf_len; > @@ -200,6 +201,7 @@ struct cxl_region { > struct daxctl_region *dax_region; > struct kmod_module *module; > struct list_head mappings; > + struct list_head extents; > }; > > struct cxl_memdev_mapping { > @@ -209,6 +211,15 @@ struct cxl_memdev_mapping { > struct list_node list; > }; > > +#define CXL_REGION_EXTENT_TAG 0x10 defined but never used DJ > +struct cxl_region_extent { > + struct cxl_region *region; > + u64 offset; > + u64 length; > + uuid_t uuid; > + struct list_node list; > +}; > + > enum cxl_cmd_query_status { > CXL_CMD_QUERY_NOT_RUN = 0, > CXL_CMD_QUERY_OK, > diff --git a/cxl/libcxl.h b/cxl/libcxl.h > index fd41122..a60509f 100644 > --- a/cxl/libcxl.h > +++ b/cxl/libcxl.h > @@ -394,6 +394,17 @@ unsigned int cxl_mapping_get_position(struct > cxl_memdev_mapping *mapping); > mapping != NULL; \ > mapping = cxl_mapping_get_next(mapping)) > > +struct cxl_region_extent; > +struct cxl_region_extent *cxl_extent_get_first(struct cxl_region *region); > +struct cxl_region_extent *cxl_extent_get_next(struct cxl_region_extent > *extent); > +#define cxl_extent_foreach(region, extent) \ > + for (extent = cxl_extent_get_first(region); \ > + extent != NULL; \ > + extent = cxl_extent_get_next(extent)) > +unsigned long long cxl_extent_get_offset(struct cxl_region_extent *extent); > +unsigned long long cxl_extent_get_length(struct cxl_region_extent *extent); > +void cxl_extent_get_uuid(struct cxl_region_extent *extent, uuid_t uuid); > + > struct cxl_cmd; > const char *cxl_cmd_get_devname(struct cxl_cmd *cmd); > struct cxl_cmd *cxl_cmd_new_raw(struct cxl_memdev *memdev, int opcode);
