From cafe4b2d4970b0d7f2193abb9cb32f58c03cbe3b Mon Sep 17 00:00:00 2001 From: Vishal Verma 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 Reviewed-by: Dan Williams Signed-off-by: Vishal Verma --- 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 #include #include +#include #include #include @@ -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