Add major/minor discovery for the FWCTL character device that is associated with supprting CXL Features under 'struct cxl_fwctl'. A 'struct cxl_fwctl' may be installed under cxl_memdev if CXL Features are supported and FWCTL is enabled. Add libcxl API functions to retrieve the major and minor of the FWCTL character device.
Signed-off-by: Dave Jiang <[email protected]> --- v5: - Add documentation. (Alison) - Alloc path on stack. (Alison) - Deal with out of entry and no match case. (Alison) - Make fwctl operations part of 'struct cxl_fwctl' (Dan) --- Documentation/cxl/lib/libcxl.txt | 21 +++++++++ cxl/lib/libcxl.c | 78 ++++++++++++++++++++++++++++++++ cxl/lib/libcxl.sym | 3 ++ cxl/lib/private.h | 8 ++++ cxl/libcxl.h | 5 ++ 5 files changed, 115 insertions(+) diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt index 25ff406c2920..1e00e2dd1abc 100644 --- a/Documentation/cxl/lib/libcxl.txt +++ b/Documentation/cxl/lib/libcxl.txt @@ -42,6 +42,7 @@ struct cxl_memdev *cxl_memdev_get_next(struct cxl_memdev *memdev); struct cxl_ctx *cxl_memdev_get_ctx(struct cxl_memdev *memdev); const char *cxl_memdev_get_host(struct cxl_memdev *memdev) struct cxl_memdev *cxl_endpoint_get_memdev(struct cxl_endpoint *endpoint); +struct cxl_fwctl *cxl_memdev_get_fwctl(struct cxl_memdev *memdev); #define cxl_memdev_foreach(ctx, memdev) \ for (memdev = cxl_memdev_get_first(ctx); \ @@ -59,6 +60,9 @@ specific memdev. The host of a memdev is the PCIe Endpoint device that registered its CXL capabilities with the Linux CXL core. +A memdev may host a 'struct cxl_fwctl' if CXL Features are supported and +Firmware Contrl (FWCTL) is also enabled. + === MEMDEV: Attributes ---- int cxl_memdev_get_id(struct cxl_memdev *memdev); @@ -185,6 +189,23 @@ device is in use. When CXL_SETPART_NEXTBOOT mode is set, the change in partitioning shall become the “next” configuration, to become active on the next device reset. +FWCTL +----- +The object representing a Firmware Control (FWCTL) device is 'struct cxl_fwctl'. +Library interfaces related to these devices have the prefix 'cxl_fwctl_'. +These interfaces are associated with retrieving attributes related to the +CXL FWCTL character device that is a child of the memdev. + +=== FWCTL: Attributes +---- +int cxl_fwctl_get_major(struct cxl_memdev *memdev); +int cxl_fwctl_get_minor(struct cxl_memdev *memdev); +---- + +The character device node for Feature (firmware) control can be found by +default at /dev/fwctl/fwctl%d, or created with a major / minor returned +from cxl_memdev_get_fwctl_{major,minor}(). + BUSES ----- The CXL Memory space is CPU and Device coherent. The address ranges that diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c index bab7343e8a4a..be54db1b9bb9 100644 --- a/cxl/lib/libcxl.c +++ b/cxl/lib/libcxl.c @@ -88,6 +88,7 @@ static void free_memdev(struct cxl_memdev *memdev, struct list_head *head) free(memdev->dev_buf); free(memdev->dev_path); free(memdev->host_path); + free(memdev->fwctl); free(memdev); } @@ -1253,6 +1254,64 @@ static int add_cxl_memdev_fwl(struct cxl_memdev *memdev, return -ENOMEM; } +static const char fwctl_prefix[] = "fwctl"; +static int get_feature_chardev(const char *base, char *chardev_path) +{ + char path[CXL_PATH_MAX]; + struct dirent *entry; + bool found = false; + int rc = 0; + DIR *dir; + + sprintf(path, "%s/fwctl/", base); + dir = opendir(path); + if (!dir) + return -errno; + + while ((entry = readdir(dir)) != NULL) { + if (strncmp(entry->d_name, fwctl_prefix, strlen(fwctl_prefix)) == 0) { + found = true; + break; + } + } + + if (!entry || !found) { + rc = -ENOENT; + goto read_err; + } + + sprintf(chardev_path, "/dev/fwctl/%s", entry->d_name); + +read_err: + closedir(dir); + return rc; +} + +static int memdev_add_fwctl(struct cxl_memdev *memdev, const char *cxlmem_base) +{ + struct cxl_fwctl *fwctl; + char path[CXL_PATH_MAX]; + struct stat st; + int rc; + + rc = get_feature_chardev(cxlmem_base, path); + if (rc) + return rc; + + if (stat(path, &st) < 0) + return -errno; + + fwctl = calloc(1, sizeof(*fwctl)); + if (!fwctl) + return -ENOMEM; + + fwctl->major = major(st.st_rdev); + fwctl->minor = minor(st.st_rdev); + memdev->fwctl = fwctl; + + return 0; +} + static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base) { const char *devname = devpath_to_devname(cxlmem_base); @@ -1279,6 +1338,10 @@ static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base) memdev->major = major(st.st_rdev); memdev->minor = minor(st.st_rdev); + /* If this fails, no Features support. */ + if (memdev_add_fwctl(memdev, cxlmem_base)) + dbg(ctx, "%s: no Features support.\n", devname); + sprintf(path, "%s/pmem/size", cxlmem_base); if (sysfs_read_attr(ctx, path, buf) == 0) memdev->pmem_size = strtoull(buf, NULL, 0); @@ -1515,6 +1578,21 @@ CXL_EXPORT int cxl_memdev_get_minor(struct cxl_memdev *memdev) return memdev->minor; } +CXL_EXPORT struct cxl_fwctl *cxl_memdev_get_fwctl(struct cxl_memdev *memdev) +{ + return memdev->fwctl; +} + +CXL_EXPORT int cxl_fwctl_get_major(struct cxl_fwctl *fwctl) +{ + return fwctl->major; +} + +CXL_EXPORT int cxl_fwctl_get_minor(struct cxl_fwctl *fwctl) +{ + return fwctl->minor; +} + CXL_EXPORT unsigned long long cxl_memdev_get_pmem_size(struct cxl_memdev *memdev) { return memdev->pmem_size; diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym index 4c9760f377e6..3ad0cd06e25a 100644 --- a/cxl/lib/libcxl.sym +++ b/cxl/lib/libcxl.sym @@ -291,4 +291,7 @@ global: LIBCXL_9 { global: cxl_bus_get_by_provider; + cxl_memdev_get_fwctl; + cxl_fwctl_get_major; + cxl_fwctl_get_minor; } LIBECXL_8; diff --git a/cxl/lib/private.h b/cxl/lib/private.h index b6cd910e9335..8bb3308cc036 100644 --- a/cxl/lib/private.h +++ b/cxl/lib/private.h @@ -13,6 +13,8 @@ #define CXL_EXPORT __attribute__ ((visibility("default"))) +#define CXL_PATH_MAX 512 + struct cxl_pmem { int id; void *dev_buf; @@ -34,6 +36,11 @@ enum cxl_fwl_loading { CXL_FWL_LOADING_START, }; +struct cxl_fwctl { + int major; + int minor; +}; + struct cxl_endpoint; struct cxl_memdev { int id, major, minor; @@ -56,6 +63,7 @@ struct cxl_memdev { unsigned long long serial; struct cxl_endpoint *endpoint; struct cxl_fw_loader *fwl; + struct cxl_fwctl *fwctl; }; struct cxl_dport { diff --git a/cxl/libcxl.h b/cxl/libcxl.h index 7a32b9b65736..54d97d7bb501 100644 --- a/cxl/libcxl.h +++ b/cxl/libcxl.h @@ -59,6 +59,7 @@ static inline enum cxl_fwl_status cxl_fwl_status_from_ident(char *status) } struct cxl_memdev; +struct cxl_fwctl; struct cxl_memdev *cxl_memdev_get_first(struct cxl_ctx *ctx); struct cxl_memdev *cxl_memdev_get_next(struct cxl_memdev *memdev); int cxl_memdev_get_id(struct cxl_memdev *memdev); @@ -69,6 +70,7 @@ const char *cxl_memdev_get_host(struct cxl_memdev *memdev); struct cxl_bus *cxl_memdev_get_bus(struct cxl_memdev *memdev); int cxl_memdev_get_major(struct cxl_memdev *memdev); int cxl_memdev_get_minor(struct cxl_memdev *memdev); +struct cxl_fwctl *cxl_memdev_get_fwctl(struct cxl_memdev *memdev); struct cxl_ctx *cxl_memdev_get_ctx(struct cxl_memdev *memdev); unsigned long long cxl_memdev_get_pmem_size(struct cxl_memdev *memdev); unsigned long long cxl_memdev_get_ram_size(struct cxl_memdev *memdev); @@ -81,6 +83,9 @@ int cxl_memdev_update_fw(struct cxl_memdev *memdev, const char *fw_path); int cxl_memdev_cancel_fw_update(struct cxl_memdev *memdev); int cxl_memdev_wait_sanitize(struct cxl_memdev *memdev, int timeout_ms); +int cxl_fwctl_get_major(struct cxl_fwctl *fwctl); +int cxl_fwctl_get_minor(struct cxl_fwctl *fwctl); + /* ABI spelling mistakes are forever */ static inline const char *cxl_memdev_get_firmware_version( struct cxl_memdev *memdev) -- 2.49.0
