The v6.11 Linux kernel adds CXL protocl (CXL.cache & CXL.mem) error injection for platforms that implement the error types as according to the v6.5+ ACPI specification. The interface for injecting these errors are provided by the kernel under the CXL debugfs. The relevant files in the interface are the einj_types file, which provides the available CXL error types for injection, and the einj_inject file, which injects the error into a CXL VH root port or CXL RCH downstream port.
Add a library API to retrieve the CXL error types and inject them. This API will be used in a later commit by the 'cxl-inject-error' and 'cxl-list' commands. Signed-off-by: Ben Cheatham <[email protected]> --- cxl/lib/libcxl.c | 193 +++++++++++++++++++++++++++++++++++++++++++++ cxl/lib/libcxl.sym | 5 ++ cxl/lib/private.h | 14 ++++ cxl/libcxl.h | 13 +++ 4 files changed, 225 insertions(+) diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c index 3718b76..44d5ce2 100644 --- a/cxl/lib/libcxl.c +++ b/cxl/lib/libcxl.c @@ -46,11 +46,13 @@ struct cxl_ctx { void *userdata; int memdevs_init; int buses_init; + int perrors_init; unsigned long timeout; struct udev *udev; struct udev_queue *udev_queue; struct list_head memdevs; struct list_head buses; + struct list_head perrors; struct kmod_ctx *kmod_ctx; struct daxctl_ctx *daxctl_ctx; void *private_data; @@ -205,6 +207,14 @@ static void free_bus(struct cxl_bus *bus, struct list_head *head) free(bus); } +static void free_protocol_error(struct cxl_protocol_error *perror, + struct list_head *head) +{ + if (head) + list_del_from(head, &perror->list); + free(perror); +} + /** * cxl_get_userdata - retrieve stored data pointer from library context * @ctx: cxl library context @@ -328,6 +338,7 @@ CXL_EXPORT int cxl_new(struct cxl_ctx **ctx) *ctx = c; list_head_init(&c->memdevs); list_head_init(&c->buses); + list_head_init(&c->perrors); c->kmod_ctx = kmod_ctx; c->daxctl_ctx = daxctl_ctx; c->udev = udev; @@ -369,6 +380,7 @@ CXL_EXPORT struct cxl_ctx *cxl_ref(struct cxl_ctx *ctx) */ CXL_EXPORT void cxl_unref(struct cxl_ctx *ctx) { + struct cxl_protocol_error *perror, *_p; struct cxl_memdev *memdev, *_d; struct cxl_bus *bus, *_b; @@ -384,6 +396,9 @@ CXL_EXPORT void cxl_unref(struct cxl_ctx *ctx) list_for_each_safe(&ctx->buses, bus, _b, port.list) free_bus(bus, &ctx->buses); + list_for_each_safe(&ctx->perrors, perror, _p, list) + free_protocol_error(perror, &ctx->perrors); + udev_queue_unref(ctx->udev_queue); udev_unref(ctx->udev); kmod_unref(ctx->kmod_ctx); @@ -3416,6 +3431,184 @@ CXL_EXPORT int cxl_port_decoders_committed(struct cxl_port *port) return port->decoders_committed; } +const struct cxl_protocol_error cxl_protocol_errors[] = { + CXL_PROTOCOL_ERROR(12, "cache-correctable"), + CXL_PROTOCOL_ERROR(13, "cache-uncorrectable"), + CXL_PROTOCOL_ERROR(14, "cache-fatal"), + CXL_PROTOCOL_ERROR(15, "mem-correctable"), + CXL_PROTOCOL_ERROR(16, "mem-uncorrectable"), + CXL_PROTOCOL_ERROR(17, "mem-fatal") +}; + +static struct cxl_protocol_error *create_cxl_protocol_error(struct cxl_ctx *ctx, + unsigned int n) +{ + struct cxl_protocol_error *perror; + + for (unsigned long i = 0; i < ARRAY_SIZE(cxl_protocol_errors); i++) { + if (n != BIT(cxl_protocol_errors[i].num)) + continue; + + perror = calloc(1, sizeof(*perror)); + if (!perror) + return NULL; + + *perror = cxl_protocol_errors[i]; + perror->ctx = ctx; + return perror; + } + + return NULL; +} + +static void cxl_add_protocol_errors(struct cxl_ctx *ctx) +{ + struct cxl_protocol_error *perror; + char buf[SYSFS_ATTR_SIZE]; + char *path, *num, *save; + size_t path_len, len; + unsigned long n; + int rc = 0; + + if (!ctx->debugfs) + return; + + path_len = strlen(ctx->debugfs) + 100; + path = calloc(1, path_len); + if (!path) + return; + + len = snprintf(path, path_len, "%s/cxl/einj_types", ctx->debugfs); + if (len >= path_len) { + err(ctx, "Buffer too small\n"); + goto err; + } + + rc = access(path, F_OK); + if (rc) { + err(ctx, "failed to access %s: %s\n", path, strerror(errno)); + goto err; + } + + rc = sysfs_read_attr(ctx, path, buf); + if (rc) { + err(ctx, "failed to read %s: %s\n", path, strerror(errno)); + goto err; + } + + /* + * The format of the output of the einj_types attr is: + * <Error number in hex 1> <Error name 1> + * <Error number in hex 2> <Error name 2> + * ... + * + * We only need the number, so parse that and skip the rest of + * the line. + */ + num = strtok_r(buf, " \n", &save); + while (num) { + n = strtoul(num, NULL, 16); + perror = create_cxl_protocol_error(ctx, n); + if (perror) + list_add(&ctx->perrors, &perror->list); + + num = strtok_r(NULL, "\n", &save); + if (!num) + break; + + num = strtok_r(NULL, " \n", &save); + } + +err: + free(path); +} + +static void cxl_protocol_errors_init(struct cxl_ctx *ctx) +{ + if (ctx->perrors_init) + return; + + ctx->perrors_init = 1; + cxl_add_protocol_errors(ctx); +} + +CXL_EXPORT struct cxl_protocol_error * +cxl_protocol_error_get_first(struct cxl_ctx *ctx) +{ + cxl_protocol_errors_init(ctx); + + return list_top(&ctx->perrors, struct cxl_protocol_error, list); +} + +CXL_EXPORT struct cxl_protocol_error * +cxl_protocol_error_get_next(struct cxl_protocol_error *perror) +{ + struct cxl_ctx *ctx = perror->ctx; + + return list_next(&ctx->perrors, perror, list); +} + +CXL_EXPORT unsigned int +cxl_protocol_error_get_num(struct cxl_protocol_error *perror) +{ + return perror->num; +} + +CXL_EXPORT const char * +cxl_protocol_error_get_str(struct cxl_protocol_error *perror) +{ + return perror->string; +} + +CXL_EXPORT int cxl_dport_protocol_error_inject(struct cxl_dport *dport, + unsigned int error) +{ + struct cxl_ctx *ctx = dport->port->ctx; + char buf[32] = { 0 }; + size_t path_len, len; + char *path; + int rc; + + if (!ctx->debugfs) + return -ENOENT; + + path_len = strlen(ctx->debugfs) + 100; + path = calloc(path_len, sizeof(char)); + if (!path) + return -ENOMEM; + + len = snprintf(path, path_len, "%s/cxl/%s/einj_inject", ctx->debugfs, + cxl_dport_get_devname(dport)); + if (len >= path_len) { + err(ctx, "%s: buffer too small\n", cxl_dport_get_devname(dport)); + free(path); + return -ENOMEM; + } + + rc = access(path, F_OK); + if (rc) { + err(ctx, "failed to access %s: %s\n", path, strerror(errno)); + free(path); + return -errno; + } + + len = snprintf(buf, sizeof(buf), "0x%lx\n", BIT(error)); + if (len >= sizeof(buf)) { + err(ctx, "%s: buffer too small\n", cxl_dport_get_devname(dport)); + free(path); + return -ENOMEM; + } + + rc = sysfs_write_attr(ctx, path, buf); + if (rc) { + err(ctx, "failed to write %s: %s\n", path, strerror(errno)); + free(path); + return -errno; + } + + return 0; +} + static void *add_cxl_bus(void *parent, int id, const char *cxlbus_base) { const char *devname = devpath_to_devname(cxlbus_base); diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym index e01a676..02d5119 100644 --- a/cxl/lib/libcxl.sym +++ b/cxl/lib/libcxl.sym @@ -299,4 +299,9 @@ global: LIBCXL_10 { global: cxl_memdev_is_port_ancestor; + cxl_protocol_error_get_first; + cxl_protocol_error_get_next; + cxl_protocol_error_get_num; + cxl_protocol_error_get_str; + cxl_dport_protocol_error_inject; } LIBCXL_9; diff --git a/cxl/lib/private.h b/cxl/lib/private.h index 7d5a1bc..8860669 100644 --- a/cxl/lib/private.h +++ b/cxl/lib/private.h @@ -108,6 +108,20 @@ struct cxl_port { struct list_head dports; }; +struct cxl_protocol_error { + unsigned int num; + const char *string; + struct cxl_ctx *ctx; + struct list_node list; +}; + +#define CXL_PROTOCOL_ERROR(n, str) \ + ((struct cxl_protocol_error){ \ + .num = (n), \ + .string = (str), \ + .ctx = NULL, \ + }) + struct cxl_bus { struct cxl_port port; }; diff --git a/cxl/libcxl.h b/cxl/libcxl.h index 54bc025..adb5716 100644 --- a/cxl/libcxl.h +++ b/cxl/libcxl.h @@ -496,6 +496,19 @@ int cxl_cmd_alert_config_set_enable_alert_actions(struct cxl_cmd *cmd, int enable); struct cxl_cmd *cxl_cmd_new_set_alert_config(struct cxl_memdev *memdev); +struct cxl_protocol_error; +struct cxl_protocol_error *cxl_protocol_error_get_first(struct cxl_ctx *ctx); +struct cxl_protocol_error * +cxl_protocol_error_get_next(struct cxl_protocol_error *perror); +unsigned int cxl_protocol_error_get_num(struct cxl_protocol_error *perror); +const char *cxl_protocol_error_get_str(struct cxl_protocol_error *perror); +int cxl_dport_protocol_error_inject(struct cxl_dport *dport, + unsigned int error); + +#define cxl_protocol_error_foreach(ctx, perror) \ + for (perror = cxl_protocol_error_get_first(ctx); perror != NULL; \ + perror = cxl_protocol_error_get_next(perror)) + #ifdef __cplusplus } /* extern "C" */ #endif -- 2.51.1
