From patchwork Tue Feb 18 22:59:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 13981050 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 645761B3725 for ; Tue, 18 Feb 2025 23:01:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739919681; cv=none; b=r0TR6++jcrACoDcGft+A6kKBpqp6X/iVG2EYlnOFXn4+kRHDDSRHe7u0fbMpq9oDnZeUqQ+HVRRGDBBudAod6X5VT1zRVjTyMleBJAo0QLMDsDOVU9QTNq7AFH61Aa2DwFl74PfvYihVMcpECWnS1jbI0UXxLuqaGocF4URVw2Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739919681; c=relaxed/simple; bh=tFViK+KgAmQI3b662C7w78A0G4xr1wEsh2C/04CsDNQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jwKOYElmNcoRfBbF9DI7vGPAnk+xUKWEKmG2c61nCi8ZIZSpAXlsYjGGakzDm8TWWuB3MHwqE7h9iiBquvgB+up8hMrBTQV5RzOdGbeq+SryG0WA4/8h/uCJBssM9t86QOktayJ1wb0kFmyN5etp7zq/3icYxnYwbfE3G4kohMo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25D5FC4CEE2; Tue, 18 Feb 2025 23:01:21 +0000 (UTC) From: Dave Jiang To: linux-cxl@vger.kernel.org Cc: alison.schofield@intel.com Subject: [NDCTL PATCH v4 2/3] cxl: Enumerate major/minor of FWCTL char device Date: Tue, 18 Feb 2025 15:59:55 -0700 Message-ID: <20250218230116.2689627-3-dave.jiang@intel.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250218230116.2689627-1-dave.jiang@intel.com> References: <20250218230116.2689627-1-dave.jiang@intel.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add major/minor discovery for the FWCTL character device that is associated with supprting CXL Features under the cxl_memdev. Add libcxl API functions to retrieve the major and minor of the FWCTL character device. Signed-off-by: Dave Jiang --- cxl/lib/libcxl.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++ cxl/lib/libcxl.sym | 2 ++ cxl/lib/private.h | 1 + cxl/libcxl.h | 2 ++ 4 files changed, 79 insertions(+) diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c index bab7343e8a4a..566870acb30a 100644 --- a/cxl/lib/libcxl.c +++ b/cxl/lib/libcxl.c @@ -1253,6 +1253,66 @@ 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 = calloc(1, strlen(base) + 100); + struct dirent *entry; + int rc = 0; + DIR *dir; + + if (!path) + return -ENOMEM; + + sprintf(path, "%s/fwctl/", base); + dir = opendir(path); + if (!dir) { + rc = -errno; + goto err; + } + + while ((entry = readdir(dir)) != NULL) + if (strncmp(entry->d_name, fwctl_prefix, strlen(fwctl_prefix)) == 0) + break; + + if (!entry) { + rc = -ENOENT; + goto read_err; + } + + sprintf(chardev_path, "/dev/fwctl/%s", entry->d_name); + +read_err: + closedir(dir); +err: + free(path); + return rc; +} + +static int memdev_get_fwctl_chardev(struct cxl_memdev *memdev, + const char *cxlmem_base) +{ + char *path = calloc(1, strlen(cxlmem_base) + 100); + struct stat st; + int rc; + + rc = get_feature_chardev(cxlmem_base, path); + if (rc) + goto out; + + if (stat(path, &st) < 0) { + rc = -errno; + goto out; + } + + memdev->fwctl_major = major(st.st_rdev); + memdev->fwctl_minor = minor(st.st_rdev); + +out: + free(path); + return rc; +} + static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base) { const char *devname = devpath_to_devname(cxlmem_base); @@ -1279,6 +1339,10 @@ 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_get_fwctl_chardev(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 +1579,16 @@ CXL_EXPORT int cxl_memdev_get_minor(struct cxl_memdev *memdev) return memdev->minor; } +CXL_EXPORT int cxl_memdev_get_fwctl_major(struct cxl_memdev *memdev) +{ + return memdev->fwctl_major; +} + +CXL_EXPORT int cxl_memdev_get_fwctl_minor(struct cxl_memdev *memdev) +{ + return memdev->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 1fc33cc6e1a4..b2b51a72673c 100644 --- a/cxl/lib/libcxl.sym +++ b/cxl/lib/libcxl.sym @@ -292,4 +292,6 @@ global: LIBCXL_9 { global: cxl_bus_get_by_provider; + cxl_memdev_get_fwctl_major; + cxl_memdev_get_fwctl_minor; } LIBECXL_8; diff --git a/cxl/lib/private.h b/cxl/lib/private.h index b6cd910e9335..676bf1573487 100644 --- a/cxl/lib/private.h +++ b/cxl/lib/private.h @@ -37,6 +37,7 @@ enum cxl_fwl_loading { struct cxl_endpoint; struct cxl_memdev { int id, major, minor; + int fwctl_major, fwctl_minor; int numa_node; void *dev_buf; size_t buf_len; diff --git a/cxl/libcxl.h b/cxl/libcxl.h index 3b309968a808..26aa906740af 100644 --- a/cxl/libcxl.h +++ b/cxl/libcxl.h @@ -69,6 +69,8 @@ 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); +int cxl_memdev_get_fwctl_major(struct cxl_memdev *memdev); +int cxl_memdev_get_fwctl_minor(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);