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.
Acked-by: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Dave Jiang <dave.ji...@intel.com>
---
Documentation/cxl/lib/libcxl.txt | 24 +++++++++
config.h.meson | 3 ++
cxl/lib/libcxl.c | 83 ++++++++++++++++++++++++++++++++
cxl/lib/libcxl.sym | 3 ++
cxl/lib/private.h | 6 +++
cxl/libcxl.h | 5 ++
meson.build | 1 +
meson_options.txt | 2 +
8 files changed, 127 insertions(+)
diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
index 25ff406c2920..2a512fd9d276 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 +60,11 @@ 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,
+CONFIG_CXL_FEATURES is enabled, and Firmware Control (FWCTL) is also enabled.
+By default the 'fwctl' option is enabled for CXL CLI. The discovery can
+be disabled by meson build option.
+
=== MEMDEV: Attributes
----
int cxl_memdev_get_id(struct cxl_memdev *memdev);
@@ -185,6 +191,24 @@ 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 interacting with the FWCTL aspect of the
+memdev. And currently specifically with 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/config.h.meson b/config.h.meson
index 5441dff9fce7..f75db3e6360f 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -155,3 +155,6 @@
#mesondefine DAXCTL_MODPROBE_DATA
#mesondefine DAXCTL_MODPROBE_INSTALL
#mesondefine PREFIX
+
+/* cxl fwctl support */
+#mesondefine ENABLE_FWCTL
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index bab7343e8a4a..af28f976bdc8 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 +1254,67 @@ static int add_cxl_memdev_fwl(struct cxl_memdev *memdev,
return -ENOMEM;
}
+#ifdef ENABLE_FWCTL
+static const char fwctl_prefix[] = "fwctl";
+static int get_feature_chardev(struct cxl_memdev *memdev, const char *base,
+ char *chardev_path)
+{
+ char *path = memdev->dev_buf;
+ 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)
+{
+ char *path = memdev->dev_buf;
+ struct cxl_fwctl *fwctl;
+ struct stat st;
+ int rc;
+
+ rc = get_feature_chardev(memdev, 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;
+}
+#endif
+
static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base)
{
const char *devname = devpath_to_devname(cxlmem_base);
@@ -1353,6 +1415,12 @@ static void *add_cxl_memdev(void *parent, int id, const
char *cxlmem_base)
goto err_read;
memdev->buf_len = strlen(cxlmem_base) + 50;
+#ifdef ENABLE_FWCTL
+ /* If this fails, no Features support. */
+ if (memdev_add_fwctl(memdev, cxlmem_base))
+ dbg(ctx, "%s: no Features support.\n", devname);
+#endif
+
device_parse(ctx, cxlmem_base, "pmem", memdev, add_cxl_pmem);
if (add_cxl_memdev_fwl(memdev, cxlmem_base))
@@ -1515,6 +1583,21 @@ 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..7d5a1bcc14ac 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -34,6 +34,11 @@ 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 +61,7 @@ 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)
diff --git a/meson.build b/meson.build
index 3171ef1024ea..7bc40c7df12a 100644
--- a/meson.build
+++ b/meson.build
@@ -237,6 +237,7 @@ conf.set('ENABLE_DESTRUCTIVE',
get_option('destructive').enabled())
conf.set('ENABLE_LOGGING', get_option('logging').enabled())
conf.set('ENABLE_DEBUG', get_option('dbg').enabled())
conf.set('ENABLE_LIBTRACEFS', get_option('libtracefs').enabled())
+conf.set('ENABLE_FWCTL', get_option('fwctl').enabled())
typeof_code = '''
void func() {
diff --git a/meson_options.txt b/meson_options.txt
index 5c41b1abe1f1..acc19be4ff0a 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -28,3 +28,5 @@ option('iniparserdir', type : 'string',
description : 'Path containing the iniparser header files')
option('modprobedatadir', type : 'string',
description : '''${sysconfdir}/modprobe.d/''')
+option('fwctl', type : 'feature', value : 'enabled',
+ description : 'enable firmware control')
--
2.49.0
