Add new libdaxctl interfaces to disable a device_dax based devices, and
to enable it into a given mode. The modes available are 'device_dax',
and 'system-ram', where device_dax is the normal device DAX mode used
via a character device, and 'system-ram' uses the kernel's 'kmem'
facility to hotplug the device into the system's memory space, and can
be used as normal system memory.
This adds the following new interfaces:
daxctl_dev_disable;
daxctl_dev_enable_devdax;
daxctl_dev_enable_ram;
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Vishal Verma <vishal.l.ve...@intel.com>
---
daxctl/lib/Makefile.am | 3 +-
daxctl/lib/libdaxctl-private.h | 15 ++
daxctl/lib/libdaxctl.c | 241 +++++++++++++++++++++++++++++++++
daxctl/lib/libdaxctl.sym | 3 +
daxctl/libdaxctl.h | 9 ++
5 files changed, 270 insertions(+), 1 deletion(-)
diff --git a/daxctl/lib/Makefile.am b/daxctl/lib/Makefile.am
index d3d4852..9f0e444 100644
--- a/daxctl/lib/Makefile.am
+++ b/daxctl/lib/Makefile.am
@@ -16,7 +16,8 @@ libdaxctl_la_SOURCES =\
libdaxctl.c
libdaxctl_la_LIBADD =\
- $(UUID_LIBS)
+ $(UUID_LIBS) \
+ $(KMOD_LIBS)
daxctl_modprobe_data_DATA = daxctl.conf
diff --git a/daxctl/lib/libdaxctl-private.h b/daxctl/lib/libdaxctl-private.h
index 4a462e7..e64d0a7 100644
--- a/daxctl/lib/libdaxctl-private.h
+++ b/daxctl/lib/libdaxctl-private.h
@@ -13,6 +13,8 @@
#ifndef _LIBDAXCTL_PRIVATE_H_
#define _LIBDAXCTL_PRIVATE_H_
+#include <libkmod.h>
+
#define DAXCTL_EXPORT __attribute__ ((visibility("default")))
enum dax_subsystem {
@@ -26,6 +28,11 @@ static const char *dax_subsystems[] = {
[DAX_BUS] = "/sys/bus/dax/devices",
};
+static const char *dax_modules[] = {
+ [DAXCTL_DEV_MODE_DEVDAX] = "device_dax",
+ [DAXCTL_DEV_MODE_RAM] = "kmem",
+};
+
/**
* struct daxctl_region - container for dax_devices
*/
@@ -53,6 +60,14 @@ struct daxctl_dev {
char *dev_path;
struct list_node list;
unsigned long long size;
+ struct kmod_module *module;
+ struct kmod_list *kmod_list;
struct daxctl_region *region;
};
+
+static inline int check_kmod(struct kmod_ctx *kmod_ctx)
+{
+ return kmod_ctx ? 0 : -ENXIO;
+}
+
#endif /* _LIBDAXCTL_PRIVATE_H_ */
diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c
index f8f5b8c..d50b321 100644
--- a/daxctl/lib/libdaxctl.c
+++ b/daxctl/lib/libdaxctl.c
@@ -47,6 +47,7 @@ struct daxctl_ctx {
int regions_init;
struct list_head regions;
enum dax_subsystem subsys;
+ struct kmod_ctx *kmod_ctx;
};
/**
@@ -85,12 +86,20 @@ DAXCTL_EXPORT void daxctl_set_userdata(struct daxctl_ctx
*ctx, void *userdata)
*/
DAXCTL_EXPORT int daxctl_new(struct daxctl_ctx **ctx)
{
+ struct kmod_ctx *kmod_ctx;
struct daxctl_ctx *c;
+ int rc = 0;
c = calloc(1, sizeof(struct daxctl_ctx));
if (!c)
return -ENOMEM;
+ kmod_ctx = kmod_new(NULL, NULL);
+ if (check_kmod(kmod_ctx) != 0) {
+ rc = -ENXIO;
+ goto out;
+ }
+
c->refcount = 1;
log_init(&c->ctx, "libdaxctl", "DAXCTL_LOG");
info(c, "ctx %p created\n", c);
@@ -98,8 +107,12 @@ DAXCTL_EXPORT int daxctl_new(struct daxctl_ctx **ctx)
*ctx = c;
list_head_init(&c->regions);
c->subsys = DAX_UNKNOWN;
+ c->kmod_ctx = kmod_ctx;
return 0;
+out:
+ free(c);
+ return rc;
}
/**
@@ -134,6 +147,7 @@ DAXCTL_EXPORT void daxctl_unref(struct daxctl_ctx *ctx)
list_for_each_safe(&ctx->regions, region, _r, list)
free_region(region, &ctx->regions);
+ kmod_unref(ctx->kmod_ctx);
info(ctx, "context %p released\n", ctx);
free(ctx);
}
@@ -191,6 +205,7 @@ static void free_dev(struct daxctl_dev *dev, struct
list_head *head)
{
if (head)
list_del_from(head, &dev->list);
+ kmod_module_unref_list(dev->kmod_list);
free(dev->dev_buf);
free(dev->dev_path);
free(dev);
@@ -308,6 +323,27 @@ DAXCTL_EXPORT struct daxctl_region
*daxctl_new_region(struct daxctl_ctx *ctx,
return region;
}
+static struct kmod_list *to_module_list(struct daxctl_ctx *ctx,
+ const char *alias)
+{
+ struct kmod_list *list = NULL;
+ int rc;
+
+ if (!ctx->kmod_ctx || !alias)
+ return NULL;
+ if (alias[0] == 0)
+ return NULL;
+
+ rc = kmod_module_new_from_lookup(ctx->kmod_ctx, alias, &list);
+ if (rc < 0 || !list) {
+ dbg(ctx, "failed to find modules for alias: %s %d list: %s\n",
+ alias, rc, list ? "populated" : "empty");
+ return NULL;
+ }
+
+ return list;
+}
+
static void *add_dax_dev(void *parent, int id, const char *daxdev_base)
{
const char *devname = devpath_to_devname(daxdev_base);
@@ -317,6 +353,7 @@ static void *add_dax_dev(void *parent, int id, const char
*daxdev_base)
struct daxctl_dev *dev, *dev_dup;
char buf[SYSFS_ATTR_SIZE];
struct stat st;
+ int rc;
if (!path)
return NULL;
@@ -348,6 +385,18 @@ static void *add_dax_dev(void *parent, int id, const char
*daxdev_base)
goto err_read;
dev->buf_len = strlen(daxdev_base) + 50;
+ sprintf(path, "%s/modalias", daxdev_base);
+ rc = sysfs_read_attr(ctx, path, buf);
+ /* older kernels may be lack the modalias attribute */
+ if (rc < 0 && rc != -ENOENT)
+ goto err_read;
+ if (rc == 0) {
+ dev->kmod_list = to_module_list(ctx, buf);
+ if (dev->kmod_list == NULL)
+ goto err_read;
+ } else
+ dbg(ctx, "%s: modalias attribute missing\n", devname);
+
daxctl_dev_foreach(region, dev_dup)
if (dev_dup->id == dev->id) {
free_dev(dev, NULL);
@@ -577,6 +626,83 @@ static int is_enabled(const char *drvpath)
return 1;
}
+static int daxctl_bind(struct daxctl_ctx *ctx, const char *devname,
+ const char *mod_name)
+{
+ DIR *dir;
+ int rc = 0;
+ char path[200];
+ struct dirent *de;
+ const int len = sizeof(path);
+
+ if (!devname) {
+ err(ctx, "missing devname\n");
+ return -EINVAL;
+ }
+
+ /* this is only called by daxctl_dev_enable which gates on dax-bus */
+ if (snprintf(path, len, "/sys/bus/dax/drivers") >= len) {
+ err(ctx, "%s: buffer too small!\n", devname);
+ return -ENXIO;
+ }
+
+ dir = opendir(path);
+ if (!dir) {
+ err(ctx, "%s: opendir(\"%s\") failed\n", devname, path);
+ return -ENXIO;
+ }
+
+ while ((de = readdir(dir)) != NULL) {
+ char *drv_path;
+
+ if (de->d_ino == 0)
+ continue;
+ if (de->d_name[0] == '.')
+ continue;
+ if (strcmp(de->d_name, mod_name) != 0)
+ continue;
+
+ if (asprintf(&drv_path, "%s/%s/new_id", path, de->d_name) < 0) {
+ err(ctx, "%s: path allocation failure\n", devname);
+ rc = -ENOMEM;
+ break;
+ }
+ rc = sysfs_write_attr_quiet(ctx, drv_path, devname);
+ free(drv_path);
+
+ if (asprintf(&drv_path, "%s/%s/bind", path, de->d_name) < 0) {
+ err(ctx, "%s: path allocation failure\n", devname);
+ rc = -ENOMEM;
+ break;
+ }
+ rc = sysfs_write_attr_quiet(ctx, drv_path, devname);
+ free(drv_path);
+ break;
+ }
+ closedir(dir);
+
+ if (rc) {
+ dbg(ctx, "%s: bind failed\n", devname);
+ return rc;
+ }
+ return 0;
+}
+
+static int daxctl_unbind(struct daxctl_ctx *ctx, const char *devpath)
+{
+ const char *devname = devpath_to_devname(devpath);
+ char path[200];
+ const int len = sizeof(path);
+
+ /* this is only called by daxctl_dev_disable which gates on dax-bus */
+ if (snprintf(path, len, "%s/driver/unbind", devpath) >= len) {
+ err(ctx, "%s: buffer too small!\n", devname);
+ return -ENXIO;
+ }
+
+ return sysfs_write_attr(ctx, path, devname);
+}
+
DAXCTL_EXPORT int daxctl_dev_is_enabled(struct daxctl_dev *dev)
{
struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
@@ -592,6 +718,121 @@ DAXCTL_EXPORT int daxctl_dev_is_enabled(struct daxctl_dev
*dev)
return is_enabled(path);
}
+static int daxctl_insert_kmod_for_mode(struct daxctl_dev *dev,
+ const char *mod_name)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ struct kmod_list *iter;
+ int rc = -ENXIO;
+
+ if (dev->kmod_list == NULL) {
+ err(ctx, "%s: a modalias lookup list was not created\n",
+ devname);
+ return rc;
+ }
+
+ kmod_list_foreach(iter, dev->kmod_list) {
+ struct kmod_module *mod = kmod_module_get_module(iter);
+ const char *name = kmod_module_get_name(mod);
+
+ if (strcmp(name, mod_name) != 0) {
+ kmod_module_unref(mod);
+ continue;
+ }
+ dbg(ctx, "%s inserting module: %s\n", devname, name);
+ rc = kmod_module_probe_insert_module(mod,
+ KMOD_PROBE_APPLY_BLACKLIST, NULL, NULL, NULL,
+ NULL);
+ if (rc < 0) {
+ err(ctx, "%s: insert failure: %d\n", devname, rc);
+ return rc;
+ }
+ dev->module = mod;
+ }
+
+ if (rc == -ENXIO)
+ err(ctx, "%s: Unable to find module: %s in alias list\n",
+ devname, mod_name);
+ return rc;
+}
+
+static int daxctl_dev_enable(struct daxctl_dev *dev, enum daxctl_dev_mode mode)
+{
+ struct daxctl_region *region = daxctl_dev_get_region(dev);
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ const char *mod_name = dax_modules[mode];
+ int rc;
+
+ if (daxctl_dev_is_enabled(dev))
+ return 0;
+
+ if (ctx->subsys != DAX_BUS) {
+ err(ctx, "%s: invalid operation for dax subsystem\n", devname);
+ err(ctx, "%s: see daxctl-migrate-device-model(1)\n", devname);
+ return -ENXIO;
+ }
+
+ if (mode == DAXCTL_DEV_MODE_UNKNOWN || mod_name == NULL) {
+ err(ctx, "%s: Invalid mode: %d\n", devname, mode);
+ return -EINVAL;
+ }
+
+ rc = daxctl_insert_kmod_for_mode(dev, mod_name);
+ if (rc)
+ return rc;
+
+ rc = daxctl_bind(ctx, devname, mod_name);
+ if (!daxctl_dev_is_enabled(dev)) {
+ err(ctx, "%s: failed to enable\n", devname);
+ return rc ? rc : -ENXIO;
+ }
+
+ region->devices_init = 0;
+ dax_devices_init(region);
+ rc = 0;
+ dbg(ctx, "%s: enabled\n", devname);
+ return rc;
+}
+
+DAXCTL_EXPORT int daxctl_dev_enable_devdax(struct daxctl_dev *dev)
+{
+ return daxctl_dev_enable(dev, DAXCTL_DEV_MODE_DEVDAX);
+}
+
+DAXCTL_EXPORT int daxctl_dev_enable_ram(struct daxctl_dev *dev)
+{
+ return daxctl_dev_enable(dev, DAXCTL_DEV_MODE_RAM);
+}
+
+DAXCTL_EXPORT int daxctl_dev_disable(struct daxctl_dev *dev)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+
+ if (!daxctl_dev_is_enabled(dev))
+ return 0;
+
+ if (ctx->subsys != DAX_BUS) {
+ err(ctx, "%s: invalid operation for dax subsystem\n", devname);
+ err(ctx, "%s: see daxctl-migrate-device-model(1)\n", devname);
+ return -ENXIO;
+ }
+
+ daxctl_unbind(ctx, dev->dev_path);
+
+ if (daxctl_dev_is_enabled(dev)) {
+ err(ctx, "%s: failed to disable\n", devname);
+ return -EBUSY;
+ }
+
+ kmod_module_unref(dev->module);
+ dbg(ctx, "%s: disabled\n", devname);
+
+ return 0;
+}
+
DAXCTL_EXPORT struct daxctl_ctx *daxctl_dev_get_ctx(struct daxctl_dev *dev)
{
return dev->region->ctx;
diff --git a/daxctl/lib/libdaxctl.sym b/daxctl/lib/libdaxctl.sym
index c4af9a7..19904a2 100644
--- a/daxctl/lib/libdaxctl.sym
+++ b/daxctl/lib/libdaxctl.sym
@@ -55,4 +55,7 @@ LIBDAXCTL_6 {
global:
daxctl_dev_get_ctx;
daxctl_dev_is_enabled;
+ daxctl_dev_disable;
+ daxctl_dev_enable_devdax;
+ daxctl_dev_enable_ram;
} LIBDAXCTL_5;
diff --git a/daxctl/libdaxctl.h b/daxctl/libdaxctl.h
index e20ccb4..b80488e 100644
--- a/daxctl/libdaxctl.h
+++ b/daxctl/libdaxctl.h
@@ -69,6 +69,9 @@ int daxctl_dev_get_minor(struct daxctl_dev *dev);
unsigned long long daxctl_dev_get_size(struct daxctl_dev *dev);
struct daxctl_ctx *daxctl_dev_get_ctx(struct daxctl_dev *dev);
int daxctl_dev_is_enabled(struct daxctl_dev *dev);
+int daxctl_dev_disable(struct daxctl_dev *dev);
+int daxctl_dev_enable_devdax(struct daxctl_dev *dev);
+int daxctl_dev_enable_ram(struct daxctl_dev *dev);
#define daxctl_dev_foreach(region, dev) \
for (dev = daxctl_dev_get_first(region); \
@@ -81,6 +84,12 @@ int daxctl_dev_is_enabled(struct daxctl_dev *dev);
region != NULL; \
region = daxctl_region_get_next(region))
+enum daxctl_dev_mode {
+ DAXCTL_DEV_MODE_UNKNOWN,
+ DAXCTL_DEV_MODE_RAM,
+ DAXCTL_DEV_MODE_DEVDAX,
+};
+
#ifdef __cplusplus
} /* extern "C" */
#endif
--
2.20.1
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