Module autoprobing support for virtio drivers.

This adds the logic to convert the virtio ids into module aliases, and
includes a modalias entry in sysfs and the env var to make probing work.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

2 files changed, 36 insertions, 0 deletions

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index f640e0b732b7..15d7787dea87 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -20,10 +20,19 @@ static ssize_t status_show(struct device *_d,
         struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
         return sprintf(buf, "0x%08x", dev->config->get_status(dev));
 }
+static ssize_t modalias_show(struct device *_d,
+                             struct device_attribute *attr, char *buf)
+{
+        struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+
+        return sprintf(buf, "virtio:d%08Xv%08X\n",
+                       dev->id.device, dev->id.vendor);
+}
 static struct device_attribute virtio_dev_attrs[] = {
         __ATTR_RO(device),
         __ATTR_RO(vendor),
         __ATTR_RO(status),
+        __ATTR_RO(modalias),
         __ATTR_NULL
 };
 
@@ -51,10 +60,19 @@ static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
         return 0;
 }
 
+static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
+{
+        struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+
+        return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
+                              dev->id.device, dev->id.vendor);
+}
+
 static struct bus_type virtio_bus = {
         .name  = "virtio",
         .match = virtio_dev_match,
         .dev_attrs = virtio_dev_attrs,
+        .uevent = virtio_uevent,
 };
 
 static void add_status(struct virtio_device *dev, unsigned status)
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 91c15da2680b..d802b5afae89 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -525,6 +525,20 @@ static int do_ssb_entry(const char *filename,
         return 1;
 }
 
+/* Looks like: virtio:dNvN */
+static int do_virtio_entry(const char *filename, struct virtio_device_id *id,
+                           char *alias)
+{
+        id->device = TO_NATIVE(id->device);
+        id->vendor = TO_NATIVE(id->vendor);
+
+        strcpy(alias, "virtio:");
+        ADD(alias, "d", 1, id->device);
+        ADD(alias, "v", id->vendor != VIRTIO_DEV_ANY_ID, id->vendor);
+
+        return 1;
+}
+
 /* Ignore any prefix, eg. v850 prepends _ */
 static inline int sym_is(const char *symbol, const char *name)
 {
@@ -651,6 +665,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
                 do_table(symval, sym->st_size,
                          sizeof(struct ssb_device_id), "ssb",
                          do_ssb_entry, mod);
+        else if (sym_is(symname, "__mod_virtio_device_table"))
+                do_table(symval, sym->st_size,
+                         sizeof(struct virtio_device_id), "virtio",
+                         do_virtio_entry, mod);
         free(zeros);
 }