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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-04 02:58:32 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-04 02:58:32 +0400
commitabb139e75c2cdbb955e840d6331cb5863e409d0e (patch)
tree2b6c986488d3a2444095153b167c0e0f82a0b487 /drivers/base
parentdf5a2a1fbca44bebeebb78530ac93c734f289707 (diff)
downloadlinux-abb139e75c2cdbb955e840d6331cb5863e409d0e.tar.xz
firmware: teach the kernel to load firmware files directly from the filesystem
This is a first step in allowing people to by-pass udev for loading device firmware. Current versions of udev will deadlock (causing us to block for the 30 second timeout) under some circumstances if the firmware is loaded as part of the module initialization path, and this is causing problems for media drivers in particular. The current patch hardcodes the firmware path that udev uses by default, and will fall back to the legacy udev mode if the firmware cannot be found there. We'd like to add support for both configuring the paths and the fallback behaviour, but in the meantime this hopefully fixes the immediate problem, while also giving us a way forward. [ v2: Some VFS layer interface cleanups suggested by Al Viro ] [ v3: use the default udev paths suggested by Kay Sievers ] Suggested-by: Ivan Kalvachev <ikalvachev@gmail.com> Acked-by: Greg KH <gregkh@linuxfoundation.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Kay Sievers <kay@redhat.com> Cc: Ming Lei <ming.lei@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/firmware_class.c78
1 files changed, 77 insertions, 1 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 6e210802c37b..e85763de928f 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -21,18 +21,85 @@
#include <linux/firmware.h>
#include <linux/slab.h>
#include <linux/sched.h>
+#include <linux/file.h>
#include <linux/list.h>
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
+#include <generated/utsrelease.h>
+
#include "base.h"
MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");
+static const char *fw_path[] = {
+ "/lib/firmware/updates/" UTS_RELEASE,
+ "/lib/firmware/updates",
+ "/lib/firmware/" UTS_RELEASE,
+ "/lib/firmware"
+};
+
+/* Don't inline this: 'struct kstat' is biggish */
+static noinline long fw_file_size(struct file *file)
+{
+ struct kstat st;
+ if (vfs_getattr(file->f_path.mnt, file->f_path.dentry, &st))
+ return -1;
+ if (!S_ISREG(st.mode))
+ return -1;
+ if (st.size != (long)st.size)
+ return -1;
+ return st.size;
+}
+
+static bool fw_read_file_contents(struct file *file, struct firmware *fw)
+{
+ loff_t pos;
+ long size;
+ char *buf;
+
+ size = fw_file_size(file);
+ if (size < 0)
+ return false;
+ buf = vmalloc(size);
+ if (!buf)
+ return false;
+ pos = 0;
+ if (vfs_read(file, buf, size, &pos) != size) {
+ vfree(buf);
+ return false;
+ }
+ fw->data = buf;
+ fw->size = size;
+ return true;
+}
+
+static bool fw_get_filesystem_firmware(struct firmware *fw, const char *name)
+{
+ int i;
+ bool success = false;
+ char *path = __getname();
+
+ for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+ struct file *file;
+ snprintf(path, PATH_MAX, "%s/%s", fw_path[i], name);
+
+ file = filp_open(path, O_RDONLY, 0);
+ if (IS_ERR(file))
+ continue;
+ success = fw_read_file_contents(file, fw);
+ fput(file);
+ if (success)
+ break;
+ }
+ __putname(path);
+ return success;
+}
+
/* Builtin firmware support */
#ifdef CONFIG_FW_LOADER
@@ -346,7 +413,11 @@ static ssize_t firmware_loading_show(struct device *dev,
/* firmware holds the ownership of pages */
static void firmware_free_data(const struct firmware *fw)
{
- WARN_ON(!fw->priv);
+ /* Loaded directly? */
+ if (!fw->priv) {
+ vfree(fw->data);
+ return;
+ }
fw_free_buf(fw->priv);
}
@@ -709,6 +780,11 @@ _request_firmware_prepare(const struct firmware **firmware_p, const char *name,
return NULL;
}
+ if (fw_get_filesystem_firmware(firmware, name)) {
+ dev_dbg(device, "firmware: direct-loading firmware %s\n", name);
+ return NULL;
+ }
+
ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
if (!ret)
fw_priv = fw_create_instance(firmware, name, device,