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firmware: Add support for loading compressed files 

This patch adds the support for loading compressed firmware files.
The primary motivation is to reduce the storage size; e.g. currently
the files in /lib/firmware on my machine counts up to 419MB, while
they can be reduced to 130MB by file compression.

The patch introduces a new kconfig option CONFIG_FW_LOADER_COMPRESS.
Even with this option set, the firmware loader still tries to load the
original firmware file as-is at first, but then falls back to the file
with ".xz" extension when it's not found, and the decompressed file
content is returned to the caller of request_firmware().  So, no
change is needed for the rest.

Currently only XZ format is supported.  A caveat is that the kernel XZ
helper code supports only CRC32 (or none) integrity check type, so
you'll have to compress the files via xz -C crc32 option.

Since we can't determine the expanded size immediately from an XZ
file, the patch re-uses the paged buffer that was used for the
user-mode fallback; it puts the decompressed content page, which are
vmapped at the end.  The paged buffer code is conditionally built with
a new Kconfig that is selected automatically.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alistair/sunxi64-5.4-dsi
Takashi Iwai 2019-06-11 14:26:25 +02:00 committed by Greg Kroah-Hartman
parent 5342e7093f
commit 82fd7a8142
3 changed files with 161 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/base/firmware_loader/Kconfig
View File

@ -26,6 +26,9 @@ config FW_LOADER
if FW_LOADER
config FW_LOADER_PAGED_BUF
bool
config EXTRA_FIRMWARE
string "Build named firmware blobs into the kernel binary"
help
@ -67,6 +70,7 @@ config EXTRA_FIRMWARE_DIR
config FW_LOADER_USER_HELPER
bool "Enable the firmware sysfs fallback mechanism"
select FW_LOADER_PAGED_BUF
help
This option enables a sysfs loading facility to enable firmware
loading to the kernel through userspace as a fallback mechanism
@ -151,5 +155,19 @@ config FW_LOADER_USER_HELPER_FALLBACK
If you are unsure about this, say N here.
config FW_LOADER_COMPRESS
bool "Enable compressed firmware support"
select FW_LOADER_PAGED_BUF
select XZ_DEC
help
This option enables the support for loading compressed firmware
files. The caller of firmware API receives the decompressed file
content. The compressed file is loaded as a fallback, only after
loading the raw file failed at first.
Currently only XZ-compressed files are supported, and they have to
be compressed with either none or crc32 integrity check type (pass
"-C crc32" option to xz command).
endif # FW_LOADER
endmenu

8
drivers/base/firmware_loader/firmware.h
View File

@ -64,12 +64,14 @@ struct fw_priv {
void *data;
size_t size;
size_t allocated_size;
#ifdef CONFIG_FW_LOADER_USER_HELPER
#ifdef CONFIG_FW_LOADER_PAGED_BUF
bool is_paged_buf;
bool need_uevent;
struct page **pages;
int nr_pages;
int page_array_size;
#endif
#ifdef CONFIG_FW_LOADER_USER_HELPER
bool need_uevent;
struct list_head pending_list;
#endif
const char *fw_name;
@ -133,7 +135,7 @@ static inline void fw_state_done(struct fw_priv *fw_priv)
int assign_fw(struct firmware *fw, struct device *device,
enum fw_opt opt_flags);
#ifdef CONFIG_FW_LOADER_USER_HELPER
#ifdef CONFIG_FW_LOADER_PAGED_BUF
void fw_free_paged_buf(struct fw_priv *fw_priv);
int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
int fw_map_paged_buf(struct fw_priv *fw_priv);

147
drivers/base/firmware_loader/main.c
View File

@ -33,6 +33,7 @@
#include <linux/syscore_ops.h>
#include <linux/reboot.h>
#include <linux/security.h>
#include <linux/xz.h>
#include <generated/utsrelease.h>
@ -266,7 +267,7 @@ static void free_fw_priv(struct fw_priv *fw_priv)
spin_unlock(&fwc->lock);
}
#ifdef CONFIG_FW_LOADER_USER_HELPER
#ifdef CONFIG_FW_LOADER_PAGED_BUF
void fw_free_paged_buf(struct fw_priv *fw_priv)
{
int i;
@ -335,6 +336,105 @@ int fw_map_paged_buf(struct fw_priv *fw_priv)
}
#endif
/*
* XZ-compressed firmware support
*/
#ifdef CONFIG_FW_LOADER_COMPRESS
/* show an error and return the standard error code */
static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
{
if (xz_ret != XZ_STREAM_END) {
dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
}
return 0;
}
/* single-shot decompression onto the pre-allocated buffer */
static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
struct xz_dec *xz_dec;
struct xz_buf xz_buf;
enum xz_ret xz_ret;
xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
if (!xz_dec)
return -ENOMEM;
xz_buf.in_size = in_size;
xz_buf.in = in_buffer;
xz_buf.in_pos = 0;
xz_buf.out_size = fw_priv->allocated_size;
xz_buf.out = fw_priv->data;
xz_buf.out_pos = 0;
xz_ret = xz_dec_run(xz_dec, &xz_buf);
xz_dec_end(xz_dec);
fw_priv->size = xz_buf.out_pos;
return fw_decompress_xz_error(dev, xz_ret);
}
/* decompression on paged buffer and map it */
static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
struct xz_dec *xz_dec;
struct xz_buf xz_buf;
enum xz_ret xz_ret;
struct page *page;
int err = 0;
xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
if (!xz_dec)
return -ENOMEM;
xz_buf.in_size = in_size;
xz_buf.in = in_buffer;
xz_buf.in_pos = 0;
fw_priv->is_paged_buf = true;
fw_priv->size = 0;
do {
if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
err = -ENOMEM;
goto out;
}
/* decompress onto the new allocated page */
page = fw_priv->pages[fw_priv->nr_pages - 1];
xz_buf.out = kmap(page);
xz_buf.out_pos = 0;
xz_buf.out_size = PAGE_SIZE;
xz_ret = xz_dec_run(xz_dec, &xz_buf);
kunmap(page);
fw_priv->size += xz_buf.out_pos;
/* partial decompression means either end or error */
if (xz_buf.out_pos != PAGE_SIZE)
break;
} while (xz_ret == XZ_OK);
err = fw_decompress_xz_error(dev, xz_ret);
if (!err)
err = fw_map_paged_buf(fw_priv);
out:
xz_dec_end(xz_dec);
return err;
}
static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
/* if the buffer is pre-allocated, we can perform in single-shot mode */
if (fw_priv->data)
return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
else
return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
}
#endif /* CONFIG_FW_LOADER_COMPRESS */
/* direct firmware loading support */
static char fw_path_para[256];
static const char * const fw_path[] = {
@ -354,7 +454,12 @@ module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
static int
fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
const char *suffix,
int (*decompress)(struct device *dev,
struct fw_priv *fw_priv,
size_t in_size,
const void *in_buffer))
{
loff_t size;
int i, len;
@ -362,9 +467,11 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
char *path;
enum kernel_read_file_id id = READING_FIRMWARE;
size_t msize = INT_MAX;
void *buffer = NULL;
/* Already populated data member means we're loading into a buffer */
if (fw_priv->data) {
if (!decompress && fw_priv->data) {
buffer = fw_priv->data;
id = READING_FIRMWARE_PREALLOC_BUFFER;
msize = fw_priv->allocated_size;
}
@ -378,15 +485,15 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
if (!fw_path[i][0])
continue;
len = snprintf(path, PATH_MAX, "%s/%s",
fw_path[i], fw_priv->fw_name);
len = snprintf(path, PATH_MAX, "%s/%s%s",
fw_path[i], fw_priv->fw_name, suffix);
if (len >= PATH_MAX) {
rc = -ENAMETOOLONG;
break;
}
fw_priv->size = 0;
rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
rc = kernel_read_file_from_path(path, &buffer, &size,
msize, id);
if (rc) {
if (rc != -ENOENT)
@ -397,8 +504,24 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
path);
continue;
}
dev_dbg(device, "direct-loading %s\n", fw_priv->fw_name);
fw_priv->size = size;
if (decompress) {
dev_dbg(device, "f/w decompressing %s\n",
fw_priv->fw_name);
rc = decompress(device, fw_priv, size, buffer);
/* discard the superfluous original content */
vfree(buffer);
buffer = NULL;
if (rc) {
fw_free_paged_buf(fw_priv);
continue;
}
} else {
dev_dbg(device, "direct-loading %s\n",
fw_priv->fw_name);
if (!fw_priv->data)
fw_priv->data = buffer;
fw_priv->size = size;
}
fw_state_done(fw_priv);
break;
}
@ -645,7 +768,13 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
if (ret <= 0) /* error or already assigned */
goto out;
ret = fw_get_filesystem_firmware(device, fw->priv);
ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
#ifdef CONFIG_FW_LOADER_COMPRESS
if (ret == -ENOENT)
ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
fw_decompress_xz);
#endif
if (ret) {
if (!(opt_flags & FW_OPT_NO_WARN))
dev_warn(device,