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 --- v1->v2: Slight code refactoring, no functional changes

drivers/base/firmware_loader/Kconfig | 18 ++++ drivers/base/firmware_loader/firmware.h | 8 +- drivers/base/firmware_loader/main.c | 147 ++++++++++++++++++++++++++++++-- 3 files changed, 161 insertions(+), 12 deletions(-)

diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig index 38f2da6f5c2b..3f9e274e2ed3 100644 --- a/drivers/base/firmware_loader/Kconfig +++ b/drivers/base/firmware_loader/Kconfig @@ -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 diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h index 35f4e58b2d98..7048a41973ed 100644 --- a/drivers/base/firmware_loader/firmware.h +++ b/drivers/base/firmware_loader/firmware.h @@ -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); diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index 7e12732f4705..bf44c79beae9 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -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,