diff options
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/firmware/efi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/firmware/efi/capsule-loader.c | 343 |
3 files changed, 354 insertions, 0 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 0b0b635aa101..6394152f648f 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -102,6 +102,16 @@ config EFI_BOOTLOADER_CONTROL bootloader reads this reboot reason and takes particular action according to its policy. +config EFI_CAPSULE_LOADER + tristate "EFI capsule loader" + depends on EFI + help + This option exposes a loader interface "/dev/efi_capsule_loader" for + users to load EFI capsules. This driver requires working runtime + capsule support in the firmware, which many OEMs do not provide. + + Most users should say N. + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index fb8ad5db6547..a219640f881f 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -24,3 +24,4 @@ obj-$(CONFIG_EFI_BOOTLOADER_CONTROL) += efibc.o arm-obj-$(CONFIG_EFI) := arm-init.o arm-runtime.o obj-$(CONFIG_ARM) += $(arm-obj-y) obj-$(CONFIG_ARM64) += $(arm-obj-y) +obj-$(CONFIG_EFI_CAPSULE_LOADER) += capsule-loader.o diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c new file mode 100644 index 000000000000..c99c24bc79b0 --- /dev/null +++ b/drivers/firmware/efi/capsule-loader.c @@ -0,0 +1,343 @@ +/* + * EFI capsule loader driver. + * + * Copyright 2015 Intel Corporation + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + */ + +#define pr_fmt(fmt) "efi: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/miscdevice.h> +#include <linux/highmem.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/efi.h> + +#define NO_FURTHER_WRITE_ACTION -1 + +struct capsule_info { + bool header_obtained; + int reset_type; + long index; + size_t count; + size_t total_size; + struct page **pages; + size_t page_bytes_remain; +}; + +/** + * efi_free_all_buff_pages - free all previous allocated buffer pages + * @cap_info: pointer to current instance of capsule_info structure + * + * In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION + * to cease processing data in subsequent write(2) calls until close(2) + * is called. + **/ +static void efi_free_all_buff_pages(struct capsule_info *cap_info) +{ + while (cap_info->index > 0) + __free_page(cap_info->pages[--cap_info->index]); + + cap_info->index = NO_FURTHER_WRITE_ACTION; +} + +/** + * efi_capsule_setup_info - obtain the efi capsule header in the binary and + * setup capsule_info structure + * @cap_info: pointer to current instance of capsule_info structure + * @kbuff: a mapped first page buffer pointer + * @hdr_bytes: the total received number of bytes for efi header + **/ +static ssize_t efi_capsule_setup_info(struct capsule_info *cap_info, + void *kbuff, size_t hdr_bytes) +{ + efi_capsule_header_t *cap_hdr; + size_t pages_needed; + int ret; + void *temp_page; + + /* Only process data block that is larger than efi header size */ + if (hdr_bytes < sizeof(efi_capsule_header_t)) + return 0; + + /* Reset back to the correct offset of header */ + cap_hdr = kbuff - cap_info->count; + pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> PAGE_SHIFT; + + if (pages_needed == 0) { + pr_err("%s: pages count invalid\n", __func__); + return -EINVAL; + } + + /* Check if the capsule binary supported */ + ret = efi_capsule_supported(cap_hdr->guid, cap_hdr->flags, + cap_hdr->imagesize, + &cap_info->reset_type); + if (ret) { + pr_err("%s: efi_capsule_supported() failed\n", + __func__); + return ret; + } + + cap_info->total_size = cap_hdr->imagesize; + temp_page = krealloc(cap_info->pages, + pages_needed * sizeof(void *), + GFP_KERNEL | __GFP_ZERO); + if (!temp_page) { + pr_debug("%s: krealloc() failed\n", __func__); + return -ENOMEM; + } + + cap_info->pages = temp_page; + cap_info->header_obtained = true; + + return 0; +} + +/** + * efi_capsule_submit_update - invoke the efi_capsule_update API once binary + * upload done + * @cap_info: pointer to current instance of capsule_info structure + **/ +static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info) +{ + int ret; + void *cap_hdr_temp; + + cap_hdr_temp = kmap(cap_info->pages[0]); + if (!cap_hdr_temp) { + pr_debug("%s: kmap() failed\n", __func__); + return -EFAULT; + } + + ret = efi_capsule_update(cap_hdr_temp, cap_info->pages); + kunmap(cap_info->pages[0]); + if (ret) { + pr_err("%s: efi_capsule_update() failed\n", __func__); + return ret; + } + + /* Indicate capsule binary uploading is done */ + cap_info->index = NO_FURTHER_WRITE_ACTION; + pr_info("%s: Successfully upload capsule file with reboot type '%s'\n", + __func__, !cap_info->reset_type ? "RESET_COLD" : + cap_info->reset_type == 1 ? "RESET_WARM" : + "RESET_SHUTDOWN"); + return 0; +} + +/** + * efi_capsule_write - store the capsule binary and pass it to + * efi_capsule_update() API + * @file: file pointer + * @buff: buffer pointer + * @count: number of bytes in @buff + * @offp: not used + * + * Expectation: + * - A user space tool should start at the beginning of capsule binary and + * pass data in sequentially. + * - Users should close and re-open this file note in order to upload more + * capsules. + * - After an error returned, user should close the file and restart the + * operation for the next try otherwise -EIO will be returned until the + * file is closed. + * - An EFI capsule header must be located at the beginning of capsule + * binary file and passed in as first block data of write operation. + **/ +static ssize_t efi_capsule_write(struct file *file, const char __user *buff, + size_t count, loff_t *offp) +{ + int ret = 0; + struct capsule_info *cap_info = file->private_data; + struct page *page; + void *kbuff = NULL; + size_t write_byte; + + if (count == 0) + return 0; + + /* Return error while NO_FURTHER_WRITE_ACTION is flagged */ + if (cap_info->index < 0) + return -EIO; + + /* Only alloc a new page when previous page is full */ + if (!cap_info->page_bytes_remain) { + page = alloc_page(GFP_KERNEL); + if (!page) { + pr_debug("%s: alloc_page() failed\n", __func__); + ret = -ENOMEM; + goto failed; + } + + cap_info->pages[cap_info->index++] = page; + cap_info->page_bytes_remain = PAGE_SIZE; + } + + page = cap_info->pages[cap_info->index - 1]; + + kbuff = kmap(page); + if (!kbuff) { + pr_debug("%s: kmap() failed\n", __func__); + ret = -EFAULT; + goto failed; + } + kbuff += PAGE_SIZE - cap_info->page_bytes_remain; + + /* Copy capsule binary data from user space to kernel space buffer */ + write_byte = min_t(size_t, count, cap_info->page_bytes_remain); + if (copy_from_user(kbuff, buff, write_byte)) { + pr_debug("%s: copy_from_user() failed\n", __func__); + ret = -EFAULT; + goto fail_unmap; + } + cap_info->page_bytes_remain -= write_byte; + + /* Setup capsule binary info structure */ + if (!cap_info->header_obtained) { + ret = efi_capsule_setup_info(cap_info, kbuff, + cap_info->count + write_byte); + if (ret) + goto fail_unmap; + } + + cap_info->count += write_byte; + kunmap(page); + + /* Submit the full binary to efi_capsule_update() API */ + if (cap_info->header_obtained && + cap_info->count >= cap_info->total_size) { + if (cap_info->count > cap_info->total_size) { + pr_err("%s: upload size exceeded header defined size\n", + __func__); + ret = -EINVAL; + goto failed; + } + + ret = efi_capsule_submit_update(cap_info); + if (ret) + goto failed; + } + + return write_byte; + +fail_unmap: + kunmap(page); +failed: + efi_free_all_buff_pages(cap_info); + return ret; +} + +/** + * efi_capsule_flush - called by file close or file flush + * @file: file pointer + * @id: not used + * + * If a capsule is being partially uploaded then calling this function + * will be treated as upload termination and will free those completed + * buffer pages and -ECANCELED will be returned. + **/ +static int efi_capsule_flush(struct file *file, fl_owner_t id) +{ + int ret = 0; + struct capsule_info *cap_info = file->private_data; + + if (cap_info->index > 0) { + pr_err("%s: capsule upload not complete\n", __func__); + efi_free_all_buff_pages(cap_info); + ret = -ECANCELED; + } + + return ret; +} + +/** + * efi_capsule_release - called by file close + * @inode: not used + * @file: file pointer + * + * We will not free successfully submitted pages since efi update + * requires data to be maintained across system reboot. + **/ +static int efi_capsule_release(struct inode *inode, struct file *file) +{ + struct capsule_info *cap_info = file->private_data; + + kfree(cap_info->pages); + kfree(file->private_data); + file->private_data = NULL; + return 0; +} + +/** + * efi_capsule_open - called by file open + * @inode: not used + * @file: file pointer + * + * Will allocate each capsule_info memory for each file open call. + * This provided the capability to support multiple file open feature + * where user is not needed to wait for others to finish in order to + * upload their capsule binary. + **/ +static int efi_capsule_open(struct inode *inode, struct file *file) +{ + struct capsule_info *cap_info; + + cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL); + if (!cap_info) + return -ENOMEM; + + cap_info->pages = kzalloc(sizeof(void *), GFP_KERNEL); + if (!cap_info->pages) { + kfree(cap_info); + return -ENOMEM; + } + + file->private_data = cap_info; + + return 0; +} + +static const struct file_operations efi_capsule_fops = { + .owner = THIS_MODULE, + .open = efi_capsule_open, + .write = efi_capsule_write, + .flush = efi_capsule_flush, + .release = efi_capsule_release, + .llseek = no_llseek, +}; + +static struct miscdevice efi_capsule_misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = "efi_capsule_loader", + .fops = &efi_capsule_fops, +}; + +static int __init efi_capsule_loader_init(void) +{ + int ret; + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) + return -ENODEV; + + ret = misc_register(&efi_capsule_misc); + if (ret) + pr_err("%s: Failed to register misc char file note\n", + __func__); + + return ret; +} +module_init(efi_capsule_loader_init); + +static void __exit efi_capsule_loader_exit(void) +{ + misc_deregister(&efi_capsule_misc); +} +module_exit(efi_capsule_loader_exit); + +MODULE_DESCRIPTION("EFI capsule firmware binary loader"); +MODULE_LICENSE("GPL v2"); |