From: "Kweh, Hock Leong" <hock.leong.k...@intel.com> Introducing a kernel module to expose capsule loader interface (misc char device file note) for user to upload capsule binaries.
Example method to load the capsule binary: cat firmware.bin > /dev/efi_capsule_loader Cc: Matt Fleming <matt.flem...@intel.com> Signed-off-by: Kweh, Hock Leong <hock.leong.k...@intel.com> --- drivers/firmware/efi/Kconfig | 10 ++ drivers/firmware/efi/Makefile | 1 + drivers/firmware/efi/efi-capsule-loader.c | 218 +++++++++++++++++++++++++++++ 3 files changed, 229 insertions(+) create mode 100644 drivers/firmware/efi/efi-capsule-loader.c diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index f712d47..0be8ee3 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -60,6 +60,16 @@ config EFI_RUNTIME_WRAPPERS config EFI_ARMSTUB bool +config EFI_CAPSULE_LOADER + tristate "EFI capsule loader" + depends on EFI + help + This option exposes a loader interface "/dev/efi_capsule_loader" for + user to load EFI capsule binary and update the EFI firmware through + system reboot. + + If unsure, say N. + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 698846e..5ab031a 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_UEFI_CPER) += cper.o obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o obj-$(CONFIG_EFI_STUB) += libstub/ +obj-$(CONFIG_EFI_CAPSULE_LOADER) += efi-capsule-loader.o diff --git a/drivers/firmware/efi/efi-capsule-loader.c b/drivers/firmware/efi/efi-capsule-loader.c new file mode 100644 index 0000000..1da8608 --- /dev/null +++ b/drivers/firmware/efi/efi-capsule-loader.c @@ -0,0 +1,218 @@ +/* + * 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) KBUILD_MODNAME ": " 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 DEV_NAME "efi_capsule_loader" + +struct capsule_info { + int curr_index; + int curr_size; + int total_size; + struct page **pages; +}; + +static DEFINE_MUTEX(capsule_loader_lock); + +/* + * This function will store the capsule binary and pass it to + * efi_capsule_update() API in capsule.c + */ +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 *kbuff_page; + void *kbuff; + + pr_debug("%s: Entering Write()\n", __func__); + if (count == 0) + return 0; + + if (cap_info->curr_index == -1) + return count; + + kbuff_page = alloc_page(GFP_KERNEL); + if (!kbuff_page) { + pr_err("%s: alloc_page() failed\n", __func__); + if (!cap_info->curr_index) + return -ENOMEM; + ret = -ENOMEM; + goto failed; + } + + kbuff = kmap(kbuff_page); + if (!kbuff) { + pr_err("%s: kmap() failed\n", __func__); + if (cap_info->curr_index) + cap_info->pages[cap_info->curr_index++] = kbuff_page; + ret = -EFAULT; + goto failed; + } + + /* copy capsule binary data from user space to kernel space buffer */ + if (copy_from_user(kbuff, buff, min_t(size_t, count, PAGE_SIZE))) { + pr_err("%s: copy_from_user() failed\n", __func__); + if (cap_info->curr_index) + cap_info->pages[cap_info->curr_index++] = kbuff_page; + kunmap(kbuff_page); + ret = -EFAULT; + goto failed; + } + + /* setup capsule binary info structure */ + if (cap_info->curr_index == 0) { + efi_capsule_header_t *cap_hdr = kbuff; + int reset_type; + int pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> + PAGE_SHIFT; + + if (pages_needed <= 0) { + pr_err("%s: pages count invalid\n", __func__); + ret = -EINVAL; + kunmap(kbuff_page); + goto failed; + } + + /* check if the capsule binary supported */ + ret = efi_capsule_supported(cap_hdr->guid, cap_hdr->flags, + cap_hdr->imagesize, &reset_type); + if (ret) { + pr_err("%s: efi_capsule_supported() failed\n", + __func__); + kunmap(kbuff_page); + goto failed; + } + + cap_info->total_size = cap_hdr->imagesize; + cap_info->pages = kmalloc_array(pages_needed, sizeof(void *), + GFP_KERNEL); + if (!cap_info->pages) { + pr_err("%s: kmalloc_array() failed\n", __func__); + ret = -ENOMEM; + kunmap(kbuff_page); + goto failed; + } + } + + cap_info->pages[cap_info->curr_index++] = kbuff_page; + cap_info->curr_size += count; + kunmap(kbuff_page); + + /* submit the full binary to efi_capsule_update() API */ + if (cap_info->curr_size >= cap_info->total_size) { + ret = efi_capsule_update(kmap(cap_info->pages[0]), + cap_info->pages); + kunmap(cap_info->pages[0]); + if (ret) { + pr_err("%s: efi_capsule_update() failed\n", __func__); + goto failed; + } + /* indicate capsule binary uploading is done */ + cap_info->curr_index = -1; + } + + /* + * we cannot free the pages here due to reboot need that data + * maintained. + */ + return count; + +failed: + if (!cap_info->curr_index) { + __free_page(kbuff_page); + } else { + while (cap_info->curr_index > 0) + __free_page(cap_info->pages[--cap_info->curr_index]); + kfree(cap_info->pages); + } + + return ret; +} + +static int efi_capsule_release(struct inode *inode, struct file *file) +{ + int ret = 0; + struct capsule_info *cap_info = file->private_data; + + pr_debug("%s: Exit in Release()\n", __func__); + /* release those uncompleted uploaded block */ + if (cap_info->curr_index > 0) { + pr_err("%s: capsule upload not complete\n", __func__); + while (cap_info->curr_index > 0) + __free_page(cap_info->pages[--cap_info->curr_index]); + kfree(cap_info->pages); + ret = -ECANCELED; + } + kfree(file->private_data); + file->private_data = NULL; + mutex_unlock(&capsule_loader_lock); + return ret; +} + +static int efi_capsule_open(struct inode *inode, struct file *file) +{ + int ret = -EBUSY; + struct capsule_info *cap_info; + + pr_debug("%s: Entering Open()\n", __func__); + if (mutex_trylock(&capsule_loader_lock)) { + cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL); + file->private_data = cap_info; + ret = 0; + } + return ret; +} + +static const struct file_operations efi_capsule_fops = { + .owner = THIS_MODULE, + .open = efi_capsule_open, + .write = efi_capsule_write, + .release = efi_capsule_release, + .llseek = no_llseek, +}; + +static struct miscdevice efi_capsule_misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = DEV_NAME, + .fops = &efi_capsule_fops, +}; + +static int __init efi_capsule_loader_init(void) +{ + int ret; + + mutex_init(&capsule_loader_lock); + + ret = misc_register(&efi_capsule_misc); + if (ret) + pr_err("%s: misc_register() failed\n", __func__); + + return ret; +} +module_init(efi_capsule_loader_init); + +static void __exit efi_capsule_loader_exit(void) +{ + mutex_destroy(&capsule_loader_lock); + misc_deregister(&efi_capsule_misc); +} +module_exit(efi_capsule_loader_exit); + +MODULE_DESCRIPTION("EFI capsule firmware binary loader"); +MODULE_LICENSE("GPL v2"); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/