| Message ID | 1443733554-22743-3-git-send-email-hock.leong.kweh@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 02, 2015 at 05:05:54AM +0800, Kweh, Hock Leong wrote: > From: "Kweh, Hock Leong" <hock.leong.kweh@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.fleming@intel.com> > Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com> > --- > drivers/firmware/efi/Kconfig | 10 ++ > drivers/firmware/efi/Makefile | 1 + > drivers/firmware/efi/efi-capsule-loader.c | 246 +++++++++++++++++++++++++++++ > 3 files changed, 257 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. Do you mean here: user has to cat the fw binary *and* *then* reboot the box? If so, we probably should issue such note to dmesg after successful write... > + > + 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..571e0c8 > --- /dev/null > +++ b/drivers/firmware/efi/efi-capsule-loader.c > @@ -0,0 +1,246 @@ > +/* > + * 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" > + > +static struct capsule_info { > + char header_obtained; > + long index; > + unsigned long count; > + unsigned long total_size; > + struct page **pages; > + unsigned long page_count_remain; > +} cap_info; > + > +static DEFINE_MUTEX(capsule_loader_lock); > + > +/* > + * This function will free the current & all previous allocated buffer pages. No need to start the comment with "This function" - that's implicitly the case. Same for the other comments below. > + * The input parameter is the allocated buffer page for current execution which > + * has not yet assigned to pages array. The input param can be NULL if the > + * current execution has not allocated any buffer page. We have the standard format of documenting those: * @kbuff_page: the allocated buffer page... > + */ > +static void efi_free_all_buff_pages(struct page *kbuff_page) > +{ > + if (!kbuff_page) > + __free_page(kbuff_page); > + > + if (cap_info.index > 0) > + while (cap_info.index > 0) > + __free_page(cap_info.pages[--cap_info.index]); > + > + if (cap_info.header_obtained) > + kfree(cap_info.pages); > + > + /* indicate to the next that error had occurred */ > + cap_info.index = -2; > +} > + > +/* > + * This function will store the capsule binary and pass it to > + * efi_capsule_update() API in capsule.c. > + * > + * Expectation: > + * - userspace tool should start at the beginning of capsule binary and pass > + * data in sequential. > + * - user should close and re-open this file note in order to upload more > + * capsules. > + * - any error occurred, user should close the file and restart the operation > + * for the next try otherwise -EIO will be returned until the file is closed. > + */ > +static ssize_t efi_capsule_write(struct file *file, const char __user *buff, > + size_t count, loff_t *offp) > +{ > + int ret = 0; > + struct page *kbuff_page; > + void *kbuff; > + size_t write_byte; > + > + pr_debug("%s: Entering Write()\n", __func__); > + if (count == 0) > + return 0; > + > + /* return error while error had occurred or capsule uploading is done */ > + if (cap_info.index < 0) > + return -EIO; > + > + /* only alloc a new page when the current page is full */ > + if (!cap_info.page_count_remain) { > + kbuff_page = alloc_page(GFP_KERNEL); > + if (!kbuff_page) { > + pr_debug("%s: alloc_page() failed\n", __func__); > + efi_free_all_buff_pages(NULL); > + return -ENOMEM; > + } > + cap_info.page_count_remain = PAGE_SIZE; > + } else { > + kbuff_page = cap_info.pages[--cap_info.index]; > + } > + kbuff = kmap(kbuff_page); > + if (!kbuff) { > + pr_debug("%s: kmap() failed\n", __func__); > + efi_free_all_buff_pages(kbuff_page); > + return -EFAULT; > + } > + kbuff += PAGE_SIZE - cap_info.page_count_remain; > + > + /* copy capsule binary data from user space to kernel space buffer */ > + write_byte = min_t(size_t, count, cap_info.page_count_remain); > + if (copy_from_user(kbuff, buff, write_byte)) { > + pr_debug("%s: copy_from_user() failed\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -EFAULT; > + } > + cap_info.page_count_remain -= write_byte; > + > + /* setup capsule binary info structure */ > + if (cap_info.header_obtained == 0 && cap_info.index == 0) { > + efi_capsule_header_t *cap_hdr = kbuff; > + int reset_type; > + size_t pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> > + PAGE_SHIFT; > + > + if (pages_needed == 0) { > + pr_err("%s: pages count invalid\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -EINVAL; > + } > + > + /* 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); > + efi_free_all_buff_pages(kbuff_page); > + return ret; > + } > + > + cap_info.total_size = cap_hdr->imagesize; > + cap_info.pages = kmalloc_array(pages_needed, sizeof(void *), > + GFP_KERNEL); > + if (!cap_info.pages) { > + pr_debug("%s: kmalloc_array() failed\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -ENOMEM; > + } > + > + cap_info.header_obtained = 1; > + } > + > + cap_info.pages[cap_info.index++] = kbuff_page; > + cap_info.count += write_byte; > + kunmap(kbuff_page); > + > + /* submit the full binary to efi_capsule_update() API */ > + if (cap_info.count >= cap_info.total_size) { > + void *cap_hdr_temp; > + > + cap_hdr_temp = kmap(cap_info.pages[0]); > + if (!cap_hdr_temp) { > + pr_debug("%s: kmap() failed\n", __func__); > + efi_free_all_buff_pages(NULL); > + 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__); > + efi_free_all_buff_pages(NULL); > + return ret; > + } > + /* indicate capsule binary uploading is done */ > + cap_info.index = -1; > + } > + > + return write_byte; > +} This function is huuuge and it could use some splitting. At least the code blocks under /* setup capsule binary info structure */ and /* submit the full binary to efi_capsule_update() API */ could be separate, helper functions. And you have the same repeated pattern on the error path: kunmap(); efi_free_all_buff_pages(NULL); return -<errno> Mind rewriting that with goto err_... labels like it is normally done in the kernel. > + > +static int efi_capsule_release(struct inode *inode, struct file *file) > +{ > + int ret = 0; > + > + pr_debug("%s: Exit in Release()\n", __func__); > + /* release uncompleted capsule upload */ That should be above the function. > + if (cap_info.index > 0) { > + pr_err("%s: capsule upload not complete\n", __func__); > + efi_free_all_buff_pages(NULL); > + ret = -ECANCELED; > + } > + mutex_unlock(&capsule_loader_lock); > + > + /* > + * we would not free the successful submitted buffer pages here due to > + * efi update require system reboot with data maintained. > + */ That too. > + return ret; > +} > + > +static int efi_capsule_open(struct inode *inode, struct file *file) > +{ > + pr_debug("%s: Entering Open()\n", __func__); Do we really need those? > + if (!mutex_trylock(&capsule_loader_lock)) > + return -EBUSY; > + > + memset(&cap_info, 0, sizeof(cap_info)); > + return 0; > +} > + > +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: Failed to register misc char file note\n", > + __func__); mutex_destroy() on the error path. > + > + 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); Those are in the wrong order - you need to destroy the mutex last. > +} > +module_exit(efi_capsule_loader_exit); > + > +MODULE_DESCRIPTION("EFI capsule firmware binary loader"); > +MODULE_LICENSE("GPL v2"); > -- > 1.7.9.5 > >
On Thu, Oct 1, 2015 at 2:05 PM, Kweh, Hock Leong <hock.leong.kweh@intel.com> wrote: > From: "Kweh, Hock Leong" <hock.leong.kweh@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.fleming@intel.com> > Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com> > --- > drivers/firmware/efi/Kconfig | 10 ++ > drivers/firmware/efi/Makefile | 1 + > drivers/firmware/efi/efi-capsule-loader.c | 246 +++++++++++++++++++++++++++++ > 3 files changed, 257 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..571e0c8 > --- /dev/null > +++ b/drivers/firmware/efi/efi-capsule-loader.c > @@ -0,0 +1,246 @@ > +/* > + * 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" > + > +static struct capsule_info { > + char header_obtained; > + long index; > + unsigned long count; > + unsigned long total_size; > + struct page **pages; > + unsigned long page_count_remain; > +} cap_info; > + Why is this static? > +static DEFINE_MUTEX(capsule_loader_lock); > + > +/* > + * This function will free the current & all previous allocated buffer pages. > + * The input parameter is the allocated buffer page for current execution which > + * has not yet assigned to pages array. The input param can be NULL if the > + * current execution has not allocated any buffer page. > + */ > +static void efi_free_all_buff_pages(struct page *kbuff_page) > +{ > + if (!kbuff_page) > + __free_page(kbuff_page); > + > + if (cap_info.index > 0) > + while (cap_info.index > 0) > + __free_page(cap_info.pages[--cap_info.index]); > + > + if (cap_info.header_obtained) > + kfree(cap_info.pages); > + > + /* indicate to the next that error had occurred */ > + cap_info.index = -2; This -2 to too magical. > +} > + > +/* > + * This function will store the capsule binary and pass it to > + * efi_capsule_update() API in capsule.c. > + * > + * Expectation: > + * - userspace tool should start at the beginning of capsule binary and pass > + * data in sequential. > + * - user should close and re-open this file note in order to upload more > + * capsules. > + * - any error occurred, user should close the file and restart the operation > + * for the next try otherwise -EIO will be returned until the file is closed. > + */ > +static ssize_t efi_capsule_write(struct file *file, const char __user *buff, > + size_t count, loff_t *offp) > +{ > + int ret = 0; > + struct page *kbuff_page; > + void *kbuff; > + size_t write_byte; > + > + pr_debug("%s: Entering Write()\n", __func__); Unnecessary. > + if (count == 0) > + return 0; > + > + /* return error while error had occurred or capsule uploading is done */ > + if (cap_info.index < 0) > + return -EIO; > + > + /* only alloc a new page when the current page is full */ > + if (!cap_info.page_count_remain) { > + kbuff_page = alloc_page(GFP_KERNEL); > + if (!kbuff_page) { > + pr_debug("%s: alloc_page() failed\n", __func__); > + efi_free_all_buff_pages(NULL); > + return -ENOMEM; > + } > + cap_info.page_count_remain = PAGE_SIZE; > + } else { > + kbuff_page = cap_info.pages[--cap_info.index]; > + } > + kbuff = kmap(kbuff_page); > + if (!kbuff) { > + pr_debug("%s: kmap() failed\n", __func__); > + efi_free_all_buff_pages(kbuff_page); > + return -EFAULT; > + } > + kbuff += PAGE_SIZE - cap_info.page_count_remain; > + > + /* copy capsule binary data from user space to kernel space buffer */ > + write_byte = min_t(size_t, count, cap_info.page_count_remain); > + if (copy_from_user(kbuff, buff, write_byte)) { > + pr_debug("%s: copy_from_user() failed\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -EFAULT; > + } > + cap_info.page_count_remain -= write_byte; > + > + /* setup capsule binary info structure */ > + if (cap_info.header_obtained == 0 && cap_info.index == 0) { > + efi_capsule_header_t *cap_hdr = kbuff; > + int reset_type; > + size_t pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> > + PAGE_SHIFT; > + > + if (pages_needed == 0) { > + pr_err("%s: pages count invalid\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -EINVAL; > + } > + > + /* check if the capsule binary supported */ > + ret = efi_capsule_supported(cap_hdr->guid, cap_hdr->flags, > + cap_hdr->imagesize, &reset_type); And what if cap_hdr isn't written yet? > + if (ret) { > + pr_err("%s: efi_capsule_supported() failed\n", > + __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return ret; > + } > + > + cap_info.total_size = cap_hdr->imagesize; > + cap_info.pages = kmalloc_array(pages_needed, sizeof(void *), > + GFP_KERNEL); > + if (!cap_info.pages) { > + pr_debug("%s: kmalloc_array() failed\n", __func__); > + kunmap(kbuff_page); > + efi_free_all_buff_pages(kbuff_page); > + return -ENOMEM; > + } > + > + cap_info.header_obtained = 1; I don't see how you know that the header is obtained. > + } > + > + cap_info.pages[cap_info.index++] = kbuff_page; Huh? You might now have allocated a whole page. > + cap_info.count += write_byte; > + kunmap(kbuff_page); > + > + /* submit the full binary to efi_capsule_update() API */ > + if (cap_info.count >= cap_info.total_size) { > + void *cap_hdr_temp; > + > + cap_hdr_temp = kmap(cap_info.pages[0]); > + if (!cap_hdr_temp) { > + pr_debug("%s: kmap() failed\n", __func__); > + efi_free_all_buff_pages(NULL); > + 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__); > + efi_free_all_buff_pages(NULL); > + return ret; > + } > + /* indicate capsule binary uploading is done */ > + cap_info.index = -1; Should count > cap_info.total_size be an error? --Andy > +static int efi_capsule_release(struct inode *inode, struct file *file) > +{ > + int ret = 0; > + > + pr_debug("%s: Exit in Release()\n", __func__); > + /* release uncompleted capsule upload */ > + if (cap_info.index > 0) { > + pr_err("%s: capsule upload not complete\n", __func__); > + efi_free_all_buff_pages(NULL); > + ret = -ECANCELED; > + } > + mutex_unlock(&capsule_loader_lock); Holding mutexes in userspace seems like an error. In fact, doesn't lockdep warn when you do that? --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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..571e0c8 --- /dev/null +++ b/drivers/firmware/efi/efi-capsule-loader.c @@ -0,0 +1,246 @@ +/* + * 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" + +static struct capsule_info { + char header_obtained; + long index; + unsigned long count; + unsigned long total_size; + struct page **pages; + unsigned long page_count_remain; +} cap_info; + +static DEFINE_MUTEX(capsule_loader_lock); + +/* + * This function will free the current & all previous allocated buffer pages. + * The input parameter is the allocated buffer page for current execution which + * has not yet assigned to pages array. The input param can be NULL if the + * current execution has not allocated any buffer page. + */ +static void efi_free_all_buff_pages(struct page *kbuff_page) +{ + if (!kbuff_page) + __free_page(kbuff_page); + + if (cap_info.index > 0) + while (cap_info.index > 0) + __free_page(cap_info.pages[--cap_info.index]); + + if (cap_info.header_obtained) + kfree(cap_info.pages); + + /* indicate to the next that error had occurred */ + cap_info.index = -2; +} + +/* + * This function will store the capsule binary and pass it to + * efi_capsule_update() API in capsule.c. + * + * Expectation: + * - userspace tool should start at the beginning of capsule binary and pass + * data in sequential. + * - user should close and re-open this file note in order to upload more + * capsules. + * - any error occurred, user should close the file and restart the operation + * for the next try otherwise -EIO will be returned until the file is closed. + */ +static ssize_t efi_capsule_write(struct file *file, const char __user *buff, + size_t count, loff_t *offp) +{ + int ret = 0; + struct page *kbuff_page; + void *kbuff; + size_t write_byte; + + pr_debug("%s: Entering Write()\n", __func__); + if (count == 0) + return 0; + + /* return error while error had occurred or capsule uploading is done */ + if (cap_info.index < 0) + return -EIO; + + /* only alloc a new page when the current page is full */ + if (!cap_info.page_count_remain) { + kbuff_page = alloc_page(GFP_KERNEL); + if (!kbuff_page) { + pr_debug("%s: alloc_page() failed\n", __func__); + efi_free_all_buff_pages(NULL); + return -ENOMEM; + } + cap_info.page_count_remain = PAGE_SIZE; + } else { + kbuff_page = cap_info.pages[--cap_info.index]; + } + kbuff = kmap(kbuff_page); + if (!kbuff) { + pr_debug("%s: kmap() failed\n", __func__); + efi_free_all_buff_pages(kbuff_page); + return -EFAULT; + } + kbuff += PAGE_SIZE - cap_info.page_count_remain; + + /* copy capsule binary data from user space to kernel space buffer */ + write_byte = min_t(size_t, count, cap_info.page_count_remain); + if (copy_from_user(kbuff, buff, write_byte)) { + pr_debug("%s: copy_from_user() failed\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -EFAULT; + } + cap_info.page_count_remain -= write_byte; + + /* setup capsule binary info structure */ + if (cap_info.header_obtained == 0 && cap_info.index == 0) { + efi_capsule_header_t *cap_hdr = kbuff; + int reset_type; + size_t pages_needed = ALIGN(cap_hdr->imagesize, PAGE_SIZE) >> + PAGE_SHIFT; + + if (pages_needed == 0) { + pr_err("%s: pages count invalid\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -EINVAL; + } + + /* 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); + efi_free_all_buff_pages(kbuff_page); + return ret; + } + + cap_info.total_size = cap_hdr->imagesize; + cap_info.pages = kmalloc_array(pages_needed, sizeof(void *), + GFP_KERNEL); + if (!cap_info.pages) { + pr_debug("%s: kmalloc_array() failed\n", __func__); + kunmap(kbuff_page); + efi_free_all_buff_pages(kbuff_page); + return -ENOMEM; + } + + cap_info.header_obtained = 1; + } + + cap_info.pages[cap_info.index++] = kbuff_page; + cap_info.count += write_byte; + kunmap(kbuff_page); + + /* submit the full binary to efi_capsule_update() API */ + if (cap_info.count >= cap_info.total_size) { + void *cap_hdr_temp; + + cap_hdr_temp = kmap(cap_info.pages[0]); + if (!cap_hdr_temp) { + pr_debug("%s: kmap() failed\n", __func__); + efi_free_all_buff_pages(NULL); + 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__); + efi_free_all_buff_pages(NULL); + return ret; + } + /* indicate capsule binary uploading is done */ + cap_info.index = -1; + } + + return write_byte; +} + +static int efi_capsule_release(struct inode *inode, struct file *file) +{ + int ret = 0; + + pr_debug("%s: Exit in Release()\n", __func__); + /* release uncompleted capsule upload */ + if (cap_info.index > 0) { + pr_err("%s: capsule upload not complete\n", __func__); + efi_free_all_buff_pages(NULL); + ret = -ECANCELED; + } + mutex_unlock(&capsule_loader_lock); + + /* + * we would not free the successful submitted buffer pages here due to + * efi update require system reboot with data maintained. + */ + return ret; +} + +static int efi_capsule_open(struct inode *inode, struct file *file) +{ + pr_debug("%s: Entering Open()\n", __func__); + if (!mutex_trylock(&capsule_loader_lock)) + return -EBUSY; + + memset(&cap_info, 0, sizeof(cap_info)); + return 0; +} + +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: 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) +{ + 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");