2016-04-25 22:06:59 +02:00
|
|
|
/*
|
|
|
|
* EFI capsule support.
|
|
|
|
*
|
|
|
|
* Copyright 2013 Intel Corporation; author Matt Fleming
|
|
|
|
*
|
|
|
|
* 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/slab.h>
|
|
|
|
#include <linux/mutex.h>
|
|
|
|
#include <linux/highmem.h>
|
|
|
|
#include <linux/efi.h>
|
|
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include <asm/io.h>
|
|
|
|
|
|
|
|
typedef struct {
|
|
|
|
u64 length;
|
|
|
|
u64 data;
|
|
|
|
} efi_capsule_block_desc_t;
|
|
|
|
|
|
|
|
static bool capsule_pending;
|
2016-05-06 23:39:27 +02:00
|
|
|
static bool stop_capsules;
|
2016-04-25 22:06:59 +02:00
|
|
|
static int efi_reset_type = -1;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* capsule_mutex serialises access to both capsule_pending and
|
2016-05-06 23:39:27 +02:00
|
|
|
* efi_reset_type and stop_capsules.
|
2016-04-25 22:06:59 +02:00
|
|
|
*/
|
|
|
|
static DEFINE_MUTEX(capsule_mutex);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* efi_capsule_pending - has a capsule been passed to the firmware?
|
|
|
|
* @reset_type: store the type of EFI reset if capsule is pending
|
|
|
|
*
|
|
|
|
* To ensure that the registered capsule is processed correctly by the
|
|
|
|
* firmware we need to perform a specific type of reset. If a capsule is
|
|
|
|
* pending return the reset type in @reset_type.
|
|
|
|
*
|
|
|
|
* This function will race with callers of efi_capsule_update(), for
|
|
|
|
* example, calling this function while somebody else is in
|
|
|
|
* efi_capsule_update() but hasn't reached efi_capsue_update_locked()
|
|
|
|
* will miss the updates to capsule_pending and efi_reset_type after
|
|
|
|
* efi_capsule_update_locked() completes.
|
|
|
|
*
|
|
|
|
* A non-racy use is from platform reboot code because we use
|
|
|
|
* system_state to ensure no capsules can be sent to the firmware once
|
|
|
|
* we're at SYSTEM_RESTART. See efi_capsule_update_locked().
|
|
|
|
*/
|
|
|
|
bool efi_capsule_pending(int *reset_type)
|
|
|
|
{
|
|
|
|
if (!capsule_pending)
|
2016-05-06 23:39:27 +02:00
|
|
|
return false;
|
2016-04-25 22:06:59 +02:00
|
|
|
|
|
|
|
if (reset_type)
|
|
|
|
*reset_type = efi_reset_type;
|
2016-05-06 23:39:27 +02:00
|
|
|
|
|
|
|
return true;
|
2016-04-25 22:06:59 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Whitelist of EFI capsule flags that we support.
|
|
|
|
*
|
|
|
|
* We do not handle EFI_CAPSULE_INITIATE_RESET because that would
|
|
|
|
* require us to prepare the kernel for reboot. Refuse to load any
|
|
|
|
* capsules with that flag and any other flags that we do not know how
|
|
|
|
* to handle.
|
|
|
|
*/
|
|
|
|
#define EFI_CAPSULE_SUPPORTED_FLAG_MASK \
|
|
|
|
(EFI_CAPSULE_PERSIST_ACROSS_RESET | EFI_CAPSULE_POPULATE_SYSTEM_TABLE)
|
|
|
|
|
|
|
|
/**
|
|
|
|
* efi_capsule_supported - does the firmware support the capsule?
|
|
|
|
* @guid: vendor guid of capsule
|
|
|
|
* @flags: capsule flags
|
|
|
|
* @size: size of capsule data
|
|
|
|
* @reset: the reset type required for this capsule
|
|
|
|
*
|
|
|
|
* Check whether a capsule with @flags is supported by the firmware
|
|
|
|
* and that @size doesn't exceed the maximum size for a capsule.
|
|
|
|
*
|
|
|
|
* No attempt is made to check @reset against the reset type required
|
|
|
|
* by any pending capsules because of the races involved.
|
|
|
|
*/
|
|
|
|
int efi_capsule_supported(efi_guid_t guid, u32 flags, size_t size, int *reset)
|
|
|
|
{
|
2016-05-06 23:39:29 +02:00
|
|
|
efi_capsule_header_t capsule;
|
|
|
|
efi_capsule_header_t *cap_list[] = { &capsule };
|
2016-04-25 22:06:59 +02:00
|
|
|
efi_status_t status;
|
|
|
|
u64 max_size;
|
|
|
|
|
|
|
|
if (flags & ~EFI_CAPSULE_SUPPORTED_FLAG_MASK)
|
|
|
|
return -EINVAL;
|
|
|
|
|
2016-05-06 23:39:29 +02:00
|
|
|
capsule.headersize = capsule.imagesize = sizeof(capsule);
|
|
|
|
memcpy(&capsule.guid, &guid, sizeof(efi_guid_t));
|
|
|
|
capsule.flags = flags;
|
2016-04-25 22:06:59 +02:00
|
|
|
|
2016-05-06 23:39:29 +02:00
|
|
|
status = efi.query_capsule_caps(cap_list, 1, &max_size, reset);
|
|
|
|
if (status != EFI_SUCCESS)
|
|
|
|
return efi_status_to_err(status);
|
2016-04-25 22:06:59 +02:00
|
|
|
|
|
|
|
if (size > max_size)
|
2016-05-06 23:39:29 +02:00
|
|
|
return -ENOSPC;
|
|
|
|
|
|
|
|
return 0;
|
2016-04-25 22:06:59 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(efi_capsule_supported);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Every scatter gather list (block descriptor) page must end with a
|
|
|
|
* continuation pointer. The last continuation pointer of the last
|
|
|
|
* page must be zero to mark the end of the chain.
|
|
|
|
*/
|
|
|
|
#define SGLIST_PER_PAGE ((PAGE_SIZE / sizeof(efi_capsule_block_desc_t)) - 1)
|
|
|
|
|
|
|
|
/*
|
|
|
|
* How many scatter gather list (block descriptor) pages do we need
|
|
|
|
* to map @count pages?
|
|
|
|
*/
|
|
|
|
static inline unsigned int sg_pages_num(unsigned int count)
|
|
|
|
{
|
|
|
|
return DIV_ROUND_UP(count, SGLIST_PER_PAGE);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* efi_capsule_update_locked - pass a single capsule to the firmware
|
|
|
|
* @capsule: capsule to send to the firmware
|
|
|
|
* @sg_pages: array of scatter gather (block descriptor) pages
|
|
|
|
* @reset: the reset type required for @capsule
|
|
|
|
*
|
|
|
|
* Since this function must be called under capsule_mutex check
|
|
|
|
* whether efi_reset_type will conflict with @reset, and atomically
|
|
|
|
* set it and capsule_pending if a capsule was successfully sent to
|
|
|
|
* the firmware.
|
|
|
|
*
|
|
|
|
* We also check to see if the system is about to restart, and if so,
|
|
|
|
* abort. This avoids races between efi_capsule_update() and
|
|
|
|
* efi_capsule_pending().
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
efi_capsule_update_locked(efi_capsule_header_t *capsule,
|
|
|
|
struct page **sg_pages, int reset)
|
|
|
|
{
|
|
|
|
efi_physical_addr_t sglist_phys;
|
|
|
|
efi_status_t status;
|
|
|
|
|
|
|
|
lockdep_assert_held(&capsule_mutex);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If someone has already registered a capsule that requires a
|
|
|
|
* different reset type, we're out of luck and must abort.
|
|
|
|
*/
|
|
|
|
if (efi_reset_type >= 0 && efi_reset_type != reset) {
|
|
|
|
pr_err("Conflicting capsule reset type %d (%d).\n",
|
|
|
|
reset, efi_reset_type);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If the system is getting ready to restart it may have
|
|
|
|
* called efi_capsule_pending() to make decisions (such as
|
|
|
|
* whether to force an EFI reboot), and we're racing against
|
|
|
|
* that call. Abort in that case.
|
|
|
|
*/
|
2016-05-06 23:39:27 +02:00
|
|
|
if (unlikely(stop_capsules)) {
|
2016-04-25 22:06:59 +02:00
|
|
|
pr_warn("Capsule update raced with reboot, aborting.\n");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
sglist_phys = page_to_phys(sg_pages[0]);
|
|
|
|
|
|
|
|
status = efi.update_capsule(&capsule, 1, sglist_phys);
|
|
|
|
if (status == EFI_SUCCESS) {
|
|
|
|
capsule_pending = true;
|
|
|
|
efi_reset_type = reset;
|
|
|
|
}
|
|
|
|
|
|
|
|
return efi_status_to_err(status);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* efi_capsule_update - send a capsule to the firmware
|
|
|
|
* @capsule: capsule to send to firmware
|
|
|
|
* @pages: an array of capsule data pages
|
|
|
|
*
|
|
|
|
* Build a scatter gather list with EFI capsule block descriptors to
|
|
|
|
* map the capsule described by @capsule with its data in @pages and
|
|
|
|
* send it to the firmware via the UpdateCapsule() runtime service.
|
|
|
|
*
|
2016-08-11 12:42:00 +02:00
|
|
|
* @capsule must be a virtual mapping of the complete capsule update in the
|
|
|
|
* kernel address space, as the capsule can be consumed immediately.
|
|
|
|
* A capsule_header_t that describes the entire contents of the capsule
|
2016-04-25 22:06:59 +02:00
|
|
|
* must be at the start of the first data page.
|
|
|
|
*
|
|
|
|
* Even though this function will validate that the firmware supports
|
|
|
|
* the capsule guid, users will likely want to check that
|
|
|
|
* efi_capsule_supported() returns true before calling this function
|
|
|
|
* because it makes it easier to print helpful error messages.
|
|
|
|
*
|
|
|
|
* If the capsule is successfully submitted to the firmware, any
|
|
|
|
* subsequent calls to efi_capsule_pending() will return true. @pages
|
|
|
|
* must not be released or modified if this function returns
|
|
|
|
* successfully.
|
|
|
|
*
|
|
|
|
* Callers must be prepared for this function to fail, which can
|
|
|
|
* happen if we raced with system reboot or if there is already a
|
|
|
|
* pending capsule that has a reset type that conflicts with the one
|
|
|
|
* required by @capsule. Do NOT use efi_capsule_pending() to detect
|
|
|
|
* this conflict since that would be racy. Instead, submit the capsule
|
|
|
|
* to efi_capsule_update() and check the return value.
|
|
|
|
*
|
|
|
|
* Return 0 on success, a converted EFI status code on failure.
|
|
|
|
*/
|
|
|
|
int efi_capsule_update(efi_capsule_header_t *capsule, struct page **pages)
|
|
|
|
{
|
|
|
|
u32 imagesize = capsule->imagesize;
|
|
|
|
efi_guid_t guid = capsule->guid;
|
|
|
|
unsigned int count, sg_count;
|
|
|
|
u32 flags = capsule->flags;
|
|
|
|
struct page **sg_pages;
|
|
|
|
int rv, reset_type;
|
|
|
|
int i, j;
|
|
|
|
|
|
|
|
rv = efi_capsule_supported(guid, flags, imagesize, &reset_type);
|
|
|
|
if (rv)
|
|
|
|
return rv;
|
|
|
|
|
|
|
|
count = DIV_ROUND_UP(imagesize, PAGE_SIZE);
|
|
|
|
sg_count = sg_pages_num(count);
|
|
|
|
|
|
|
|
sg_pages = kzalloc(sg_count * sizeof(*sg_pages), GFP_KERNEL);
|
|
|
|
if (!sg_pages)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
for (i = 0; i < sg_count; i++) {
|
|
|
|
sg_pages[i] = alloc_page(GFP_KERNEL);
|
|
|
|
if (!sg_pages[i]) {
|
|
|
|
rv = -ENOMEM;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
for (i = 0; i < sg_count; i++) {
|
|
|
|
efi_capsule_block_desc_t *sglist;
|
|
|
|
|
|
|
|
sglist = kmap(sg_pages[i]);
|
|
|
|
if (!sglist) {
|
|
|
|
rv = -ENOMEM;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (j = 0; j < SGLIST_PER_PAGE && count > 0; j++) {
|
|
|
|
u64 sz = min_t(u64, imagesize, PAGE_SIZE);
|
|
|
|
|
|
|
|
sglist[j].length = sz;
|
|
|
|
sglist[j].data = page_to_phys(*pages++);
|
|
|
|
|
|
|
|
imagesize -= sz;
|
|
|
|
count--;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Continuation pointer */
|
|
|
|
sglist[j].length = 0;
|
|
|
|
|
|
|
|
if (i + 1 == sg_count)
|
|
|
|
sglist[j].data = 0;
|
|
|
|
else
|
|
|
|
sglist[j].data = page_to_phys(sg_pages[i + 1]);
|
|
|
|
|
|
|
|
kunmap(sg_pages[i]);
|
|
|
|
}
|
|
|
|
|
|
|
|
mutex_lock(&capsule_mutex);
|
|
|
|
rv = efi_capsule_update_locked(capsule, sg_pages, reset_type);
|
|
|
|
mutex_unlock(&capsule_mutex);
|
|
|
|
|
|
|
|
out:
|
|
|
|
for (i = 0; rv && i < sg_count; i++) {
|
|
|
|
if (sg_pages[i])
|
|
|
|
__free_page(sg_pages[i]);
|
|
|
|
}
|
|
|
|
|
|
|
|
kfree(sg_pages);
|
|
|
|
return rv;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(efi_capsule_update);
|
2016-05-06 23:39:27 +02:00
|
|
|
|
|
|
|
static int capsule_reboot_notify(struct notifier_block *nb, unsigned long event, void *cmd)
|
|
|
|
{
|
|
|
|
mutex_lock(&capsule_mutex);
|
|
|
|
stop_capsules = true;
|
|
|
|
mutex_unlock(&capsule_mutex);
|
|
|
|
|
|
|
|
return NOTIFY_DONE;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct notifier_block capsule_reboot_nb = {
|
|
|
|
.notifier_call = capsule_reboot_notify,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init capsule_reboot_register(void)
|
|
|
|
{
|
|
|
|
return register_reboot_notifier(&capsule_reboot_nb);
|
|
|
|
}
|
|
|
|
core_initcall(capsule_reboot_register);
|