Files
android_kernel_xiaomi_sm8450/drivers/firmware/efi/arm-runtime.c
Ard Biesheuvel c5b591e96d efi: Get rid of the EFI_SYSTEM_TABLES status bit
The EFI_SYSTEM_TABLES status bit is set by all EFI supporting architectures
upon discovery of the EFI system table, but the bit is never tested in any
code we have in the tree. So remove it.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Luck, Tony <tony.luck@intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28 11:33:46 +02:00

135 lines
3.1 KiB
C

/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 2.4
*
* Copyright (C) 2013, 2014 Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/efi.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/preempt.h>
#include <linux/rbtree.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/cacheflush.h>
#include <asm/efi.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
extern u64 efi_system_table;
static struct mm_struct efi_mm = {
.mm_rb = RB_ROOT,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
.mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
};
static bool __init efi_virtmap_init(void)
{
efi_memory_desc_t *md;
efi_mm.pgd = pgd_alloc(&efi_mm);
init_new_context(NULL, &efi_mm);
for_each_efi_memory_desc(&memmap, md) {
phys_addr_t phys = md->phys_addr;
int ret;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (md->virt_addr == 0)
return false;
ret = efi_create_mapping(&efi_mm, md);
if (!ret) {
pr_info(" EFI remap %pa => %p\n",
&phys, (void *)(unsigned long)md->virt_addr);
} else {
pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
&phys, ret);
return false;
}
}
return true;
}
/*
* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
* non-early mapping of the UEFI system table and virtual mappings for all
* EFI_MEMORY_RUNTIME regions.
*/
static int __init arm_enable_runtime_services(void)
{
u64 mapsize;
if (!efi_enabled(EFI_BOOT)) {
pr_info("EFI services will not be available.\n");
return 0;
}
if (efi_runtime_disabled()) {
pr_info("EFI runtime services will be disabled.\n");
return 0;
}
pr_info("Remapping and enabling EFI services.\n");
mapsize = memmap.map_end - memmap.map;
memmap.map = (__force void *)ioremap_cache(memmap.phys_map,
mapsize);
if (!memmap.map) {
pr_err("Failed to remap EFI memory map\n");
return -ENOMEM;
}
memmap.map_end = memmap.map + mapsize;
efi.memmap = &memmap;
efi.systab = (__force void *)ioremap_cache(efi_system_table,
sizeof(efi_system_table_t));
if (!efi.systab) {
pr_err("Failed to remap EFI System Table\n");
return -ENOMEM;
}
if (!efi_virtmap_init()) {
pr_err("No UEFI virtual mapping was installed -- runtime services will not be available\n");
return -ENOMEM;
}
/* Set up runtime services function pointers */
efi_native_runtime_setup();
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
efi.runtime_version = efi.systab->hdr.revision;
return 0;
}
early_initcall(arm_enable_runtime_services);
void efi_virtmap_load(void)
{
preempt_disable();
efi_set_pgd(&efi_mm);
}
void efi_virtmap_unload(void)
{
efi_set_pgd(current->active_mm);
preempt_enable();
}