linux/arch/arm64/include/asm/efi.h
Ard Biesheuvel 6208857b8f efi/libstub: arm32: Base FDT and initrd placement on image address
The way we use the base of DRAM in the EFI stub is problematic as it
is ill defined what the base of DRAM actually means. There are some
restrictions on the placement of FDT and initrd which are defined in
terms of dram_base, but given that the placement of the kernel in
memory is what defines these boundaries (as on ARM, this is where the
linear region starts), it is better to use the image address in these
cases, and disregard dram_base altogether.

Reviewed-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Tested-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16 18:53:42 +03:00

145 lines
4.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_EFI_H
#define _ASM_EFI_H
#include <asm/boot.h>
#include <asm/cpufeature.h>
#include <asm/fpsimd.h>
#include <asm/io.h>
#include <asm/memory.h>
#include <asm/mmu_context.h>
#include <asm/neon.h>
#include <asm/ptrace.h>
#include <asm/tlbflush.h>
#ifdef CONFIG_EFI
extern void efi_init(void);
#else
#define efi_init()
#endif
int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
#define arch_efi_call_virt_setup() \
({ \
efi_virtmap_load(); \
__efi_fpsimd_begin(); \
})
#define arch_efi_call_virt(p, f, args...) \
({ \
efi_##f##_t *__f; \
__f = p->f; \
__efi_rt_asm_wrapper(__f, #f, args); \
})
#define arch_efi_call_virt_teardown() \
({ \
__efi_fpsimd_end(); \
efi_virtmap_unload(); \
})
efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...);
#define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT)
/*
* Even when Linux uses IRQ priorities for IRQ disabling, EFI does not.
* And EFI shouldn't really play around with priority masking as it is not aware
* which priorities the OS has assigned to its interrupts.
*/
#define arch_efi_save_flags(state_flags) \
((void)((state_flags) = read_sysreg(daif)))
#define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif)
/* arch specific definitions used by the stub code */
/*
* In some configurations (e.g. VMAP_STACK && 64K pages), stacks built into the
* kernel need greater alignment than we require the segments to be padded to.
*/
#define EFI_KIMG_ALIGN \
(SEGMENT_ALIGN > THREAD_ALIGN ? SEGMENT_ALIGN : THREAD_ALIGN)
/* on arm64, the FDT may be located anywhere in system RAM */
static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr)
{
return ULONG_MAX;
}
/*
* On arm64, we have to ensure that the initrd ends up in the linear region,
* which is a 1 GB aligned region of size '1UL << (VA_BITS_MIN - 1)' that is
* guaranteed to cover the kernel Image.
*
* Since the EFI stub is part of the kernel Image, we can relax the
* usual requirements in Documentation/arm64/booting.rst, which still
* apply to other bootloaders, and are required for some kernel
* configurations.
*/
static inline unsigned long efi_get_max_initrd_addr(unsigned long image_addr)
{
return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS_MIN - 1));
}
#define alloc_screen_info(x...) &screen_info
static inline void free_screen_info(struct screen_info *si)
{
}
static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
{
}
#define EFI_ALLOC_ALIGN SZ_64K
/*
* On ARM systems, virtually remapped UEFI runtime services are set up in two
* distinct stages:
* - The stub retrieves the final version of the memory map from UEFI, populates
* the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
* service to communicate the new mapping to the firmware (Note that the new
* mapping is not live at this time)
* - During an early initcall(), the EFI system table is permanently remapped
* and the virtual remapping of the UEFI Runtime Services regions is loaded
* into a private set of page tables. If this all succeeds, the Runtime
* Services are enabled and the EFI_RUNTIME_SERVICES bit set.
*/
static inline void efi_set_pgd(struct mm_struct *mm)
{
__switch_mm(mm);
if (system_uses_ttbr0_pan()) {
if (mm != current->active_mm) {
/*
* Update the current thread's saved ttbr0 since it is
* restored as part of a return from exception. Enable
* access to the valid TTBR0_EL1 and invoke the errata
* workaround directly since there is no return from
* exception when invoking the EFI run-time services.
*/
update_saved_ttbr0(current, mm);
uaccess_ttbr0_enable();
post_ttbr_update_workaround();
} else {
/*
* Defer the switch to the current thread's TTBR0_EL1
* until uaccess_enable(). Restore the current
* thread's saved ttbr0 corresponding to its active_mm
*/
uaccess_ttbr0_disable();
update_saved_ttbr0(current, current->active_mm);
}
}
}
void efi_virtmap_load(void);
void efi_virtmap_unload(void);
#endif /* _ASM_EFI_H */