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Diffstat (limited to '')
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h new file mode 100644 index 000000000..62c846be2 --- /dev/null +++ b/arch/arm64/include/asm/efi.h @@ -0,0 +1,156 @@ +/* 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); + +bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg); +#else +#define efi_init() + +static inline +bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg) +{ + return false; +} +#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(); \ + raw_spin_lock(&efi_rt_lock); \ +}) + +#undef arch_efi_call_virt +#define arch_efi_call_virt(p, f, args...) \ + __efi_rt_asm_wrapper((p)->f, #f, args) + +#define arch_efi_call_virt_teardown() \ +({ \ + raw_spin_unlock(&efi_rt_lock); \ + __efi_fpsimd_end(); \ + efi_virtmap_unload(); \ +}) + +extern raw_spinlock_t efi_rt_lock; +extern u64 *efi_rt_stack_top; +efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...); + +/* + * efi_rt_stack_top[-1] contains the value the stack pointer had before + * switching to the EFI runtime stack. + */ +#define current_in_efi() \ + (!preemptible() && efi_rt_stack_top != NULL && \ + on_task_stack(current, READ_ONCE(efi_rt_stack_top[-1]), 1)) + +#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, 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) +{ +} + +#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); + +static inline void efi_capsule_flush_cache_range(void *addr, int size) +{ + dcache_clean_inval_poc((unsigned long)addr, (unsigned long)addr + size); +} + +#endif /* _ASM_EFI_H */ |