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efi/arm64: Preserve FP/SIMD registers on UEFI runtime services calls 

According to the UEFI spec section 2.3.6.4, the use of FP/SIMD
instructions is allowed, and should adhere to the AAPCS64 calling
convention, which states that 'only the bottom 64 bits of each value
stored in registers v8-v15 need to be preserved' (section 5.1.2).

This applies equally to UEFI Runtime Services called by the kernel, so
make sure the FP/SIMD register file is preserved in this case. We do this
by enabling the wrappers for UEFI Runtime Services (CONFIG_EFI_RUNTIME_WRAPPERS)
and inserting calls to kernel_neon_begin()and kernel_neon_end() into
these wrappers.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
hifive-unleashed-5.1
Ard Biesheuvel 2014-07-04 19:41:53 +02:00 committed by Matt Fleming
parent 022ee6c558
commit e15dd4949a
3 changed files with 23 additions and 13 deletions
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1
arch/arm64/Kconfig
View File

@ -298,6 +298,7 @@ config EFI
select LIBFDT
select UCS2_STRING
select EFI_PARAMS_FROM_FDT
select EFI_RUNTIME_WRAPPERS
default y
help
This option provides support for runtime services provided

21
arch/arm64/include/asm/efi.h
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@ -2,6 +2,7 @@
#define _ASM_EFI_H
#include <asm/io.h>
#include <asm/neon.h>
#ifdef CONFIG_EFI
extern void efi_init(void);
@ -11,4 +12,24 @@ extern void efi_idmap_init(void);
#define efi_idmap_init()
#endif
#define efi_call_virt(f, ...) \
({ \
efi_##f##_t *__f = efi.systab->runtime->f; \
efi_status_t __s; \
\
kernel_neon_begin(); \
__s = __f(__VA_ARGS__); \
kernel_neon_end(); \
__s; \
})
#define __efi_call_virt(f, ...) \
({ \
efi_##f##_t *__f = efi.systab->runtime->f; \
\
kernel_neon_begin(); \
__f(__VA_ARGS__); \
kernel_neon_end(); \
})
#endif /* _ASM_EFI_H */

14
arch/arm64/kernel/efi.c
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@ -449,19 +449,7 @@ static int __init arm64_enter_virtual_mode(void)
/* Set up runtime services function pointers */
runtime = efi.systab->runtime;
efi.get_time = runtime->get_time;
efi.set_time = runtime->set_time;
efi.get_wakeup_time = runtime->get_wakeup_time;
efi.set_wakeup_time = runtime->set_wakeup_time;
efi.get_variable = runtime->get_variable;
efi.get_next_variable = runtime->get_next_variable;
efi.set_variable = runtime->set_variable;
efi.query_variable_info = runtime->query_variable_info;
efi.update_capsule = runtime->update_capsule;
efi.query_capsule_caps = runtime->query_capsule_caps;
efi.get_next_high_mono_count = runtime->get_next_high_mono_count;
efi.reset_system = runtime->reset_system;
efi_native_runtime_setup();
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return 0;