linux/arch/x86/include/asm/efi.h
Ard Biesheuvel 243b6754cd efi/x86: Move x86 back to libstub
This reverts commit 84be880560, which itself reverted my original
attempt to move x86 from #include'ing .c files from across the tree
to using the EFI stub built as a static library.

The issue that affected the original approach was that splitting
the implementation into several .o files resulted in the variable
'efi_early' becoming a global with external linkage, which under
-fPIC implies that references to it must go through the GOT. However,
dealing with this additional GOT entry turned out to be troublesome
on some EFI implementations. (GCC's visibility=hidden attribute is
supposed to lift this requirement, but it turned out not to work on
the 32-bit build.)

Instead, use a pure getter function to get a reference to efi_early.
This approach results in no additional GOT entries being generated,
so there is no need for any changes in the early GOT handling.

Tested-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-11-11 22:23:11 +00:00

196 lines
5.3 KiB
C

#ifndef _ASM_X86_EFI_H
#define _ASM_X86_EFI_H
#include <asm/i387.h>
/*
* We map the EFI regions needed for runtime services non-contiguously,
* with preserved alignment on virtual addresses starting from -4G down
* for a total max space of 64G. This way, we provide for stable runtime
* services addresses across kernels so that a kexec'd kernel can still
* use them.
*
* This is the main reason why we're doing stable VA mappings for RT
* services.
*
* This flag is used in conjuction with a chicken bit called
* "efi=old_map" which can be used as a fallback to the old runtime
* services mapping method in case there's some b0rkage with a
* particular EFI implementation (haha, it is hard to hold up the
* sarcasm here...).
*/
#define EFI_OLD_MEMMAP EFI_ARCH_1
#define EFI32_LOADER_SIGNATURE "EL32"
#define EFI64_LOADER_SIGNATURE "EL64"
#ifdef CONFIG_X86_32
extern unsigned long asmlinkage efi_call_phys(void *, ...);
/*
* Wrap all the virtual calls in a way that forces the parameters on the stack.
*/
/* Use this macro if your virtual returns a non-void value */
#define efi_call_virt(f, args...) \
({ \
efi_status_t __s; \
kernel_fpu_begin(); \
__s = ((efi_##f##_t __attribute__((regparm(0)))*) \
efi.systab->runtime->f)(args); \
kernel_fpu_end(); \
__s; \
})
/* Use this macro if your virtual call does not return any value */
#define __efi_call_virt(f, args...) \
({ \
kernel_fpu_begin(); \
((efi_##f##_t __attribute__((regparm(0)))*) \
efi.systab->runtime->f)(args); \
kernel_fpu_end(); \
})
#define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size)
#else /* !CONFIG_X86_32 */
#define EFI_LOADER_SIGNATURE "EL64"
extern u64 asmlinkage efi_call(void *fp, ...);
#define efi_call_phys(f, args...) efi_call((f), args)
#define efi_call_virt(f, ...) \
({ \
efi_status_t __s; \
\
efi_sync_low_kernel_mappings(); \
preempt_disable(); \
__kernel_fpu_begin(); \
__s = efi_call((void *)efi.systab->runtime->f, __VA_ARGS__); \
__kernel_fpu_end(); \
preempt_enable(); \
__s; \
})
/*
* All X86_64 virt calls return non-void values. Thus, use non-void call for
* virt calls that would be void on X86_32.
*/
#define __efi_call_virt(f, args...) efi_call_virt(f, args)
extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
u32 type, u64 attribute);
#endif /* CONFIG_X86_32 */
extern struct efi_scratch efi_scratch;
extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
extern int __init efi_memblock_x86_reserve_range(void);
extern void __init efi_call_phys_prolog(void);
extern void __init efi_call_phys_epilog(void);
extern void __init efi_unmap_memmap(void);
extern void __init efi_memory_uc(u64 addr, unsigned long size);
extern void __init efi_map_region(efi_memory_desc_t *md);
extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
extern void efi_sync_low_kernel_mappings(void);
extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init old_map_region(efi_memory_desc_t *md);
extern void __init runtime_code_page_mkexec(void);
extern void __init efi_runtime_mkexec(void);
extern void __init efi_dump_pagetable(void);
extern void __init efi_apply_memmap_quirks(void);
extern int __init efi_reuse_config(u64 tables, int nr_tables);
extern void efi_delete_dummy_variable(void);
struct efi_setup_data {
u64 fw_vendor;
u64 runtime;
u64 tables;
u64 smbios;
u64 reserved[8];
};
extern u64 efi_setup;
#ifdef CONFIG_EFI
static inline bool efi_is_native(void)
{
return IS_ENABLED(CONFIG_X86_64) == efi_enabled(EFI_64BIT);
}
static inline bool efi_runtime_supported(void)
{
if (efi_is_native())
return true;
if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_enabled(EFI_OLD_MEMMAP))
return true;
return false;
}
extern struct console early_efi_console;
extern void parse_efi_setup(u64 phys_addr, u32 data_len);
#ifdef CONFIG_EFI_MIXED
extern void efi_thunk_runtime_setup(void);
extern efi_status_t efi_thunk_set_virtual_address_map(
void *phys_set_virtual_address_map,
unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
efi_memory_desc_t *virtual_map);
#else
static inline void efi_thunk_runtime_setup(void) {}
static inline efi_status_t efi_thunk_set_virtual_address_map(
void *phys_set_virtual_address_map,
unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
efi_memory_desc_t *virtual_map)
{
return EFI_SUCCESS;
}
#endif /* CONFIG_EFI_MIXED */
/* arch specific definitions used by the stub code */
struct efi_config {
u64 image_handle;
u64 table;
u64 allocate_pool;
u64 allocate_pages;
u64 get_memory_map;
u64 free_pool;
u64 free_pages;
u64 locate_handle;
u64 handle_protocol;
u64 exit_boot_services;
u64 text_output;
efi_status_t (*call)(unsigned long, ...);
bool is64;
} __packed;
__pure const struct efi_config *__efi_early(void);
#define efi_call_early(f, ...) \
__efi_early()->call(__efi_early()->f, __VA_ARGS__);
extern bool efi_reboot_required(void);
#else
static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
static inline bool efi_reboot_required(void)
{
return false;
}
#endif /* CONFIG_EFI */
#endif /* _ASM_X86_EFI_H */