diff options
Diffstat (limited to 'arch/x86/include/asm/fixmap.h')
| -rw-r--r-- | arch/x86/include/asm/fixmap.h | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index b0c505fe9a95..b61f0242f9d0 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -44,6 +44,19 @@ extern unsigned long __FIXADDR_TOP; PAGE_SIZE) #endif +/* + * cpu_entry_area is a percpu region in the fixmap that contains things + * needed by the CPU and early entry/exit code. Real types aren't used + * for all fields here to avoid circular header dependencies. + * + * Every field is a virtual alias of some other allocated backing store. + * There is no direct allocation of a struct cpu_entry_area. + */ +struct cpu_entry_area { + char gdt[PAGE_SIZE]; +}; + +#define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE) /* * Here we define all the compile-time 'special' virtual @@ -101,8 +114,8 @@ enum fixed_addresses { FIX_LNW_VRTC, #endif /* Fixmap entries to remap the GDTs, one per processor. */ - FIX_GDT_REMAP_BEGIN, - FIX_GDT_REMAP_END = FIX_GDT_REMAP_BEGIN + NR_CPUS - 1, + FIX_CPU_ENTRY_AREA_TOP, + FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1, #ifdef CONFIG_ACPI_APEI_GHES /* Used for GHES mapping from assorted contexts */ @@ -191,5 +204,25 @@ void __init *early_memremap_decrypted_wp(resource_size_t phys_addr, void __early_set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags); +static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page) +{ + BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0); + + return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page; +} + +#define __get_cpu_entry_area_offset_index(cpu, offset) ({ \ + BUILD_BUG_ON(offset % PAGE_SIZE != 0); \ + __get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \ + }) + +#define get_cpu_entry_area_index(cpu, field) \ + __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field)) + +static inline struct cpu_entry_area *get_cpu_entry_area(int cpu) +{ + return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0)); +} + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_FIXMAP_H */ |