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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_CPU_ENTRY_AREA_H
#define _ASM_X86_CPU_ENTRY_AREA_H
#include <linux/percpu-defs.h>
#include <asm/processor.h>
#include <asm/intel_ds.h>
#include <asm/pgtable_areas.h>
#ifdef CONFIG_X86_64
#ifdef CONFIG_AMD_MEM_ENCRYPT
#define VC_EXCEPTION_STKSZ EXCEPTION_STKSZ
#else
#define VC_EXCEPTION_STKSZ 0
#endif
/* Macro to enforce the same ordering and stack sizes */
#define ESTACKS_MEMBERS(guardsize, optional_stack_size) \
char DF_stack_guard[guardsize]; \
char DF_stack[EXCEPTION_STKSZ]; \
char NMI_stack_guard[guardsize]; \
char NMI_stack[EXCEPTION_STKSZ]; \
char DB_stack_guard[guardsize]; \
char DB_stack[EXCEPTION_STKSZ]; \
char MCE_stack_guard[guardsize]; \
char MCE_stack[EXCEPTION_STKSZ]; \
char VC_stack_guard[guardsize]; \
char VC_stack[optional_stack_size]; \
char VC2_stack_guard[guardsize]; \
char VC2_stack[optional_stack_size]; \
char IST_top_guard[guardsize]; \
/* The exception stacks' physical storage. No guard pages required */
struct exception_stacks {
ESTACKS_MEMBERS(0, VC_EXCEPTION_STKSZ)
};
/* The effective cpu entry area mapping with guard pages. */
struct cea_exception_stacks {
ESTACKS_MEMBERS(PAGE_SIZE, EXCEPTION_STKSZ)
};
/*
* The exception stack ordering in [cea_]exception_stacks
*/
enum exception_stack_ordering {
ESTACK_DF,
ESTACK_NMI,
ESTACK_DB,
ESTACK_MCE,
ESTACK_VC,
ESTACK_VC2,
N_EXCEPTION_STACKS
};
#define CEA_ESTACK_SIZE(st) \
sizeof(((struct cea_exception_stacks *)0)->st## _stack)
#define CEA_ESTACK_BOT(ceastp, st) \
((unsigned long)&(ceastp)->st## _stack)
#define CEA_ESTACK_TOP(ceastp, st) \
(CEA_ESTACK_BOT(ceastp, st) + CEA_ESTACK_SIZE(st))
#define CEA_ESTACK_OFFS(st) \
offsetof(struct cea_exception_stacks, st## _stack)
#define CEA_ESTACK_PAGES \
(sizeof(struct cea_exception_stacks) / PAGE_SIZE)
#endif
#ifdef CONFIG_X86_32
struct doublefault_stack {
unsigned long stack[(PAGE_SIZE - sizeof(struct x86_hw_tss)) / sizeof(unsigned long)];
struct x86_hw_tss tss;
} __aligned(PAGE_SIZE);
#endif
/*
* cpu_entry_area is a percpu region 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];
/*
* The GDT is just below entry_stack and thus serves (on x86_64) as
* a read-only guard page. On 32-bit the GDT must be writeable, so
* it needs an extra guard page.
*/
#ifdef CONFIG_X86_32
char guard_entry_stack[PAGE_SIZE];
#endif
struct entry_stack_page entry_stack_page;
#ifdef CONFIG_X86_32
char guard_doublefault_stack[PAGE_SIZE];
struct doublefault_stack doublefault_stack;
#endif
/*
* On x86_64, the TSS is mapped RO. On x86_32, it's mapped RW because
* we need task switches to work, and task switches write to the TSS.
*/
struct tss_struct tss;
#ifdef CONFIG_X86_64
/*
* Exception stacks used for IST entries with guard pages.
*/
struct cea_exception_stacks estacks;
#endif
/*
* Per CPU debug store for Intel performance monitoring. Wastes a
* full page at the moment.
*/
struct debug_store cpu_debug_store;
/*
* The actual PEBS/BTS buffers must be mapped to user space
* Reserve enough fixmap PTEs.
*/
struct debug_store_buffers cpu_debug_buffers;
};
#define CPU_ENTRY_AREA_SIZE (sizeof(struct cpu_entry_area))
DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks);
extern void setup_cpu_entry_areas(void);
extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags);
extern struct cpu_entry_area *get_cpu_entry_area(int cpu);
static __always_inline struct entry_stack *cpu_entry_stack(int cpu)
{
return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
}
#define __this_cpu_ist_top_va(name) \
CEA_ESTACK_TOP(__this_cpu_read(cea_exception_stacks), name)
#define __this_cpu_ist_bottom_va(name) \
CEA_ESTACK_BOT(__this_cpu_read(cea_exception_stacks), name)
#endif