151 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			151 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| 
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| #ifndef _ASM_X86_CPU_ENTRY_AREA_H
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| #define _ASM_X86_CPU_ENTRY_AREA_H
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| 
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| #include <linux/percpu-defs.h>
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| #include <asm/processor.h>
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| #include <asm/intel_ds.h>
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| 
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| #ifdef CONFIG_X86_64
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| 
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| #ifdef CONFIG_AMD_MEM_ENCRYPT
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| #define VC_EXCEPTION_STKSZ	EXCEPTION_STKSZ
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| #else
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| #define VC_EXCEPTION_STKSZ	0
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| #endif
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| 
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| /* Macro to enforce the same ordering and stack sizes */
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| #define ESTACKS_MEMBERS(guardsize, optional_stack_size)		\
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| 	char	DF_stack_guard[guardsize];			\
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| 	char	DF_stack[EXCEPTION_STKSZ];			\
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| 	char	NMI_stack_guard[guardsize];			\
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| 	char	NMI_stack[EXCEPTION_STKSZ];			\
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| 	char	DB_stack_guard[guardsize];			\
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| 	char	DB_stack[EXCEPTION_STKSZ];			\
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| 	char	MCE_stack_guard[guardsize];			\
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| 	char	MCE_stack[EXCEPTION_STKSZ];			\
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| 	char	VC_stack_guard[guardsize];			\
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| 	char	VC_stack[optional_stack_size];			\
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| 	char	VC2_stack_guard[guardsize];			\
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| 	char	VC2_stack[optional_stack_size];			\
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| 	char	IST_top_guard[guardsize];			\
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| 
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| /* The exception stacks' physical storage. No guard pages required */
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| struct exception_stacks {
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| 	ESTACKS_MEMBERS(0, VC_EXCEPTION_STKSZ)
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| };
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| 
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| /* The effective cpu entry area mapping with guard pages. */
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| struct cea_exception_stacks {
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| 	ESTACKS_MEMBERS(PAGE_SIZE, EXCEPTION_STKSZ)
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| };
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| 
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| /*
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|  * The exception stack ordering in [cea_]exception_stacks
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|  */
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| enum exception_stack_ordering {
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| 	ESTACK_DF,
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| 	ESTACK_NMI,
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| 	ESTACK_DB,
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| 	ESTACK_MCE,
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| 	ESTACK_VC,
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| 	ESTACK_VC2,
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| 	N_EXCEPTION_STACKS
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| };
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| 
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| #define CEA_ESTACK_SIZE(st)					\
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| 	sizeof(((struct cea_exception_stacks *)0)->st## _stack)
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| 
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| #define CEA_ESTACK_BOT(ceastp, st)				\
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| 	((unsigned long)&(ceastp)->st## _stack)
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| 
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| #define CEA_ESTACK_TOP(ceastp, st)				\
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| 	(CEA_ESTACK_BOT(ceastp, st) + CEA_ESTACK_SIZE(st))
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| 
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| #define CEA_ESTACK_OFFS(st)					\
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| 	offsetof(struct cea_exception_stacks, st## _stack)
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| 
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| #define CEA_ESTACK_PAGES					\
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| 	(sizeof(struct cea_exception_stacks) / PAGE_SIZE)
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| 
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| #endif
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| 
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| /*
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|  * cpu_entry_area is a percpu region that contains things needed by the CPU
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|  * and early entry/exit code.  Real types aren't used for all fields here
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|  * to avoid circular header dependencies.
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|  *
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|  * Every field is a virtual alias of some other allocated backing store.
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|  * There is no direct allocation of a struct cpu_entry_area.
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|  */
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| struct cpu_entry_area {
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| 	char gdt[PAGE_SIZE];
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| 
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| 	/*
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| 	 * The GDT is just below entry_stack and thus serves (on x86_64) as
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| 	 * a a read-only guard page.
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| 	 */
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| 	struct entry_stack_page entry_stack_page;
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| 
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| 	/*
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| 	 * On x86_64, the TSS is mapped RO.  On x86_32, it's mapped RW because
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| 	 * we need task switches to work, and task switches write to the TSS.
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| 	 */
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| 	struct tss_struct tss;
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| 
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| #ifdef CONFIG_X86_64
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| 	/*
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| 	 * Exception stacks used for IST entries with guard pages.
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| 	 */
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| 	struct cea_exception_stacks estacks;
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| #endif
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| 	/*
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| 	 * Per CPU debug store for Intel performance monitoring. Wastes a
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| 	 * full page at the moment.
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| 	 */
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| 	struct debug_store cpu_debug_store;
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| 	/*
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| 	 * The actual PEBS/BTS buffers must be mapped to user space
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| 	 * Reserve enough fixmap PTEs.
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| 	 */
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| 	struct debug_store_buffers cpu_debug_buffers;
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| };
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| 
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| #define CPU_ENTRY_AREA_SIZE		(sizeof(struct cpu_entry_area))
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| 
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| DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
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| DECLARE_PER_CPU(struct cea_exception_stacks *, cea_exception_stacks);
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| 
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| extern void setup_cpu_entry_areas(void);
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| extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags);
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| 
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| /* Single page reserved for the readonly IDT mapping: */
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| #define	CPU_ENTRY_AREA_RO_IDT		CPU_ENTRY_AREA_BASE
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| #define CPU_ENTRY_AREA_PER_CPU		(CPU_ENTRY_AREA_RO_IDT + PAGE_SIZE)
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| 
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| #define CPU_ENTRY_AREA_RO_IDT_VADDR	((void *)CPU_ENTRY_AREA_RO_IDT)
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| 
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| #ifdef CONFIG_X86_32
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| #define CPU_ENTRY_AREA_MAP_SIZE		(CPU_ENTRY_AREA_PER_CPU +		\
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| 					(CPU_ENTRY_AREA_SIZE * NR_CPUS) -	\
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| 					CPU_ENTRY_AREA_BASE)
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| #else
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| #define CPU_ENTRY_AREA_MAP_SIZE		P4D_SIZE
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| #endif
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| 
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| extern struct cpu_entry_area *get_cpu_entry_area(int cpu);
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| 
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| static inline struct entry_stack *cpu_entry_stack(int cpu)
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| {
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| 	return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
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| }
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| 
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| #define __this_cpu_ist_top_va(name)					\
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| 	CEA_ESTACK_TOP(__this_cpu_read(cea_exception_stacks), name)
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| 
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| #define __this_cpu_ist_bottom_va(name)					\
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| 	CEA_ESTACK_BOT(__this_cpu_read(cea_exception_stacks), name)
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| 
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| #endif
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