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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/include/asm/cpu_entry_area.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/cpu_entry_area.h')
-rw-r--r-- | arch/x86/include/asm/cpu_entry_area.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h new file mode 100644 index 000000000..75efc4c6f --- /dev/null +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -0,0 +1,157 @@ +/* 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)) +#define CPU_ENTRY_AREA_ARRAY_SIZE (CPU_ENTRY_AREA_SIZE * NR_CPUS) + +/* Total size includes the readonly IDT mapping page as well: */ +#define CPU_ENTRY_AREA_TOTAL_SIZE (CPU_ENTRY_AREA_ARRAY_SIZE + PAGE_SIZE) + +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 |