linux/arch/x86/include/asm/processor-flags.h

57 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PROCESSOR_FLAGS_H
#define _ASM_X86_PROCESSOR_FLAGS_H
#include <uapi/asm/processor-flags.h>
#include <linux/mem_encrypt.h>
#ifdef CONFIG_VM86
#define X86_VM_MASK X86_EFLAGS_VM
#else
#define X86_VM_MASK 0 /* No VM86 support */
#endif
/*
* CR3's layout varies depending on several things.
*
* If CR4.PCIDE is set (64-bit only), then CR3[11:0] is the address space ID.
* If PAE is enabled, then CR3[11:5] is part of the PDPT address
* (i.e. it's 32-byte aligned, not page-aligned) and CR3[4:0] is ignored.
* Otherwise (non-PAE, non-PCID), CR3[3] is PWT, CR3[4] is PCD, and
* CR3[2:0] and CR3[11:5] are ignored.
*
* In all cases, Linux puts zeros in the low ignored bits and in PWT and PCD.
*
* CR3[63] is always read as zero. If CR4.PCIDE is set, then CR3[63] may be
* written as 1 to prevent the write to CR3 from flushing the TLB.
*
* On systems with SME, one bit (in a variable position!) is stolen to indicate
* that the top-level paging structure is encrypted.
*
* All of the remaining bits indicate the physical address of the top-level
* paging structure.
*
* CR3_ADDR_MASK is the mask used by read_cr3_pa().
*/
#ifdef CONFIG_X86_64
/* Mask off the address space ID and SME encryption bits. */
#define CR3_ADDR_MASK __sme_clr(0x7FFFFFFFFFFFF000ull)
#define CR3_PCID_MASK 0xFFFull
#define CR3_NOFLUSH BIT_ULL(63)
#ifdef CONFIG_PAGE_TABLE_ISOLATION
# define X86_CR3_PTI_PCID_USER_BIT 11
#endif
#else
/*
* CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save
* a tiny bit of code size by setting all the bits.
*/
#define CR3_ADDR_MASK 0xFFFFFFFFull
#define CR3_PCID_MASK 0ull
#define CR3_NOFLUSH 0
#endif
#endif /* _ASM_X86_PROCESSOR_FLAGS_H */