Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef _ASM_X86_PROCESSOR_FLAGS_H
2#define _ASM_X86_PROCESSOR_FLAGS_H
3
4#include <uapi/asm/processor-flags.h>
5
6#ifdef CONFIG_VM86
7#define X86_VM_MASK X86_EFLAGS_VM
8#else
9#define X86_VM_MASK 0 /* No VM86 support */
10#endif
11
12/*
13 * CR3's layout varies depending on several things.
14 *
15 * If CR4.PCIDE is set (64-bit only), then CR3[11:0] is the address space ID.
16 * If PAE is enabled, then CR3[11:5] is part of the PDPT address
17 * (i.e. it's 32-byte aligned, not page-aligned) and CR3[4:0] is ignored.
18 * Otherwise (non-PAE, non-PCID), CR3[3] is PWT, CR3[4] is PCD, and
19 * CR3[2:0] and CR3[11:5] are ignored.
20 *
21 * In all cases, Linux puts zeros in the low ignored bits and in PWT and PCD.
22 *
23 * CR3[63] is always read as zero. If CR4.PCIDE is set, then CR3[63] may be
24 * written as 1 to prevent the write to CR3 from flushing the TLB.
25 *
26 * On systems with SME, one bit (in a variable position!) is stolen to indicate
27 * that the top-level paging structure is encrypted.
28 *
29 * All of the remaining bits indicate the physical address of the top-level
30 * paging structure.
31 *
32 * CR3_ADDR_MASK is the mask used by read_cr3_pa().
33 */
34#ifdef CONFIG_X86_64
35/* Mask off the address space ID bits. */
36#define CR3_ADDR_MASK 0x7FFFFFFFFFFFF000ull
37#define CR3_PCID_MASK 0xFFFull
38#else
39/*
40 * CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save
41 * a tiny bit of code size by setting all the bits.
42 */
43#define CR3_ADDR_MASK 0xFFFFFFFFull
44#define CR3_PCID_MASK 0ull
45#endif
46
47#endif /* _ASM_X86_PROCESSOR_FLAGS_H */