xref: /linux/arch/x86/include/asm/processor-flags.h (revision cf09e3c904bf424f8b6a8203958e09bf7d9bcbc0)
1 #ifndef _ASM_X86_PROCESSOR_FLAGS_H
2 #define _ASM_X86_PROCESSOR_FLAGS_H
3 
4 #include <uapi/asm/processor-flags.h>
5 #include <linux/mem_encrypt.h>
6 
7 #ifdef CONFIG_VM86
8 #define X86_VM_MASK	X86_EFLAGS_VM
9 #else
10 #define X86_VM_MASK	0 /* No VM86 support */
11 #endif
12 
13 /*
14  * CR3's layout varies depending on several things.
15  *
16  * If CR4.PCIDE is set (64-bit only), then CR3[11:0] is the address space ID.
17  * If PAE is enabled, then CR3[11:5] is part of the PDPT address
18  * (i.e. it's 32-byte aligned, not page-aligned) and CR3[4:0] is ignored.
19  * Otherwise (non-PAE, non-PCID), CR3[3] is PWT, CR3[4] is PCD, and
20  * CR3[2:0] and CR3[11:5] are ignored.
21  *
22  * In all cases, Linux puts zeros in the low ignored bits and in PWT and PCD.
23  *
24  * CR3[63] is always read as zero.  If CR4.PCIDE is set, then CR3[63] may be
25  * written as 1 to prevent the write to CR3 from flushing the TLB.
26  *
27  * On systems with SME, one bit (in a variable position!) is stolen to indicate
28  * that the top-level paging structure is encrypted.
29  *
30  * All of the remaining bits indicate the physical address of the top-level
31  * paging structure.
32  *
33  * CR3_ADDR_MASK is the mask used by read_cr3_pa().
34  */
35 #ifdef CONFIG_X86_64
36 /* Mask off the address space ID and SME encryption bits. */
37 #define CR3_ADDR_MASK	__sme_clr(0x7FFFFFFFFFFFF000ull)
38 #define CR3_PCID_MASK	0xFFFull
39 #define CR3_NOFLUSH	BIT_ULL(63)
40 #else
41 /*
42  * CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save
43  * a tiny bit of code size by setting all the bits.
44  */
45 #define CR3_ADDR_MASK	0xFFFFFFFFull
46 #define CR3_PCID_MASK	0ull
47 #define CR3_NOFLUSH	0
48 #endif
49 
50 #endif /* _ASM_X86_PROCESSOR_FLAGS_H */
51