1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _VDSO_DATAPAGE_H
3 #define _VDSO_DATAPAGE_H
4 #ifdef __KERNEL__
5 
6 /*
7  * Copyright (C) 2002 Peter Bergner <bergner@vnet.ibm.com>, IBM
8  * Copyright (C) 2005 Benjamin Herrenschmidy <benh@kernel.crashing.org>,
9  * 		      IBM Corp.
10  */
11 
12 
13 /*
14  * Note about this structure:
15  *
16  * This structure was historically called systemcfg and exposed to
17  * userland via /proc/ppc64/systemcfg. Unfortunately, this became an
18  * ABI issue as some proprietary software started relying on being able
19  * to mmap() it, thus we have to keep the base layout at least for a
20  * few kernel versions.
21  *
22  * However, since ppc32 doesn't suffer from this backward handicap,
23  * a simpler version of the data structure is used there with only the
24  * fields actually used by the vDSO.
25  *
26  */
27 
28 /*
29  * If the major version changes we are incompatible.
30  * Minor version changes are a hint.
31  */
32 #define SYSTEMCFG_MAJOR 1
33 #define SYSTEMCFG_MINOR 1
34 
35 #ifndef __ASSEMBLY__
36 
37 #include <linux/unistd.h>
38 #include <linux/time.h>
39 #include <vdso/datapage.h>
40 
41 #define SYSCALL_MAP_SIZE      ((NR_syscalls + 31) / 32)
42 
43 /*
44  * So here is the ppc64 backward compatible version
45  */
46 
47 #ifdef CONFIG_PPC64
48 
49 struct vdso_arch_data {
50 	__u8  eye_catcher[16];		/* Eyecatcher: SYSTEMCFG:PPC64	0x00 */
51 	struct {			/* Systemcfg version numbers	     */
52 		__u32 major;		/* Major number			0x10 */
53 		__u32 minor;		/* Minor number			0x14 */
54 	} version;
55 
56 	/* Note about the platform flags: it now only contains the lpar
57 	 * bit. The actual platform number is dead and buried
58 	 */
59 	__u32 platform;			/* Platform flags		0x18 */
60 	__u32 processor;		/* Processor type		0x1C */
61 	__u64 processorCount;		/* # of physical processors	0x20 */
62 	__u64 physicalMemorySize;	/* Size of real memory(B)	0x28 */
63 	__u64 tb_orig_stamp;		/* (NU) Timebase at boot	0x30 */
64 	__u64 tb_ticks_per_sec;		/* Timebase tics / sec		0x38 */
65 	__u64 tb_to_xs;			/* (NU) Inverse of TB to 2^20	0x40 */
66 	__u64 stamp_xsec;		/* (NU)				0x48 */
67 	__u64 tb_update_count;		/* (NU) Timebase atomicity ctr	0x50 */
68 	__u32 tz_minuteswest;		/* (NU) Min. west of Greenwich	0x58 */
69 	__u32 tz_dsttime;		/* (NU) Type of dst correction	0x5C */
70 	__u32 dcache_size;		/* L1 d-cache size		0x60 */
71 	__u32 dcache_line_size;		/* L1 d-cache line size		0x64 */
72 	__u32 icache_size;		/* L1 i-cache size		0x68 */
73 	__u32 icache_line_size;		/* L1 i-cache line size		0x6C */
74 
75 	/* those additional ones don't have to be located anywhere
76 	 * special as they were not part of the original systemcfg
77 	 */
78 	__u32 dcache_block_size;		/* L1 d-cache block size     */
79 	__u32 icache_block_size;		/* L1 i-cache block size     */
80 	__u32 dcache_log_block_size;		/* L1 d-cache log block size */
81 	__u32 icache_log_block_size;		/* L1 i-cache log block size */
82 	__u32 syscall_map[SYSCALL_MAP_SIZE];	/* Map of syscalls  */
83 	__u32 compat_syscall_map[SYSCALL_MAP_SIZE];	/* Map of compat syscalls */
84 
85 	struct vdso_data data[CS_BASES];
86 };
87 
88 #else /* CONFIG_PPC64 */
89 
90 /*
91  * And here is the simpler 32 bits version
92  */
93 struct vdso_arch_data {
94 	__u64 tb_ticks_per_sec;		/* Timebase tics / sec		0x38 */
95 	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
96 	__u32 compat_syscall_map[0];	/* No compat syscalls on PPC32 */
97 	struct vdso_data data[CS_BASES];
98 };
99 
100 #endif /* CONFIG_PPC64 */
101 
102 extern struct vdso_arch_data *vdso_data;
103 
104 #else /* __ASSEMBLY__ */
105 
106 .macro get_datapage ptr
107 	bcl	20, 31, .+4
108 999:
109 	mflr	\ptr
110 	addis	\ptr, \ptr, (_vdso_datapage - 999b)@ha
111 	addi	\ptr, \ptr, (_vdso_datapage - 999b)@l
112 .endm
113 
114 #include <asm/asm-offsets.h>
115 #include <asm/page.h>
116 
117 .macro get_realdatapage ptr scratch
118 	get_datapage \ptr
119 #ifdef CONFIG_TIME_NS
120 	lwz	\scratch, VDSO_CLOCKMODE_OFFSET(\ptr)
121 	xoris	\scratch, \scratch, VDSO_CLOCKMODE_TIMENS@h
122 	xori	\scratch, \scratch, VDSO_CLOCKMODE_TIMENS@l
123 	cntlzw	\scratch, \scratch
124 	rlwinm	\scratch, \scratch, PAGE_SHIFT - 5, 1 << PAGE_SHIFT
125 	add	\ptr, \ptr, \scratch
126 #endif
127 .endm
128 
129 #endif /* __ASSEMBLY__ */
130 
131 #endif /* __KERNEL__ */
132 #endif /* _SYSTEMCFG_H */
133