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  	struct vdso_rng_data rng_data;
87  };
88  
89  #else /* CONFIG_PPC64 */
90  
91  /*
92   * And here is the simpler 32 bits version
93   */
94  struct vdso_arch_data {
95  	__u64 tb_ticks_per_sec;		/* Timebase tics / sec		0x38 */
96  	__u32 syscall_map[SYSCALL_MAP_SIZE]; /* Map of syscalls */
97  	__u32 compat_syscall_map[0];	/* No compat syscalls on PPC32 */
98  	struct vdso_data data[CS_BASES];
99  	struct vdso_rng_data rng_data;
100  };
101  
102  #endif /* CONFIG_PPC64 */
103  
104  extern struct vdso_arch_data *vdso_data;
105  
106  #else /* __ASSEMBLY__ */
107  
108  .macro get_datapage ptr
109  	bcl	20, 31, .+4
110  999:
111  	mflr	\ptr
112  	addis	\ptr, \ptr, (_vdso_datapage - 999b)@ha
113  	addi	\ptr, \ptr, (_vdso_datapage - 999b)@l
114  .endm
115  
116  #include <asm/asm-offsets.h>
117  #include <asm/page.h>
118  
119  .macro get_realdatapage ptr scratch
120  	get_datapage \ptr
121  #ifdef CONFIG_TIME_NS
122  	lwz	\scratch, VDSO_CLOCKMODE_OFFSET(\ptr)
123  	xoris	\scratch, \scratch, VDSO_CLOCKMODE_TIMENS@h
124  	xori	\scratch, \scratch, VDSO_CLOCKMODE_TIMENS@l
125  	cntlzw	\scratch, \scratch
126  	rlwinm	\scratch, \scratch, PAGE_SHIFT - 5, 1 << PAGE_SHIFT
127  	add	\ptr, \ptr, \scratch
128  #endif
129  .endm
130  
131  #endif /* __ASSEMBLY__ */
132  
133  #endif /* __KERNEL__ */
134  #endif /* _SYSTEMCFG_H */
135