1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __VDSO_DATAPAGE_H 2 #ifndef __VDSO_DATAPAGE_H
3 #define __VDSO_DATAPAGE_H 3 #define __VDSO_DATAPAGE_H
4 4
5 #ifndef __ASSEMBLY__ 5 #ifndef __ASSEMBLY__
6 6
7 #include <linux/compiler.h> !! 7 #include <linux/bits.h>
8 #include <uapi/linux/time.h> !! 8 #include <linux/time.h>
9 #include <uapi/linux/types.h> !! 9 #include <linux/types.h>
10 #include <uapi/asm-generic/errno-base.h> <<
11 <<
12 #include <vdso/bits.h> <<
13 #include <vdso/clocksource.h> <<
14 #include <vdso/ktime.h> <<
15 #include <vdso/limits.h> <<
16 #include <vdso/math64.h> <<
17 #include <vdso/processor.h> <<
18 #include <vdso/time.h> <<
19 #include <vdso/time32.h> <<
20 #include <vdso/time64.h> <<
21 <<
22 #ifdef CONFIG_ARCH_HAS_VDSO_DATA <<
23 #include <asm/vdso/data.h> <<
24 #else <<
25 struct arch_vdso_data {}; <<
26 #endif <<
27 10
28 #define VDSO_BASES (CLOCK_TAI + 1) 11 #define VDSO_BASES (CLOCK_TAI + 1)
29 #define VDSO_HRES (BIT(CLOCK_REALTIME) 12 #define VDSO_HRES (BIT(CLOCK_REALTIME) | \
30 BIT(CLOCK_MONOTONIC) 13 BIT(CLOCK_MONOTONIC) | \
31 BIT(CLOCK_BOOTTIME) 14 BIT(CLOCK_BOOTTIME) | \
32 BIT(CLOCK_TAI)) 15 BIT(CLOCK_TAI))
33 #define VDSO_COARSE (BIT(CLOCK_REALTIME_CO 16 #define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \
34 BIT(CLOCK_MONOTONIC_C 17 BIT(CLOCK_MONOTONIC_COARSE))
35 #define VDSO_RAW (BIT(CLOCK_MONOTONIC_R 18 #define VDSO_RAW (BIT(CLOCK_MONOTONIC_RAW))
36 19
37 #define CS_HRES_COARSE 0 20 #define CS_HRES_COARSE 0
38 #define CS_RAW 1 21 #define CS_RAW 1
39 #define CS_BASES (CS_RAW + 1) 22 #define CS_BASES (CS_RAW + 1)
40 23
41 /** 24 /**
42 * struct vdso_timestamp - basetime per clock_ 25 * struct vdso_timestamp - basetime per clock_id
43 * @sec: seconds 26 * @sec: seconds
44 * @nsec: nanoseconds 27 * @nsec: nanoseconds
45 * 28 *
46 * There is one vdso_timestamp object in vvar 29 * There is one vdso_timestamp object in vvar for each vDSO-accelerated
47 * clock_id. For high-resolution clocks, this 30 * clock_id. For high-resolution clocks, this encodes the time
48 * corresponding to vdso_data.cycle_last. For 31 * corresponding to vdso_data.cycle_last. For coarse clocks this encodes
49 * the actual time. 32 * the actual time.
50 * 33 *
51 * To be noticed that for highres clocks nsec 34 * To be noticed that for highres clocks nsec is left-shifted by
52 * vdso_data.cs[x].shift. 35 * vdso_data.cs[x].shift.
53 */ 36 */
54 struct vdso_timestamp { 37 struct vdso_timestamp {
55 u64 sec; 38 u64 sec;
56 u64 nsec; 39 u64 nsec;
57 }; 40 };
58 41
59 /** 42 /**
60 * struct vdso_data - vdso datapage representa 43 * struct vdso_data - vdso datapage representation
61 * @seq: timebase sequence coun 44 * @seq: timebase sequence counter
62 * @clock_mode: clock mode 45 * @clock_mode: clock mode
63 * @cycle_last: timebase at clocksourc 46 * @cycle_last: timebase at clocksource init
64 * @max_cycles: maximum cycles which w <<
65 * @mask: clocksource mask 47 * @mask: clocksource mask
66 * @mult: clocksource multiplier 48 * @mult: clocksource multiplier
67 * @shift: clocksource shift 49 * @shift: clocksource shift
68 * @basetime[clock_id]: basetime per clock_id 50 * @basetime[clock_id]: basetime per clock_id
69 * @offset[clock_id]: time namespace offset <<
70 * @tz_minuteswest: minutes west of Greenw 51 * @tz_minuteswest: minutes west of Greenwich
71 * @tz_dsttime: type of DST correction 52 * @tz_dsttime: type of DST correction
72 * @hrtimer_res: hrtimer resolution 53 * @hrtimer_res: hrtimer resolution
73 * @__unused: unused 54 * @__unused: unused
74 * @arch_data: architecture specific <<
75 * to an empty struct) <<
76 * 55 *
77 * vdso_data will be accessed by 64 bit and co 56 * vdso_data will be accessed by 64 bit and compat code at the same time
78 * so we should be careful before modifying th 57 * so we should be careful before modifying this structure.
79 * <<
80 * The ordering of the struct members is optim <<
81 * often required struct members which are rel <<
82 * CLOCK_MONOTONIC. This information is stored <<
83 * <<
84 * @basetime is used to store the base time fo <<
85 * VVAR page. <<
86 * <<
87 * @offset is used by the special time namespa <<
88 * installed instead of the real VVAR page. Th <<
89 * @seq to 1 and @clock_mode to VDSO_CLOCKMODE <<
90 * the time namespace slow path. The namespace <<
91 * real system wide VVAR page, read host time <<
92 * For clocks which are not affected by time n <<
93 * offset must be zero. <<
94 */ 58 */
95 struct vdso_data { 59 struct vdso_data {
96 u32 seq; 60 u32 seq;
97 61
98 s32 clock_mode; 62 s32 clock_mode;
99 u64 cycle_last; 63 u64 cycle_last;
100 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT <<
101 u64 max_cycles; <<
102 #endif <<
103 u64 mask; 64 u64 mask;
104 u32 mult; 65 u32 mult;
105 u32 shift; 66 u32 shift;
106 67
107 union { !! 68 struct vdso_timestamp basetime[VDSO_BASES];
108 struct vdso_timestamp baseti <<
109 struct timens_offset offset <<
110 }; <<
111 69
112 s32 tz_minuteswest 70 s32 tz_minuteswest;
113 s32 tz_dsttime; 71 s32 tz_dsttime;
114 u32 hrtimer_res; 72 u32 hrtimer_res;
115 u32 __unused; 73 u32 __unused;
116 <<
117 struct arch_vdso_data arch_data; <<
118 }; <<
119 <<
120 /** <<
121 * struct vdso_rng_data - vdso RNG state infor <<
122 * @generation: counter representing the numbe <<
123 * @is_ready: boolean signaling whether the <<
124 */ <<
125 struct vdso_rng_data { <<
126 u64 generation; <<
127 u8 is_ready; <<
128 }; 74 };
129 75
130 /* 76 /*
131 * We use the hidden visibility to prevent the 77 * We use the hidden visibility to prevent the compiler from generating a GOT
132 * relocation. Not only is going through a GOT 78 * relocation. Not only is going through a GOT useless (the entry couldn't and
133 * must not be overridden by another library), 79 * must not be overridden by another library), it does not even work: the linker
134 * cannot generate an absolute address to the 80 * cannot generate an absolute address to the data page.
135 * 81 *
136 * With the hidden visibility, the compiler si 82 * With the hidden visibility, the compiler simply generates a PC-relative
137 * relocation, and this is what we need. 83 * relocation, and this is what we need.
138 */ 84 */
139 extern struct vdso_data _vdso_data[CS_BASES] _ 85 extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));
140 extern struct vdso_data _timens_data[CS_BASES] <<
141 extern struct vdso_rng_data _vdso_rng_data __a <<
142 <<
143 /** <<
144 * union vdso_data_store - Generic vDSO data p <<
145 */ <<
146 union vdso_data_store { <<
147 struct vdso_data data[CS_BASES] <<
148 u8 page[1U << CON <<
149 }; <<
150 <<
151 /* <<
152 * The generic vDSO implementation requires th <<
153 * provides: <<
154 * - __arch_get_vdso_data(): to get the vdso d <<
155 * - __arch_get_hw_counter(): to get the hw co <<
156 * clock_mode. <<
157 * - gettimeofday_fallback(): fallback for get <<
158 * - clock_gettime_fallback(): fallback for cl <<
159 * - clock_getres_fallback(): fallback for clo <<
160 */ <<
161 #ifdef ENABLE_COMPAT_VDSO <<
162 #include <asm/vdso/compat_gettimeofday.h> <<
163 #else <<
164 #include <asm/vdso/gettimeofday.h> <<
165 #endif /* ENABLE_COMPAT_VDSO */ <<
166 86
167 #endif /* !__ASSEMBLY__ */ 87 #endif /* !__ASSEMBLY__ */
168 88
169 #endif /* __VDSO_DATAPAGE_H */ 89 #endif /* __VDSO_DATAPAGE_H */
170 90
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