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74609f45 | 1 | /* |
a7f290da BH |
2 | * Userland implementation of gettimeofday() for 64 bits processes in a |
3 | * ppc64 kernel for use in the vDSO | |
4 | * | |
5 | * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), | |
6 | * IBM Corp. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | */ | |
a7f290da BH |
13 | #include <asm/processor.h> |
14 | #include <asm/ppc_asm.h> | |
15 | #include <asm/vdso.h> | |
16 | #include <asm/asm-offsets.h> | |
17 | #include <asm/unistd.h> | |
18 | ||
19 | .text | |
20 | /* | |
21 | * Exact prototype of gettimeofday | |
22 | * | |
23 | * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); | |
24 | * | |
25 | */ | |
26 | V_FUNCTION_BEGIN(__kernel_gettimeofday) | |
27 | .cfi_startproc | |
28 | mflr r12 | |
29 | .cfi_register lr,r12 | |
30 | ||
31 | mr r11,r3 /* r11 holds tv */ | |
32 | mr r10,r4 /* r10 holds tz */ | |
33 | bl V_LOCAL_FUNC(__get_datapage) /* get data page */ | |
fde937d8 | 34 | cmpldi r11,0 /* check if tv is NULL */ |
74609f45 | 35 | beq 2f |
8fd63a9e PM |
36 | lis r7,1000000@ha /* load up USEC_PER_SEC */ |
37 | addi r7,r7,1000000@l | |
38 | bl V_LOCAL_FUNC(__do_get_tspec) /* get sec/us from tb & kernel */ | |
39 | std r4,TVAL64_TV_SEC(r11) /* store sec in tv */ | |
40 | std r5,TVAL64_TV_USEC(r11) /* store usec in tv */ | |
74609f45 | 41 | 2: cmpldi r10,0 /* check if tz is NULL */ |
a7f290da BH |
42 | beq 1f |
43 | lwz r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */ | |
44 | lwz r5,CFG_TZ_DSTTIME(r3) | |
45 | stw r4,TZONE_TZ_MINWEST(r10) | |
46 | stw r5,TZONE_TZ_DSTTIME(r10) | |
47 | 1: mtlr r12 | |
5d66da3d | 48 | crclr cr0*4+so |
a7f290da BH |
49 | li r3,0 /* always success */ |
50 | blr | |
51 | .cfi_endproc | |
52 | V_FUNCTION_END(__kernel_gettimeofday) | |
53 | ||
54 | ||
55 | /* | |
56 | * Exact prototype of clock_gettime() | |
57 | * | |
58 | * int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); | |
59 | * | |
60 | */ | |
61 | V_FUNCTION_BEGIN(__kernel_clock_gettime) | |
62 | .cfi_startproc | |
63 | /* Check for supported clock IDs */ | |
64 | cmpwi cr0,r3,CLOCK_REALTIME | |
65 | cmpwi cr1,r3,CLOCK_MONOTONIC | |
0c37ec2a | 66 | cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
a7f290da BH |
67 | bne cr0,99f |
68 | ||
69 | mflr r12 /* r12 saves lr */ | |
70 | .cfi_register lr,r12 | |
a7f290da BH |
71 | mr r11,r4 /* r11 saves tp */ |
72 | bl V_LOCAL_FUNC(__get_datapage) /* get data page */ | |
8fd63a9e PM |
73 | lis r7,NSEC_PER_SEC@h /* want nanoseconds */ |
74 | ori r7,r7,NSEC_PER_SEC@l | |
597bc5c0 PM |
75 | 50: bl V_LOCAL_FUNC(__do_get_tspec) /* get time from tb & kernel */ |
76 | bne cr1,80f /* if not monotonic, all done */ | |
a7f290da BH |
77 | |
78 | /* | |
79 | * CLOCK_MONOTONIC | |
80 | */ | |
81 | ||
a7f290da BH |
82 | /* now we must fixup using wall to monotonic. We need to snapshot |
83 | * that value and do the counter trick again. Fortunately, we still | |
597bc5c0 PM |
84 | * have the counter value in r8 that was returned by __do_get_tspec. |
85 | * At this point, r4,r5 contain our sec/nsec values. | |
a7f290da BH |
86 | */ |
87 | ||
597bc5c0 PM |
88 | lwa r6,WTOM_CLOCK_SEC(r3) |
89 | lwa r9,WTOM_CLOCK_NSEC(r3) | |
a7f290da | 90 | |
597bc5c0 | 91 | /* We now have our result in r6,r9. We create a fake dependency |
a7f290da BH |
92 | * on that result and re-check the counter |
93 | */ | |
597bc5c0 PM |
94 | or r0,r6,r9 |
95 | xor r0,r0,r0 | |
a7f290da BH |
96 | add r3,r3,r0 |
97 | ld r0,CFG_TB_UPDATE_COUNT(r3) | |
98 | cmpld cr0,r0,r8 /* check if updated */ | |
99 | bne- 50b | |
100 | ||
597bc5c0 | 101 | /* Add wall->monotonic offset and check for overflow or underflow. |
a7f290da | 102 | */ |
597bc5c0 PM |
103 | add r4,r4,r6 |
104 | add r5,r5,r9 | |
105 | cmpd cr0,r5,r7 | |
106 | cmpdi cr1,r5,0 | |
a7f290da | 107 | blt 1f |
597bc5c0 | 108 | subf r5,r7,r5 |
a7f290da | 109 | addi r4,r4,1 |
597bc5c0 | 110 | 1: bge cr1,80f |
0c37ec2a | 111 | addi r4,r4,-1 |
597bc5c0 PM |
112 | add r5,r5,r7 |
113 | ||
114 | 80: std r4,TSPC64_TV_SEC(r11) | |
115 | std r5,TSPC64_TV_NSEC(r11) | |
a7f290da BH |
116 | |
117 | mtlr r12 | |
5d66da3d | 118 | crclr cr0*4+so |
a7f290da BH |
119 | li r3,0 |
120 | blr | |
121 | ||
122 | /* | |
123 | * syscall fallback | |
124 | */ | |
a7f290da BH |
125 | 99: |
126 | li r0,__NR_clock_gettime | |
127 | sc | |
128 | blr | |
129 | .cfi_endproc | |
130 | V_FUNCTION_END(__kernel_clock_gettime) | |
131 | ||
132 | ||
133 | /* | |
134 | * Exact prototype of clock_getres() | |
135 | * | |
136 | * int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); | |
137 | * | |
138 | */ | |
139 | V_FUNCTION_BEGIN(__kernel_clock_getres) | |
140 | .cfi_startproc | |
141 | /* Check for supported clock IDs */ | |
142 | cmpwi cr0,r3,CLOCK_REALTIME | |
143 | cmpwi cr1,r3,CLOCK_MONOTONIC | |
0c37ec2a | 144 | cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
a7f290da BH |
145 | bne cr0,99f |
146 | ||
147 | li r3,0 | |
148 | cmpli cr0,r4,0 | |
5d66da3d | 149 | crclr cr0*4+so |
a7f290da BH |
150 | beqlr |
151 | lis r5,CLOCK_REALTIME_RES@h | |
152 | ori r5,r5,CLOCK_REALTIME_RES@l | |
153 | std r3,TSPC64_TV_SEC(r4) | |
154 | std r5,TSPC64_TV_NSEC(r4) | |
155 | blr | |
156 | ||
157 | /* | |
158 | * syscall fallback | |
159 | */ | |
160 | 99: | |
161 | li r0,__NR_clock_getres | |
162 | sc | |
163 | blr | |
164 | .cfi_endproc | |
165 | V_FUNCTION_END(__kernel_clock_getres) | |
166 | ||
fcb41a20 AZ |
167 | /* |
168 | * Exact prototype of time() | |
169 | * | |
170 | * time_t time(time *t); | |
171 | * | |
172 | */ | |
173 | V_FUNCTION_BEGIN(__kernel_time) | |
174 | .cfi_startproc | |
175 | mflr r12 | |
176 | .cfi_register lr,r12 | |
177 | ||
178 | mr r11,r3 /* r11 holds t */ | |
179 | bl V_LOCAL_FUNC(__get_datapage) | |
180 | ||
181 | ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3) | |
182 | ||
183 | cmpldi r11,0 /* check if t is NULL */ | |
184 | beq 2f | |
185 | std r4,0(r11) /* store result at *t */ | |
186 | 2: mtlr r12 | |
187 | crclr cr0*4+so | |
188 | mr r3,r4 | |
189 | blr | |
190 | .cfi_endproc | |
191 | V_FUNCTION_END(__kernel_time) | |
192 | ||
a7f290da BH |
193 | |
194 | /* | |
8fd63a9e PM |
195 | * This is the core of clock_gettime() and gettimeofday(), |
196 | * it returns the current time in r4 (seconds) and r5. | |
197 | * On entry, r7 gives the resolution of r5, either USEC_PER_SEC | |
198 | * or NSEC_PER_SEC, giving r5 in microseconds or nanoseconds. | |
597bc5c0 | 199 | * It expects the datapage ptr in r3 and doesn't clobber it. |
8fd63a9e | 200 | * It clobbers r0, r6 and r9. |
597bc5c0 PM |
201 | * On return, r8 contains the counter value that can be reused. |
202 | * This clobbers cr0 but not any other cr field. | |
203 | */ | |
204 | V_FUNCTION_BEGIN(__do_get_tspec) | |
205 | .cfi_startproc | |
206 | /* check for update count & load values */ | |
207 | 1: ld r8,CFG_TB_UPDATE_COUNT(r3) | |
208 | andi. r0,r8,1 /* pending update ? loop */ | |
209 | bne- 1b | |
210 | xor r0,r8,r8 /* create dependency */ | |
211 | add r3,r3,r0 | |
212 | ||
213 | /* Get TB & offset it. We use the MFTB macro which will generate | |
214 | * workaround code for Cell. | |
215 | */ | |
8fd63a9e | 216 | MFTB(r6) |
597bc5c0 | 217 | ld r9,CFG_TB_ORIG_STAMP(r3) |
8fd63a9e | 218 | subf r6,r9,r6 |
597bc5c0 PM |
219 | |
220 | /* Scale result */ | |
221 | ld r5,CFG_TB_TO_XS(r3) | |
8fd63a9e PM |
222 | sldi r6,r6,12 /* compute time since stamp_xtime */ |
223 | mulhdu r6,r6,r5 /* in units of 2^-32 seconds */ | |
597bc5c0 PM |
224 | |
225 | /* Add stamp since epoch */ | |
226 | ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3) | |
8fd63a9e | 227 | lwz r5,STAMP_SEC_FRAC(r3) |
597bc5c0 PM |
228 | or r0,r4,r5 |
229 | or r0,r0,r6 | |
230 | xor r0,r0,r0 | |
231 | add r3,r3,r0 | |
232 | ld r0,CFG_TB_UPDATE_COUNT(r3) | |
233 | cmpld r0,r8 /* check if updated */ | |
234 | bne- 1b /* reload if so */ | |
235 | ||
236 | /* convert to seconds & nanoseconds and add to stamp */ | |
8fd63a9e PM |
237 | add r6,r6,r5 /* add on fractional seconds of xtime */ |
238 | mulhwu r5,r6,r7 /* compute micro or nanoseconds and */ | |
597bc5c0 | 239 | srdi r6,r6,32 /* seconds since stamp_xtime */ |
8fd63a9e | 240 | clrldi r5,r5,32 |
597bc5c0 | 241 | add r4,r4,r6 |
597bc5c0 PM |
242 | blr |
243 | .cfi_endproc | |
244 | V_FUNCTION_END(__do_get_tspec) |