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0c37ec2a BH |
1 | |
2 | /* | |
a7f290da BH |
3 | * Userland implementation of gettimeofday() for 64 bits processes in a |
4 | * ppc64 kernel for use in the vDSO | |
5 | * | |
6 | * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), | |
7 | * IBM Corp. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | */ | |
a7f290da BH |
14 | #include <asm/processor.h> |
15 | #include <asm/ppc_asm.h> | |
16 | #include <asm/vdso.h> | |
17 | #include <asm/asm-offsets.h> | |
18 | #include <asm/unistd.h> | |
19 | ||
20 | .text | |
21 | /* | |
22 | * Exact prototype of gettimeofday | |
23 | * | |
24 | * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); | |
25 | * | |
26 | */ | |
27 | V_FUNCTION_BEGIN(__kernel_gettimeofday) | |
28 | .cfi_startproc | |
29 | mflr r12 | |
30 | .cfi_register lr,r12 | |
31 | ||
32 | mr r11,r3 /* r11 holds tv */ | |
33 | mr r10,r4 /* r10 holds tz */ | |
34 | bl V_LOCAL_FUNC(__get_datapage) /* get data page */ | |
35 | bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */ | |
36 | lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */ | |
37 | ori r7,r7,16960 | |
38 | rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */ | |
39 | rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */ | |
40 | std r5,TVAL64_TV_SEC(r11) /* store sec in tv */ | |
41 | subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */ | |
42 | mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) / | |
43 | * XSEC_PER_SEC | |
44 | */ | |
45 | rldicl r0,r0,44,20 | |
46 | cmpldi cr0,r10,0 /* check if tz is NULL */ | |
47 | std r0,TVAL64_TV_USEC(r11) /* store usec in tv */ | |
48 | beq 1f | |
49 | lwz r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */ | |
50 | lwz r5,CFG_TZ_DSTTIME(r3) | |
51 | stw r4,TZONE_TZ_MINWEST(r10) | |
52 | stw r5,TZONE_TZ_DSTTIME(r10) | |
53 | 1: mtlr r12 | |
5d66da3d | 54 | crclr cr0*4+so |
a7f290da BH |
55 | li r3,0 /* always success */ |
56 | blr | |
57 | .cfi_endproc | |
58 | V_FUNCTION_END(__kernel_gettimeofday) | |
59 | ||
60 | ||
61 | /* | |
62 | * Exact prototype of clock_gettime() | |
63 | * | |
64 | * int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); | |
65 | * | |
66 | */ | |
67 | V_FUNCTION_BEGIN(__kernel_clock_gettime) | |
68 | .cfi_startproc | |
69 | /* Check for supported clock IDs */ | |
70 | cmpwi cr0,r3,CLOCK_REALTIME | |
71 | cmpwi cr1,r3,CLOCK_MONOTONIC | |
0c37ec2a | 72 | cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
a7f290da BH |
73 | bne cr0,99f |
74 | ||
75 | mflr r12 /* r12 saves lr */ | |
76 | .cfi_register lr,r12 | |
77 | mr r10,r3 /* r10 saves id */ | |
78 | mr r11,r4 /* r11 saves tp */ | |
79 | bl V_LOCAL_FUNC(__get_datapage) /* get data page */ | |
80 | beq cr1,50f /* if monotonic -> jump there */ | |
81 | ||
82 | /* | |
83 | * CLOCK_REALTIME | |
84 | */ | |
85 | ||
86 | bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */ | |
87 | ||
0c37ec2a BH |
88 | lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */ |
89 | ori r7,r7,16960 | |
a7f290da BH |
90 | rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */ |
91 | rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */ | |
92 | std r5,TSPC64_TV_SEC(r11) /* store sec in tv */ | |
93 | subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */ | |
0c37ec2a | 94 | mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) / |
a7f290da BH |
95 | * XSEC_PER_SEC |
96 | */ | |
97 | rldicl r0,r0,44,20 | |
0c37ec2a | 98 | mulli r0,r0,1000 /* nsec = usec * 1000 */ |
a7f290da BH |
99 | std r0,TSPC64_TV_NSEC(r11) /* store nsec in tp */ |
100 | ||
101 | mtlr r12 | |
5d66da3d | 102 | crclr cr0*4+so |
a7f290da BH |
103 | li r3,0 |
104 | blr | |
105 | ||
106 | /* | |
107 | * CLOCK_MONOTONIC | |
108 | */ | |
109 | ||
110 | 50: bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */ | |
111 | ||
0c37ec2a BH |
112 | lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */ |
113 | ori r7,r7,16960 | |
a7f290da BH |
114 | rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */ |
115 | rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */ | |
116 | subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */ | |
0c37ec2a | 117 | mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) / |
a7f290da BH |
118 | * XSEC_PER_SEC |
119 | */ | |
120 | rldicl r6,r0,44,20 | |
0c37ec2a | 121 | mulli r6,r6,1000 /* nsec = usec * 1000 */ |
a7f290da BH |
122 | |
123 | /* now we must fixup using wall to monotonic. We need to snapshot | |
124 | * that value and do the counter trick again. Fortunately, we still | |
125 | * have the counter value in r8 that was returned by __do_get_xsec. | |
126 | * At this point, r5,r6 contain our sec/nsec values. | |
127 | * can be used | |
128 | */ | |
129 | ||
0c37ec2a BH |
130 | lwa r4,WTOM_CLOCK_SEC(r3) |
131 | lwa r7,WTOM_CLOCK_NSEC(r3) | |
a7f290da BH |
132 | |
133 | /* We now have our result in r4,r7. We create a fake dependency | |
134 | * on that result and re-check the counter | |
135 | */ | |
136 | or r9,r4,r7 | |
137 | xor r0,r9,r9 | |
138 | add r3,r3,r0 | |
139 | ld r0,CFG_TB_UPDATE_COUNT(r3) | |
140 | cmpld cr0,r0,r8 /* check if updated */ | |
141 | bne- 50b | |
142 | ||
143 | /* Calculate and store result. Note that this mimmics the C code, | |
144 | * which may cause funny results if nsec goes negative... is that | |
145 | * possible at all ? | |
146 | */ | |
147 | add r4,r4,r5 | |
148 | add r7,r7,r6 | |
149 | lis r9,NSEC_PER_SEC@h | |
150 | ori r9,r9,NSEC_PER_SEC@l | |
0c37ec2a BH |
151 | cmpl cr0,r7,r9 |
152 | cmpli cr1,r7,0 | |
a7f290da BH |
153 | blt 1f |
154 | subf r7,r9,r7 | |
155 | addi r4,r4,1 | |
0c37ec2a BH |
156 | 1: bge cr1,1f |
157 | addi r4,r4,-1 | |
158 | add r7,r7,r9 | |
a7f290da BH |
159 | 1: std r4,TSPC64_TV_SEC(r11) |
160 | std r7,TSPC64_TV_NSEC(r11) | |
161 | ||
162 | mtlr r12 | |
5d66da3d | 163 | crclr cr0*4+so |
a7f290da BH |
164 | li r3,0 |
165 | blr | |
166 | ||
167 | /* | |
168 | * syscall fallback | |
169 | */ | |
170 | 98: | |
171 | mtlr r12 | |
172 | mr r3,r10 | |
173 | mr r4,r11 | |
174 | 99: | |
175 | li r0,__NR_clock_gettime | |
176 | sc | |
177 | blr | |
178 | .cfi_endproc | |
179 | V_FUNCTION_END(__kernel_clock_gettime) | |
180 | ||
181 | ||
182 | /* | |
183 | * Exact prototype of clock_getres() | |
184 | * | |
185 | * int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); | |
186 | * | |
187 | */ | |
188 | V_FUNCTION_BEGIN(__kernel_clock_getres) | |
189 | .cfi_startproc | |
190 | /* Check for supported clock IDs */ | |
191 | cmpwi cr0,r3,CLOCK_REALTIME | |
192 | cmpwi cr1,r3,CLOCK_MONOTONIC | |
0c37ec2a | 193 | cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
a7f290da BH |
194 | bne cr0,99f |
195 | ||
196 | li r3,0 | |
197 | cmpli cr0,r4,0 | |
5d66da3d | 198 | crclr cr0*4+so |
a7f290da BH |
199 | beqlr |
200 | lis r5,CLOCK_REALTIME_RES@h | |
201 | ori r5,r5,CLOCK_REALTIME_RES@l | |
202 | std r3,TSPC64_TV_SEC(r4) | |
203 | std r5,TSPC64_TV_NSEC(r4) | |
204 | blr | |
205 | ||
206 | /* | |
207 | * syscall fallback | |
208 | */ | |
209 | 99: | |
210 | li r0,__NR_clock_getres | |
211 | sc | |
212 | blr | |
213 | .cfi_endproc | |
214 | V_FUNCTION_END(__kernel_clock_getres) | |
215 | ||
216 | ||
217 | /* | |
218 | * This is the core of gettimeofday(), it returns the xsec | |
219 | * value in r4 and expects the datapage ptr (non clobbered) | |
220 | * in r3. clobbers r0,r4,r5,r6,r7,r8 | |
221 | * When returning, r8 contains the counter value that can be reused | |
222 | */ | |
223 | V_FUNCTION_BEGIN(__do_get_xsec) | |
224 | .cfi_startproc | |
225 | /* check for update count & load values */ | |
226 | 1: ld r8,CFG_TB_UPDATE_COUNT(r3) | |
634473db | 227 | andi. r0,r8,1 /* pending update ? loop */ |
a7f290da | 228 | bne- 1b |
634473db | 229 | xor r0,r8,r8 /* create dependency */ |
a7f290da BH |
230 | add r3,r3,r0 |
231 | ||
859deea9 BH |
232 | /* Get TB & offset it. We use the MFTB macro which will generate |
233 | * workaround code for Cell. | |
234 | */ | |
235 | MFTB(r7) | |
a7f290da BH |
236 | ld r9,CFG_TB_ORIG_STAMP(r3) |
237 | subf r7,r9,r7 | |
238 | ||
239 | /* Scale result */ | |
240 | ld r5,CFG_TB_TO_XS(r3) | |
241 | mulhdu r7,r7,r5 | |
242 | ||
243 | /* Add stamp since epoch */ | |
244 | ld r6,CFG_STAMP_XSEC(r3) | |
245 | add r4,r6,r7 | |
246 | ||
247 | xor r0,r4,r4 | |
248 | add r3,r3,r0 | |
249 | ld r0,CFG_TB_UPDATE_COUNT(r3) | |
250 | cmpld cr0,r0,r8 /* check if updated */ | |
251 | bne- 1b | |
252 | blr | |
253 | .cfi_endproc | |
254 | V_FUNCTION_END(__do_get_xsec) |