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5b3b1688 DD |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 2007 by Ralf Baechle | |
7 | */ | |
8 | #include <linux/clocksource.h> | |
9 | #include <linux/init.h> | |
10 | ||
11 | #include <asm/time.h> | |
12 | ||
13 | #include <asm/octeon/octeon.h> | |
14 | #include <asm/octeon/cvmx-ipd-defs.h> | |
15 | ||
16 | /* | |
17 | * Set the current core's cvmcount counter to the value of the | |
18 | * IPD_CLK_COUNT. We do this on all cores as they are brought | |
19 | * on-line. This allows for a read from a local cpu register to | |
20 | * access a synchronized counter. | |
21 | * | |
22 | */ | |
23 | void octeon_init_cvmcount(void) | |
24 | { | |
25 | unsigned long flags; | |
26 | unsigned loops = 2; | |
27 | ||
28 | /* Clobber loops so GCC will not unroll the following while loop. */ | |
29 | asm("" : "+r" (loops)); | |
30 | ||
31 | local_irq_save(flags); | |
32 | /* | |
33 | * Loop several times so we are executing from the cache, | |
34 | * which should give more deterministic timing. | |
35 | */ | |
36 | while (loops--) | |
37 | write_c0_cvmcount(cvmx_read_csr(CVMX_IPD_CLK_COUNT)); | |
38 | local_irq_restore(flags); | |
39 | } | |
40 | ||
d0ce9a5a | 41 | static cycle_t octeon_cvmcount_read(struct clocksource *cs) |
5b3b1688 DD |
42 | { |
43 | return read_c0_cvmcount(); | |
44 | } | |
45 | ||
46 | static struct clocksource clocksource_mips = { | |
47 | .name = "OCTEON_CVMCOUNT", | |
48 | .read = octeon_cvmcount_read, | |
49 | .mask = CLOCKSOURCE_MASK(64), | |
50 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
51 | }; | |
52 | ||
c6a3c851 DD |
53 | unsigned long long notrace sched_clock(void) |
54 | { | |
0e8a1d82 | 55 | /* 64-bit arithmatic can overflow, so use 128-bit. */ |
0e8a1d82 DD |
56 | u64 t1, t2, t3; |
57 | unsigned long long rv; | |
58 | u64 mult = clocksource_mips.mult; | |
59 | u64 shift = clocksource_mips.shift; | |
60 | u64 cnt = read_c0_cvmcount(); | |
61 | ||
62 | asm ( | |
63 | "dmultu\t%[cnt],%[mult]\n\t" | |
64 | "nor\t%[t1],$0,%[shift]\n\t" | |
65 | "mfhi\t%[t2]\n\t" | |
66 | "mflo\t%[t3]\n\t" | |
67 | "dsll\t%[t2],%[t2],1\n\t" | |
68 | "dsrlv\t%[rv],%[t3],%[shift]\n\t" | |
69 | "dsllv\t%[t1],%[t2],%[t1]\n\t" | |
70 | "or\t%[rv],%[t1],%[rv]\n\t" | |
71 | : [rv] "=&r" (rv), [t1] "=&r" (t1), [t2] "=&r" (t2), [t3] "=&r" (t3) | |
72 | : [cnt] "r" (cnt), [mult] "r" (mult), [shift] "r" (shift) | |
73 | : "hi", "lo"); | |
74 | return rv; | |
c6a3c851 DD |
75 | } |
76 | ||
5b3b1688 DD |
77 | void __init plat_time_init(void) |
78 | { | |
79 | clocksource_mips.rating = 300; | |
80 | clocksource_set_clock(&clocksource_mips, mips_hpt_frequency); | |
81 | clocksource_register(&clocksource_mips); | |
82 | } | |
ca148125 DD |
83 | |
84 | static u64 octeon_udelay_factor; | |
85 | static u64 octeon_ndelay_factor; | |
86 | ||
87 | void __init octeon_setup_delays(void) | |
88 | { | |
89 | octeon_udelay_factor = octeon_get_clock_rate() / 1000000; | |
90 | /* | |
91 | * For __ndelay we divide by 2^16, so the factor is multiplied | |
92 | * by the same amount. | |
93 | */ | |
94 | octeon_ndelay_factor = (octeon_udelay_factor * 0x10000ull) / 1000ull; | |
95 | ||
96 | preset_lpj = octeon_get_clock_rate() / HZ; | |
97 | } | |
98 | ||
99 | void __udelay(unsigned long us) | |
100 | { | |
101 | u64 cur, end, inc; | |
102 | ||
103 | cur = read_c0_cvmcount(); | |
104 | ||
105 | inc = us * octeon_udelay_factor; | |
106 | end = cur + inc; | |
107 | ||
108 | while (end > cur) | |
109 | cur = read_c0_cvmcount(); | |
110 | } | |
111 | EXPORT_SYMBOL(__udelay); | |
112 | ||
113 | void __ndelay(unsigned long ns) | |
114 | { | |
115 | u64 cur, end, inc; | |
116 | ||
117 | cur = read_c0_cvmcount(); | |
118 | ||
119 | inc = ((ns * octeon_ndelay_factor) >> 16); | |
120 | end = cur + inc; | |
121 | ||
122 | while (end > cur) | |
123 | cur = read_c0_cvmcount(); | |
124 | } | |
125 | EXPORT_SYMBOL(__ndelay); | |
126 | ||
127 | void __delay(unsigned long loops) | |
128 | { | |
129 | u64 cur, end; | |
130 | ||
131 | cur = read_c0_cvmcount(); | |
132 | end = cur + loops; | |
133 | ||
134 | while (end > cur) | |
135 | cur = read_c0_cvmcount(); | |
136 | } | |
137 | EXPORT_SYMBOL(__delay); |