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1 | #ifndef _LINUX_JIFFIES_H |
1 | #ifndef _LINUX_JIFFIES_H |
2 | #define _LINUX_JIFFIES_H |
2 | #define _LINUX_JIFFIES_H |
3 | 3 | ||
4 | #include |
4 | #include |
5 | #include |
5 | #include |
6 | #include |
6 | #include |
7 | #include |
7 | #include |
8 | //#include |
8 | #include |
9 | //#include |
9 | //#include |
10 | 10 | ||
11 | 11 | ||
12 | #define HZ 100 |
12 | #define HZ 100 |
13 | #define CLOCK_TICK_RATE 1193182ul |
- | |
14 | 13 | ||
15 | /* |
14 | /* |
16 | * The following defines establish the engineering parameters of the PLL |
15 | * The following defines establish the engineering parameters of the PLL |
17 | * model. The HZ variable establishes the timer interrupt frequency, 100 Hz |
16 | * model. The HZ variable establishes the timer interrupt frequency, 100 Hz |
18 | * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the |
17 | * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the |
19 | * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the |
18 | * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the |
20 | * nearest power of two in order to avoid hardware multiply operations. |
19 | * nearest power of two in order to avoid hardware multiply operations. |
21 | */ |
20 | */ |
22 | #if HZ >= 12 && HZ < 24 |
21 | #if HZ >= 12 && HZ < 24 |
23 | # define SHIFT_HZ 4 |
22 | # define SHIFT_HZ 4 |
24 | #elif HZ >= 24 && HZ < 48 |
23 | #elif HZ >= 24 && HZ < 48 |
25 | # define SHIFT_HZ 5 |
24 | # define SHIFT_HZ 5 |
26 | #elif HZ >= 48 && HZ < 96 |
25 | #elif HZ >= 48 && HZ < 96 |
27 | # define SHIFT_HZ 6 |
26 | # define SHIFT_HZ 6 |
28 | #elif HZ >= 96 && HZ < 192 |
27 | #elif HZ >= 96 && HZ < 192 |
29 | # define SHIFT_HZ 7 |
28 | # define SHIFT_HZ 7 |
30 | #elif HZ >= 192 && HZ < 384 |
29 | #elif HZ >= 192 && HZ < 384 |
31 | # define SHIFT_HZ 8 |
30 | # define SHIFT_HZ 8 |
32 | #elif HZ >= 384 && HZ < 768 |
31 | #elif HZ >= 384 && HZ < 768 |
33 | # define SHIFT_HZ 9 |
32 | # define SHIFT_HZ 9 |
34 | #elif HZ >= 768 && HZ < 1536 |
33 | #elif HZ >= 768 && HZ < 1536 |
35 | # define SHIFT_HZ 10 |
34 | # define SHIFT_HZ 10 |
36 | #elif HZ >= 1536 && HZ < 3072 |
35 | #elif HZ >= 1536 && HZ < 3072 |
37 | # define SHIFT_HZ 11 |
36 | # define SHIFT_HZ 11 |
38 | #elif HZ >= 3072 && HZ < 6144 |
37 | #elif HZ >= 3072 && HZ < 6144 |
39 | # define SHIFT_HZ 12 |
38 | # define SHIFT_HZ 12 |
40 | #elif HZ >= 6144 && HZ < 12288 |
39 | #elif HZ >= 6144 && HZ < 12288 |
41 | # define SHIFT_HZ 13 |
40 | # define SHIFT_HZ 13 |
42 | #else |
41 | #else |
43 | # error Invalid value of HZ. |
42 | # error Invalid value of HZ. |
44 | #endif |
43 | #endif |
45 | 44 | ||
46 | /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can |
45 | /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can |
47 | * improve accuracy by shifting LSH bits, hence calculating: |
46 | * improve accuracy by shifting LSH bits, hence calculating: |
48 | * (NOM << LSH) / DEN |
47 | * (NOM << LSH) / DEN |
49 | * This however means trouble for large NOM, because (NOM << LSH) may no |
48 | * This however means trouble for large NOM, because (NOM << LSH) may no |
50 | * longer fit in 32 bits. The following way of calculating this gives us |
49 | * longer fit in 32 bits. The following way of calculating this gives us |
51 | * some slack, under the following conditions: |
50 | * some slack, under the following conditions: |
52 | * - (NOM / DEN) fits in (32 - LSH) bits. |
51 | * - (NOM / DEN) fits in (32 - LSH) bits. |
53 | * - (NOM % DEN) fits in (32 - LSH) bits. |
52 | * - (NOM % DEN) fits in (32 - LSH) bits. |
54 | */ |
53 | */ |
55 | #define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \ |
54 | #define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \ |
56 | + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN)) |
55 | + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN)) |
57 | 56 | ||
58 | /* LATCH is used in the interval timer and ftape setup. */ |
57 | /* LATCH is used in the interval timer and ftape setup. */ |
59 | #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ |
58 | #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ |
60 | 59 | ||
61 | extern int register_refined_jiffies(long clock_tick_rate); |
60 | extern int register_refined_jiffies(long clock_tick_rate); |
62 | 61 | ||
63 | /* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */ |
62 | /* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */ |
64 | #define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ) |
63 | #define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ) |
65 | 64 | ||
66 | /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ |
65 | /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ |
67 | #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) |
66 | #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) |
68 | 67 | ||
69 | /* some arch's have a small-data section that can be accessed register-relative |
68 | /* some arch's have a small-data section that can be accessed register-relative |
70 | * but that can only take up to, say, 4-byte variables. jiffies being part of |
69 | * but that can only take up to, say, 4-byte variables. jiffies being part of |
71 | * an 8-byte variable may not be correctly accessed unless we force the issue |
70 | * an 8-byte variable may not be correctly accessed unless we force the issue |
72 | */ |
71 | */ |
73 | #define __jiffy_data __attribute__((section(".data"))) |
72 | #define __jiffy_data __attribute__((section(".data"))) |
74 | 73 | ||
75 | /* |
74 | /* |
76 | * The 64-bit value is not atomic - you MUST NOT read it |
75 | * The 64-bit value is not atomic - you MUST NOT read it |
77 | * without sampling the sequence number in jiffies_lock. |
76 | * without sampling the sequence number in jiffies_lock. |
78 | * get_jiffies_64() will do this for you as appropriate. |
77 | * get_jiffies_64() will do this for you as appropriate. |
79 | */ |
78 | */ |
80 | extern u64 __jiffy_data jiffies_64; |
79 | extern u64 __jiffy_data jiffies_64; |
81 | extern unsigned long volatile __jiffy_data jiffies; |
80 | extern unsigned long volatile __jiffy_data jiffies; |
82 | 81 | ||
83 | #if (BITS_PER_LONG < 64) |
82 | #if (BITS_PER_LONG < 64) |
84 | u64 get_jiffies_64(void); |
83 | u64 get_jiffies_64(void); |
85 | #else |
84 | #else |
86 | static inline u64 get_jiffies_64(void) |
85 | static inline u64 get_jiffies_64(void) |
87 | { |
86 | { |
88 | return (u64)jiffies; |
87 | return (u64)jiffies; |
89 | } |
88 | } |
90 | #endif |
89 | #endif |
91 | 90 | ||
92 | /* |
91 | /* |
93 | * These inlines deal with timer wrapping correctly. You are |
92 | * These inlines deal with timer wrapping correctly. You are |
94 | * strongly encouraged to use them |
93 | * strongly encouraged to use them |
95 | * 1. Because people otherwise forget |
94 | * 1. Because people otherwise forget |
96 | * 2. Because if the timer wrap changes in future you won't have to |
95 | * 2. Because if the timer wrap changes in future you won't have to |
97 | * alter your driver code. |
96 | * alter your driver code. |
98 | * |
97 | * |
99 | * time_after(a,b) returns true if the time a is after time b. |
98 | * time_after(a,b) returns true if the time a is after time b. |
100 | * |
99 | * |
101 | * Do this with "<0" and ">=0" to only test the sign of the result. A |
100 | * Do this with "<0" and ">=0" to only test the sign of the result. A |
102 | * good compiler would generate better code (and a really good compiler |
101 | * good compiler would generate better code (and a really good compiler |
103 | * wouldn't care). Gcc is currently neither. |
102 | * wouldn't care). Gcc is currently neither. |
104 | */ |
103 | */ |
105 | #define time_after(a,b) \ |
104 | #define time_after(a,b) \ |
106 | (typecheck(unsigned long, a) && \ |
105 | (typecheck(unsigned long, a) && \ |
107 | typecheck(unsigned long, b) && \ |
106 | typecheck(unsigned long, b) && \ |
108 | ((long)((b) - (a)) < 0)) |
107 | ((long)((b) - (a)) < 0)) |
109 | #define time_before(a,b) time_after(b,a) |
108 | #define time_before(a,b) time_after(b,a) |
110 | 109 | ||
111 | #define time_after_eq(a,b) \ |
110 | #define time_after_eq(a,b) \ |
112 | (typecheck(unsigned long, a) && \ |
111 | (typecheck(unsigned long, a) && \ |
113 | typecheck(unsigned long, b) && \ |
112 | typecheck(unsigned long, b) && \ |
114 | ((long)((a) - (b)) >= 0)) |
113 | ((long)((a) - (b)) >= 0)) |
115 | #define time_before_eq(a,b) time_after_eq(b,a) |
114 | #define time_before_eq(a,b) time_after_eq(b,a) |
116 | 115 | ||
117 | /* |
116 | /* |
118 | * Calculate whether a is in the range of [b, c]. |
117 | * Calculate whether a is in the range of [b, c]. |
119 | */ |
118 | */ |
120 | #define time_in_range(a,b,c) \ |
119 | #define time_in_range(a,b,c) \ |
121 | (time_after_eq(a,b) && \ |
120 | (time_after_eq(a,b) && \ |
122 | time_before_eq(a,c)) |
121 | time_before_eq(a,c)) |
123 | 122 | ||
124 | /* |
123 | /* |
125 | * Calculate whether a is in the range of [b, c). |
124 | * Calculate whether a is in the range of [b, c). |
126 | */ |
125 | */ |
127 | #define time_in_range_open(a,b,c) \ |
126 | #define time_in_range_open(a,b,c) \ |
128 | (time_after_eq(a,b) && \ |
127 | (time_after_eq(a,b) && \ |
129 | time_before(a,c)) |
128 | time_before(a,c)) |
130 | 129 | ||
131 | /* Same as above, but does so with platform independent 64bit types. |
130 | /* Same as above, but does so with platform independent 64bit types. |
132 | * These must be used when utilizing jiffies_64 (i.e. return value of |
131 | * These must be used when utilizing jiffies_64 (i.e. return value of |
133 | * get_jiffies_64() */ |
132 | * get_jiffies_64() */ |
134 | #define time_after64(a,b) \ |
133 | #define time_after64(a,b) \ |
135 | (typecheck(__u64, a) && \ |
134 | (typecheck(__u64, a) && \ |
136 | typecheck(__u64, b) && \ |
135 | typecheck(__u64, b) && \ |
137 | ((__s64)((b) - (a)) < 0)) |
136 | ((__s64)((b) - (a)) < 0)) |
138 | #define time_before64(a,b) time_after64(b,a) |
137 | #define time_before64(a,b) time_after64(b,a) |
139 | 138 | ||
140 | #define time_after_eq64(a,b) \ |
139 | #define time_after_eq64(a,b) \ |
141 | (typecheck(__u64, a) && \ |
140 | (typecheck(__u64, a) && \ |
142 | typecheck(__u64, b) && \ |
141 | typecheck(__u64, b) && \ |
143 | ((__s64)((a) - (b)) >= 0)) |
142 | ((__s64)((a) - (b)) >= 0)) |
144 | #define time_before_eq64(a,b) time_after_eq64(b,a) |
143 | #define time_before_eq64(a,b) time_after_eq64(b,a) |
145 | 144 | ||
146 | #define time_in_range64(a, b, c) \ |
145 | #define time_in_range64(a, b, c) \ |
147 | (time_after_eq64(a, b) && \ |
146 | (time_after_eq64(a, b) && \ |
148 | time_before_eq64(a, c)) |
147 | time_before_eq64(a, c)) |
149 | 148 | ||
150 | /* |
149 | /* |
151 | * These four macros compare jiffies and 'a' for convenience. |
150 | * These four macros compare jiffies and 'a' for convenience. |
152 | */ |
151 | */ |
153 | 152 | ||
154 | /* time_is_before_jiffies(a) return true if a is before jiffies */ |
153 | /* time_is_before_jiffies(a) return true if a is before jiffies */ |
155 | #define time_is_before_jiffies(a) time_after(jiffies, a) |
154 | #define time_is_before_jiffies(a) time_after(jiffies, a) |
156 | 155 | ||
157 | /* time_is_after_jiffies(a) return true if a is after jiffies */ |
156 | /* time_is_after_jiffies(a) return true if a is after jiffies */ |
158 | #define time_is_after_jiffies(a) time_before(jiffies, a) |
157 | #define time_is_after_jiffies(a) time_before(jiffies, a) |
159 | 158 | ||
160 | /* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/ |
159 | /* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/ |
161 | #define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a) |
160 | #define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a) |
162 | 161 | ||
163 | /* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/ |
162 | /* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/ |
164 | #define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a) |
163 | #define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a) |
165 | 164 | ||
166 | /* |
165 | /* |
167 | * Have the 32 bit jiffies value wrap 5 minutes after boot |
166 | * Have the 32 bit jiffies value wrap 5 minutes after boot |
168 | * so jiffies wrap bugs show up earlier. |
167 | * so jiffies wrap bugs show up earlier. |
169 | */ |
168 | */ |
170 | #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) |
169 | #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) |
171 | 170 | ||
172 | /* |
171 | /* |
173 | * Change timeval to jiffies, trying to avoid the |
172 | * Change timeval to jiffies, trying to avoid the |
174 | * most obvious overflows.. |
173 | * most obvious overflows.. |
175 | * |
174 | * |
176 | * And some not so obvious. |
175 | * And some not so obvious. |
177 | * |
176 | * |
178 | * Note that we don't want to return LONG_MAX, because |
177 | * Note that we don't want to return LONG_MAX, because |
179 | * for various timeout reasons we often end up having |
178 | * for various timeout reasons we often end up having |
180 | * to wait "jiffies+1" in order to guarantee that we wait |
179 | * to wait "jiffies+1" in order to guarantee that we wait |
181 | * at _least_ "jiffies" - so "jiffies+1" had better still |
180 | * at _least_ "jiffies" - so "jiffies+1" had better still |
182 | * be positive. |
181 | * be positive. |
183 | */ |
182 | */ |
184 | #define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1) |
183 | #define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1) |
185 | 184 | ||
186 | extern unsigned long preset_lpj; |
185 | extern unsigned long preset_lpj; |
187 | 186 | ||
188 | /* |
187 | /* |
189 | * We want to do realistic conversions of time so we need to use the same |
188 | * We want to do realistic conversions of time so we need to use the same |
190 | * values the update wall clock code uses as the jiffies size. This value |
189 | * values the update wall clock code uses as the jiffies size. This value |
191 | * is: TICK_NSEC (which is defined in timex.h). This |
190 | * is: TICK_NSEC (which is defined in timex.h). This |
192 | * is a constant and is in nanoseconds. We will use scaled math |
191 | * is a constant and is in nanoseconds. We will use scaled math |
193 | * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and |
192 | * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and |
194 | * NSEC_JIFFIE_SC. Note that these defines contain nothing but |
193 | * NSEC_JIFFIE_SC. Note that these defines contain nothing but |
195 | * constants and so are computed at compile time. SHIFT_HZ (computed in |
194 | * constants and so are computed at compile time. SHIFT_HZ (computed in |
196 | * timex.h) adjusts the scaling for different HZ values. |
195 | * timex.h) adjusts the scaling for different HZ values. |
197 | 196 | ||
198 | * Scaled math??? What is that? |
197 | * Scaled math??? What is that? |
199 | * |
198 | * |
200 | * Scaled math is a way to do integer math on values that would, |
199 | * Scaled math is a way to do integer math on values that would, |
201 | * otherwise, either overflow, underflow, or cause undesired div |
200 | * otherwise, either overflow, underflow, or cause undesired div |
202 | * instructions to appear in the execution path. In short, we "scale" |
201 | * instructions to appear in the execution path. In short, we "scale" |
203 | * up the operands so they take more bits (more precision, less |
202 | * up the operands so they take more bits (more precision, less |
204 | * underflow), do the desired operation and then "scale" the result back |
203 | * underflow), do the desired operation and then "scale" the result back |
205 | * by the same amount. If we do the scaling by shifting we avoid the |
204 | * by the same amount. If we do the scaling by shifting we avoid the |
206 | * costly mpy and the dastardly div instructions. |
205 | * costly mpy and the dastardly div instructions. |
207 | 206 | ||
208 | * Suppose, for example, we want to convert from seconds to jiffies |
207 | * Suppose, for example, we want to convert from seconds to jiffies |
209 | * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The |
208 | * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The |
210 | * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We |
209 | * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We |
211 | * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we |
210 | * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we |
212 | * might calculate at compile time, however, the result will only have |
211 | * might calculate at compile time, however, the result will only have |
213 | * about 3-4 bits of precision (less for smaller values of HZ). |
212 | * about 3-4 bits of precision (less for smaller values of HZ). |
214 | * |
213 | * |
215 | * So, we scale as follows: |
214 | * So, we scale as follows: |
216 | * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE); |
215 | * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE); |
217 | * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE; |
216 | * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE; |
218 | * Then we make SCALE a power of two so: |
217 | * Then we make SCALE a power of two so: |
219 | * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE; |
218 | * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE; |
220 | * Now we define: |
219 | * Now we define: |
221 | * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) |
220 | * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) |
222 | * jiff = (sec * SEC_CONV) >> SCALE; |
221 | * jiff = (sec * SEC_CONV) >> SCALE; |
223 | * |
222 | * |
224 | * Often the math we use will expand beyond 32-bits so we tell C how to |
223 | * Often the math we use will expand beyond 32-bits so we tell C how to |
225 | * do this and pass the 64-bit result of the mpy through the ">> SCALE" |
224 | * do this and pass the 64-bit result of the mpy through the ">> SCALE" |
226 | * which should take the result back to 32-bits. We want this expansion |
225 | * which should take the result back to 32-bits. We want this expansion |
227 | * to capture as much precision as possible. At the same time we don't |
226 | * to capture as much precision as possible. At the same time we don't |
228 | * want to overflow so we pick the SCALE to avoid this. In this file, |
227 | * want to overflow so we pick the SCALE to avoid this. In this file, |
229 | * that means using a different scale for each range of HZ values (as |
228 | * that means using a different scale for each range of HZ values (as |
230 | * defined in timex.h). |
229 | * defined in timex.h). |
231 | * |
230 | * |
232 | * For those who want to know, gcc will give a 64-bit result from a "*" |
231 | * For those who want to know, gcc will give a 64-bit result from a "*" |
233 | * operator if the result is a long long AND at least one of the |
232 | * operator if the result is a long long AND at least one of the |
234 | * operands is cast to long long (usually just prior to the "*" so as |
233 | * operands is cast to long long (usually just prior to the "*" so as |
235 | * not to confuse it into thinking it really has a 64-bit operand, |
234 | * not to confuse it into thinking it really has a 64-bit operand, |
236 | * which, buy the way, it can do, but it takes more code and at least 2 |
235 | * which, buy the way, it can do, but it takes more code and at least 2 |
237 | * mpys). |
236 | * mpys). |
238 | 237 | ||
239 | * We also need to be aware that one second in nanoseconds is only a |
238 | * We also need to be aware that one second in nanoseconds is only a |
240 | * couple of bits away from overflowing a 32-bit word, so we MUST use |
239 | * couple of bits away from overflowing a 32-bit word, so we MUST use |
241 | * 64-bits to get the full range time in nanoseconds. |
240 | * 64-bits to get the full range time in nanoseconds. |
242 | 241 | ||
243 | */ |
242 | */ |
244 | 243 | ||
245 | /* |
244 | /* |
246 | * Here are the scales we will use. One for seconds, nanoseconds and |
245 | * Here are the scales we will use. One for seconds, nanoseconds and |
247 | * microseconds. |
246 | * microseconds. |
248 | * |
247 | * |
249 | * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and |
248 | * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and |
250 | * check if the sign bit is set. If not, we bump the shift count by 1. |
249 | * check if the sign bit is set. If not, we bump the shift count by 1. |
251 | * (Gets an extra bit of precision where we can use it.) |
250 | * (Gets an extra bit of precision where we can use it.) |
252 | * We know it is set for HZ = 1024 and HZ = 100 not for 1000. |
251 | * We know it is set for HZ = 1024 and HZ = 100 not for 1000. |
253 | * Haven't tested others. |
252 | * Haven't tested others. |
254 | 253 | ||
255 | * Limits of cpp (for #if expressions) only long (no long long), but |
254 | * Limits of cpp (for #if expressions) only long (no long long), but |
256 | * then we only need the most signicant bit. |
255 | * then we only need the most signicant bit. |
257 | */ |
256 | */ |
258 | 257 | ||
259 | #define SEC_JIFFIE_SC (31 - SHIFT_HZ) |
258 | #define SEC_JIFFIE_SC (31 - SHIFT_HZ) |
260 | #if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000) |
259 | #if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000) |
261 | #undef SEC_JIFFIE_SC |
260 | #undef SEC_JIFFIE_SC |
262 | #define SEC_JIFFIE_SC (32 - SHIFT_HZ) |
261 | #define SEC_JIFFIE_SC (32 - SHIFT_HZ) |
263 | #endif |
262 | #endif |
264 | #define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29) |
263 | #define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29) |
265 | #define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\ |
264 | #define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\ |
266 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
265 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
267 | 266 | ||
268 | #define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\ |
267 | #define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\ |
269 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
268 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
270 | /* |
269 | /* |
271 | * The maximum jiffie value is (MAX_INT >> 1). Here we translate that |
270 | * The maximum jiffie value is (MAX_INT >> 1). Here we translate that |
272 | * into seconds. The 64-bit case will overflow if we are not careful, |
271 | * into seconds. The 64-bit case will overflow if we are not careful, |
273 | * so use the messy SH_DIV macro to do it. Still all constants. |
272 | * so use the messy SH_DIV macro to do it. Still all constants. |
274 | */ |
273 | */ |
275 | #if BITS_PER_LONG < 64 |
274 | #if BITS_PER_LONG < 64 |
276 | # define MAX_SEC_IN_JIFFIES \ |
275 | # define MAX_SEC_IN_JIFFIES \ |
277 | (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC) |
276 | (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC) |
278 | #else /* take care of overflow on 64 bits machines */ |
277 | #else /* take care of overflow on 64 bits machines */ |
279 | # define MAX_SEC_IN_JIFFIES \ |
278 | # define MAX_SEC_IN_JIFFIES \ |
280 | (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1) |
279 | (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1) |
281 | 280 | ||
282 | #endif |
281 | #endif |
283 | 282 | ||
284 | /* |
283 | /* |
285 | * Convert various time units to each other: |
284 | * Convert various time units to each other: |
286 | */ |
285 | */ |
287 | extern unsigned int jiffies_to_msecs(const unsigned long j); |
286 | extern unsigned int jiffies_to_msecs(const unsigned long j); |
288 | extern unsigned int jiffies_to_usecs(const unsigned long j); |
287 | extern unsigned int jiffies_to_usecs(const unsigned long j); |
289 | 288 | ||
290 | static inline u64 jiffies_to_nsecs(const unsigned long j) |
289 | static inline u64 jiffies_to_nsecs(const unsigned long j) |
291 | { |
290 | { |
292 | return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; |
291 | return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; |
293 | } |
292 | } |
294 | 293 | ||
295 | extern unsigned long __msecs_to_jiffies(const unsigned int m); |
294 | extern unsigned long __msecs_to_jiffies(const unsigned int m); |
296 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) |
295 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) |
297 | /* |
296 | /* |
298 | * HZ is equal to or smaller than 1000, and 1000 is a nice round |
297 | * HZ is equal to or smaller than 1000, and 1000 is a nice round |
299 | * multiple of HZ, divide with the factor between them, but round |
298 | * multiple of HZ, divide with the factor between them, but round |
300 | * upwards: |
299 | * upwards: |
301 | */ |
300 | */ |
302 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
301 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
303 | { |
302 | { |
304 | return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); |
303 | return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); |
305 | } |
304 | } |
306 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) |
305 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) |
307 | /* |
306 | /* |
308 | * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - |
307 | * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - |
309 | * simply multiply with the factor between them. |
308 | * simply multiply with the factor between them. |
310 | * |
309 | * |
311 | * But first make sure the multiplication result cannot overflow: |
310 | * But first make sure the multiplication result cannot overflow: |
312 | */ |
311 | */ |
313 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
312 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
314 | { |
313 | { |
315 | if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
314 | if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
316 | return MAX_JIFFY_OFFSET; |
315 | return MAX_JIFFY_OFFSET; |
317 | return m * (HZ / MSEC_PER_SEC); |
316 | return m * (HZ / MSEC_PER_SEC); |
318 | } |
317 | } |
319 | #else |
318 | #else |
320 | /* |
319 | /* |
321 | * Generic case - multiply, round and divide. But first check that if |
320 | * Generic case - multiply, round and divide. But first check that if |
322 | * we are doing a net multiplication, that we wouldn't overflow: |
321 | * we are doing a net multiplication, that we wouldn't overflow: |
323 | */ |
322 | */ |
324 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
323 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
325 | { |
324 | { |
326 | if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
325 | if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
327 | return MAX_JIFFY_OFFSET; |
326 | return MAX_JIFFY_OFFSET; |
328 | 327 | ||
329 | return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; |
328 | return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; |
330 | } |
329 | } |
331 | #endif |
330 | #endif |
332 | /** |
331 | /** |
333 | * msecs_to_jiffies: - convert milliseconds to jiffies |
332 | * msecs_to_jiffies: - convert milliseconds to jiffies |
334 | * @m: time in milliseconds |
333 | * @m: time in milliseconds |
335 | * |
334 | * |
336 | * conversion is done as follows: |
335 | * conversion is done as follows: |
337 | * |
336 | * |
338 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) |
337 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) |
339 | * |
338 | * |
340 | * - 'too large' values [that would result in larger than |
339 | * - 'too large' values [that would result in larger than |
341 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
340 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
342 | * |
341 | * |
343 | * - all other values are converted to jiffies by either multiplying |
342 | * - all other values are converted to jiffies by either multiplying |
344 | * the input value by a factor or dividing it with a factor and |
343 | * the input value by a factor or dividing it with a factor and |
345 | * handling any 32-bit overflows. |
344 | * handling any 32-bit overflows. |
346 | * for the details see __msecs_to_jiffies() |
345 | * for the details see __msecs_to_jiffies() |
347 | * |
346 | * |
348 | * msecs_to_jiffies() checks for the passed in value being a constant |
347 | * msecs_to_jiffies() checks for the passed in value being a constant |
349 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
348 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
350 | * code, __msecs_to_jiffies() is called if the value passed does not |
349 | * code, __msecs_to_jiffies() is called if the value passed does not |
351 | * allow constant folding and the actual conversion must be done at |
350 | * allow constant folding and the actual conversion must be done at |
352 | * runtime. |
351 | * runtime. |
353 | * the HZ range specific helpers _msecs_to_jiffies() are called both |
352 | * the HZ range specific helpers _msecs_to_jiffies() are called both |
354 | * directly here and from __msecs_to_jiffies() in the case where |
353 | * directly here and from __msecs_to_jiffies() in the case where |
355 | * constant folding is not possible. |
354 | * constant folding is not possible. |
356 | */ |
355 | */ |
357 | static __always_inline unsigned long msecs_to_jiffies(const unsigned int m) |
356 | static __always_inline unsigned long msecs_to_jiffies(const unsigned int m) |
358 | { |
357 | { |
359 | if (__builtin_constant_p(m)) { |
358 | if (__builtin_constant_p(m)) { |
360 | if ((int)m < 0) |
359 | if ((int)m < 0) |
361 | return MAX_JIFFY_OFFSET; |
360 | return MAX_JIFFY_OFFSET; |
362 | return _msecs_to_jiffies(m); |
361 | return _msecs_to_jiffies(m); |
363 | } else { |
362 | } else { |
364 | return __msecs_to_jiffies(m); |
363 | return __msecs_to_jiffies(m); |
365 | } |
364 | } |
366 | } |
365 | } |
367 | 366 | ||
368 | extern unsigned long __usecs_to_jiffies(const unsigned int u); |
367 | extern unsigned long __usecs_to_jiffies(const unsigned int u); |
369 | #if !(USEC_PER_SEC % HZ) |
368 | #if !(USEC_PER_SEC % HZ) |
370 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
369 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
371 | { |
370 | { |
372 | return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); |
371 | return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); |
373 | } |
372 | } |
374 | #else |
373 | #else |
375 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
374 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
376 | { |
375 | { |
377 | return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) |
376 | return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) |
378 | >> USEC_TO_HZ_SHR32; |
377 | >> USEC_TO_HZ_SHR32; |
379 | } |
378 | } |
380 | #endif |
379 | #endif |
381 | 380 | ||
382 | /** |
381 | /** |
383 | * usecs_to_jiffies: - convert microseconds to jiffies |
382 | * usecs_to_jiffies: - convert microseconds to jiffies |
384 | * @u: time in microseconds |
383 | * @u: time in microseconds |
385 | * |
384 | * |
386 | * conversion is done as follows: |
385 | * conversion is done as follows: |
387 | * |
386 | * |
388 | * - 'too large' values [that would result in larger than |
387 | * - 'too large' values [that would result in larger than |
389 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
388 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
390 | * |
389 | * |
391 | * - all other values are converted to jiffies by either multiplying |
390 | * - all other values are converted to jiffies by either multiplying |
392 | * the input value by a factor or dividing it with a factor and |
391 | * the input value by a factor or dividing it with a factor and |
393 | * handling any 32-bit overflows as for msecs_to_jiffies. |
392 | * handling any 32-bit overflows as for msecs_to_jiffies. |
394 | * |
393 | * |
395 | * usecs_to_jiffies() checks for the passed in value being a constant |
394 | * usecs_to_jiffies() checks for the passed in value being a constant |
396 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
395 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
397 | * code, __usecs_to_jiffies() is called if the value passed does not |
396 | * code, __usecs_to_jiffies() is called if the value passed does not |
398 | * allow constant folding and the actual conversion must be done at |
397 | * allow constant folding and the actual conversion must be done at |
399 | * runtime. |
398 | * runtime. |
400 | * the HZ range specific helpers _usecs_to_jiffies() are called both |
399 | * the HZ range specific helpers _usecs_to_jiffies() are called both |
401 | * directly here and from __msecs_to_jiffies() in the case where |
400 | * directly here and from __msecs_to_jiffies() in the case where |
402 | * constant folding is not possible. |
401 | * constant folding is not possible. |
403 | */ |
402 | */ |
404 | static __always_inline unsigned long usecs_to_jiffies(const unsigned int u) |
403 | static __always_inline unsigned long usecs_to_jiffies(const unsigned int u) |
405 | { |
404 | { |
406 | if (__builtin_constant_p(u)) { |
405 | if (__builtin_constant_p(u)) { |
407 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) |
406 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) |
408 | return MAX_JIFFY_OFFSET; |
407 | return MAX_JIFFY_OFFSET; |
409 | return _usecs_to_jiffies(u); |
408 | return _usecs_to_jiffies(u); |
410 | } else { |
409 | } else { |
411 | return __usecs_to_jiffies(u); |
410 | return __usecs_to_jiffies(u); |
412 | } |
411 | } |
413 | } |
412 | } |
414 | 413 | ||
415 | extern unsigned long timespec64_to_jiffies(const struct timespec64 *value); |
414 | extern unsigned long timespec64_to_jiffies(const struct timespec64 *value); |
416 | extern void jiffies_to_timespec64(const unsigned long jiffies, |
415 | extern void jiffies_to_timespec64(const unsigned long jiffies, |
417 | struct timespec64 *value); |
416 | struct timespec64 *value); |
418 | static inline unsigned long timespec_to_jiffies(const struct timespec *value) |
417 | static inline unsigned long timespec_to_jiffies(const struct timespec *value) |
419 | { |
418 | { |
420 | struct timespec64 ts = timespec_to_timespec64(*value); |
419 | struct timespec64 ts = timespec_to_timespec64(*value); |
421 | 420 | ||
422 | return timespec64_to_jiffies(&ts); |
421 | return timespec64_to_jiffies(&ts); |
423 | } |
422 | } |
424 | 423 | ||
425 | static inline void jiffies_to_timespec(const unsigned long jiffies, |
424 | static inline void jiffies_to_timespec(const unsigned long jiffies, |
426 | struct timespec *value) |
425 | struct timespec *value) |
427 | { |
426 | { |
428 | struct timespec64 ts; |
427 | struct timespec64 ts; |
429 | 428 | ||
430 | jiffies_to_timespec64(jiffies, &ts); |
429 | jiffies_to_timespec64(jiffies, &ts); |
431 | *value = timespec64_to_timespec(ts); |
430 | *value = timespec64_to_timespec(ts); |
432 | } |
431 | } |
433 | 432 | ||
434 | extern unsigned long timeval_to_jiffies(const struct timeval *value); |
433 | extern unsigned long timeval_to_jiffies(const struct timeval *value); |
435 | extern void jiffies_to_timeval(const unsigned long jiffies, |
434 | extern void jiffies_to_timeval(const unsigned long jiffies, |
436 | struct timeval *value); |
435 | struct timeval *value); |
437 | 436 | ||
438 | extern clock_t jiffies_to_clock_t(unsigned long x); |
437 | extern clock_t jiffies_to_clock_t(unsigned long x); |
439 | static inline clock_t jiffies_delta_to_clock_t(long delta) |
438 | static inline clock_t jiffies_delta_to_clock_t(long delta) |
440 | { |
439 | { |
441 | return jiffies_to_clock_t(max(0L, delta)); |
440 | return jiffies_to_clock_t(max(0L, delta)); |
442 | } |
441 | } |
443 | 442 | ||
444 | extern unsigned long clock_t_to_jiffies(unsigned long x); |
443 | extern unsigned long clock_t_to_jiffies(unsigned long x); |
445 | extern u64 jiffies_64_to_clock_t(u64 x); |
444 | extern u64 jiffies_64_to_clock_t(u64 x); |
446 | extern u64 nsec_to_clock_t(u64 x); |
445 | extern u64 nsec_to_clock_t(u64 x); |
447 | extern u64 nsecs_to_jiffies64(u64 n); |
446 | extern u64 nsecs_to_jiffies64(u64 n); |
448 | extern unsigned long nsecs_to_jiffies(u64 n); |
447 | extern unsigned long nsecs_to_jiffies(u64 n); |
449 | 448 | ||
450 | #define TIMESTAMP_SIZE 30 |
449 | #define TIMESTAMP_SIZE 30 |
451 | 450 | ||
452 | #endif>=>>><>><>><>><>><>><>>>0">>><>><>><>><>>>>>>>>>>> |
451 | #endif>=>>><>><>><>><>><>><>>>0">>><>><>><>><>>>>>>>>>>> |