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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-07-02 15:36:20 +1000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-07-02 15:36:20 +1000 |
commit | 1d880992fd8c8457a2d990ac6622cfd58fb1b261 (patch) | |
tree | c4c843b12e96b5612c315db5a23c5da1a900618c /core/timebase.c | |
download | skiboot-1d880992fd8c8457a2d990ac6622cfd58fb1b261.zip skiboot-1d880992fd8c8457a2d990ac6622cfd58fb1b261.tar.gz skiboot-1d880992fd8c8457a2d990ac6622cfd58fb1b261.tar.bz2 |
Initial commit of Open Source release
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'core/timebase.c')
-rw-r--r-- | core/timebase.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/core/timebase.c b/core/timebase.c new file mode 100644 index 0000000..d51e96b --- /dev/null +++ b/core/timebase.c @@ -0,0 +1,67 @@ +/* Copyright 2013-2014 IBM Corp. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + * implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <timebase.h> +#include <fsp.h> + +void time_wait(unsigned long duration) +{ + unsigned long end = mftb() + duration; + + while(tb_compare(mftb(), end) != TB_AAFTERB) + fsp_poll(); +} + +void time_wait_ms(unsigned long ms) +{ + time_wait(msecs_to_tb(ms)); +} + +void time_wait_us(unsigned long us) +{ + time_wait(usecs_to_tb(us)); +} + +unsigned long timespec_to_tb(const struct timespec *ts) +{ + unsigned long ns; + + /* First convert to ns */ + ns = ts->tv_sec * 1000000000ul; + ns += ts->tv_nsec; + + /* + * This is a very rough approximation, it works provided + * we never try to pass too long delays here and the TB + * frequency isn't significantly lower than 512Mhz. + * + * We could improve the precision by shifting less bits + * at the expense of capacity or do 128 bit math which + * I'm not eager to do :-) + */ + return (ns * (tb_hz >> 24)) / (1000000000ul >> 24); +} + +int nanosleep(const struct timespec *req, struct timespec *rem) +{ + time_wait(timespec_to_tb(req)); + + if (rem) { + rem->tv_sec = 0; + rem->tv_nsec = 0; + } + return 0; +} |