Since we already moved to GENERIC_TIME, we should implement alternatives
of old do_gettimeoffset routines to get sub-jiffies resolution from
gettimeofday(). This patch includes:
* MIPS clocksource support (based on works by Manish Lachwani).
* remove unused gettimeoffset routines and related codes.
* remove unised 64bit do_div64_32().
* simplify mips_hpt_init. (no argument needed, __init tag)
* simplify c0_hpt_timer_init. (no need to write to c0_count)
* remove some hpt_init routines.
* mips_hpt_mask variable to specify bitmask of hpt value.
* convert jmr3927_do_gettimeoffset to jmr3927_hpt_read.
* convert ip27_do_gettimeoffset to ip27_hpt_read.
* convert bcm1480_do_gettimeoffset to bcm1480_hpt_read.
* simplify sb1250 hpt functions. (no need to subtract and shift)
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Running a UP kernel on a bcm1480 board, I get nonsensical timing
results, like this:
release@unknown:~/tmp$ time ./a.out
real 0m22.906s
user 0m45.792s
sys 0m0.010s
According to my watch, this program took 23 seconds to run, so the real
time clock is OK. It is process accounting that is broken.
I tracked this down to a problem with the function
bcm1480_timer_interrupt in the file sibyte/bcm1480/time.c. This
function calls ll_timer_interrupt for cpu0, and ll_local_timer_interrupt
for all cpus. However, both of these functions do process accounting.
Thus processes running on cpu0 end up with doubled times. This is very
obvious in a UP kernel where all processes run on cpu0.
The correct way to do this is to only call ll_local_timer interrupt if
this is not cpu0. This can be seen in the mips-board/generic/time.c
file, and also in the sibyte/sb1250/time.c file, both of which handle
this correctly. I fixed the bcm1480/time.c file by copying over the
correct code from the sb1250/time.c file.
With this fix, I now get sensible results.
release@unknown:~/tmp$ time ./a.out
real 0m22.903s
user 0m22.894s
sys 0m0.006s
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
- Kconfig and Makefile changes
- arch/mips/sibyte/bcm1480/
- changes to sibyte common code to support 1480
Signed-Off-By: Andy Isaacson <adi@broadcom.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
