Hello.
Atsushi Nemoto wrote:
[Sorry, resend without unrelated changes ...]
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)
Other than board independent part are not tested. Please test if you
have those platforms. Thank you.
Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
Documentation/mips/time.README | 35 ---
arch/mips/au1000/common/time.c | 98 ----------
If the generic implementation is working well, the Alchemy code doesn't
need its own anymore. However, my patch that fixes the mips_hpt_frequency
calculation needs to be applied first before deleing this code. I'll try to
look into this and test some time...
arch/mips/dec/time.c | 9
arch/mips/jmr3927/rbhma3100/setup.c | 46 +---
arch/mips/kernel/time.c | 312 ++++----------------------------
arch/mips/philips/pnx8550/common/time.c | 4
arch/mips/pmc-sierra/yosemite/smp.c | 6
arch/mips/sgi-ip27/ip27-timer.c | 16 -
arch/mips/sibyte/bcm1480/time.c | 40 ++--
arch/mips/sibyte/sb1250/time.c | 28 --
include/asm-mips/div64.h | 21 --
include/asm-mips/sibyte/sb1250.h | 2
include/asm-mips/time.h | 10 -
13 files changed, 105 insertions(+), 522 deletions(-)
diff --git a/arch/mips/jmr3927/rbhma3100/setup.c b/arch/mips/jmr3927/rbhma3100/setup.c
index 0254340..744f746 100644
--- a/arch/mips/jmr3927/rbhma3100/setup.c
+++ b/arch/mips/jmr3927/rbhma3100/setup.c
@@ -170,12 +170,26 @@ static void jmr3927_machine_power_off(vo
while (1);
}
+static unsigned int jmr3927_hpt_read(void)
+{
+ unsigned int count;
+ unsigned long j;
+ /* read consistent jiffies and counter */
+ do {
+ count = jmr3927_tmrptr->trr;
+ j = jiffies;
+ } while (count > jmr3927_tmrptr->trr);
+ return j * (JMR3927_TIMER_CLK / HZ) + count;
+}
That emulation trick looks very dubious. I'd suggest to implement a
different clocksource driver instead, since this is, after all, is not a CPU
counter. And this will get in the way of the clockevent implementation later.
Also, it's stops to be continuous this way. And I don't understand why you
need this trick at all if you have the variable mips_hpt_mask...
And the same complaint about BCM1480 code.
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index debe86c..2c6d52b 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -11,6 +11,7 @@
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
+#include <linux/clocksource.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
+void (*mips_hpt_init)(void) __initdata = null_hpt_init;
+unsigned int mips_hpt_mask = 0xffffffff;
/* last time when xtime and rtc are sync'ed up */
static long last_rtc_update;
@@ -533,13 +310,41 @@ static unsigned int __init calibrate_hpt
} while (--i);
hpt_end = mips_hpt_read();
- hpt_count = hpt_end - hpt_start;
+ hpt_count = (hpt_end - hpt_start) & mips_hpt_mask;
hz = HZ;
frequency = (u64)hpt_count * (u64)hz;
return frequency >> log_2_loops;
}
+static cycle_t read_mips_hpt(void)
+{
+ return (cycle_t)mips_hpt_read();
+}
+
+static struct clocksource clocksource_mips = {
+ .name = "MIPS",
+ .rating = 250,
+ .read = read_mips_hpt,
+ .shift = 24,
+ .is_continuous = 1,
+};
+
+static void __init init_mips_clocksource(void)
+{
+ u64 temp;
+
+ if (!mips_hpt_frequency || mips_hpt_read == null_hpt_read)
+ return;
+
+ temp = (u64) NSEC_PER_SEC << clocksource_mips.shift;
+ do_div(temp, mips_hpt_frequency);
+ clocksource_mips.mult = (unsigned)temp;
+ clocksource_mips.mask = mips_hpt_mask;
+
+ clocksource_register(&clocksource_mips);
+}
+
Well, I'd vote against the generic implementation. It's not quite correct
to call all the diverse timers here "MIPS", IMHO...
@@ -633,6 +411,8 @@ void __init time_init(void)
* is not invoked accidentally.
*/
plat_timer_setup(&timer_irqaction);
+
+ init_mips_clocksource();
Well, this is usually done via module_init()...
WBR, Sergei
