Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933788AbZGQAPL (ORCPT ); Thu, 16 Jul 2009 20:15:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933715AbZGQAPJ (ORCPT ); Thu, 16 Jul 2009 20:15:09 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:53364 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933689AbZGQAPF (ORCPT ); Thu, 16 Jul 2009 20:15:05 -0400 Subject: [RESEND][PATCH] Convert m32r to use arch_gettimeoffset() From: john stultz To: takata@linux-m32r.org Cc: lkml , linux-m32r@ml.linux-m32r.org, Andrew Morton In-Reply-To: <1244758210.7192.5.camel@localhost.localdomain> References: <1244758210.7192.5.camel@localhost.localdomain> Content-Type: text/plain Date: Thu, 16 Jul 2009 17:09:55 -0700 Message-Id: <1247789395.7398.3.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4190 Lines: 152 This patch converts m32r to use GENERIC_TIME via the arch_getoffset() infrastructure, reducing the amount of arch specific code we need to maintain. I also noted that m32r doesn't seem to be taking the xtime write lock before calling do_timer()! That looks like a pretty bad bug to me. If folks agree, let me know and I can move the lock grab to the correct spot. This patch applies on top of Linus' current -git tree (2.6.31-rc3). I've taken my best swing at converting this, but I'm not 100% confident I got it right. My cross-compiler is now out of date (gcc4.2) so I wasn't able to check if it compiled. Any assistance from arch maintainers or testers to get this merged would be great. thanks -john Signed-off-by: John Stultz --- Kconfig | 6 ++++ kernel/time.c | 74 ++-------------------------------------------------------- 2 files changed, 9 insertions(+), 71 deletions(-) diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig index cabba33..c41234f 100644 --- a/arch/m32r/Kconfig +++ b/arch/m32r/Kconfig @@ -41,6 +41,12 @@ config HZ int default 100 +config GENERIC_TIME + def_bool y + +config ARCH_USES_GETTIMEOFFSET + def_bool y + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/m32r/kernel/time.c b/arch/m32r/kernel/time.c index cada3ba..ba61c4c 100644 --- a/arch/m32r/kernel/time.c +++ b/arch/m32r/kernel/time.c @@ -48,7 +48,7 @@ extern void smp_local_timer_interrupt(void); static unsigned long latch; -static unsigned long do_gettimeoffset(void) +u32 arch_gettimeoffset(void) { unsigned long elapsed_time = 0; /* [us] */ @@ -93,79 +93,10 @@ static unsigned long do_gettimeoffset(void) #error no chip configuration #endif - return elapsed_time; + return elapsed_time * 1000; } /* - * This version of gettimeofday has near microsecond resolution. - */ -void do_gettimeofday(struct timeval *tv) -{ - unsigned long seq; - unsigned long usec, sec; - unsigned long max_ntp_tick = tick_usec - tickadj; - - do { - seq = read_seqbegin(&xtime_lock); - - usec = do_gettimeoffset(); - - /* - * If time_adjust is negative then NTP is slowing the clock - * so make sure not to go into next possible interval. - * Better to lose some accuracy than have time go backwards.. - */ - if (unlikely(time_adjust < 0)) - usec = min(usec, max_ntp_tick); - - sec = xtime.tv_sec; - usec += (xtime.tv_nsec / 1000); - } while (read_seqretry(&xtime_lock, seq)); - - while (usec >= 1000000) { - usec -= 1000000; - sec++; - } - - tv->tv_sec = sec; - tv->tv_usec = usec; -} - -EXPORT_SYMBOL(do_gettimeofday); - -int do_settimeofday(struct timespec *tv) -{ - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - /* - * This is revolting. We need to set "xtime" correctly. However, the - * value in this location is the value at the most recent update of - * wall time. Discover what correction gettimeofday() would have - * made, and then undo it! - */ - nsec -= do_gettimeoffset() * NSEC_PER_USEC; - - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - - ntp_clear(); - write_sequnlock_irq(&xtime_lock); - clock_was_set(); - - return 0; -} - -EXPORT_SYMBOL(do_settimeofday); - -/* * In order to set the CMOS clock precisely, set_rtc_mmss has to be * called 500 ms after the second nowtime has started, because when * nowtime is written into the registers of the CMOS clock, it will @@ -192,6 +123,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) #ifndef CONFIG_SMP profile_tick(CPU_PROFILING); #endif + /* XXX FIXME. Uh, the xtime_lock should be held here, no? */ do_timer(1); #ifndef CONFIG_SMP -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/