From patchwork Tue Oct 28 10:18:11 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 6079 X-Patchwork-Delegate: paulus@samba.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 070C9DDF9A for ; Tue, 28 Oct 2008 21:18:31 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: by ozlabs.org (Postfix, from userid 1003) id AE25DDDE23; Tue, 28 Oct 2008 21:18:16 +1100 (EST) MIME-Version: 1.0 Message-ID: <18694.59107.371757.322710@cargo.ozlabs.ibm.com> Date: Tue, 28 Oct 2008 21:18:11 +1100 From: Paul Mackerras To: linuxppc-dev@ozlabs.org Subject: [PATCH] powerpc: Eliminate unused do_gtod variable X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu) X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Since we started using the generic timekeeping code, we haven't had a powerpc-specific version of do_gettimeofday, and hence there is now nothing that reads do_gtod variable in arch/powerpc/kernel/time.c. This therefore removes it and the code that sets it. Signed-off-by: Paul Mackerras diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index febd581..27ccb76 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -48,26 +48,6 @@ extern unsigned long ppc_proc_freq; extern unsigned long ppc_tb_freq; #define DEFAULT_TB_FREQ 125000000UL -/* - * By putting all of this stuff into a single struct we - * reduce the number of cache lines touched by do_gettimeofday. - * Both by collecting all of the data in one cache line and - * by touching only one TOC entry on ppc64. - */ -struct gettimeofday_vars { - u64 tb_to_xs; - u64 stamp_xsec; - u64 tb_orig_stamp; -}; - -struct gettimeofday_struct { - unsigned long tb_ticks_per_sec; - struct gettimeofday_vars vars[2]; - struct gettimeofday_vars * volatile varp; - unsigned var_idx; - unsigned tb_to_us; -}; - struct div_result { u64 result_high; u64 result_low; diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 8389c5b..e1f3a51 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -164,8 +164,6 @@ static u64 tb_to_ns_scale __read_mostly; static unsigned tb_to_ns_shift __read_mostly; static unsigned long boot_tb __read_mostly; -static struct gettimeofday_struct do_gtod; - extern struct timezone sys_tz; static long timezone_offset; @@ -415,31 +413,9 @@ void udelay(unsigned long usecs) } EXPORT_SYMBOL(udelay); - -/* - * There are two copies of tb_to_xs and stamp_xsec so that no - * lock is needed to access and use these values in - * do_gettimeofday. We alternate the copies and as long as a - * reasonable time elapses between changes, there will never - * be inconsistent values. ntpd has a minimum of one minute - * between updates. - */ static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, u64 new_tb_to_xs) { - unsigned temp_idx; - struct gettimeofday_vars *temp_varp; - - temp_idx = (do_gtod.var_idx == 0); - temp_varp = &do_gtod.vars[temp_idx]; - - temp_varp->tb_to_xs = new_tb_to_xs; - temp_varp->tb_orig_stamp = new_tb_stamp; - temp_varp->stamp_xsec = new_stamp_xsec; - smp_mb(); - do_gtod.varp = temp_varp; - do_gtod.var_idx = temp_idx; - /* * tb_update_count is used to allow the userspace gettimeofday code * to assure itself that it sees a consistent view of the tb_to_xs and @@ -515,9 +491,7 @@ static int __init iSeries_tb_recal(void) tb_ticks_per_sec = new_tb_ticks_per_sec; calc_cputime_factors(); div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); - do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; tb_to_xs = divres.result_low; - do_gtod.varp->tb_to_xs = tb_to_xs; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; vdso_data->tb_to_xs = tb_to_xs; } @@ -989,15 +963,6 @@ void __init time_init(void) sys_tz.tz_dsttime = 0; } - do_gtod.varp = &do_gtod.vars[0]; - do_gtod.var_idx = 0; - do_gtod.varp->tb_orig_stamp = tb_last_jiffy; - __get_cpu_var(last_jiffy) = tb_last_jiffy; - do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; - do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; - do_gtod.varp->tb_to_xs = tb_to_xs; - do_gtod.tb_to_us = tb_to_us; - vdso_data->tb_orig_stamp = tb_last_jiffy; vdso_data->tb_update_count = 0; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;