From 0a45d4491d0f172e02126370f312405c5d473363 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Wed, 15 Mar 2006 13:47:15 +1100 Subject: powerpc: Fix problem with time going backwards The recent changes to keep gettimeofday in sync with xtime had the side effect that it was occasionally possible for the time reported by gettimeofday to go back by a microsecond. There were two reasons: (1) when we recalculated the offsets used by gettimeofday every 2^31 timebase ticks, we lost an accumulated fractional microsecond, and (2) because the update is done some time after the notional start of jiffy, if ntp is slowing the clock, it is possible to see time go backwards when the timebase factor gets reduced. This fixes it by (a) slowing the gettimeofday clock by about 1us in 2^31 timebase ticks (a factor of less than 1 in 3.7 million), and (b) adjusting the timebase offsets in the rare case that the gettimeofday result could possibly go backwards (i.e. when ntp is slowing the clock and the timer interrupt is late). In this case the adjustment will reduce to zero eventually because of (a). Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/time.c | 48 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 14 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 2a7ddc579379..86f7e3d154d8 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -283,9 +283,9 @@ static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, * the two values of tb_update_count match and are even then the * tb_to_xs and stamp_xsec values are consistent. If not, then it * loops back and reads them again until this criteria is met. + * We expect the caller to have done the first increment of + * vdso_data->tb_update_count already. */ - ++(vdso_data->tb_update_count); - smp_wmb(); vdso_data->tb_orig_stamp = new_tb_stamp; vdso_data->stamp_xsec = new_stamp_xsec; vdso_data->tb_to_xs = new_tb_to_xs; @@ -310,20 +310,15 @@ static __inline__ void timer_recalc_offset(u64 cur_tb) unsigned long offset; u64 new_stamp_xsec; u64 tlen, t2x; + u64 tb, xsec_old, xsec_new; + struct gettimeofday_vars *varp; if (__USE_RTC()) return; tlen = current_tick_length(); offset = cur_tb - do_gtod.varp->tb_orig_stamp; - if (tlen == last_tick_len && offset < 0x80000000u) { - /* check that we're still in sync; if not, resync */ - struct timeval tv; - __do_gettimeofday(&tv, cur_tb); - if (tv.tv_sec <= xtime.tv_sec && - (tv.tv_sec < xtime.tv_sec || - tv.tv_usec * 1000 <= xtime.tv_nsec)) - return; - } + if (tlen == last_tick_len && offset < 0x80000000u) + return; if (tlen != last_tick_len) { t2x = mulhdu(tlen << TICKLEN_SHIFT, ticklen_to_xs); last_tick_len = tlen; @@ -332,6 +327,21 @@ static __inline__ void timer_recalc_offset(u64 cur_tb) new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; do_div(new_stamp_xsec, 1000000000); new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + + ++vdso_data->tb_update_count; + smp_mb(); + + /* + * Make sure time doesn't go backwards for userspace gettimeofday. + */ + tb = get_tb(); + varp = do_gtod.varp; + xsec_old = mulhdu(tb - varp->tb_orig_stamp, varp->tb_to_xs) + + varp->stamp_xsec; + xsec_new = mulhdu(tb - cur_tb, t2x) + new_stamp_xsec; + if (xsec_new < xsec_old) + new_stamp_xsec += xsec_old - xsec_new; + update_gtod(cur_tb, new_stamp_xsec, t2x); } @@ -564,6 +574,10 @@ int do_settimeofday(struct timespec *tv) } #endif + /* Make userspace gettimeofday spin until we're done. */ + ++vdso_data->tb_update_count; + smp_mb(); + /* * Subtract off the number of nanoseconds since the * beginning of the last tick. @@ -724,10 +738,16 @@ void __init time_init(void) * It is computed as: * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9) * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT - * so as to give the result as a 0.64 fixed-point fraction. + * which turns out to be N = 51 - SHIFT_HZ. + * This gives the result as a 0.64 fixed-point fraction. + * That value is reduced by an offset amounting to 1 xsec per + * 2^31 timebase ticks to avoid problems with time going backwards + * by 1 xsec when we do timer_recalc_offset due to losing the + * fractional xsec. That offset is equal to ppc_tb_freq/2^51 + * since there are 2^20 xsec in a second. */ - div128_by_32(1ULL << (64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT), 0, - tb_ticks_per_jiffy, &res); + div128_by_32((1ULL << 51) - ppc_tb_freq, 0, + tb_ticks_per_jiffy << SHIFT_HZ, &res); div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res); ticklen_to_xs = res.result_low; -- cgit v1.2.1 From 0e8ed479125a6d246e17cfe6c24e140bfeb01972 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Tue, 14 Mar 2006 17:11:51 +1100 Subject: [PATCH] powerpc: RTC memory corruption We should be memset'ing the data we are pointing to, not the pointer itself. This is in an error path so we probably don't hit it much. Signed-off-by: Michael Neuling Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/rtas-rtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/rtas-rtc.c b/arch/powerpc/kernel/rtas-rtc.c index 635d3b9a8811..34d073fb6091 100644 --- a/arch/powerpc/kernel/rtas-rtc.c +++ b/arch/powerpc/kernel/rtas-rtc.c @@ -52,7 +52,7 @@ void rtas_get_rtc_time(struct rtc_time *rtc_tm) error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret); if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) { if (in_interrupt() && printk_ratelimit()) { - memset(&rtc_tm, 0, sizeof(struct rtc_time)); + memset(rtc_tm, 0, sizeof(struct rtc_time)); printk(KERN_WARNING "error: reading clock" " would delay interrupt\n"); return; /* delay not allowed */ -- cgit v1.2.1 From 920573bd03bf690135967b5022362d34ede589c3 Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Tue, 14 Mar 2006 21:21:11 +0100 Subject: [PATCH] powerpc: remove duplicate EXPORT_SYMBOLS remove warnings when building a 64bit kernel. smp_call_function triggers also with 32bit kernel. WARNING: vmlinux: duplicate symbol 'smp_call_function' previous definition was in vmlinux arch/powerpc/kernel/ppc_ksyms.c:164:EXPORT_SYMBOL(smp_call_function); arch/powerpc/kernel/smp.c:300:EXPORT_SYMBOL(smp_call_function); WARNING: vmlinux: duplicate symbol 'ioremap' previous definition was in vmlinux arch/powerpc/kernel/ppc_ksyms.c:113:EXPORT_SYMBOL(ioremap); arch/powerpc/mm/pgtable_64.c:321:EXPORT_SYMBOL(ioremap); WARNING: vmlinux: duplicate symbol '__ioremap' previous definition was in vmlinux arch/powerpc/kernel/ppc_ksyms.c:117:EXPORT_SYMBOL(__ioremap); arch/powerpc/mm/pgtable_64.c:322:EXPORT_SYMBOL(__ioremap); WARNING: vmlinux: duplicate symbol 'iounmap' previous definition was in vmlinux arch/powerpc/kernel/ppc_ksyms.c:118:EXPORT_SYMBOL(iounmap); arch/powerpc/mm/pgtable_64.c:323:EXPORT_SYMBOL(iounmap); Signed-off-by: Olaf Hering Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/ppc_ksyms.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index 8a731ea877b7..63ecbec05202 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -110,15 +110,6 @@ EXPORT_SYMBOL(_insw_ns); EXPORT_SYMBOL(_outsw_ns); EXPORT_SYMBOL(_insl_ns); EXPORT_SYMBOL(_outsl_ns); -EXPORT_SYMBOL(ioremap); -#ifdef CONFIG_44x -EXPORT_SYMBOL(ioremap64); -#endif -EXPORT_SYMBOL(__ioremap); -EXPORT_SYMBOL(iounmap); -#ifdef CONFIG_PPC32 -EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ -#endif #if defined(CONFIG_PPC32) && (defined(CONFIG_BLK_DEV_IDE) || defined(CONFIG_BLK_DEV_IDE_MODULE)) EXPORT_SYMBOL(ppc_ide_md); @@ -161,7 +152,6 @@ EXPORT_SYMBOL(__flush_icache_range); EXPORT_SYMBOL(flush_dcache_range); #ifdef CONFIG_SMP -EXPORT_SYMBOL(smp_call_function); #ifdef CONFIG_PPC32 EXPORT_SYMBOL(smp_hw_index); #endif -- cgit v1.2.1 From 92eb4602eb5c37db86cd9d2b1f4c8ca304fbc49f Mon Sep 17 00:00:00 2001 From: John Rose Date: Tue, 14 Mar 2006 17:46:45 -0600 Subject: [PATCH] powerpc: properly configure DDR/P5IOC children devs The dynamic add path for PCI Host Bridges can fail to configure children adapters under P5IOC controllers. It fails to properly fixup bus/device resources, and it fails to properly enable EEH. Both of these steps need to occur before any children devices are enabled in pci_bus_add_devices(). Signed-off-by: John Rose Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/pci_64.c | 5 +++-- arch/powerpc/kernel/rtas_pci.c | 24 +----------------------- 2 files changed, 4 insertions(+), 25 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c index c367520bc1c3..ba92bab7cc2c 100644 --- a/arch/powerpc/kernel/pci_64.c +++ b/arch/powerpc/kernel/pci_64.c @@ -589,7 +589,6 @@ void __devinit scan_phb(struct pci_controller *hose) #endif /* CONFIG_PPC_MULTIPLATFORM */ if (mode == PCI_PROBE_NORMAL) hose->last_busno = bus->subordinate = pci_scan_child_bus(bus); - pci_bus_add_devices(bus); } static int __init pcibios_init(void) @@ -608,8 +607,10 @@ static int __init pcibios_init(void) printk("PCI: Probing PCI hardware\n"); /* Scan all of the recorded PCI controllers. */ - list_for_each_entry_safe(hose, tmp, &hose_list, list_node) + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { scan_phb(hose); + pci_bus_add_devices(hose->bus); + } #ifndef CONFIG_PPC_ISERIES if (pci_probe_only) diff --git a/arch/powerpc/kernel/rtas_pci.c b/arch/powerpc/kernel/rtas_pci.c index 5579f6559912..7442775ef2a1 100644 --- a/arch/powerpc/kernel/rtas_pci.c +++ b/arch/powerpc/kernel/rtas_pci.c @@ -280,8 +280,7 @@ static int phb_set_bus_ranges(struct device_node *dev, return 0; } -static int __devinit setup_phb(struct device_node *dev, - struct pci_controller *phb) +int __devinit setup_phb(struct device_node *dev, struct pci_controller *phb) { if (is_python(dev)) python_countermeasures(dev); @@ -359,27 +358,6 @@ unsigned long __init find_and_init_phbs(void) return 0; } -struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn) -{ - struct pci_controller *phb; - int primary; - - primary = list_empty(&hose_list); - phb = pcibios_alloc_controller(dn); - if (!phb) - return NULL; - setup_phb(dn, phb); - pci_process_bridge_OF_ranges(phb, dn, primary); - - pci_setup_phb_io_dynamic(phb, primary); - - pci_devs_phb_init_dynamic(phb); - scan_phb(phb); - - return phb; -} -EXPORT_SYMBOL(init_phb_dynamic); - /* RPA-specific bits for removing PHBs */ int pcibios_remove_root_bus(struct pci_controller *phb) { -- cgit v1.2.1