From: Tony Luck Date: Tue, 7 Feb 2006 23:25:57 +0000 (-0800) Subject: [IA64] Fix CONFIG_PRINTK_TIME X-Git-Tag: v2.6.16-rc3~51^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d6e56a2a088935f3c1feee5ff5a06c67f2ec6002;p=linux-2.6 [IA64] Fix CONFIG_PRINTK_TIME There were two problems with enabling the PRINTK_TIME config option: 1) The first calls to printk() occur before per-cpu data virtual address is pinned into the TLB, so sched_clock() can fault. 2) sched_clock() is based on ar.itc, which may not be synchronized across cpus. Ken Chen started this patch, Tony Luck tinkered with it, and Jes Sorensen perfected it. Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index fbc7ea35dd..f1778a84ea 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -352,6 +352,7 @@ start_ap: mov ar.rsc=0 // place RSE in enforced lazy mode ;; loadrs // clear the dirty partition + mov IA64_KR(PER_CPU_DATA)=r0 // clear physical per-CPU base ;; mov ar.bspstore=r2 // establish the new RSE stack ;; diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index c0766575a3..35f7835294 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -71,6 +71,8 @@ unsigned long __per_cpu_offset[NR_CPUS]; EXPORT_SYMBOL(__per_cpu_offset); #endif +extern void ia64_setup_printk_clock(void); + DEFINE_PER_CPU(struct cpuinfo_ia64, cpu_info); DEFINE_PER_CPU(unsigned long, local_per_cpu_offset); DEFINE_PER_CPU(unsigned long, ia64_phys_stacked_size_p8); @@ -445,6 +447,8 @@ setup_arch (char **cmdline_p) /* process SAL system table: */ ia64_sal_init(efi.sal_systab); + ia64_setup_printk_clock(); + #ifdef CONFIG_SMP cpu_physical_id(0) = hard_smp_processor_id(); diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 028a2b9593..a094ec49cc 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -278,3 +278,30 @@ udelay (unsigned long usecs) } } EXPORT_SYMBOL(udelay); + +static unsigned long long ia64_itc_printk_clock(void) +{ + if (ia64_get_kr(IA64_KR_PER_CPU_DATA)) + return sched_clock(); + return 0; +} + +static unsigned long long ia64_default_printk_clock(void) +{ + return (unsigned long long)(jiffies_64 - INITIAL_JIFFIES) * + (1000000000/HZ); +} + +unsigned long long (*ia64_printk_clock)(void) = &ia64_default_printk_clock; + +unsigned long long printk_clock(void) +{ + return ia64_printk_clock(); +} + +void __init +ia64_setup_printk_clock(void) +{ + if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) + ia64_printk_clock = ia64_itc_printk_clock; +} diff --git a/arch/ia64/sn/kernel/setup.c b/arch/ia64/sn/kernel/setup.c index ee36bff93c..6ea5b8a37c 100644 --- a/arch/ia64/sn/kernel/setup.c +++ b/arch/ia64/sn/kernel/setup.c @@ -67,6 +67,7 @@ extern unsigned long last_time_offset; extern void (*ia64_mark_idle) (int); extern void snidle(int); extern unsigned char acpi_kbd_controller_present; +extern unsigned long long (*ia64_printk_clock)(void); unsigned long sn_rtc_cycles_per_second; EXPORT_SYMBOL(sn_rtc_cycles_per_second); @@ -372,6 +373,16 @@ sn_scan_pcdp(void) } } +static unsigned long sn2_rtc_initial; + +static unsigned long long ia64_sn2_printk_clock(void) +{ + unsigned long rtc_now = rtc_time(); + + return (rtc_now - sn2_rtc_initial) * + (1000000000 / sn_rtc_cycles_per_second); +} + /** * sn_setup - SN platform setup routine * @cmdline_p: kernel command line @@ -386,6 +397,7 @@ void __init sn_setup(char **cmdline_p) u32 version = sn_sal_rev(); extern void sn_cpu_init(void); + sn2_rtc_initial = rtc_time(); ia64_sn_plat_set_error_handling_features(); // obsolete ia64_sn_set_os_feature(OSF_MCA_SLV_TO_OS_INIT_SLV); ia64_sn_set_os_feature(OSF_FEAT_LOG_SBES); @@ -437,19 +449,6 @@ void __init sn_setup(char **cmdline_p) */ build_cnode_tables(); - /* - * Old PROMs do not provide an ACPI FADT. Disable legacy keyboard - * support here so we don't have to listen to failed keyboard probe - * messages. - */ - if (version <= 0x0209 && acpi_kbd_controller_present) { - printk(KERN_INFO "Disabling legacy keyboard support as prom " - "is too old and doesn't provide FADT\n"); - acpi_kbd_controller_present = 0; - } - - printk("SGI SAL version %x.%02x\n", version >> 8, version & 0x00FF); - status = ia64_sal_freq_base(SAL_FREQ_BASE_REALTIME_CLOCK, &ticks_per_sec, &drift); @@ -463,6 +462,21 @@ void __init sn_setup(char **cmdline_p) platform_intr_list[ACPI_INTERRUPT_CPEI] = IA64_CPE_VECTOR; + ia64_printk_clock = ia64_sn2_printk_clock; + + /* + * Old PROMs do not provide an ACPI FADT. Disable legacy keyboard + * support here so we don't have to listen to failed keyboard probe + * messages. + */ + if (version <= 0x0209 && acpi_kbd_controller_present) { + printk(KERN_INFO "Disabling legacy keyboard support as prom " + "is too old and doesn't provide FADT\n"); + acpi_kbd_controller_present = 0; + } + + printk("SGI SAL version %x.%02x\n", version >> 8, version & 0x00FF); + /* * we set the default root device to /dev/hda * to make simulation easy