diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | arch/i386/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/i386/kernel/hpet.c | 67 | ||||
| -rw-r--r-- | arch/i386/kernel/i8253.c | 53 | ||||
| -rw-r--r-- | arch/i386/kernel/time.c | 3 | ||||
| -rw-r--r-- | arch/i386/kernel/tsc.c | 161 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clocksource/acpi_pm.c | 177 | ||||
| -rw-r--r-- | drivers/clocksource/cyclone.c | 119 | ||||
| -rw-r--r-- | kernel/time/clocksource.c | 11 |
11 files changed, 594 insertions, 6 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9686316..2e352a6 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -180,6 +180,11 @@ running once the system is up. override platform specific driver. See also Documentation/acpi-hotkey.txt. + acpi_pm_good [IA-32,X86-64] + Override the pmtimer bug detection: force the kernel + to assume that this machine's pmtimer latches its value + and always returns good values. + enable_timer_pin_1 [i386,x86-64] Enable PIN 1 of APIC timer Can be useful to work around chipset bugs diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index f238cb6..0fac85d 100644 --- a/arch/i386/kernel/Makefile +++ b/arch/i386/kernel/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_EFI) += efi.o efi_stub.o obj-$(CONFIG_DOUBLEFAULT) += doublefault.o obj-$(CONFIG_VM86) += vm86.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +obj-$(CONFIG_HPET_TIMER) += hpet.o EXTRA_AFLAGS := -traditional diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c new file mode 100644 index 0000000..91a5bdd --- /dev/null +++ b/arch/i386/kernel/hpet.c @@ -0,0 +1,67 @@ +#include <linux/clocksource.h> +#include <linux/errno.h> +#include <linux/hpet.h> +#include <linux/init.h> + +#include <asm/hpet.h> +#include <asm/io.h> + +#define HPET_MASK 0xFFFFFFFF +#define HPET_SHIFT 22 + +/* FSEC = 10^-15 NSEC = 10^-9 */ +#define FSEC_PER_NSEC 1000000 + +static void *hpet_ptr; + +static cycle_t read_hpet(void) +{ + return (cycle_t)readl(hpet_ptr); +} + +static struct clocksource clocksource_hpet = { + .name = "hpet", + .rating = 250, + .read = read_hpet, + .mask = (cycle_t)HPET_MASK, + .mult = 0, /* set below */ + .shift = HPET_SHIFT, + .is_continuous = 1, +}; + +static int __init init_hpet_clocksource(void) +{ + unsigned long hpet_period; + void __iomem* hpet_base; + u64 tmp; + + if (!hpet_address) + return -ENODEV; + + /* calculate the hpet address: */ + hpet_base = + (void __iomem*)ioremap_nocache(hpet_address, HPET_MMAP_SIZE); + hpet_ptr = hpet_base + HPET_COUNTER; + + /* calculate the frequency: */ + hpet_period = readl(hpet_base + HPET_PERIOD); + + /* + * hpet period is in femto seconds per cycle + * so we need to convert this to ns/cyc units + * aproximated by mult/2^shift + * + * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift + * fsec/cyc * 1ns/1000000fsec * 2^shift = mult + * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult + * (fsec/cyc << shift)/1000000 = mult + * (hpet_period << shift)/FSEC_PER_NSEC = mult + */ + tmp = (u64)hpet_period << HPET_SHIFT; + do_div(tmp, FSEC_PER_NSEC); + clocksource_hpet.mult = (u32)tmp; + + return register_clocksource(&clocksource_hpet); +} + +module_init(init_hpet_clocksource); diff --git a/arch/i386/kernel/i8253.c b/arch/i386/kernel/i8253.c index 29cb2eb..a276bce 100644 --- a/arch/i386/kernel/i8253.c +++ b/arch/i386/kernel/i8253.c @@ -2,6 +2,7 @@ * i8253.c 8253/PIT functions * */ +#include <linux/clocksource.h> #include <linux/spinlock.h> #include <linux/jiffies.h> #include <linux/sysdev.h> @@ -30,3 +31,55 @@ void setup_pit_timer(void) outb(LATCH >> 8 , PIT_CH0); /* MSB */ spin_unlock_irqrestore(&i8253_lock, flags); } + +/* + * Since the PIT overflows every tick, its not very useful + * to just read by itself. So use jiffies to emulate a free + * running counter: + */ +static cycle_t pit_read(void) +{ + unsigned long flags; + int count; + u64 jifs; + + spin_lock_irqsave(&i8253_lock, flags); + outb_p(0x00, PIT_MODE); /* latch the count ASAP */ + count = inb_p(PIT_CH0); /* read the latched count */ + count |= inb_p(PIT_CH0) << 8; + + /* VIA686a test code... reset the latch if count > max + 1 */ + if (count > LATCH) { + outb_p(0x34, PIT_MODE); + outb_p(LATCH & 0xff, PIT_CH0); + outb(LATCH >> 8, PIT_CH0); + count = LATCH - 1; + } + spin_unlock_irqrestore(&i8253_lock, flags); + + jifs = jiffies_64; + + jifs -= INITIAL_JIFFIES; + count = (LATCH-1) - count; + + return (cycle_t)(jifs * LATCH) + count; +} + +static struct clocksource clocksource_pit = { + .name = "pit", + .rating = 110, + .read = pit_read, + .mask = (cycle_t)-1, + .mult = 0, + .shift = 20, +}; + +static int __init init_pit_clocksource(void) +{ + if (num_possible_cpus() > 4) /* PIT does not scale! */ + return 0; + + clocksource_pit.mult = clocksource_hz2mult(CLOCK_TICK_RATE, 20); + return register_clocksource(&clocksource_pit); +} +module_init(init_pit_clocksource); diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index 2a6ab86..5f43d04 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -82,9 +82,6 @@ extern unsigned long wall_jiffies; DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL(rtc_lock); -/* XXX - necessary to keep things compiling. to be removed later */ -u32 pmtmr_ioport; - /* * This is a special lock that is owned by the CPU and holds the index * register we are working with. It is required for NMI access to the diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c index 96b3074..7713f86 100644 --- a/arch/i386/kernel/tsc.c +++ b/arch/i386/kernel/tsc.c @@ -4,11 +4,14 @@ * See comments there for proper credits. */ +#include <linux/clocksource.h> #include <linux/workqueue.h> #include <linux/cpufreq.h> #include <linux/jiffies.h> #include <linux/init.h> +#include <linux/dmi.h> +#include <asm/delay.h> #include <asm/tsc.h> #include <asm/delay.h> #include <asm/io.h> @@ -315,3 +318,161 @@ static int __init cpufreq_tsc(void) core_initcall(cpufreq_tsc); #endif + +/* clock source code */ + +static unsigned long current_tsc_khz = 0; +static int tsc_update_callback(void); + +static cycle_t read_tsc(void) +{ + cycle_t ret; + + rdtscll(ret); + + return ret; +} + +static struct clocksource clocksource_tsc = { + .name = "tsc", + .rating = 300, + .read = read_tsc, + .mask = (cycle_t)-1, + .mult = 0, /* to be set */ + .shift = 22, + .update_callback = tsc_update_callback, + .is_continuous = 1, +}; + +static int tsc_update_callback(void) +{ + int change = 0; + + /* check to see if we should switch to the safe clocksource: */ + if (clocksource_tsc.rating != 50 && check_tsc_unstable()) { + clocksource_tsc.rating = 50; + reselect_clocksource(); + change = 1; + } + + /* only update if tsc_khz has changed: */ + if (current_tsc_khz != tsc_khz) { + current_tsc_khz = tsc_khz; + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, + clocksource_tsc.shift); + change = 1; + } + + return change; +} + +static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d) +{ + printk(KERN_NOTICE "%s detected: marking TSC unstable.\n", + d->ident); + mark_tsc_unstable(); + return 0; +} + +/* List of systems that have known TSC problems */ +static struct dmi_system_id __initdata bad_tsc_dmi_table[] = { + { + .callback = dmi_mark_tsc_unstable, + .ident = "IBM Thinkpad 380XD", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), + DMI_MATCH(DMI_BOARD_NAME, "2635FA0"), + }, + }, + {} +}; + +#define TSC_FREQ_CHECK_INTERVAL (10*MSEC_PER_SEC) /* 10sec in MS */ +static struct timer_list verify_tsc_freq_timer; + +/* XXX - Probably should add locking */ +static void verify_tsc_freq(unsigned long unused) +{ + static u64 last_tsc; + static unsigned long last_jiffies; + + u64 now_tsc, interval_tsc; + unsigned long now_jiffies, interval_jiffies; + + + if (check_tsc_unstable()) + return; + + rdtscll(now_tsc); + now_jiffies = jiffies; + + if (!last_jiffies) { + goto out; + } + + interval_jiffies = now_jiffies - last_jiffies; + interval_tsc = now_tsc - last_tsc; + interval_tsc *= HZ; + do_div(interval_tsc, cpu_khz*1000); + + if (interval_tsc < (interval_jiffies * 3 / 4)) { + printk("TSC appears to be running slowly. " + "Marking it as unstable\n"); + mark_tsc_unstable(); + return; + } + +out: + last_tsc = now_tsc; + last_jiffies = now_jiffies; + /* set us up to go off on the next interval: */ + mod_timer(&verify_tsc_freq_timer, + jiffies + msecs_to_jiffies(TSC_FREQ_CHECK_INTERVAL)); +} + +/* + * Make an educated guess if the TSC is trustworthy and synchronized + * over all CPUs. + */ +static __init int unsynchronized_tsc(void) +{ + /* + * Intel systems are normally all synchronized. + * Exceptions must mark TSC as unstable: + */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + return 0; + + /* assume multi socket systems are not synchronized: */ + return num_possible_cpus() > 1; +} + +static int __init init_tsc_clocksource(void) +{ + + if (cpu_has_tsc && tsc_khz && !tsc_disable) { + /* check blacklist */ + dmi_check_system(bad_tsc_dmi_table); + + if (unsynchronized_tsc()) /* mark unstable if unsynced */ + mark_tsc_unstable(); + current_tsc_khz = tsc_khz; + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, + clocksource_tsc.shift); + /* lower the rating if we already know its unstable: */ + if (check_tsc_unstable()) + clocksource_tsc.rating = 50; + + init_timer(&verify_tsc_freq_timer); + verify_tsc_freq_timer.function = verify_tsc_freq; + verify_tsc_freq_timer.expires = + jiffies + msecs_to_jiffies(TSC_FREQ_CHECK_INTERVAL); + add_timer(&verify_tsc_freq_timer); + + return register_clocksource(&clocksource_tsc); + } + + return 0; +} + +module_init(init_tsc_clocksource); diff --git a/drivers/Makefile b/drivers/Makefile index 3c51703..fc2d744 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -74,4 +74,5 @@ obj-$(CONFIG_SGI_SN) += sn/ obj-y += firmware/ obj-$(CONFIG_CRYPTO) += crypto/ obj-$(CONFIG_SUPERH) += sh/ +obj-$(CONFIG_GENERIC_TIME) += clocksource/ obj-$(CONFIG_DMA_ENGINE) += dma/ diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile new file mode 100644 index 0000000..be3511a --- /dev/null +++ b/drivers/clocksource/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o +obj-$(CONFIG_X86_PM_TIMER) += acpi_pm.o diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c new file mode 100644 index 0000000..a0e5cde --- /dev/null +++ b/drivers/clocksource/acpi_pm.c @@ -0,0 +1,177 @@ +/* + * linux/drivers/clocksource/acpi_pm.c + * + * This file contains the ACPI PM based clocksource. + * + * This code was largely moved from the i386 timer_pm.c file + * which was (C) Dominik Brodowski <linux@brodo.de> 2003 + * and contained the following comments: + * + * Driver to use the Power Management Timer (PMTMR) available in some + * southbridges as primary timing source for the Linux kernel. + * + * Based on parts of linux/drivers/acpi/hardware/hwtimer.c, timer_pit.c, + * timer_hpet.c, and on Arjan van de Ven's implementation for 2.4. + * + * This file is licensed under the GPL v2. + */ + +#include <linux/clocksource.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <asm/io.h> + +/* Number of PMTMR ticks expected during calibration run */ +#define PMTMR_TICKS_PER_SEC 3579545 + +/* + * The I/O port the PMTMR resides at. + * The location is detected during setup_arch(), + * in arch/i386/acpi/boot.c + */ +u32 pmtmr_ioport; + +#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */ + +static inline u32 read_pmtmr(void) +{ + /* mask the output to 24 bits */ + return inl(pmtmr_ioport) & ACPI_PM_MASK; +} + +static cycle_t acpi_pm_read_verified(void) +{ + u32 v1 = 0, v2 = 0, v3 = 0; + + /* + * It has been reported that because of various broken + * chipsets (ICH4, PIIX4 and PIIX4E) where the ACPI PM clock + * source is not latched, so you must read it multiple + * times to ensure a safe value is read: + */ + do { + v1 = read_pmtmr(); + v2 = read_pmtmr(); + v3 = read_pmtmr(); + } while ((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1) + || (v3 > v1 && v3 < v2)); + + return (cycle_t)v2; +} + +static cycle_t acpi_pm_read(void) +{ + return (cycle_t)read_pmtmr(); +} + +static struct clocksource clocksource_acpi_pm = { + .name = "acpi_pm", + .rating = 200, + .read = acpi_pm_read, + .mask = (cycle_t)ACPI_PM_MASK, + .mult = 0, /*to be caluclated*/ + .shift = 22, + .is_continuous = 1, +}; + + +#ifdef CONFIG_PCI +static int acpi_pm_good; +static int __init acpi_pm_good_setup(char *__str) +{ + acpi_pm_good = 1; + return 1; +} +__setup("acpi_pm_good", acpi_pm_good_setup); + +static inline void acpi_pm_need_workaround(void) +{ + clocksource_acpi_pm.read = acpi_pm_read_verified; + clocksource_acpi_pm.rating = 110; +} + +/* + * PIIX4 Errata: + * + * The power management timer may return improper results when read. + * Although the timer value settles properly after incrementing, + * while incrementing there is a 3 ns window every 69.8 ns where the + * timer value is indeterminate (a 4.2% chance that the data will be + * incorrect when read). As a result, the ACPI free running count up + * timer specification is violated due to erroneous reads. + */ +static void __devinit acpi_pm_check_blacklist(struct pci_dev *dev) +{ + u8 rev; + + if (acpi_pm_good) + return; + + pci_read_config_byte(dev, PCI_REVISION_ID, &rev); + /* the bug has been fixed in PIIX4M */ + if (rev < 3) { + printk(KERN_WARNING "* Found PM-Timer Bug on the chipset." + " Due to workarounds for a bug,\n" + "* this clock source is slow. Consider trying" + " other clock sources\n"); + + acpi_pm_need_workaround(); + } +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3, + acpi_pm_check_blacklist); + +static void __devinit acpi_pm_check_graylist(struct pci_dev *dev) +{ + if (acpi_pm_good) + return; + + printk(KERN_WARNING "* The chipset may have PM-Timer Bug. Due to" + " workarounds for a bug,\n" + "* this clock source is slow. If you are sure your timer" + " does not have\n" + "* this bug, please use \"acpi_pm_good\" to disable the" + " workaround\n"); + + acpi_pm_need_workaround(); +} +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0, + acpi_pm_check_graylist); +#endif + + +static int __init init_acpi_pm_clocksource(void) +{ + u32 value1, value2; + unsigned int i; + + if (!pmtmr_ioport) + return -ENODEV; + + clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, + clocksource_acpi_pm.shift); + + /* "verify" this timing source: */ + value1 = read_pmtmr(); + for (i = 0; i < 10000; i++) { + value2 = read_pmtmr(); + if (value2 == value1) + continue; + if (value2 > value1) + goto pm_good; + if ((value2 < value1) && ((value2) < 0xFFF)) + goto pm_good; + printk(KERN_INFO "PM-Timer had inconsistent results:" + " 0x%#x, 0x%#x - aborting.\n", value1, value2); + return -EINVAL; + } + printk(KERN_INFO "PM-Timer had no reasonable result:" + " 0x%#x - aborting.\n", value1); + return -ENODEV; + +pm_good: + return register_clocksource(&clocksource_acpi_pm); +} + +module_init(init_acpi_pm_clocksource); diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c new file mode 100644 index 0000000..444eb11 --- /dev/null +++ b/drivers/clocksource/cyclone.c @@ -0,0 +1,119 @@ +#include <linux/clocksource.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/timex.h> +#include <linux/init.h> + +#include <asm/pgtable.h> +#include <asm/io.h> + +#include "mach_timer.h" + +#define CYCLONE_CBAR_ADDR 0xFEB00CD0 /* base address ptr */ +#define CYCLONE_PMCC_OFFSET 0x51A0 /* offset to control register */ +#define CYCLONE_MPCS_OFFSET 0x51A8 /* offset to select register */ +#define CYCLONE_MPMC_OFFSET 0x51D0 /* offset to count register */ +#define CYCLONE_TIMER_FREQ 99780000 /* 100Mhz, but not really */ +#define CYCLONE_TIMER_MASK 0xFFFFFFFF /* 32 bit mask */ + +int use_cyclone = 0; +static void __iomem *cyclone_ptr; + +static cycle_t read_cyclone(void) +{ + return (cycle_t)readl(cyclone_ptr); +} + +static struct clocksource clocksource_cyclone = { + .name = "cyclone", + .rating = 250, + .read = read_cyclone, + .mask = (cycle_t)CYCLONE_TIMER_MASK, + .mult = 10, + .shift = 0, + .is_continuous = 1, +}; + +static int __init init_cyclone_clocksource(void) +{ + unsigned long base; /* saved value from CBAR */ + unsigned long offset; + u32 __iomem* volatile cyclone_timer; /* Cyclone MPMC0 register */ + u32 __iomem* reg; + int i; + + /* make sure we're on a summit box: */ + if (!use_cyclone) + return -ENODEV; + + printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n"); + + /* find base address: */ + offset = CYCLONE_CBAR_ADDR; + reg = ioremap_nocache(offset, sizeof(reg)); + if (!reg) { + printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n"); + return -ENODEV; + } + /* even on 64bit systems, this is only 32bits: */ + base = readl(reg); + if (!base) { + printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n"); + return -ENODEV; + } + iounmap(reg); + + /* setup PMCC: */ + offset = base + CYCLONE_PMCC_OFFSET; + reg = ioremap_nocache(offset, sizeof(reg)); + if (!reg) { + printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n"); + return -ENODEV; + } + writel(0x00000001,reg); + iounmap(reg); + + /* setup MPCS: */ + offset = base + CYCLONE_MPCS_OFFSET; + reg = ioremap_nocache(offset, sizeof(reg)); + if (!reg) { + printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n"); + return -ENODEV; + } + writel(0x00000001,reg); + iounmap(reg); + + /* map in cyclone_timer: */ + offset = base + CYCLONE_MPMC_OFFSET; + cyclone_timer = ioremap_nocache(offset, sizeof(u64)); + if (!cyclone_timer) { + printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n"); + return -ENODEV; + } + + /* quick test to make sure its ticking: */ + for (i = 0; i < 3; i++){ + u32 old = readl(cyclone_timer); + int stall = 100; + + while (stall--) + barrier(); + + if (readl(cyclone_timer) == old) { + printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n"); + iounmap(cyclone_timer); + cyclone_timer = NULL; + return -ENODEV; + } + } + cyclone_ptr = cyclone_timer; + + /* sort out mult/shift values: */ + clocksource_cyclone.shift = 22; + clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ, + clocksource_cyclone.shift); + + return register_clocksource(&clocksource_cyclone); +} + +module_init(init_cyclone_clocksource); diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 4288bfa..a9f387e 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -174,7 +174,7 @@ EXPORT_SYMBOL(register_clocksource); * reselect_clocksource - Rescan list for next clocksource * * A quick helper function to be used if a clocksource changes its - * rating. Forces the clocksource list to be re-scaned for the best + * rating. Forces the clocksource list to be re-scanned for the best * clocksource. */ void reselect_clocksource(void) @@ -336,8 +336,13 @@ __setup("clocksource=", boot_override_clocksource); */ static int __init boot_override_clock(char* str) { - printk("Warning! clock= boot option is deprecated.\n"); - + if (!strcmp(str, "pmtmr")) { + printk("Warning: clock=pmtmr is deprecated. " + "Use clocksource=acpi_pm.\n"); + return boot_override_clocksource("acpi_pm"); + } + printk("Warning! clock= boot option is deprecated. " + "Use clocksource=xyz\n"); return boot_override_clocksource(str); } |
