diff options
Diffstat (limited to 'drivers/clocksource/acpi_pm.c')
| -rw-r--r-- | drivers/clocksource/acpi_pm.c | 136 |
1 files changed, 85 insertions, 51 deletions
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index 8ab61ef97b4..6eab8898567 100644 --- a/drivers/clocksource/acpi_pm.c +++ b/drivers/clocksource/acpi_pm.c @@ -16,31 +16,29 @@ * This file is licensed under the GPL v2. */ +#include <linux/acpi_pmtmr.h> #include <linux/clocksource.h> +#include <linux/timex.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/pci.h> +#include <linux/delay.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 + * in arch/i386/kernel/acpi/boot.c */ u32 pmtmr_ioport __read_mostly; -#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) /* 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 acpi_pm_read_verified(void) { u32 v1 = 0, v2 = 0, v3 = 0; @@ -57,10 +55,10 @@ static cycle_t acpi_pm_read_verified(void) } while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); - return (cycle_t)v2; + return v2; } -static cycle_t acpi_pm_read(void) +static cycle_t acpi_pm_read(struct clocksource *cs) { return (cycle_t)read_pmtmr(); } @@ -70,9 +68,7 @@ static struct clocksource clocksource_acpi_pm = { .rating = 200, .read = acpi_pm_read, .mask = (cycle_t)ACPI_PM_MASK, - .mult = 0, /*to be caluclated*/ - .shift = 22, - .is_continuous = 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -80,15 +76,20 @@ static struct clocksource clocksource_acpi_pm = { static int acpi_pm_good; static int __init acpi_pm_good_setup(char *__str) { - acpi_pm_good = 1; - return 1; + acpi_pm_good = 1; + return 1; } __setup("acpi_pm_good", acpi_pm_good_setup); +static cycle_t acpi_pm_read_slow(struct clocksource *cs) +{ + return (cycle_t)acpi_pm_read_verified(); +} + static inline void acpi_pm_need_workaround(void) { - clocksource_acpi_pm.read = acpi_pm_read_verified; - clocksource_acpi_pm.rating = 110; + clocksource_acpi_pm.read = acpi_pm_read_slow; + clocksource_acpi_pm.rating = 120; } /* @@ -101,16 +102,13 @@ static inline void acpi_pm_need_workaround(void) * 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) +static void 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) { + if (dev->revision < 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" @@ -122,7 +120,7 @@ static void __devinit acpi_pm_check_blacklist(struct pci_dev *dev) 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) +static void acpi_pm_check_graylist(struct pci_dev *dev) { if (acpi_pm_good) return; @@ -143,22 +141,22 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE, #endif #ifndef CONFIG_X86_64 -#include "mach_timer.h" +#include <asm/mach_timer.h> #define PMTMR_EXPECTED_RATE \ - ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_TICK_RATE>>10)) + ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (PIT_TICK_RATE>>10)) /* * Some boards have the PMTMR running way too fast. We check * the PMTMR rate against PIT channel 2 to catch these cases. */ static int verify_pmtmr_rate(void) { - u32 value1, value2; + cycle_t value1, value2; unsigned long count, delta; mach_prepare_counter(); - value1 = read_pmtmr(); + value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm); mach_countup(&count); - value2 = read_pmtmr(); + value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm); delta = (value2 - value1) & ACPI_PM_MASK; /* Check that the PMTMR delta is within 5% of what we expect */ @@ -176,40 +174,76 @@ static int verify_pmtmr_rate(void) #define verify_pmtmr_rate() (0) #endif +/* Number of monotonicity checks to perform during initialization */ +#define ACPI_PM_MONOTONICITY_CHECKS 10 +/* Number of reads we try to get two different values */ +#define ACPI_PM_READ_CHECKS 10000 + static int __init init_acpi_pm_clocksource(void) { - u32 value1, value2; - unsigned int i; + cycle_t value1, value2; + unsigned int i, j = 0; 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; + for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) { + udelay(100 * j); + value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm); + for (i = 0; i < ACPI_PM_READ_CHECKS; i++) { + value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm); + if (value2 == value1) + continue; + if (value2 > value1) + break; + if ((value2 < value1) && ((value2) < 0xFFF)) + break; + printk(KERN_INFO "PM-Timer had inconsistent results:" + " %#llx, %#llx - aborting.\n", + value1, value2); + pmtmr_ioport = 0; + return -EINVAL; + } + if (i == ACPI_PM_READ_CHECKS) { + printk(KERN_INFO "PM-Timer failed consistency check " + " (%#llx) - aborting.\n", value1); + pmtmr_ioport = 0; + return -ENODEV; + } } - printk(KERN_INFO "PM-Timer had no reasonable result:" - " 0x%#x - aborting.\n", value1); - return -ENODEV; -pm_good: - if (verify_pmtmr_rate() != 0) + if (verify_pmtmr_rate() != 0){ + pmtmr_ioport = 0; return -ENODEV; + } - return clocksource_register(&clocksource_acpi_pm); + return clocksource_register_hz(&clocksource_acpi_pm, + PMTMR_TICKS_PER_SEC); } -module_init(init_acpi_pm_clocksource); +/* We use fs_initcall because we want the PCI fixups to have run + * but we still need to load before device_initcall + */ +fs_initcall(init_acpi_pm_clocksource); + +/* + * Allow an override of the IOPort. Stupid BIOSes do not tell us about + * the PMTimer, but we might know where it is. + */ +static int __init parse_pmtmr(char *arg) +{ + unsigned int base; + int ret; + + ret = kstrtouint(arg, 16, &base); + if (ret) + return ret; + + pr_info("PMTMR IOPort override: 0x%04x -> 0x%04x\n", pmtmr_ioport, + base); + pmtmr_ioport = base; + + return 1; +} +__setup("pmtmr=", parse_pmtmr); |