* This file is licensed under the GPL v2.
*/
+#include <linux/acpi_pmtmr.h>
#include <linux/clocksource.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;
-
-#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
+u32 pmtmr_ioport __read_mostly;
static inline u32 read_pmtmr(void)
{
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;
/*
* 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
+ * source is not latched, 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));
+ } 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();
}
.rating = 200,
.read = acpi_pm_read,
.mask = (cycle_t)ACPI_PM_MASK,
- .mult = 0, /*to be caluclated*/
+ .mult = 0, /*to be calculated*/
.shift = 22,
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+
};
#ifdef CONFIG_PCI
-static int acpi_pm_good;
+static int __devinitdata 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;
}
/*
*/
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) {
+ 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"
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
acpi_pm_check_graylist);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
+ acpi_pm_check_graylist);
#endif
+#ifndef CONFIG_X86_64
+#include <asm/mach_timer.h>
+#define PMTMR_EXPECTED_RATE \
+ ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_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)
+{
+ cycle_t value1, value2;
+ unsigned long count, delta;
+
+ mach_prepare_counter();
+ value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
+ mach_countup(&count);
+ 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 */
+ if (delta < (PMTMR_EXPECTED_RATE * 19) / 20 ||
+ delta > (PMTMR_EXPECTED_RATE * 21) / 20) {
+ printk(KERN_INFO "PM-Timer running at invalid rate: %lu%% "
+ "of normal - aborting.\n",
+ 100UL * delta / PMTMR_EXPECTED_RATE);
+ return -1;
+ }
+
+ return 0;
+}
+#else
+#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.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:"
+ " 0x%#llx, 0x%#llx - aborting.\n",
+ value1, value2);
+ return -EINVAL;
+ }
+ if (i == ACPI_PM_READ_CHECKS) {
+ printk(KERN_INFO "PM-Timer failed consistency check "
+ " (0x%#llx) - aborting.\n", value1);
+ 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)
+ return -ENODEV;
+
return clocksource_register(&clocksource_acpi_pm);
}
-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 long base;
+
+ if (strict_strtoul(arg, 16, &base))
+ return -EINVAL;
+#ifdef CONFIG_X86_64
+ if (base > UINT_MAX)
+ return -ERANGE;
+#endif
+ printk(KERN_INFO "PMTMR IOPort override: 0x%04x -> 0x%04lx\n",
+ pmtmr_ioport, base);
+ pmtmr_ioport = base;
+
+ return 1;
+}
+__setup("pmtmr=", parse_pmtmr);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff