[PATCH] cciss: fix for 2TB support

[powerpc.git] / drivers / clocksource / acpi_pm.c

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 7ad3be8..d42060e 100644 (file)
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -16,15 +16,13 @@
  * 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 <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(),
@@ -32,15 +30,13 @@
  */
 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;
 
@@ -54,10 +50,15 @@ static cycle_t acpi_pm_read_verified(void)
                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_slow(void)
+{
+       return (cycle_t)acpi_pm_read_verified();
 }
 
 static cycle_t acpi_pm_read(void)
@@ -72,22 +73,23 @@ static struct clocksource clocksource_acpi_pm = {
        .mask           = (cycle_t)ACPI_PM_MASK,
        .mult           = 0, /*to be caluclated*/
        .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 inline void acpi_pm_need_workaround(void)
 {
-       clocksource_acpi_pm.read = acpi_pm_read_verified;
+       clocksource_acpi_pm.read = acpi_pm_read_slow;
        clocksource_acpi_pm.rating = 110;
 }
 
@@ -138,8 +140,43 @@ static void __devinit acpi_pm_check_graylist(struct pci_dev *dev)
 }
 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 "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)
+{
+       u32 value1, value2;
+       unsigned long count, delta;
+
+       mach_prepare_counter();
+       value1 = read_pmtmr();
+       mach_countup(&count);
+       value2 = read_pmtmr();
+       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
 
 static int __init init_acpi_pm_clocksource(void)
 {
@@ -171,7 +208,13 @@ static int __init init_acpi_pm_clocksource(void)
        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);