4 files changed, 77 insertions, 32 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 9b5cfcdfc426..ea230ec69057 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -17,7 +17,7 @@
 
 /* FSEC = 10^-15
    NSEC = 10^-9 */
-#define FSEC_PER_NSEC   1000000
+#define FSEC_PER_NSEC   1000000L
 
 /*
  * HPET address is set in acpi/boot.c, when an ACPI entry exists
@@ -206,20 +206,19 @@ static void hpet_enable_legacy_int(void)
 
 static void hpet_legacy_clockevent_register(void)
 {
-        uint64_t hpet_freq;
-
         /* Start HPET legacy interrupts */
         hpet_enable_legacy_int();
 
         /*
-         * The period is a femto seconds value. We need to calculate the
-         * scaled math multiplication factor for nanosecond to hpet tick
-         * conversion.
+         * The mult factor is defined as (include/linux/clockchips.h)
+         *  mult/2^shift = cyc/ns (in contrast to ns/cyc in clocksource.h)
+         * hpet_period is in units of femtoseconds (per cycle), so
+         *  mult/2^shift = cyc/ns = 10^6/hpet_period
+         *  mult = (10^6 * 2^shift)/hpet_period
+         *  mult = (FSEC_PER_NSEC << hpet_clockevent.shift)/hpet_period
          */
-        hpet_freq = 1000000000000000ULL;
-        do_div(hpet_freq, hpet_period);
-        hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
-                                      NSEC_PER_SEC, hpet_clockevent.shift);
+        hpet_clockevent.mult = div_sc((unsigned long) FSEC_PER_NSEC,
+                                      hpet_period, hpet_clockevent.shift);
         /* Calculate the min / max delta */
         hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
                                                            &hpet_clockevent);
@@ -324,7 +323,7 @@ static struct clocksource clocksource_hpet = {
 
 static int hpet_clocksource_register(void)
 {
-        u64 tmp, start, now;
+        u64 start, now;
         cycle_t t1;
 
         /* Start the counter */
@@ -351,21 +350,15 @@ static int hpet_clocksource_register(void)
                 return -ENODEV;
         }
 
-        /* Initialize and register HPET clocksource
-         *
-         * hpet period is in femto seconds per cycle
-         * so we need to convert this to ns/cyc units
-         * approximated 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
+        /*
+         * The definition of mult is (include/linux/clocksource.h)
+         * mult/2^shift = ns/cyc and hpet_period is in units of fsec/cyc
+         * so we first need to convert hpet_period to ns/cyc units:
+         *  mult/2^shift = ns/cyc = hpet_period/10^6
+         *  mult = (hpet_period * 2^shift)/10^6
+         *  mult = (hpet_period << shift)/FSEC_PER_NSEC
          */
-        tmp = (u64)hpet_period << HPET_SHIFT;
-        do_div(tmp, FSEC_PER_NSEC);
-        clocksource_hpet.mult = (u32)tmp;
+        clocksource_hpet.mult = div_sc(hpet_period, FSEC_PER_NSEC, HPET_SHIFT);
 
         clocksource_register(&clocksource_hpet);
 
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index d89a648fe710..79bdcd11c66e 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -65,6 +65,7 @@ static enum {
         ICH_FORCE_HPET_RESUME,
         VT8237_FORCE_HPET_RESUME,
         NVIDIA_FORCE_HPET_RESUME,
+        ATI_FORCE_HPET_RESUME,
 } force_hpet_resume_type;
 
 static void __iomem *rcba_base;
@@ -158,6 +159,8 @@ static void ich_force_enable_hpet(struct pci_dev *dev)
 
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0,
                          ich_force_enable_hpet);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0,
+                         ich_force_enable_hpet);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1,
                          ich_force_enable_hpet);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0,
@@ -174,6 +177,12 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_7,
 
 static struct pci_dev *cached_dev;
 
+static void hpet_print_force_info(void)
+{
+        printk(KERN_INFO "HPET not enabled in BIOS. "
+               "You might try hpet=force boot option\n");
+}
+
 static void old_ich_force_hpet_resume(void)
 {
         u32 val;
@@ -253,6 +262,8 @@ static void old_ich_force_enable_hpet_user(struct pci_dev *dev)
 {
         if (hpet_force_user)
                 old_ich_force_enable_hpet(dev);
+        else
+                hpet_print_force_info();
 }
 
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
@@ -290,8 +301,13 @@ static void vt8237_force_enable_hpet(struct pci_dev *dev)
 {
         u32 uninitialized_var(val);
 
-        if (!hpet_force_user || hpet_address || force_hpet_address)
+        if (hpet_address || force_hpet_address)
+                return;
+
+        if (!hpet_force_user) {
+                hpet_print_force_info();
                 return;
+        }
 
         pci_read_config_dword(dev, 0x68, &val);
         /*
@@ -330,6 +346,36 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235,
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237,
                          vt8237_force_enable_hpet);
 
+static void ati_force_hpet_resume(void)
+{
+        pci_write_config_dword(cached_dev, 0x14, 0xfed00000);
+        printk(KERN_DEBUG "Force enabled HPET at resume\n");
+}
+
+static void ati_force_enable_hpet(struct pci_dev *dev)
+{
+        u32 uninitialized_var(val);
+
+        if (hpet_address || force_hpet_address)
+                return;
+
+        if (!hpet_force_user) {
+                hpet_print_force_info();
+                return;
+        }
+
+        pci_write_config_dword(dev, 0x14, 0xfed00000);
+        pci_read_config_dword(dev, 0x14, &val);
+        force_hpet_address = val;
+        force_hpet_resume_type = ATI_FORCE_HPET_RESUME;
+        dev_printk(KERN_DEBUG, &dev->dev, "Force enabled HPET at 0x%lx\n",
+                   force_hpet_address);
+        cached_dev = dev;
+        return;
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
+                         ati_force_enable_hpet);
+
 /*
  * Undocumented chipset feature taken from LinuxBIOS.
  */
@@ -343,8 +389,13 @@ static void nvidia_force_enable_hpet(struct pci_dev *dev)
 {
         u32 uninitialized_var(val);
 
-        if (!hpet_force_user || hpet_address || force_hpet_address)
+        if (hpet_address || force_hpet_address)
+                return;
+
+        if (!hpet_force_user) {
+                hpet_print_force_info();
                 return;
+        }
 
         pci_write_config_dword(dev, 0x44, 0xfed00001);
         pci_read_config_dword(dev, 0x44, &val);
@@ -397,6 +448,9 @@ void force_hpet_resume(void)
         case NVIDIA_FORCE_HPET_RESUME:
                 nvidia_force_hpet_resume();
                 return;
+        case ATI_FORCE_HPET_RESUME:
+                ati_force_hpet_resume();
+                return;
         default:
                 break;
         }
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index 65b70637ad97..774a5a83c296 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -286,7 +286,6 @@ core_initcall(cpufreq_tsc);
 
 /* clock source code */
 
-static unsigned long current_tsc_khz;
 static struct clocksource clocksource_tsc;
 
 /*
@@ -439,9 +438,8 @@ void __init tsc_init(void)
 
         unsynchronized_tsc();
         check_geode_tsc_reliable();
-        current_tsc_khz = tsc_khz;
-        clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
-                                                        clocksource_tsc.shift);
+        clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
+                                                    clocksource_tsc.shift);
         /* lower the rating if we already know its unstable: */
         if (check_tsc_unstable()) {
                 clocksource_tsc.rating = 0;
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 1784b8077a12..9898fb01edfd 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -242,7 +242,7 @@ void __init tsc_calibrate(void)
         if (hpet) {
                 printk(KERN_INFO "TSC calibrated against HPET\n");
                 if (hpet2 < hpet1)
-                        hpet2 += 0x100000000;
+                        hpet2 += 0x100000000UL;
                 hpet2 -= hpet1;
                 tsc1 = (hpet2 * hpet_readl(HPET_PERIOD)) / 1000000;
         } else {