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authorVenki Pallipadi <venkatesh.pallipadi@intel.com>2007-10-12 23:04:23 +0200
committerThomas Gleixner <tglx@inhelltoy.tec.linutronix.de>2007-10-12 23:04:23 +0200
commitd54bd57d6580250e6551261f3b15c45a9d90c77b (patch)
tree12cb06b4adb9494e67cefdc691643e333fef3b91 /arch
parent610bf2f143b9c5cda768a2d428d66d3a16769930 (diff)
downloadlinux-d54bd57d6580250e6551261f3b15c45a9d90c77b.tar.bz2
x86: HPET force enable o ICH7 and later
Force detect and/or enable HPET on ICH chipsets. This patch just handles the detection part and following patches use this information. Adds a function to repeat the force enabling during resume time. Using HPET this way, instead of PIT increases the time CPUs can reside in C-state when system is totally idle. On my test system with Core 2 Duo, average C-state residency goes up from ~20mS to ~80mS. [ Build fixed from Andrew Morton ] Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/quirks.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 6722469c2633..d3ac703867d6 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -4,6 +4,8 @@
#include <linux/pci.h>
#include <linux/irq.h>
+#include <asm/hpet.h>
+
#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
@@ -47,3 +49,103 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7320_MCH, quir
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7525_MCH, quirk_intel_irqbalance);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, quirk_intel_irqbalance);
#endif
+
+#if defined(CONFIG_HPET_TIMER)
+unsigned long force_hpet_address;
+
+static void __iomem *rcba_base;
+
+void ich_force_hpet_resume(void)
+{
+ u32 val;
+
+ if (!force_hpet_address)
+ return;
+
+ if (rcba_base == NULL)
+ BUG();
+
+ /* read the Function Disable register, dword mode only */
+ val = readl(rcba_base + 0x3404);
+ if (!(val & 0x80)) {
+ /* HPET disabled in HPTC. Trying to enable */
+ writel(val | 0x80, rcba_base + 0x3404);
+ }
+
+ val = readl(rcba_base + 0x3404);
+ if (!(val & 0x80))
+ BUG();
+ else
+ printk(KERN_DEBUG "Force enabled HPET at resume\n");
+
+ return;
+}
+
+static void ich_force_enable_hpet(struct pci_dev *dev)
+{
+ u32 val;
+ u32 uninitialized_var(rcba);
+ int err = 0;
+
+ if (hpet_address || force_hpet_address)
+ return;
+
+ pci_read_config_dword(dev, 0xF0, &rcba);
+ rcba &= 0xFFFFC000;
+ if (rcba == 0) {
+ printk(KERN_DEBUG "RCBA disabled. Cannot force enable HPET\n");
+ return;
+ }
+
+ /* use bits 31:14, 16 kB aligned */
+ rcba_base = ioremap_nocache(rcba, 0x4000);
+ if (rcba_base == NULL) {
+ printk(KERN_DEBUG "ioremap failed. Cannot force enable HPET\n");
+ return;
+ }
+
+ /* read the Function Disable register, dword mode only */
+ val = readl(rcba_base + 0x3404);
+
+ if (val & 0x80) {
+ /* HPET is enabled in HPTC. Just not reported by BIOS */
+ val = val & 0x3;
+ force_hpet_address = 0xFED00000 | (val << 12);
+ printk(KERN_DEBUG "Force enabled HPET at base address 0x%lx\n",
+ force_hpet_address);
+ iounmap(rcba_base);
+ return;
+ }
+
+ /* HPET disabled in HPTC. Trying to enable */
+ writel(val | 0x80, rcba_base + 0x3404);
+
+ val = readl(rcba_base + 0x3404);
+ if (!(val & 0x80)) {
+ err = 1;
+ } else {
+ val = val & 0x3;
+ force_hpet_address = 0xFED00000 | (val << 12);
+ }
+
+ if (err) {
+ force_hpet_address = 0;
+ iounmap(rcba_base);
+ printk(KERN_DEBUG "Failed to force enable HPET\n");
+ } else {
+ printk(KERN_DEBUG "Force enabled HPET at base address 0x%lx\n",
+ force_hpet_address);
+ }
+}
+
+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_1,
+ ich_force_enable_hpet);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1,
+ ich_force_enable_hpet);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_31,
+ ich_force_enable_hpet);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_1,
+ ich_force_enable_hpet);
+#endif