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>
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 6722469..d3ac703 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_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
diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h
index 64446a9..7c93324 100644
--- a/include/asm-x86/hpet.h
+++ b/include/asm-x86/hpet.h
@@ -66,6 +66,7 @@
extern int is_hpet_enabled(void);
extern int hpet_enable(void);
extern unsigned long hpet_readl(unsigned long a);
+extern void ich_force_hpet_resume(void);
#ifdef CONFIG_HPET_EMULATE_RTC