From d54bd57d6580250e6551261f3b15c45a9d90c77b Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Fri, 12 Oct 2007 23:04:23 +0200 Subject: [PATCH] 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 Cc: Andi Kleen Cc: john stultz Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Thomas Gleixner --- arch/x86/kernel/quirks.c | 102 +++++++++++++++++++++++++++++++++++++++ include/asm-x86/hpet.h | 1 + 2 files changed, 103 insertions(+) diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c index 6722469c26..d3ac703867 100644 --- a/arch/x86/kernel/quirks.c +++ b/arch/x86/kernel/quirks.c @@ -4,6 +4,8 @@ #include #include +#include + #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 diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h index 64446a9577..7c93324236 100644 --- a/include/asm-x86/hpet.h +++ b/include/asm-x86/hpet.h @@ -66,6 +66,7 @@ extern unsigned long hpet_address; 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 -- 2.39.5