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x86: HPET force enable o ICH7 and later

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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>
This commit is contained in:
Venki Pallipadi 2007-10-12 23:04:23 +02:00 committed by Thomas Gleixner
parent 610bf2f143
commit d54bd57d65
2 changed files with 103 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

102
arch/x86/kernel/quirks.c
View File

@ -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

1
include/asm-x86/hpet.h
View File

@ -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