android_kernel_xiaomi_sdm845/arch/x86_64/kernel/early-quirks.c
Andi Kleen fa18f477d0 [PATCH] x86: Add acpi_user_timer_override option for Asus boards
Timer overrides are normally disabled on Nvidia board because
they are commonly wrong, except on new ones with HPET support.
Unfortunately there are quite some Asus boards around that
don't have HPET, but need a timer override.

We don't know yet how to handle this transparently,
but at least add a command line option to force the timer override
and let them boot.

Cc: len.brown@intel.com

Signed-off-by: Andi Kleen <ak@suse.de>
2006-11-14 16:57:46 +01:00

132 lines
3.0 KiB
C

/* Various workarounds for chipset bugs.
This code runs very early and can't use the regular PCI subsystem
The entries are keyed to PCI bridges which usually identify chipsets
uniquely.
This is only for whole classes of chipsets with specific problems which
need early invasive action (e.g. before the timers are initialized).
Most PCI device specific workarounds can be done later and should be
in standard PCI quirks
Mainboard specific bugs should be handled by DMI entries.
CPU specific bugs in setup.c */
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/pci_ids.h>
#include <asm/pci-direct.h>
#include <asm/proto.h>
#include <asm/dma.h>
static void via_bugs(void)
{
#ifdef CONFIG_IOMMU
if ((end_pfn > MAX_DMA32_PFN || force_iommu) &&
!iommu_aperture_allowed) {
printk(KERN_INFO
"Looks like a VIA chipset. Disabling IOMMU. Override with iommu=allowed\n");
iommu_aperture_disabled = 1;
}
#endif
}
#ifdef CONFIG_ACPI
static int nvidia_hpet_detected __initdata;
static int __init nvidia_hpet_check(unsigned long phys, unsigned long size)
{
nvidia_hpet_detected = 1;
return 0;
}
#endif
static void nvidia_bugs(void)
{
#ifdef CONFIG_ACPI
/*
* All timer overrides on Nvidia are
* wrong unless HPET is enabled.
* Unfortunately that's not true on many Asus boards.
* We don't know yet how to detect this automatically, but
* at least allow a command line override.
*/
if (acpi_use_timer_override)
return;
nvidia_hpet_detected = 0;
acpi_table_parse(ACPI_HPET, nvidia_hpet_check);
if (nvidia_hpet_detected == 0) {
acpi_skip_timer_override = 1;
printk(KERN_INFO "Nvidia board "
"detected. Ignoring ACPI "
"timer override.\n");
printk(KERN_INFO "If you got timer trouble "
"try acpi_use_timer_override\n");
}
#endif
/* RED-PEN skip them on mptables too? */
}
static void ati_bugs(void)
{
if (timer_over_8254 == 1) {
timer_over_8254 = 0;
printk(KERN_INFO
"ATI board detected. Disabling timer routing over 8254.\n");
}
}
struct chipset {
u16 vendor;
void (*f)(void);
};
static struct chipset early_qrk[] = {
{ PCI_VENDOR_ID_NVIDIA, nvidia_bugs },
{ PCI_VENDOR_ID_VIA, via_bugs },
{ PCI_VENDOR_ID_ATI, ati_bugs },
{}
};
void __init early_quirks(void)
{
int num, slot, func;
if (!early_pci_allowed())
return;
/* Poor man's PCI discovery */
for (num = 0; num < 32; num++) {
for (slot = 0; slot < 32; slot++) {
for (func = 0; func < 8; func++) {
u32 class;
u32 vendor;
u8 type;
int i;
class = read_pci_config(num,slot,func,
PCI_CLASS_REVISION);
if (class == 0xffffffff)
break;
if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
continue;
vendor = read_pci_config(num, slot, func,
PCI_VENDOR_ID);
vendor &= 0xffff;
for (i = 0; early_qrk[i].f; i++)
if (early_qrk[i].vendor == vendor) {
early_qrk[i].f();
return;
}
type = read_pci_config_byte(num, slot, func,
PCI_HEADER_TYPE);
if (!(type & 0x80))
break;
}
}
}
}