From f4df73c2914a49bf6a55896aaecb0563c955e167 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 15 Nov 2007 21:41:50 -0500 Subject: [PATCH] x86: add hpet sanity checks Some BIOSes advertise HPET at 0x0. We really do no want to allocate a resource there. Check for it and leave early. Other BIOSes tell us the HPET is at 0xfed0000000000000 instead of 0xfed00000. Add a check and fix it up with a warning on user request. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/acpi/boot.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 289247d974c6..0ca27c7b0e8d 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -637,6 +637,38 @@ static int __init acpi_parse_hpet(struct acpi_table_header *table) } hpet_address = hpet_tbl->address.address; + + /* + * Some broken BIOSes advertise HPET at 0x0. We really do not + * want to allocate a resource there. + */ + if (!hpet_address) { + printk(KERN_WARNING PREFIX + "HPET id: %#x base: %#lx is invalid\n", + hpet_tbl->id, hpet_address); + return 0; + } +#ifdef CONFIG_X86_64 + /* + * Some even more broken BIOSes advertise HPET at + * 0xfed0000000000000 instead of 0xfed00000. Fix it up and add + * some noise: + */ + if (hpet_address == 0xfed0000000000000UL) { + if (!hpet_force_user) { + printk(KERN_WARNING PREFIX "HPET id: %#x " + "base: 0xfed0000000000000 is bogus\n " + "try hpet=force on the kernel command line to " + "fix it up to 0xfed00000.\n", hpet_tbl->id); + hpet_address = 0; + return 0; + } + printk(KERN_WARNING PREFIX + "HPET id: %#x base: 0xfed0000000000000 fixed up " + "to 0xfed00000.\n", hpet_tbl->id); + hpet_address >>= 32; + } +#endif printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n", hpet_tbl->id, hpet_address); -- 2.20.1