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ACPI: tables: complete searching upon RSDP w/ bad checksum.

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ACPI tables follow a tree structure in memory.
The root of the tree is the RSDP (Root System Description Pointer).

To find the RSDP, the OS searches for the signature "RSD PTR "
in well known physical memory locations.  Then the OS computes
a table checksum to verify that the signature is really part
of a valid table header.

Some systems have a proper signature but an invalid checksum;
followed elsewhere by a proper signature with valid checksum.

http://bugzilla.kernel.org/show_bug.cgi?id=9444

The Linux RSDP scanning code bailed out on those systems
and as a result they booted with ACPI disabled.

Fix this by deleting the Linux RSDP scanning code and
plugging in the ACPICA RSDP scanning code.

Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Len Brown
2007-11-23 20:08:02 -05:00
parent 2ffbb8377c
commit 239665a3bb
7 changed files with 23 additions and 60 deletions
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40
arch/x86/kernel/acpi/boot.c
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@ -581,25 +581,6 @@ int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
EXPORT_SYMBOL(acpi_unregister_ioapic);
static unsigned long __init
acpi_scan_rsdp(unsigned long start, unsigned long length)
{
unsigned long offset = 0;
unsigned long sig_len = sizeof("RSD PTR ") - 1;
/*
* Scan all 16-byte boundaries of the physical memory region for the
* RSDP signature.
*/
for (offset = 0; offset < length; offset += 16) {
if (strncmp((char *)(phys_to_virt(start) + offset), "RSD PTR ", sig_len))
continue;
return (start + offset);
}
return 0;
}
static int __init acpi_parse_sbf(struct acpi_table_header *table)
{
struct acpi_table_boot *sb;
@ -742,27 +723,6 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
return 0;
}
unsigned long __init acpi_find_rsdp(void)
{
unsigned long rsdp_phys = 0;
if (efi_enabled) {
if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
return efi.acpi20;
else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
return efi.acpi;
}
/*
* Scan memory looking for the RSDP signature. First search EBDA (low
* memory) paragraphs and then search upper memory (E0000-FFFFF).
*/
rsdp_phys = acpi_scan_rsdp(0, 0x400);
if (!rsdp_phys)
rsdp_phys = acpi_scan_rsdp(0xE0000, 0x20000);
return rsdp_phys;
}
#ifdef CONFIG_X86_LOCAL_APIC
/*
* Parse LAPIC entries in MADT