From 239665a3bb0a2234980f918913add31bc536cfd1 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 23 Nov 2007 20:08:02 -0500 Subject: ACPI: tables: complete searching upon RSDP w/ bad checksum. 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 --- arch/x86/kernel/acpi/boot.c | 40 ---------------------------------------- 1 file changed, 40 deletions(-) (limited to 'arch/x86/kernel/acpi/boot.c') diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 0ca27c7b0e8d..719c74b0141a 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -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 -- cgit v1.2.1