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Commit 239665a3 authored by Len Brown's avatar Len Brown
Browse files

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: default avatarLen Brown <len.brown@intel.com>
parent 2ffbb837

arch/ia64/kernel/acpi.c

+14 −12
Original line number Diff line number Diff line
@@ -69,6 +69,20 @@ unsigned int acpi_cpei_phys_cpuid; 


unsigned long acpi_wakeup_address = 0;



#ifdef CONFIG_IA64_GENERIC

static unsigned long __init acpi_find_rsdp(void)

{

	unsigned long rsdp_phys = 0;



	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)

		rsdp_phys = efi.acpi20;

	else if (efi.acpi != EFI_INVALID_TABLE_ADDR)

		printk(KERN_WARNING PREFIX

		       "v1.0/r0.71 tables no longer supported\n");

	return rsdp_phys;

}

#endif



const char __init *

acpi_get_sysname(void)

{
@@ -631,18 +645,6 @@ 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.acpi20 != EFI_INVALID_TABLE_ADDR)

		rsdp_phys = efi.acpi20;

	else if (efi.acpi != EFI_INVALID_TABLE_ADDR)

		printk(KERN_WARNING PREFIX

		       "v1.0/r0.71 tables no longer supported\n");

	return rsdp_phys;

}



int __init acpi_boot_init(void)

{

arch/x86/kernel/acpi/boot.c

+0 −40
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/srat_32.c

+1 −1
Original line number Diff line number Diff line
@@ -276,7 +276,7 @@ int __init get_memcfg_from_srat(void) 
	int tables = 0;

	int i = 0;



	rsdp_address = acpi_find_rsdp();

	rsdp_address = acpi_os_get_root_pointer();

	if (!rsdp_address) {

		printk("%s: System description tables not found\n",

		       __FUNCTION__);

drivers/acpi/osl.c

+6 −2
Original line number Diff line number Diff line
@@ -207,8 +207,12 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) 
			       "System description tables not found\n");

			return 0;

		}

	} else

		return acpi_find_rsdp();

	} else {

		acpi_physical_address pa = 0;



		acpi_find_root_pointer(&pa);

		return pa;

	}

}



void __iomem *acpi_os_map_memory(acpi_physical_address phys, acpi_size size)

drivers/acpi/tables/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -2,6 +2,6 @@ 
# Makefile for all Linux ACPI interpreter subdirectories

#



obj-y := tbxface.o tbinstal.o  tbutils.o tbfind.o tbfadt.o

obj-y := tbxface.o tbinstal.o tbutils.o tbfind.o tbfadt.o tbxfroot.o



EXTRA_CFLAGS += $(ACPI_CFLAGS)