[PATCH 014/112] ACPI: tables: complete searching upon RSDP w/ bad checksum.

Len Brown
2008-02-07T09:35:37Z

From: Len Brown <len.brown@intel.com>

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>
---
arch/ia64/kernel/acpi.c | 26 ++++++++++++++------------
arch/x86/kernel/acpi/boot.c | 40 ----------------------------------------
arch/x86/kernel/srat_32.c | 2 +-
drivers/acpi/osl.c | 8 ++++++--
drivers/acpi/tables/Makefile | 2 +-
drivers/acpi/tables/tbxfroot.c | 4 +---
include/linux/acpi.h | 1 -
7 files changed, 23 insertions(+), 60 deletions(-)

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 897e208..63d6dcd 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -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)
{

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 0ca27c7..719c74b 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
diff --git a/arch/x86/kernel/srat_32.c b/arch/x86/kernel/srat_32.c
index 2a8713e..b3b2c95 100644
--- a/arch/x86/kernel/srat_32.c
+++ b/arch/x86/kernel/srat_32.c
@@ -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__);
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index aabc6ca..101691e 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -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)
diff --git a/drivers/acpi/tables/Makefile b/drivers/acpi/tables/Makefile
index 0a7d7af..7385efa 100644
--- a/drivers/acpi/tables/Makefile
+++ b/drivers/acpi/tables/Makefile
@@ -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)
diff --git a/drivers/acpi/tables/tbxfroot.c b/drivers/acpi/tables/tbxfroot.c
index cf8fa51..9ecb4b6 100644
--- a/drivers/acpi/tables/tbxfroot.c
+++ b/drivers/acpi/tables/tbxfroot.c
@@ -100,7 +100,7 @@ static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)

/*******************************************************************************
*
- * FUNCTION: acpi_tb_find_rsdp
+ * FUNCTION: acpi_find_root_pointer
*
* PARAMETERS: table_address - Where the table pointer is returned
*
@@ -219,8 +219,6 @@ acpi_status acpi_find_root_pointer(acpi_native_uint * table_address)
return_ACPI_STATUS(AE_NOT_FOUND);
}

-ACPI_EXPORT_SYMBOL(acpi_find_root_pointer)
-
/*******************************************************************************
*
* FUNCTION: acpi_tb_scan_memory_for_rsdp
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 8ccedf7..8deb611 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -79,7 +79,6 @@ typedef int (*acpi_table_handler) (struct acpi_table_header *table);
typedef int (*acpi_table_entry_handler) (struct acpi_subtable_header *header, const unsigned long end);

char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
-unsigned long acpi_find_rsdp (void);
int acpi_boot_init (void);
int acpi_boot_table_init (void);
int acpi_numa_init (void);
--
1.5.4.23.gef5b9