[patch] fix ACPI table discovery from EFI for x86

From: Matt Tolentino
Date: Wed Jul 13 2005 - 20:00:30 EST



This patch addresses a problem on x86 EFI systems with larger memory
configurations. Up until now, we've relied on the fact that the
ACPI RSDT would reside somewhere in low memory that could be permanently
mapped in kernel address space - so __va() has been sufficient. However,
on EFI systems, the RSDT is often anywhere in the lower 4GB of physical
address space. So, we may need to remap it on x86 systems.

Second, this fixes some miscalculations in one of the EFI memmap
callback functions.

Lastly, this also removes all of the va->pa->va contortions and
stores the physical location in the efi struct while preserving the
validity checks. This change is the only reason this impacts
ia64.

Tested on x86 EFI machines and boot tested on one ia64 machine
thanks to Tony. Additional testing on ia64 machines would be
appreciated!

Problem reported and original patch proposed by Ping Wei.

Signed-off-by: Matt Tolentino <matthew.e.tolentino@xxxxxxxxx>
---
diff -urNp linux-2.6.13-rc3/arch/i386/kernel/acpi/boot.c linux-2.6.13-rc3-efi/arch/i386/kernel/acpi/boot.c
--- linux-2.6.13-rc3/arch/i386/kernel/acpi/boot.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/arch/i386/kernel/acpi/boot.c 2005-07-13 10:32:54.073297792 -0400
@@ -682,10 +682,10 @@ acpi_find_rsdp (void)
unsigned long rsdp_phys = 0;

if (efi_enabled) {
- if (efi.acpi20)
- return __pa(efi.acpi20);
- else if (efi.acpi)
- return __pa(efi.acpi);
+ if (efi.phys_acpi20 != EFI_INVALID_ACPI_TABLE_ADDR)
+ return efi.phys_acpi20;
+ else if (efi.phys_acpi != EFI_INVALID_ACPI_TABLE_ADDR)
+ return efi.phys_acpi;
}
/*
* Scan memory looking for the RSDP signature. First search EBDA (low
diff -urNp linux-2.6.13-rc3/arch/i386/kernel/efi.c linux-2.6.13-rc3-efi/arch/i386/kernel/efi.c
--- linux-2.6.13-rc3/arch/i386/kernel/efi.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/arch/i386/kernel/efi.c 2005-07-13 10:32:04.731798840 -0400
@@ -376,17 +376,20 @@ void __init efi_init(void)
if (config_tables == NULL)
printk(KERN_ERR PFX "Could not map EFI Configuration Table!\n");

+ efi.phys_acpi20 = EFI_INVALID_ACPI_TABLE_ADDR;
+ efi.phys_acpi = EFI_INVALID_ACPI_TABLE_ADDR;
+
for (i = 0; i < num_config_tables; i++) {
if (efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID) == 0) {
efi.mps = (void *)config_tables[i].table;
printk(KERN_INFO " MPS=0x%lx ", config_tables[i].table);
} else
if (efi_guidcmp(config_tables[i].guid, ACPI_20_TABLE_GUID) == 0) {
- efi.acpi20 = __va(config_tables[i].table);
+ efi.phys_acpi20 = config_tables[i].table;
printk(KERN_INFO " ACPI 2.0=0x%lx ", config_tables[i].table);
} else
if (efi_guidcmp(config_tables[i].guid, ACPI_TABLE_GUID) == 0) {
- efi.acpi = __va(config_tables[i].table);
+ efi.phys_acpi = config_tables[i].table;
printk(KERN_INFO " ACPI=0x%lx ", config_tables[i].table);
} else
if (efi_guidcmp(config_tables[i].guid, SMBIOS_TABLE_GUID) == 0) {
diff -urNp linux-2.6.13-rc3/arch/i386/kernel/setup.c linux-2.6.13-rc3-efi/arch/i386/kernel/setup.c
--- linux-2.6.13-rc3/arch/i386/kernel/setup.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/arch/i386/kernel/setup.c 2005-07-13 10:24:25.149665944 -0400
@@ -1034,10 +1034,10 @@ static int __init
free_available_memory(unsigned long start, unsigned long end, void *arg)
{
/* check max_low_pfn */
- if (start >= ((max_low_pfn + 1) << PAGE_SHIFT))
+ if (start >= (max_low_pfn << PAGE_SHIFT))
return 0;
- if (end >= ((max_low_pfn + 1) << PAGE_SHIFT))
- end = (max_low_pfn + 1) << PAGE_SHIFT;
+ if (end >= (max_low_pfn << PAGE_SHIFT))
+ end = max_low_pfn << PAGE_SHIFT;
if (start < end)
free_bootmem(start, end - start);

diff -urNp linux-2.6.13-rc3/arch/ia64/kernel/acpi.c linux-2.6.13-rc3-efi/arch/ia64/kernel/acpi.c
--- linux-2.6.13-rc3/arch/ia64/kernel/acpi.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/arch/ia64/kernel/acpi.c 2005-07-13 10:33:51.614550192 -0400
@@ -615,9 +615,9 @@ acpi_find_rsdp (void)
{
unsigned long rsdp_phys = 0;

- if (efi.acpi20)
- rsdp_phys = __pa(efi.acpi20);
- else if (efi.acpi)
+ if (efi.phys_acpi20 != EFI_INVALID_ACPI_TABLE_ADDR)
+ rsdp_phys = efi.phys_acpi20;
+ else if (efi.phys_acpi != EFI_INVALID_ACPI_TABLE_ADDR)
printk(KERN_WARNING PREFIX "v1.0/r0.71 tables no longer supported\n");
return rsdp_phys;
}
diff -urNp linux-2.6.13-rc3/arch/ia64/kernel/efi.c linux-2.6.13-rc3-efi/arch/ia64/kernel/efi.c
--- linux-2.6.13-rc3/arch/ia64/kernel/efi.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/arch/ia64/kernel/efi.c 2005-07-13 10:33:32.002531672 -0400
@@ -596,15 +596,18 @@ efi_init (void)
printk(KERN_INFO "EFI v%u.%.02u by %s:",
efi.systab->hdr.revision >> 16, efi.systab->hdr.revision & 0xffff, vendor);

+ efi.phys_acpi20 = EFI_INVALID_ACPI_TABLE_ADDR;
+ efi.phys_acpi = EFI_INVALID_ACPI_TABLE_ADDR;
+
for (i = 0; i < (int) efi.systab->nr_tables; i++) {
if (efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID) == 0) {
efi.mps = __va(config_tables[i].table);
printk(" MPS=0x%lx", config_tables[i].table);
} else if (efi_guidcmp(config_tables[i].guid, ACPI_20_TABLE_GUID) == 0) {
- efi.acpi20 = __va(config_tables[i].table);
+ efi.phys_acpi20 = config_tables[i].table;
printk(" ACPI 2.0=0x%lx", config_tables[i].table);
} else if (efi_guidcmp(config_tables[i].guid, ACPI_TABLE_GUID) == 0) {
- efi.acpi = __va(config_tables[i].table);
+ efi.phys_acpi = config_tables[i].table;
printk(" ACPI=0x%lx", config_tables[i].table);
} else if (efi_guidcmp(config_tables[i].guid, SMBIOS_TABLE_GUID) == 0) {
efi.smbios = __va(config_tables[i].table);
diff -urNp linux-2.6.13-rc3/drivers/acpi/osl.c linux-2.6.13-rc3-efi/drivers/acpi/osl.c
--- linux-2.6.13-rc3/drivers/acpi/osl.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/drivers/acpi/osl.c 2005-07-13 10:34:25.417411376 -0400
@@ -163,12 +163,12 @@ acpi_os_get_root_pointer(u32 flags, stru
{
if (efi_enabled) {
addr->pointer_type = ACPI_PHYSICAL_POINTER;
- if (efi.acpi20)
+ if (efi.phys_acpi20 != EFI_INVALID_ACPI_TABLE_ADDR)
addr->pointer.physical =
- (acpi_physical_address) virt_to_phys(efi.acpi20);
- else if (efi.acpi)
+ (acpi_physical_address)efi.phys_acpi20;
+ else if (efi.phys_acpi != EFI_INVALID_ACPI_TABLE_ADDR)
addr->pointer.physical =
- (acpi_physical_address) virt_to_phys(efi.acpi);
+ (acpi_physical_address)efi.phys_acpi;
else {
printk(KERN_ERR PREFIX "System description tables not found\n");
return AE_NOT_FOUND;
@@ -187,7 +187,9 @@ acpi_status
acpi_os_map_memory(acpi_physical_address phys, acpi_size size, void __iomem **virt)
{
if (efi_enabled) {
- if (EFI_MEMORY_WB & efi_mem_attributes(phys)) {
+ /* determine whether or not we need to call ioremap */
+ if ((EFI_MEMORY_WB & efi_mem_attributes(phys)) &&
+ ((unsigned long)phys < (unsigned long)__pa(high_memory))) {
*virt = (void __iomem *) phys_to_virt(phys);
} else {
*virt = ioremap(phys, size);
diff -urNp linux-2.6.13-rc3/drivers/acpi/tables.c linux-2.6.13-rc3-efi/drivers/acpi/tables.c
--- linux-2.6.13-rc3/drivers/acpi/tables.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/drivers/acpi/tables.c 2005-07-13 10:24:25.180661232 -0400
@@ -581,7 +581,8 @@ acpi_table_init (void)
return -ENODEV;
}

- rsdp = (struct acpi_table_rsdp *) __va(rsdp_phys);
+ rsdp = (struct acpi_table_rsdp *) __acpi_map_table(rsdp_phys,
+ sizeof(struct acpi_table_rsdp));
if (!rsdp) {
printk(KERN_WARNING PREFIX "Unable to map RSDP\n");
return -ENODEV;
diff -urNp linux-2.6.13-rc3/drivers/firmware/efivars.c linux-2.6.13-rc3-efi/drivers/firmware/efivars.c
--- linux-2.6.13-rc3/drivers/firmware/efivars.c 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/drivers/firmware/efivars.c 2005-07-13 10:24:25.183660776 -0400
@@ -570,10 +570,10 @@ systab_read(struct subsystem *entry, cha

if (efi.mps)
str += sprintf(str, "MPS=0x%lx\n", __pa(efi.mps));
- if (efi.acpi20)
- str += sprintf(str, "ACPI20=0x%lx\n", __pa(efi.acpi20));
- if (efi.acpi)
- str += sprintf(str, "ACPI=0x%lx\n", __pa(efi.acpi));
+ if (efi.phys_acpi20 != ~0UL)
+ str += sprintf(str, "ACPI20=0x%lx\n", efi.phys_acpi20);
+ if (efi.phys_acpi != ~0UL)
+ str += sprintf(str, "ACPI=0x%lx\n", efi.phys_acpi);
if (efi.smbios)
str += sprintf(str, "SMBIOS=0x%lx\n", __pa(efi.smbios));
if (efi.hcdp)
diff -urNp linux-2.6.13-rc3/include/linux/efi.h linux-2.6.13-rc3-efi/include/linux/efi.h
--- linux-2.6.13-rc3/include/linux/efi.h 2005-07-13 00:46:46.000000000 -0400
+++ linux-2.6.13-rc3-efi/include/linux/efi.h 2005-07-13 10:36:24.999232176 -0400
@@ -246,14 +246,16 @@ struct efi_memory_map {
unsigned long desc_version;
};

+#define EFI_INVALID_ACPI_TABLE_ADDR (~0UL)
+
/*
* All runtime access to EFI goes through this structure:
*/
extern struct efi {
efi_system_table_t *systab; /* EFI system table */
void *mps; /* MPS table */
- void *acpi; /* ACPI table (IA64 ext 0.71) */
- void *acpi20; /* ACPI table (ACPI 2.0) */
+ unsigned long phys_acpi; /* ACPI table */
+ unsigned long phys_acpi20; /* ACPI table (ACPI 2.0) */
void *smbios; /* SM BIOS table */
void *sal_systab; /* SAL system table */
void *boot_info; /* boot info table */
-
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