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ACPICA: avoid "Info: mapping multiple BARs. Your kernel is fine."

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Ensure that memory mappings created for operation regions
do not cross page boundaries.  Crossing a page boundary
while mapping regions can cause warnings if the pages have different attributes.

Such regions are probably BIOS bugs, and this is the workaround.

http://bugzilla.kernel.org/show_bug.cgi?id=14445

[Kernel summit hacking hour]

Signed-off-by: Bob Moore <robert.moore@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Bob Moore 2009-10-22 09:11:11 +08:00 committed by Len Brown
parent b419148e56
commit d410ee5109
2 changed files with 27 additions and 12 deletions
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4
drivers/acpi/acpica/acconfig.h
View File

@ -103,9 +103,9 @@
#define ACPI_MAX_REFERENCE_COUNT 0x1000
/* Size of cached memory mapping for system memory operation region */
/* Default page size for use in mapping memory for operation regions */
#define ACPI_SYSMEM_REGION_WINDOW_SIZE 4096
#define ACPI_DEFAULT_PAGE_SIZE 4096 /* Must be power of 2 */
/* owner_id tracking. 8 entries allows for 255 owner_ids */

35
drivers/acpi/acpica/exregion.c
View File

@ -77,7 +77,8 @@ acpi_ex_system_memory_space_handler(u32 function,
void *logical_addr_ptr = NULL;
struct acpi_mem_space_context *mem_info = region_context;
u32 length;
acpi_size window_size;
acpi_size map_length;
acpi_size page_boundary_map_length;
#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
u32 remainder;
#endif
@ -144,25 +145,39 @@ acpi_ex_system_memory_space_handler(u32 function,
}
/*
* Don't attempt to map memory beyond the end of the region, and
* constrain the maximum mapping size to something reasonable.
* Attempt to map from the requested address to the end of the region.
* However, we will never map more than one page, nor will we cross
* a page boundary.
*/
window_size = (acpi_size)
map_length = (acpi_size)
((mem_info->address + mem_info->length) - address);
if (window_size > ACPI_SYSMEM_REGION_WINDOW_SIZE) {
window_size = ACPI_SYSMEM_REGION_WINDOW_SIZE;
/*
* If mapping the entire remaining portion of the region will cross
* a page boundary, just map up to the page boundary, do not cross.
* On some systems, crossing a page boundary while mapping regions
* can cause warnings if the pages have different attributes
* due to resource management
*/
page_boundary_map_length =
ACPI_ROUND_UP(address, ACPI_DEFAULT_PAGE_SIZE) - address;
if (!page_boundary_map_length) {
page_boundary_map_length = ACPI_DEFAULT_PAGE_SIZE;
}
if (map_length > page_boundary_map_length) {
map_length = page_boundary_map_length;
}
/* Create a new mapping starting at the address given */
mem_info->mapped_logical_address =
acpi_os_map_memory((acpi_physical_address) address, window_size);
mem_info->mapped_logical_address = acpi_os_map_memory((acpi_physical_address) address, map_length);
if (!mem_info->mapped_logical_address) {
ACPI_ERROR((AE_INFO,
"Could not map memory at %8.8X%8.8X, size %X",
ACPI_FORMAT_NATIVE_UINT(address),
(u32) window_size));
(u32) map_length));
mem_info->mapped_length = 0;
return_ACPI_STATUS(AE_NO_MEMORY);
}
@ -170,7 +185,7 @@ acpi_ex_system_memory_space_handler(u32 function,
/* Save the physical address and mapping size */
mem_info->mapped_physical_address = address;
mem_info->mapped_length = window_size;
mem_info->mapped_length = map_length;
}
/*