ACPICA: avoid "Info: mapping multiple BARs. Your kernel is fine."
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>
diff --git a/drivers/acpi/acpica/acconfig.h b/drivers/acpi/acpica/acconfig.h
index 8e679ef..a4471e3 100644
--- a/drivers/acpi/acpica/acconfig.h
+++ b/drivers/acpi/acpica/acconfig.h
@@ -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 */
diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c
index 3a54b73..2bd83ac 100644
--- a/drivers/acpi/acpica/exregion.c
+++ b/drivers/acpi/acpica/exregion.c
@@ -77,7 +77,8 @@
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 @@
}
/*
- * 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 @@
/* 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;
}
/*