Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[sfrench/cifs-2.6.git] / drivers / acpi / acpica / exregion.c

diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c
index 3a54b737d2da6f5a8d8bdcbcc09f9025b1bef03f..2bd83ac57c3ae5030dab9bf17150a7db0442fda0 100644 (file)
--- a/drivers/acpi/acpica/exregion.c
+++ b/drivers/acpi/acpica/exregion.c
@@ -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;
        }
 
        /*