diff options
| author | Bob Moore <robert.moore@intel.com> | 2009-10-22 05:11:11 +0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-11-06 01:01:58 +0300 |
| commit | d410ee5109a1633a686a5663c6743a92e1181f9b (patch) | |
| tree | 02451f4ccfd8307f41181360d55b1126eea6d1bf /drivers/acpi/acpica/exregion.c | |
| parent | b419148e567728f6af0c3b01965c1cc141e3e13a (diff) | |
| download | linux-d410ee5109a1633a686a5663c6743a92e1181f9b.tar.xz | |
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>
Diffstat (limited to 'drivers/acpi/acpica/exregion.c')
| -rw-r--r-- | drivers/acpi/acpica/exregion.c | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c index 3a54b737d2da..2bd83ac57c3a 100644 --- 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; } /* |