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authorBob Moore <robert.moore@intel.com>2009-10-21 21:11:11 -0400
committerLen Brown <len.brown@intel.com>2009-11-05 17:01:58 -0500
commitd410ee5109a1633a686a5663c6743a92e1181f9b (patch)
tree02451f4ccfd8307f41181360d55b1126eea6d1bf /drivers/acpi
parentb419148e567728f6af0c3b01965c1cc141e3e13a (diff)
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')
-rw-r--r--drivers/acpi/acpica/acconfig.h4
-rw-r--r--drivers/acpi/acpica/exregion.c35
2 files changed, 27 insertions, 12 deletions
diff --git a/drivers/acpi/acpica/acconfig.h b/drivers/acpi/acpica/acconfig.h
index 8e679ef5b231..a4471e3d3853 100644
--- a/drivers/acpi/acpica/acconfig.h
+++ b/drivers/acpi/acpica/acconfig.h
@@ -103,9 +103,9 @@
103 103
104#define ACPI_MAX_REFERENCE_COUNT 0x1000 104#define ACPI_MAX_REFERENCE_COUNT 0x1000
105 105
106/* Size of cached memory mapping for system memory operation region */ 106/* Default page size for use in mapping memory for operation regions */
107 107
108#define ACPI_SYSMEM_REGION_WINDOW_SIZE 4096 108#define ACPI_DEFAULT_PAGE_SIZE 4096 /* Must be power of 2 */
109 109
110/* owner_id tracking. 8 entries allows for 255 owner_ids */ 110/* owner_id tracking. 8 entries allows for 255 owner_ids */
111 111
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,
77 void *logical_addr_ptr = NULL; 77 void *logical_addr_ptr = NULL;
78 struct acpi_mem_space_context *mem_info = region_context; 78 struct acpi_mem_space_context *mem_info = region_context;
79 u32 length; 79 u32 length;
80 acpi_size window_size; 80 acpi_size map_length;
81 acpi_size page_boundary_map_length;
81#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED 82#ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
82 u32 remainder; 83 u32 remainder;
83#endif 84#endif
@@ -144,25 +145,39 @@ acpi_ex_system_memory_space_handler(u32 function,
144 } 145 }
145 146
146 /* 147 /*
147 * Don't attempt to map memory beyond the end of the region, and 148 * Attempt to map from the requested address to the end of the region.
148 * constrain the maximum mapping size to something reasonable. 149 * However, we will never map more than one page, nor will we cross
150 * a page boundary.
149 */ 151 */
150 window_size = (acpi_size) 152 map_length = (acpi_size)
151 ((mem_info->address + mem_info->length) - address); 153 ((mem_info->address + mem_info->length) - address);
152 154
153 if (window_size > ACPI_SYSMEM_REGION_WINDOW_SIZE) { 155 /*
154 window_size = ACPI_SYSMEM_REGION_WINDOW_SIZE; 156 * If mapping the entire remaining portion of the region will cross
157 * a page boundary, just map up to the page boundary, do not cross.
158 * On some systems, crossing a page boundary while mapping regions
159 * can cause warnings if the pages have different attributes
160 * due to resource management
161 */
162 page_boundary_map_length =
163 ACPI_ROUND_UP(address, ACPI_DEFAULT_PAGE_SIZE) - address;
164
165 if (!page_boundary_map_length) {
166 page_boundary_map_length = ACPI_DEFAULT_PAGE_SIZE;
167 }
168
169 if (map_length > page_boundary_map_length) {
170 map_length = page_boundary_map_length;
155 } 171 }
156 172
157 /* Create a new mapping starting at the address given */ 173 /* Create a new mapping starting at the address given */
158 174
159 mem_info->mapped_logical_address = 175 mem_info->mapped_logical_address = acpi_os_map_memory((acpi_physical_address) address, map_length);
160 acpi_os_map_memory((acpi_physical_address) address, window_size);
161 if (!mem_info->mapped_logical_address) { 176 if (!mem_info->mapped_logical_address) {
162 ACPI_ERROR((AE_INFO, 177 ACPI_ERROR((AE_INFO,
163 "Could not map memory at %8.8X%8.8X, size %X", 178 "Could not map memory at %8.8X%8.8X, size %X",
164 ACPI_FORMAT_NATIVE_UINT(address), 179 ACPI_FORMAT_NATIVE_UINT(address),
165 (u32) window_size)); 180 (u32) map_length));
166 mem_info->mapped_length = 0; 181 mem_info->mapped_length = 0;
167 return_ACPI_STATUS(AE_NO_MEMORY); 182 return_ACPI_STATUS(AE_NO_MEMORY);
168 } 183 }
@@ -170,7 +185,7 @@ acpi_ex_system_memory_space_handler(u32 function,
170 /* Save the physical address and mapping size */ 185 /* Save the physical address and mapping size */
171 186
172 mem_info->mapped_physical_address = address; 187 mem_info->mapped_physical_address = address;
173 mem_info->mapped_length = window_size; 188 mem_info->mapped_length = map_length;
174 } 189 }
175 190
176 /* 191 /*