]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blobdiff - drivers/acpi/acpica/hwregs.c
Merge branches 'for-4.11/upstream-fixes', 'for-4.12/accutouch', 'for-4.12/cp2112...
[mirror_ubuntu-artful-kernel.git] / drivers / acpi / acpica / hwregs.c
index 3b7fb99362b6945ecc5ebe3f192405718ecd33fb..de74a4c25085b63b1b0fa8d0d29e8ac1a0b93521 100644 (file)
@@ -6,7 +6,7 @@
  ******************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2016, Intel Corp.
+ * Copyright (C) 2000 - 2017, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -52,7 +52,8 @@ ACPI_MODULE_NAME("hwregs")
 #if (!ACPI_REDUCED_HARDWARE)
 /* Local Prototypes */
 static u8
-acpi_hw_get_access_bit_width(struct acpi_generic_address *reg,
+acpi_hw_get_access_bit_width(u64 address,
+                            struct acpi_generic_address *reg,
                             u8 max_bit_width);
 
 static acpi_status
@@ -71,7 +72,8 @@ acpi_hw_write_multiple(u32 value,
  *
  * FUNCTION:    acpi_hw_get_access_bit_width
  *
- * PARAMETERS:  reg                 - GAS register structure
+ * PARAMETERS:  address             - GAS register address
+ *              reg                 - GAS register structure
  *              max_bit_width       - Max bit_width supported (32 or 64)
  *
  * RETURN:      Status
@@ -81,27 +83,59 @@ acpi_hw_write_multiple(u32 value,
  ******************************************************************************/
 
 static u8
-acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, u8 max_bit_width)
+acpi_hw_get_access_bit_width(u64 address,
+                            struct acpi_generic_address *reg, u8 max_bit_width)
 {
-       if (!reg->access_width) {
-               if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
-                       max_bit_width = 32;
-               }
+       u8 access_bit_width;
 
-               /*
-                * Detect old register descriptors where only the bit_width field
-                * makes senses.
-                */
-               if (reg->bit_width < max_bit_width &&
-                   !reg->bit_offset && reg->bit_width &&
-                   ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
-                   ACPI_IS_ALIGNED(reg->bit_width, 8)) {
-                       return (reg->bit_width);
-               }
-               return (max_bit_width);
+       /*
+        * GAS format "register", used by FADT:
+        *  1. Detected if bit_offset is 0 and bit_width is 8/16/32/64;
+        *  2. access_size field is ignored and bit_width field is used for
+        *     determining the boundary of the IO accesses.
+        * GAS format "region", used by APEI registers:
+        *  1. Detected if bit_offset is not 0 or bit_width is not 8/16/32/64;
+        *  2. access_size field is used for determining the boundary of the
+        *     IO accesses;
+        *  3. bit_offset/bit_width fields are used to describe the "region".
+        *
+        * Note: This algorithm assumes that the "Address" fields should always
+        *       contain aligned values.
+        */
+       if (!reg->bit_offset && reg->bit_width &&
+           ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
+           ACPI_IS_ALIGNED(reg->bit_width, 8)) {
+               access_bit_width = reg->bit_width;
+       } else if (reg->access_width) {
+               access_bit_width = (1 << (reg->access_width + 2));
        } else {
-               return (1 << (reg->access_width + 2));
+               access_bit_width =
+                   ACPI_ROUND_UP_POWER_OF_TWO_8(reg->bit_offset +
+                                                reg->bit_width);
+               if (access_bit_width <= 8) {
+                       access_bit_width = 8;
+               } else {
+                       while (!ACPI_IS_ALIGNED(address, access_bit_width >> 3)) {
+                               access_bit_width >>= 1;
+                       }
+               }
        }
+
+       /* Maximum IO port access bit width is 32 */
+
+       if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+               max_bit_width = 32;
+       }
+
+       /*
+        * Return access width according to the requested maximum access bit width,
+        * as the caller should know the format of the register and may enforce
+        * a 32-bit accesses.
+        */
+       if (access_bit_width < max_bit_width) {
+               return (access_bit_width);
+       }
+       return (max_bit_width);
 }
 
 /******************************************************************************
@@ -163,7 +197,8 @@ acpi_hw_validate_register(struct acpi_generic_address *reg,
 
        /* Validate the bit_width, convert access_width into number of bits */
 
-       access_width = acpi_hw_get_access_bit_width(reg, max_bit_width);
+       access_width =
+           acpi_hw_get_access_bit_width(*address, reg, max_bit_width);
        bit_width =
            ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width);
        if (max_bit_width < bit_width) {
@@ -219,7 +254,7 @@ acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
         * into number of bits based
         */
        *value = 0;
-       access_width = acpi_hw_get_access_bit_width(reg, 32);
+       access_width = acpi_hw_get_access_bit_width(address, reg, 32);
        bit_width = reg->bit_offset + reg->bit_width;
        bit_offset = reg->bit_offset;
 
@@ -252,20 +287,6 @@ acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
                                                           &value32,
                                                           access_width);
                        }
-
-                       /*
-                        * Use offset style bit masks because:
-                        * bit_offset < access_width/bit_width < access_width, and
-                        * access_width is ensured to be less than 32-bits by
-                        * acpi_hw_validate_register().
-                        */
-                       if (bit_offset) {
-                               value32 &= ACPI_MASK_BITS_BELOW(bit_offset);
-                               bit_offset = 0;
-                       }
-                       if (bit_width < access_width) {
-                               value32 &= ACPI_MASK_BITS_ABOVE(bit_width);
-                       }
                }
 
                /*
@@ -306,6 +327,12 @@ acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
 acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
 {
        u64 address;
+       u8 access_width;
+       u32 bit_width;
+       u8 bit_offset;
+       u64 value64;
+       u32 value32;
+       u8 index;
        acpi_status status;
 
        ACPI_FUNCTION_NAME(hw_write);
@@ -317,23 +344,61 @@ acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
                return (status);
        }
 
+       /* Convert access_width into number of bits based */
+
+       access_width = acpi_hw_get_access_bit_width(address, reg, 32);
+       bit_width = reg->bit_offset + reg->bit_width;
+       bit_offset = reg->bit_offset;
+
        /*
         * Two address spaces supported: Memory or IO. PCI_Config is
         * not supported here because the GAS structure is insufficient
         */
-       if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
-               status = acpi_os_write_memory((acpi_physical_address)
-                                             address, (u64)value,
-                                             reg->bit_width);
-       } else {                /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
-
-               status = acpi_hw_write_port((acpi_io_address)
-                                           address, value, reg->bit_width);
+       index = 0;
+       while (bit_width) {
+               /*
+                * Use offset style bit reads because "Index * AccessWidth" is
+                * ensured to be less than 32-bits by acpi_hw_validate_register().
+                */
+               value32 = ACPI_GET_BITS(&value, index * access_width,
+                                       ACPI_MASK_BITS_ABOVE_32(access_width));
+
+               if (bit_offset >= access_width) {
+                       bit_offset -= access_width;
+               } else {
+                       if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+                               value64 = (u64)value32;
+                               status =
+                                   acpi_os_write_memory((acpi_physical_address)
+                                                        address +
+                                                        index *
+                                                        ACPI_DIV_8
+                                                        (access_width),
+                                                        value64, access_width);
+                       } else {        /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
+
+                               status = acpi_hw_write_port((acpi_io_address)
+                                                           address +
+                                                           index *
+                                                           ACPI_DIV_8
+                                                           (access_width),
+                                                           value32,
+                                                           access_width);
+                       }
+               }
+
+               /*
+                * Index * access_width is ensured to be less than 32-bits by
+                * acpi_hw_validate_register().
+                */
+               bit_width -=
+                   bit_width > access_width ? access_width : bit_width;
+               index++;
        }
 
        ACPI_DEBUG_PRINT((ACPI_DB_IO,
                          "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",
-                         value, reg->bit_width, ACPI_FORMAT_UINT64(address),
+                         value, access_width, ACPI_FORMAT_UINT64(address),
                          acpi_ut_get_region_name(reg->space_id)));
 
        return (status);