ACPICA: ACPI 2.0, Hardware: Add access_width/bit_offset support for acpi_hw_write()

ACPICA commit 48eea5e7993ccb7189bd63cd726e02adafee6057

This patch adds access_width/bit_offset support in acpi_hw_write().
Lv Zheng.

Link: https://github.com/acpica/acpica/commit/48eea5e7
Link: https://bugs.acpica.org/show_bug.cgi?id=1240
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 6eee012..0f18dbc 100644 (file)
--- a/drivers/acpi/acpica/hwregs.c
+++ b/drivers/acpi/acpica/hwregs.c
@@ -311,6 +311,12 @@ 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 new_value32, old_value32;
+       u8 index;
        acpi_status status;
 
        ACPI_FUNCTION_NAME(hw_write);
@@ -322,23 +328,145 @@ 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(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().
+                */
+               new_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 {
+                       /*
+                        * Use offset style bit masks because access_width is ensured
+                        * to be less than 32-bits by acpi_hw_validate_register() and
+                        * bit_offset/bit_width is less than access_width here.
+                        */
+                       if (bit_offset) {
+                               new_value32 &= ACPI_MASK_BITS_BELOW(bit_offset);
+                       }
+                       if (bit_width < access_width) {
+                               new_value32 &= ACPI_MASK_BITS_ABOVE(bit_width);
+                       }
+
+                       if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+                               if (bit_offset || bit_width < access_width) {
+                                       /*
+                                        * Read old values in order not to modify the bits that
+                                        * are beyond the register bit_width/bit_offset setting.
+                                        */
+                                       status =
+                                           acpi_os_read_memory((acpi_physical_address)
+                                                               address +
+                                                               index *
+                                                               ACPI_DIV_8
+                                                               (access_width),
+                                                               &value64,
+                                                               access_width);
+                                       old_value32 = (u32)value64;
+
+                                       /*
+                                        * Use offset style bit masks because access_width is
+                                        * ensured to be less than 32-bits by
+                                        * acpi_hw_validate_register() and bit_offset/bit_width is
+                                        * less than access_width here.
+                                        */
+                                       if (bit_offset) {
+                                               old_value32 &=
+                                                   ACPI_MASK_BITS_ABOVE
+                                                   (bit_offset);
+                                               bit_offset = 0;
+                                       }
+                                       if (bit_width < access_width) {
+                                               old_value32 &=
+                                                   ACPI_MASK_BITS_BELOW
+                                                   (bit_width);
+                                       }
+
+                                       new_value32 |= old_value32;
+                               }
+
+                               value64 = (u64)new_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 */
+
+                               if (bit_offset || bit_width < access_width) {
+                                       /*
+                                        * Read old values in order not to modify the bits that
+                                        * are beyond the register bit_width/bit_offset setting.
+                                        */
+                                       status =
+                                           acpi_hw_read_port((acpi_io_address)
+                                                             address +
+                                                             index *
+                                                             ACPI_DIV_8
+                                                             (access_width),
+                                                             &old_value32,
+                                                             access_width);
+
+                                       /*
+                                        * Use offset style bit masks because access_width is
+                                        * ensured to be less than 32-bits by
+                                        * acpi_hw_validate_register() and bit_offset/bit_width is
+                                        * less than access_width here.
+                                        */
+                                       if (bit_offset) {
+                                               old_value32 &=
+                                                   ACPI_MASK_BITS_ABOVE
+                                                   (bit_offset);
+                                               bit_offset = 0;
+                                       }
+                                       if (bit_width < access_width) {
+                                               old_value32 &=
+                                                   ACPI_MASK_BITS_BELOW
+                                                   (bit_width);
+                                       }
+
+                                       new_value32 |= old_value32;
+                               }
+
+                               status = acpi_hw_write_port((acpi_io_address)
+                                                           address +
+                                                           index *
+                                                           ACPI_DIV_8
+                                                           (access_width),
+                                                           new_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);