[PATCH v2 11/13] ACPICA: ACPI 2.0, Hardware: Add access_width/bit_offset support for acpi_hw_write()

Lv Zheng
2016-05-05T05:00:29Z

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>
---
drivers/acpi/acpica/hwregs.c | 146 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 137 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 6eee012..0f18dbc 100644
--- 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);
--
1.7.10