diff options
Diffstat (limited to 'drivers/acpi/acpica/hwregs.c')
| -rw-r--r-- | drivers/acpi/acpica/hwregs.c | 75 |
1 files changed, 62 insertions, 13 deletions
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index 892e677f524f..6eee012cfd8f 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -195,17 +195,19 @@ acpi_hw_validate_register(struct acpi_generic_address *reg, * 64-bit values is not needed. * * LIMITATIONS: <These limitations also apply to acpi_hw_write> - * bit_width must be exactly 8, 16, or 32. * space_ID must be system_memory or system_IO. - * bit_offset and access_width are currently ignored, as there has - * not been a need to implement these. * ******************************************************************************/ acpi_status acpi_hw_read(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_read); @@ -217,28 +219,75 @@ acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg) return (status); } - /* Initialize entire 32-bit return value to zero */ - + /* + * Initialize entire 32-bit return value to zero, convert access_width + * into number of bits based + */ *value = 0; + 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_read_memory((acpi_physical_address) - address, &value64, reg->bit_width); + index = 0; + while (bit_width) { + if (bit_offset >= access_width) { + value32 = 0; + bit_offset -= access_width; + } else { + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { + status = + acpi_os_read_memory((acpi_physical_address) + address + + index * + ACPI_DIV_8 + (access_width), + &value64, access_width); + value32 = (u32)value64; + } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + + status = acpi_hw_read_port((acpi_io_address) + address + + index * + ACPI_DIV_8 + (access_width), + &value32, + access_width); + } - *value = (u32)value64; - } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + /* + * 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); + } + } + + /* + * Use offset style bit writes because "Index * AccessWidth" is + * ensured to be less than 32-bits by acpi_hw_validate_register(). + */ + ACPI_SET_BITS(value, index * access_width, + ACPI_MASK_BITS_ABOVE_32(access_width), value32); - status = acpi_hw_read_port((acpi_io_address) - address, value, reg->bit_width); + bit_width -= + bit_width > access_width ? access_width : bit_width; + index++; } ACPI_DEBUG_PRINT((ACPI_DB_IO, "Read: %8.8X width %2d from %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); |