diff options
Diffstat (limited to 'drivers/acpi/acpica/hwxface.c')
| -rw-r--r-- | drivers/acpi/acpica/hwxface.c | 43 |
1 files changed, 26 insertions, 17 deletions
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c index 5ee7a814cd9..b4b47db2dee 100644 --- a/drivers/acpi/acpica/hwxface.c +++ b/drivers/acpi/acpica/hwxface.c @@ -41,7 +41,8 @@ * POSSIBILITY OF SUCH DAMAGES. */ -#include <linux/export.h> +#define EXPORT_ACPI_INTERFACES + #include <acpi/acpi.h> #include "accommon.h" #include "acnamesp.h" @@ -83,11 +84,17 @@ acpi_status acpi_reset(void) * For I/O space, write directly to the OSL. This bypasses the port * validation mechanism, which may block a valid write to the reset * register. - * Spec section 4.7.3.6 requires register width to be 8. + * + * NOTE: + * The ACPI spec requires the reset register width to be 8, so we + * hardcode it here and ignore the FADT value. This maintains + * compatibility with other ACPI implementations that have allowed + * BIOS code with bad register width values to go unnoticed. */ status = acpi_os_write_port((acpi_io_address) reset_reg->address, - acpi_gbl_FADT.reset_value, 8); + acpi_gbl_FADT.reset_value, + ACPI_RESET_REGISTER_WIDTH); } else { /* Write the reset value to the reset register */ @@ -119,7 +126,8 @@ ACPI_EXPORT_SYMBOL(acpi_reset) ******************************************************************************/ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) { - u32 value; + u32 value_lo; + u32 value_hi; u32 width; u64 address; acpi_status status; @@ -137,13 +145,8 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) return (status); } - /* Initialize entire 64-bit return value to zero */ - - *return_value = 0; - value = 0; - /* - * Two address spaces supported: Memory or IO. PCI_Config is + * Two address spaces supported: Memory or I/O. PCI_Config is * not supported here because the GAS structure is insufficient */ if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { @@ -155,29 +158,35 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) } } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */ + value_lo = 0; + value_hi = 0; + width = reg->bit_width; if (width == 64) { width = 32; /* Break into two 32-bit transfers */ } status = acpi_hw_read_port((acpi_io_address) - address, &value, width); + address, &value_lo, width); if (ACPI_FAILURE(status)) { return (status); } - *return_value = value; if (reg->bit_width == 64) { /* Read the top 32 bits */ status = acpi_hw_read_port((acpi_io_address) - (address + 4), &value, 32); + (address + 4), &value_hi, + 32); if (ACPI_FAILURE(status)) { return (status); } - *return_value |= ((u64)value << 32); } + + /* Set the return value only if status is AE_OK */ + + *return_value = (value_lo | ((u64)value_hi << 32)); } ACPI_DEBUG_PRINT((ACPI_DB_IO, @@ -186,7 +195,7 @@ acpi_status acpi_read(u64 *return_value, struct acpi_generic_address *reg) ACPI_FORMAT_UINT64(address), acpi_ut_get_region_name(reg->space_id))); - return (status); + return (AE_OK); } ACPI_EXPORT_SYMBOL(acpi_read) @@ -561,10 +570,10 @@ acpi_get_sleep_type_data(u8 sleep_state, u8 *sleep_type_a, u8 *sleep_type_b) break; } - cleanup1: +cleanup1: acpi_ut_remove_reference(info->return_object); - cleanup: +cleanup: if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "While evaluating Sleep State [%s]", |