From: Bob Moore <robert.moore@xxxxxxxxx> Removed locking for reads from the ACPI bit registers in PM1 Status, Enable, Control, and PM2 Control. The lock is not required when reading the single-bit registers. The acpi_get_register_unlocked function is no longer needed and has been removed. This will improve performance for reads on these registers. ACPICA BZ 760. http://www.acpica.org/bugzilla/show_bug.cgi?id=760 Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- drivers/acpi/acpica/hwsleep.c | 2 +- drivers/acpi/acpica/hwxface.c | 65 +++++++++++++++++------------------------ drivers/acpi/processor_idle.c | 2 +- include/acpi/acpixf.h | 2 - 4 files changed, 29 insertions(+), 42 deletions(-) diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c index 26e249e..677ccb6 100644 --- a/drivers/acpi/acpica/hwsleep.c +++ b/drivers/acpi/acpica/hwsleep.c @@ -365,7 +365,7 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state) /* Wait until we enter sleep state */ do { - status = acpi_get_register_unlocked(ACPI_BITREG_WAKE_STATUS, + status = acpi_get_register(ACPI_BITREG_WAKE_STATUS, &in_value); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c index 4df9eac..c810019 100644 --- a/drivers/acpi/acpica/hwxface.c +++ b/drivers/acpi/acpica/hwxface.c @@ -242,24 +242,35 @@ ACPI_EXPORT_SYMBOL(acpi_write) /******************************************************************************* * - * FUNCTION: acpi_get_register_unlocked + * FUNCTION: acpi_get_register * - * PARAMETERS: register_id - ID of ACPI bit_register to access - * return_value - Value that was read from the register + * PARAMETERS: register_id - ID of ACPI Bit Register to access + * return_value - Value that was read from the register, + * normalized to bit position zero. * - * RETURN: Status and the value read from specified Register. Value + * RETURN: Status and the value read from the specified Register. Value * returned is normalized to bit0 (is shifted all the way right) * * DESCRIPTION: ACPI bit_register read function. Does not acquire the HW lock. * + * SUPPORTS: Bit fields in PM1 Status, PM1 Enable, PM1 Control, and + * PM2 Control. + * + * Note: The hardware lock is not required when reading the ACPI bit registers + * since almost all of them are single bit and it does not matter that + * the parent hardware register can be split across two physical + * registers. The only multi-bit field is SLP_TYP in the PM1 control + * register, but this field does not cross an 8-bit boundary (nor does + * it make much sense to actually read this field.) + * ******************************************************************************/ -acpi_status acpi_get_register_unlocked(u32 register_id, u32 *return_value) +acpi_status acpi_get_register(u32 register_id, u32 *return_value) { u32 register_value = 0; struct acpi_bit_register_info *bit_reg_info; acpi_status status; - ACPI_FUNCTION_TRACE(acpi_get_register_unlocked); + ACPI_FUNCTION_TRACE(acpi_get_register); /* Get the info structure corresponding to the requested ACPI Register */ @@ -268,7 +279,7 @@ acpi_status acpi_get_register_unlocked(u32 register_id, u32 *return_value) return_ACPI_STATUS(AE_BAD_PARAMETER); } - /* Read from the register */ + /* Read the entire parent register */ status = acpi_hw_register_read(bit_reg_info->parent_register, ®ister_value); @@ -291,46 +302,24 @@ acpi_status acpi_get_register_unlocked(u32 register_id, u32 *return_value) return_ACPI_STATUS(status); } -ACPI_EXPORT_SYMBOL(acpi_get_register_unlocked) - -/******************************************************************************* - * - * FUNCTION: acpi_get_register - * - * PARAMETERS: register_id - ID of ACPI bit_register to access - * return_value - Value that was read from the register - * - * RETURN: Status and the value read from specified Register. Value - * returned is normalized to bit0 (is shifted all the way right) - * - * DESCRIPTION: ACPI bit_register read function. - * - ******************************************************************************/ -acpi_status acpi_get_register(u32 register_id, u32 *return_value) -{ - acpi_status status; - acpi_cpu_flags flags; - - flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); - status = acpi_get_register_unlocked(register_id, return_value); - acpi_os_release_lock(acpi_gbl_hardware_lock, flags); - - return (status); -} - ACPI_EXPORT_SYMBOL(acpi_get_register) /******************************************************************************* * * FUNCTION: acpi_set_register * - * PARAMETERS: register_id - ID of ACPI bit_register to access - * Value - (only used on write) value to write to the - * Register, NOT pre-normalized to the bit pos + * PARAMETERS: register_id - ID of ACPI Bit Register to access + * Value - Value to write to the register, in bit + * position zero. The bit is automaticallly + * shifted to the correct position. * * RETURN: Status * - * DESCRIPTION: ACPI Bit Register write function. + * DESCRIPTION: ACPI Bit Register write function. Acquires the hardware lock + * since most operations require a read/modify/write sequence. + * + * SUPPORTS: Bit fields in PM1 Status, PM1 Enable, PM1 Control, and + * PM2 Control. * ******************************************************************************/ acpi_status acpi_set_register(u32 register_id, u32 value) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 7bc22a4..6946047 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -800,7 +800,7 @@ static int acpi_idle_bm_check(void) { u32 bm_status = 0; - acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); + acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status); if (bm_status) acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1); /* diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h index e10c896..325d4b0 100644 --- a/include/acpi/acpixf.h +++ b/include/acpi/acpixf.h @@ -347,8 +347,6 @@ acpi_status acpi_reset(void); acpi_status acpi_get_register(u32 register_id, u32 * return_value); -acpi_status acpi_get_register_unlocked(u32 register_id, u32 *return_value); - acpi_status acpi_set_register(u32 register_id, u32 value); acpi_status acpi_set_firmware_waking_vector(u32 physical_address); -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
