--- /dev/null
+/******************************************************************************
+ *
+ * Name: hwtimer.c - ACPI Power Management Timer Interface
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2015, Intel Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions, and the following disclaimer,
+ * without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ * substantially similar to the "NO WARRANTY" disclaimer below
+ * ("Disclaimer") and any redistribution must be conditioned upon
+ * including a substantially similar Disclaimer requirement for further
+ * binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ * of any contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+#define EXPORT_ACPI_INTERFACES
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+
+#define _COMPONENT ACPI_HARDWARE
+ACPI_MODULE_NAME("hwtimer")
+
+#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer_resolution
+ *
+ * PARAMETERS: resolution - Where the resolution is returned
+ *
+ * RETURN: Status and timer resolution
+ *
+ * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
+ *
+ ******************************************************************************/
+acpi_status acpi_get_timer_resolution(u32 * resolution)
+{
+ ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
+
+ if (!resolution) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
+ *resolution = 24;
+ } else {
+ *resolution = 32;
+ }
+
+ return_ACPI_STATUS(AE_OK);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
+
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer
+ *
+ * PARAMETERS: ticks - Where the timer value is returned
+ *
+ * RETURN: Status and current timer value (ticks)
+ *
+ * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
+ *
+ ******************************************************************************/
+acpi_status acpi_get_timer(u32 * ticks)
+{
+ acpi_status status;
+
+ ACPI_FUNCTION_TRACE(acpi_get_timer);
+
+ if (!ticks) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /* ACPI 5.0A: PM Timer is optional */
+
+ if (!acpi_gbl_FADT.xpm_timer_block.address) {
+ return_ACPI_STATUS(AE_SUPPORT);
+ }
+
+ status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer)
+
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer_duration
+ *
+ * PARAMETERS: start_ticks - Starting timestamp
+ * end_ticks - End timestamp
+ * time_elapsed - Where the elapsed time is returned
+ *
+ * RETURN: Status and time_elapsed
+ *
+ * DESCRIPTION: Computes the time elapsed (in microseconds) between two
+ * PM Timer time stamps, taking into account the possibility of
+ * rollovers, the timer resolution, and timer frequency.
+ *
+ * The PM Timer's clock ticks at roughly 3.6 times per
+ * _microsecond_, and its clock continues through Cx state
+ * transitions (unlike many CPU timestamp counters) -- making it
+ * a versatile and accurate timer.
+ *
+ * Note that this function accommodates only a single timer
+ * rollover. Thus for 24-bit timers, this function should only
+ * be used for calculating durations less than ~4.6 seconds
+ * (~20 minutes for 32-bit timers) -- calculations below:
+ *
+ * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
+ * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
+ *
+ ******************************************************************************/
+acpi_status
+acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
+{
+ acpi_status status;
+ u32 delta_ticks;
+ u64 quotient;
+
+ ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
+
+ if (!time_elapsed) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /* ACPI 5.0A: PM Timer is optional */
+
+ if (!acpi_gbl_FADT.xpm_timer_block.address) {
+ return_ACPI_STATUS(AE_SUPPORT);
+ }
+
+ /*
+ * Compute Tick Delta:
+ * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
+ */
+ if (start_ticks < end_ticks) {
+ delta_ticks = end_ticks - start_ticks;
+ } else if (start_ticks > end_ticks) {
+ if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
+
+ /* 24-bit Timer */
+
+ delta_ticks =
+ (((0x00FFFFFF - start_ticks) +
+ end_ticks) & 0x00FFFFFF);
+ } else {
+ /* 32-bit Timer */
+
+ delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
+ }
+ } else { /* start_ticks == end_ticks */
+
+ *time_elapsed = 0;
+ return_ACPI_STATUS(AE_OK);
+ }
+
+ /*
+ * Compute Duration (Requires a 64-bit multiply and divide):
+ *
+ * time_elapsed (microseconds) =
+ * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY;
+ */
+ status = acpi_ut_short_divide(((u64)delta_ticks) * ACPI_USEC_PER_SEC,
+ ACPI_PM_TIMER_FREQUENCY, "ient, NULL);
+
+ *time_elapsed = (u32) quotient;
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
+#endif /* !ACPI_REDUCED_HARDWARE */
Code Review / kvmfornfv.git / blobdiff