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![Suzuki K Poulose](/assets/img/avatar_default.png)
Convert the generic CLAIM tag management APIs to use the device access layer abstraction. Link: https://lore.kernel.org/r/20210110224850.1880240-7-suzuki.poulose@arm.com Cc: Mike Leach <mike.leach@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20210201181351.1475223-9-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
683 lines
16 KiB
C
683 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright(C) 2016 Linaro Limited. All rights reserved.
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* Author: Mathieu Poirier <mathieu.poirier@linaro.org>
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*/
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#include <linux/atomic.h>
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#include <linux/circ_buf.h>
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#include <linux/coresight.h>
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#include <linux/perf_event.h>
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#include <linux/slab.h>
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#include "coresight-priv.h"
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#include "coresight-tmc.h"
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#include "coresight-etm-perf.h"
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static int tmc_set_etf_buffer(struct coresight_device *csdev,
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struct perf_output_handle *handle);
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static void __tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
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{
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CS_UNLOCK(drvdata->base);
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/* Wait for TMCSReady bit to be set */
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tmc_wait_for_tmcready(drvdata);
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writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
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writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
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TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
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TMC_FFCR_TRIGON_TRIGIN,
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drvdata->base + TMC_FFCR);
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writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
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tmc_enable_hw(drvdata);
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CS_LOCK(drvdata->base);
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}
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static int tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
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{
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int rc = coresight_claim_device(drvdata->csdev);
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if (rc)
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return rc;
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__tmc_etb_enable_hw(drvdata);
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return 0;
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}
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static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
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{
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char *bufp;
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u32 read_data, lost;
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/* Check if the buffer wrapped around. */
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lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL;
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bufp = drvdata->buf;
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drvdata->len = 0;
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while (1) {
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read_data = readl_relaxed(drvdata->base + TMC_RRD);
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if (read_data == 0xFFFFFFFF)
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break;
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memcpy(bufp, &read_data, 4);
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bufp += 4;
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drvdata->len += 4;
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}
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if (lost)
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coresight_insert_barrier_packet(drvdata->buf);
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return;
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}
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static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
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{
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CS_UNLOCK(drvdata->base);
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tmc_flush_and_stop(drvdata);
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/*
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* When operating in sysFS mode the content of the buffer needs to be
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* read before the TMC is disabled.
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*/
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if (drvdata->mode == CS_MODE_SYSFS)
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tmc_etb_dump_hw(drvdata);
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tmc_disable_hw(drvdata);
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CS_LOCK(drvdata->base);
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}
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static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
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{
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__tmc_etb_disable_hw(drvdata);
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coresight_disclaim_device(drvdata->csdev);
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}
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static void __tmc_etf_enable_hw(struct tmc_drvdata *drvdata)
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{
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CS_UNLOCK(drvdata->base);
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/* Wait for TMCSReady bit to be set */
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tmc_wait_for_tmcready(drvdata);
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writel_relaxed(TMC_MODE_HARDWARE_FIFO, drvdata->base + TMC_MODE);
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writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI,
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drvdata->base + TMC_FFCR);
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writel_relaxed(0x0, drvdata->base + TMC_BUFWM);
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tmc_enable_hw(drvdata);
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CS_LOCK(drvdata->base);
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}
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static int tmc_etf_enable_hw(struct tmc_drvdata *drvdata)
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{
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int rc = coresight_claim_device(drvdata->csdev);
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if (rc)
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return rc;
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__tmc_etf_enable_hw(drvdata);
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return 0;
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}
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static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
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{
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struct coresight_device *csdev = drvdata->csdev;
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CS_UNLOCK(drvdata->base);
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tmc_flush_and_stop(drvdata);
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tmc_disable_hw(drvdata);
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coresight_disclaim_device_unlocked(csdev);
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CS_LOCK(drvdata->base);
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}
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/*
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* Return the available trace data in the buffer from @pos, with
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* a maximum limit of @len, updating the @bufpp on where to
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* find it.
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*/
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ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata,
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loff_t pos, size_t len, char **bufpp)
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{
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ssize_t actual = len;
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/* Adjust the len to available size @pos */
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if (pos + actual > drvdata->len)
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actual = drvdata->len - pos;
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if (actual > 0)
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*bufpp = drvdata->buf + pos;
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return actual;
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}
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static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
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{
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int ret = 0;
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bool used = false;
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char *buf = NULL;
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unsigned long flags;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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/*
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* If we don't have a buffer release the lock and allocate memory.
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* Otherwise keep the lock and move along.
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*/
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spin_lock_irqsave(&drvdata->spinlock, flags);
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if (!drvdata->buf) {
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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/* Allocating the memory here while outside of the spinlock */
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buf = kzalloc(drvdata->size, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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/* Let's try again */
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spin_lock_irqsave(&drvdata->spinlock, flags);
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}
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if (drvdata->reading) {
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ret = -EBUSY;
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goto out;
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}
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/*
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* In sysFS mode we can have multiple writers per sink. Since this
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* sink is already enabled no memory is needed and the HW need not be
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* touched.
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*/
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if (drvdata->mode == CS_MODE_SYSFS) {
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atomic_inc(csdev->refcnt);
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goto out;
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}
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/*
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* If drvdata::buf isn't NULL, memory was allocated for a previous
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* trace run but wasn't read. If so simply zero-out the memory.
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* Otherwise use the memory allocated above.
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*
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* The memory is freed when users read the buffer using the
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* /dev/xyz.{etf|etb} interface. See tmc_read_unprepare_etf() for
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* details.
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*/
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if (drvdata->buf) {
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memset(drvdata->buf, 0, drvdata->size);
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} else {
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used = true;
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drvdata->buf = buf;
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}
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ret = tmc_etb_enable_hw(drvdata);
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if (!ret) {
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drvdata->mode = CS_MODE_SYSFS;
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atomic_inc(csdev->refcnt);
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} else {
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/* Free up the buffer if we failed to enable */
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used = false;
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}
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out:
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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/* Free memory outside the spinlock if need be */
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if (!used)
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kfree(buf);
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return ret;
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}
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static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
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{
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int ret = 0;
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pid_t pid;
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unsigned long flags;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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struct perf_output_handle *handle = data;
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struct cs_buffers *buf = etm_perf_sink_config(handle);
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spin_lock_irqsave(&drvdata->spinlock, flags);
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do {
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ret = -EINVAL;
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if (drvdata->reading)
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break;
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/*
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* No need to continue if the ETB/ETF is already operated
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* from sysFS.
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*/
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if (drvdata->mode == CS_MODE_SYSFS) {
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ret = -EBUSY;
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break;
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}
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/* Get a handle on the pid of the process to monitor */
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pid = buf->pid;
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if (drvdata->pid != -1 && drvdata->pid != pid) {
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ret = -EBUSY;
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break;
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}
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ret = tmc_set_etf_buffer(csdev, handle);
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if (ret)
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break;
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/*
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* No HW configuration is needed if the sink is already in
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* use for this session.
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*/
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if (drvdata->pid == pid) {
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atomic_inc(csdev->refcnt);
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break;
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}
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ret = tmc_etb_enable_hw(drvdata);
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if (!ret) {
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/* Associate with monitored process. */
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drvdata->pid = pid;
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drvdata->mode = CS_MODE_PERF;
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atomic_inc(csdev->refcnt);
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}
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} while (0);
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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return ret;
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}
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static int tmc_enable_etf_sink(struct coresight_device *csdev,
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u32 mode, void *data)
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{
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int ret;
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switch (mode) {
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case CS_MODE_SYSFS:
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ret = tmc_enable_etf_sink_sysfs(csdev);
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break;
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case CS_MODE_PERF:
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ret = tmc_enable_etf_sink_perf(csdev, data);
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break;
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/* We shouldn't be here */
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default:
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ret = -EINVAL;
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break;
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}
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if (ret)
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return ret;
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dev_dbg(&csdev->dev, "TMC-ETB/ETF enabled\n");
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return 0;
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}
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static int tmc_disable_etf_sink(struct coresight_device *csdev)
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{
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unsigned long flags;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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spin_lock_irqsave(&drvdata->spinlock, flags);
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if (drvdata->reading) {
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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return -EBUSY;
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}
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if (atomic_dec_return(csdev->refcnt)) {
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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return -EBUSY;
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}
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/* Complain if we (somehow) got out of sync */
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WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
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tmc_etb_disable_hw(drvdata);
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/* Dissociate from monitored process. */
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drvdata->pid = -1;
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drvdata->mode = CS_MODE_DISABLED;
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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dev_dbg(&csdev->dev, "TMC-ETB/ETF disabled\n");
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return 0;
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}
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static int tmc_enable_etf_link(struct coresight_device *csdev,
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int inport, int outport)
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{
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int ret = 0;
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unsigned long flags;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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bool first_enable = false;
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spin_lock_irqsave(&drvdata->spinlock, flags);
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if (drvdata->reading) {
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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return -EBUSY;
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}
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if (atomic_read(&csdev->refcnt[0]) == 0) {
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ret = tmc_etf_enable_hw(drvdata);
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if (!ret) {
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drvdata->mode = CS_MODE_SYSFS;
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first_enable = true;
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}
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}
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if (!ret)
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atomic_inc(&csdev->refcnt[0]);
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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if (first_enable)
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dev_dbg(&csdev->dev, "TMC-ETF enabled\n");
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return ret;
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}
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static void tmc_disable_etf_link(struct coresight_device *csdev,
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int inport, int outport)
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{
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unsigned long flags;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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bool last_disable = false;
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spin_lock_irqsave(&drvdata->spinlock, flags);
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if (drvdata->reading) {
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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return;
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}
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if (atomic_dec_return(&csdev->refcnt[0]) == 0) {
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tmc_etf_disable_hw(drvdata);
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drvdata->mode = CS_MODE_DISABLED;
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last_disable = true;
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}
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spin_unlock_irqrestore(&drvdata->spinlock, flags);
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if (last_disable)
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dev_dbg(&csdev->dev, "TMC-ETF disabled\n");
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}
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static void *tmc_alloc_etf_buffer(struct coresight_device *csdev,
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struct perf_event *event, void **pages,
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int nr_pages, bool overwrite)
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{
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int node;
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struct cs_buffers *buf;
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node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
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/* Allocate memory structure for interaction with Perf */
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buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
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if (!buf)
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return NULL;
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buf->pid = task_pid_nr(event->owner);
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buf->snapshot = overwrite;
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buf->nr_pages = nr_pages;
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buf->data_pages = pages;
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return buf;
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}
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static void tmc_free_etf_buffer(void *config)
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{
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struct cs_buffers *buf = config;
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kfree(buf);
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}
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static int tmc_set_etf_buffer(struct coresight_device *csdev,
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struct perf_output_handle *handle)
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{
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int ret = 0;
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unsigned long head;
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struct cs_buffers *buf = etm_perf_sink_config(handle);
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if (!buf)
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return -EINVAL;
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/* wrap head around to the amount of space we have */
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head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
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/* find the page to write to */
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buf->cur = head / PAGE_SIZE;
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/* and offset within that page */
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buf->offset = head % PAGE_SIZE;
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local_set(&buf->data_size, 0);
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return ret;
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}
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static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev,
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struct perf_output_handle *handle,
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void *sink_config)
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{
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bool lost = false;
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int i, cur;
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const u32 *barrier;
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u32 *buf_ptr;
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u64 read_ptr, write_ptr;
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u32 status;
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unsigned long offset, to_read = 0, flags;
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struct cs_buffers *buf = sink_config;
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struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
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if (!buf)
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return 0;
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/* This shouldn't happen */
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if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
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return 0;
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spin_lock_irqsave(&drvdata->spinlock, flags);
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/* Don't do anything if another tracer is using this sink */
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if (atomic_read(csdev->refcnt) != 1)
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goto out;
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CS_UNLOCK(drvdata->base);
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tmc_flush_and_stop(drvdata);
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read_ptr = tmc_read_rrp(drvdata);
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write_ptr = tmc_read_rwp(drvdata);
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/*
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* Get a hold of the status register and see if a wrap around
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* has occurred. If so adjust things accordingly.
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*/
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status = readl_relaxed(drvdata->base + TMC_STS);
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if (status & TMC_STS_FULL) {
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lost = true;
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to_read = drvdata->size;
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} else {
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to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->size);
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}
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/*
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* The TMC RAM buffer may be bigger than the space available in the
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* perf ring buffer (handle->size). If so advance the RRP so that we
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* get the latest trace data. In snapshot mode none of that matters
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* since we are expected to clobber stale data in favour of the latest
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* traces.
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*/
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if (!buf->snapshot && to_read > handle->size) {
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u32 mask = tmc_get_memwidth_mask(drvdata);
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/*
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* Make sure the new size is aligned in accordance with the
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* requirement explained in function tmc_get_memwidth_mask().
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*/
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to_read = handle->size & mask;
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/* Move the RAM read pointer up */
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read_ptr = (write_ptr + drvdata->size) - to_read;
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/* Make sure we are still within our limits */
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if (read_ptr > (drvdata->size - 1))
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read_ptr -= drvdata->size;
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/* Tell the HW */
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tmc_write_rrp(drvdata, read_ptr);
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lost = true;
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}
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/*
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* Don't set the TRUNCATED flag in snapshot mode because 1) the
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* captured buffer is expected to be truncated and 2) a full buffer
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* prevents the event from being re-enabled by the perf core,
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* resulting in stale data being send to user space.
|
|
*/
|
|
if (!buf->snapshot && lost)
|
|
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
|
|
|
|
cur = buf->cur;
|
|
offset = buf->offset;
|
|
barrier = coresight_barrier_pkt;
|
|
|
|
/* for every byte to read */
|
|
for (i = 0; i < to_read; i += 4) {
|
|
buf_ptr = buf->data_pages[cur] + offset;
|
|
*buf_ptr = readl_relaxed(drvdata->base + TMC_RRD);
|
|
|
|
if (lost && *barrier) {
|
|
*buf_ptr = *barrier;
|
|
barrier++;
|
|
}
|
|
|
|
offset += 4;
|
|
if (offset >= PAGE_SIZE) {
|
|
offset = 0;
|
|
cur++;
|
|
/* wrap around at the end of the buffer */
|
|
cur &= buf->nr_pages - 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In snapshot mode we simply increment the head by the number of byte
|
|
* that were written. User space function cs_etm_find_snapshot() will
|
|
* figure out how many bytes to get from the AUX buffer based on the
|
|
* position of the head.
|
|
*/
|
|
if (buf->snapshot)
|
|
handle->head += to_read;
|
|
|
|
CS_LOCK(drvdata->base);
|
|
out:
|
|
spin_unlock_irqrestore(&drvdata->spinlock, flags);
|
|
|
|
return to_read;
|
|
}
|
|
|
|
static const struct coresight_ops_sink tmc_etf_sink_ops = {
|
|
.enable = tmc_enable_etf_sink,
|
|
.disable = tmc_disable_etf_sink,
|
|
.alloc_buffer = tmc_alloc_etf_buffer,
|
|
.free_buffer = tmc_free_etf_buffer,
|
|
.update_buffer = tmc_update_etf_buffer,
|
|
};
|
|
|
|
static const struct coresight_ops_link tmc_etf_link_ops = {
|
|
.enable = tmc_enable_etf_link,
|
|
.disable = tmc_disable_etf_link,
|
|
};
|
|
|
|
const struct coresight_ops tmc_etb_cs_ops = {
|
|
.sink_ops = &tmc_etf_sink_ops,
|
|
};
|
|
|
|
const struct coresight_ops tmc_etf_cs_ops = {
|
|
.sink_ops = &tmc_etf_sink_ops,
|
|
.link_ops = &tmc_etf_link_ops,
|
|
};
|
|
|
|
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
|
|
{
|
|
enum tmc_mode mode;
|
|
int ret = 0;
|
|
unsigned long flags;
|
|
|
|
/* config types are set a boot time and never change */
|
|
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB &&
|
|
drvdata->config_type != TMC_CONFIG_TYPE_ETF))
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&drvdata->spinlock, flags);
|
|
|
|
if (drvdata->reading) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
/* Don't interfere if operated from Perf */
|
|
if (drvdata->mode == CS_MODE_PERF) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* If drvdata::buf is NULL the trace data has been read already */
|
|
if (drvdata->buf == NULL) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
/* Disable the TMC if need be */
|
|
if (drvdata->mode == CS_MODE_SYSFS) {
|
|
/* There is no point in reading a TMC in HW FIFO mode */
|
|
mode = readl_relaxed(drvdata->base + TMC_MODE);
|
|
if (mode != TMC_MODE_CIRCULAR_BUFFER) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
__tmc_etb_disable_hw(drvdata);
|
|
}
|
|
|
|
drvdata->reading = true;
|
|
out:
|
|
spin_unlock_irqrestore(&drvdata->spinlock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
|
|
{
|
|
char *buf = NULL;
|
|
enum tmc_mode mode;
|
|
unsigned long flags;
|
|
|
|
/* config types are set a boot time and never change */
|
|
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB &&
|
|
drvdata->config_type != TMC_CONFIG_TYPE_ETF))
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&drvdata->spinlock, flags);
|
|
|
|
/* Re-enable the TMC if need be */
|
|
if (drvdata->mode == CS_MODE_SYSFS) {
|
|
/* There is no point in reading a TMC in HW FIFO mode */
|
|
mode = readl_relaxed(drvdata->base + TMC_MODE);
|
|
if (mode != TMC_MODE_CIRCULAR_BUFFER) {
|
|
spin_unlock_irqrestore(&drvdata->spinlock, flags);
|
|
return -EINVAL;
|
|
}
|
|
/*
|
|
* The trace run will continue with the same allocated trace
|
|
* buffer. As such zero-out the buffer so that we don't end
|
|
* up with stale data.
|
|
*
|
|
* Since the tracer is still enabled drvdata::buf
|
|
* can't be NULL.
|
|
*/
|
|
memset(drvdata->buf, 0, drvdata->size);
|
|
__tmc_etb_enable_hw(drvdata);
|
|
} else {
|
|
/*
|
|
* The ETB/ETF is not tracing and the buffer was just read.
|
|
* As such prepare to free the trace buffer.
|
|
*/
|
|
buf = drvdata->buf;
|
|
drvdata->buf = NULL;
|
|
}
|
|
|
|
drvdata->reading = false;
|
|
spin_unlock_irqrestore(&drvdata->spinlock, flags);
|
|
|
|
/*
|
|
* Free allocated memory outside of the spinlock. There is no need
|
|
* to assert the validity of 'buf' since calling kfree(NULL) is safe.
|
|
*/
|
|
kfree(buf);
|
|
|
|
return 0;
|
|
}
|