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683 lines
16 KiB
683 lines
16 KiB
// 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 <[email protected]> |
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*/ |
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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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|
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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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|
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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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|
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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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|
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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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|
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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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/* |
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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. |
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*/ |
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if (!buf->snapshot && lost) |
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perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); |
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cur = buf->cur; |
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offset = buf->offset; |
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barrier = coresight_barrier_pkt; |
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|
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/* for every byte to read */ |
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for (i = 0; i < to_read; i += 4) { |
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buf_ptr = buf->data_pages[cur] + offset; |
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*buf_ptr = readl_relaxed(drvdata->base + TMC_RRD); |
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if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) { |
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*buf_ptr = *barrier; |
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barrier++; |
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} |
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offset += 4; |
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if (offset >= PAGE_SIZE) { |
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offset = 0; |
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cur++; |
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/* wrap around at the end of the buffer */ |
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cur &= buf->nr_pages - 1; |
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} |
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} |
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|
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/* |
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* In snapshot mode we simply increment the head by the number of byte |
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* that were written. User space function cs_etm_find_snapshot() will |
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* figure out how many bytes to get from the AUX buffer based on the |
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* position of the head. |
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*/ |
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if (buf->snapshot) |
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handle->head += to_read; |
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|
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CS_LOCK(drvdata->base); |
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out: |
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spin_unlock_irqrestore(&drvdata->spinlock, flags); |
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|
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return to_read; |
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} |
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static const struct coresight_ops_sink tmc_etf_sink_ops = { |
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.enable = tmc_enable_etf_sink, |
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.disable = tmc_disable_etf_sink, |
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.alloc_buffer = tmc_alloc_etf_buffer, |
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.free_buffer = tmc_free_etf_buffer, |
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.update_buffer = tmc_update_etf_buffer, |
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}; |
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static const struct coresight_ops_link tmc_etf_link_ops = { |
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.enable = tmc_enable_etf_link, |
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.disable = tmc_disable_etf_link, |
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}; |
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|
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const struct coresight_ops tmc_etb_cs_ops = { |
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.sink_ops = &tmc_etf_sink_ops, |
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}; |
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|
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const struct coresight_ops tmc_etf_cs_ops = { |
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.sink_ops = &tmc_etf_sink_ops, |
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.link_ops = &tmc_etf_link_ops, |
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}; |
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|
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int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) |
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{ |
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enum tmc_mode mode; |
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int ret = 0; |
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unsigned long flags; |
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|
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/* config types are set a boot time and never change */ |
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if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB && |
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drvdata->config_type != TMC_CONFIG_TYPE_ETF)) |
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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; |
|
}
|
|
|