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path: root/drivers/hwtracing/coresight/coresight-tmc-etf.c
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Diffstat (limited to 'drivers/hwtracing/coresight/coresight-tmc-etf.c')
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etf.c623
1 files changed, 623 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
new file mode 100644
index 000000000..7f87e2c3b
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -0,0 +1,623 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(C) 2016 Linaro Limited. All rights reserved.
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ */
+
+#include <linux/circ_buf.h>
+#include <linux/coresight.h>
+#include <linux/perf_event.h>
+#include <linux/slab.h>
+#include "coresight-priv.h"
+#include "coresight-tmc.h"
+
+static void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ /* Wait for TMCSReady bit to be set */
+ tmc_wait_for_tmcready(drvdata);
+
+ writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
+ writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
+ TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
+ TMC_FFCR_TRIGON_TRIGIN,
+ drvdata->base + TMC_FFCR);
+
+ writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
+ tmc_enable_hw(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
+static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
+{
+ char *bufp;
+ u32 read_data, lost;
+ int i;
+
+ /* Check if the buffer wrapped around. */
+ lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL;
+ bufp = drvdata->buf;
+ drvdata->len = 0;
+ while (1) {
+ for (i = 0; i < drvdata->memwidth; i++) {
+ read_data = readl_relaxed(drvdata->base + TMC_RRD);
+ if (read_data == 0xFFFFFFFF)
+ goto done;
+ memcpy(bufp, &read_data, 4);
+ bufp += 4;
+ drvdata->len += 4;
+ }
+ }
+done:
+ if (lost)
+ coresight_insert_barrier_packet(drvdata->buf);
+ return;
+}
+
+static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ tmc_flush_and_stop(drvdata);
+ /*
+ * When operating in sysFS mode the content of the buffer needs to be
+ * read before the TMC is disabled.
+ */
+ if (drvdata->mode == CS_MODE_SYSFS)
+ tmc_etb_dump_hw(drvdata);
+ tmc_disable_hw(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
+static void tmc_etf_enable_hw(struct tmc_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ /* Wait for TMCSReady bit to be set */
+ tmc_wait_for_tmcready(drvdata);
+
+ writel_relaxed(TMC_MODE_HARDWARE_FIFO, drvdata->base + TMC_MODE);
+ writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI,
+ drvdata->base + TMC_FFCR);
+ writel_relaxed(0x0, drvdata->base + TMC_BUFWM);
+ tmc_enable_hw(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
+static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
+{
+ CS_UNLOCK(drvdata->base);
+
+ tmc_flush_and_stop(drvdata);
+ tmc_disable_hw(drvdata);
+
+ CS_LOCK(drvdata->base);
+}
+
+/*
+ * Return the available trace data in the buffer from @pos, with
+ * a maximum limit of @len, updating the @bufpp on where to
+ * find it.
+ */
+ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata,
+ loff_t pos, size_t len, char **bufpp)
+{
+ ssize_t actual = len;
+
+ /* Adjust the len to available size @pos */
+ if (pos + actual > drvdata->len)
+ actual = drvdata->len - pos;
+ if (actual > 0)
+ *bufpp = drvdata->buf + pos;
+ return actual;
+}
+
+static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
+{
+ int ret = 0;
+ bool used = false;
+ char *buf = NULL;
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ /*
+ * If we don't have a buffer release the lock and allocate memory.
+ * Otherwise keep the lock and move along.
+ */
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (!drvdata->buf) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ /* Allocating the memory here while outside of the spinlock */
+ buf = kzalloc(drvdata->size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ /* Let's try again */
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ }
+
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * In sysFS mode we can have multiple writers per sink. Since this
+ * sink is already enabled no memory is needed and the HW need not be
+ * touched.
+ */
+ if (drvdata->mode == CS_MODE_SYSFS)
+ goto out;
+
+ /*
+ * If drvdata::buf isn't NULL, memory was allocated for a previous
+ * trace run but wasn't read. If so simply zero-out the memory.
+ * Otherwise use the memory allocated above.
+ *
+ * The memory is freed when users read the buffer using the
+ * /dev/xyz.{etf|etb} interface. See tmc_read_unprepare_etf() for
+ * details.
+ */
+ if (drvdata->buf) {
+ memset(drvdata->buf, 0, drvdata->size);
+ } else {
+ used = true;
+ drvdata->buf = buf;
+ }
+
+ drvdata->mode = CS_MODE_SYSFS;
+ tmc_etb_enable_hw(drvdata);
+out:
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ /* Free memory outside the spinlock if need be */
+ if (!used)
+ kfree(buf);
+
+ return ret;
+}
+
+static int tmc_enable_etf_sink_perf(struct coresight_device *csdev)
+{
+ int ret = 0;
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * In Perf mode there can be only one writer per sink. There
+ * is also no need to continue if the ETB/ETR is already operated
+ * from sysFS.
+ */
+ if (drvdata->mode != CS_MODE_DISABLED) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ drvdata->mode = CS_MODE_PERF;
+ tmc_etb_enable_hw(drvdata);
+out:
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ return ret;
+}
+
+static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
+{
+ int ret;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ switch (mode) {
+ case CS_MODE_SYSFS:
+ ret = tmc_enable_etf_sink_sysfs(csdev);
+ break;
+ case CS_MODE_PERF:
+ ret = tmc_enable_etf_sink_perf(csdev);
+ break;
+ /* We shouldn't be here */
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (ret)
+ return ret;
+
+ dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
+ return 0;
+}
+
+static void tmc_disable_etf_sink(struct coresight_device *csdev)
+{
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return;
+ }
+
+ /* Disable the TMC only if it needs to */
+ if (drvdata->mode != CS_MODE_DISABLED) {
+ tmc_etb_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ }
+
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ dev_info(drvdata->dev, "TMC-ETB/ETF disabled\n");
+}
+
+static int tmc_enable_etf_link(struct coresight_device *csdev,
+ int inport, int outport)
+{
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return -EBUSY;
+ }
+
+ tmc_etf_enable_hw(drvdata);
+ drvdata->mode = CS_MODE_SYSFS;
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ dev_info(drvdata->dev, "TMC-ETF enabled\n");
+ return 0;
+}
+
+static void tmc_disable_etf_link(struct coresight_device *csdev,
+ int inport, int outport)
+{
+ unsigned long flags;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (drvdata->reading) {
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ return;
+ }
+
+ tmc_etf_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ dev_info(drvdata->dev, "TMC-ETF disabled\n");
+}
+
+static void *tmc_alloc_etf_buffer(struct coresight_device *csdev, int cpu,
+ void **pages, int nr_pages, bool overwrite)
+{
+ int node;
+ struct cs_buffers *buf;
+
+ node = (cpu == -1) ? NUMA_NO_NODE : cpu_to_node(cpu);
+
+ /* Allocate memory structure for interaction with Perf */
+ buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
+ if (!buf)
+ return NULL;
+
+ buf->snapshot = overwrite;
+ buf->nr_pages = nr_pages;
+ buf->data_pages = pages;
+
+ return buf;
+}
+
+static void tmc_free_etf_buffer(void *config)
+{
+ struct cs_buffers *buf = config;
+
+ kfree(buf);
+}
+
+static int tmc_set_etf_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ int ret = 0;
+ unsigned long head;
+ struct cs_buffers *buf = sink_config;
+
+ /* wrap head around to the amount of space we have */
+ head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
+
+ /* find the page to write to */
+ buf->cur = head / PAGE_SIZE;
+
+ /* and offset within that page */
+ buf->offset = head % PAGE_SIZE;
+
+ local_set(&buf->data_size, 0);
+
+ return ret;
+}
+
+static unsigned long tmc_reset_etf_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ long size = 0;
+ struct cs_buffers *buf = sink_config;
+
+ if (buf) {
+ /*
+ * In snapshot mode ->data_size holds the new address of the
+ * ring buffer's head. The size itself is the whole address
+ * range since we want the latest information.
+ */
+ if (buf->snapshot)
+ handle->head = local_xchg(&buf->data_size,
+ buf->nr_pages << PAGE_SHIFT);
+ /*
+ * Tell the tracer PMU how much we got in this run and if
+ * something went wrong along the way. Nobody else can use
+ * this cs_buffers instance until we are done. As such
+ * resetting parameters here and squaring off with the ring
+ * buffer API in the tracer PMU is fine.
+ */
+ size = local_xchg(&buf->data_size, 0);
+ }
+
+ return size;
+}
+
+static void tmc_update_etf_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ bool lost = false;
+ int i, cur;
+ const u32 *barrier;
+ u32 *buf_ptr;
+ u64 read_ptr, write_ptr;
+ u32 status, to_read;
+ unsigned long offset;
+ struct cs_buffers *buf = sink_config;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (!buf)
+ return;
+
+ /* This shouldn't happen */
+ if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
+ return;
+
+ CS_UNLOCK(drvdata->base);
+
+ tmc_flush_and_stop(drvdata);
+
+ read_ptr = tmc_read_rrp(drvdata);
+ write_ptr = tmc_read_rwp(drvdata);
+
+ /*
+ * Get a hold of the status register and see if a wrap around
+ * has occurred. If so adjust things accordingly.
+ */
+ status = readl_relaxed(drvdata->base + TMC_STS);
+ if (status & TMC_STS_FULL) {
+ lost = true;
+ to_read = drvdata->size;
+ } else {
+ to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->size);
+ }
+
+ /*
+ * The TMC RAM buffer may be bigger than the space available in the
+ * perf ring buffer (handle->size). If so advance the RRP so that we
+ * get the latest trace data.
+ */
+ if (to_read > handle->size) {
+ u32 mask = 0;
+
+ /*
+ * The value written to RRP must be byte-address aligned to
+ * the width of the trace memory databus _and_ to a frame
+ * boundary (16 byte), whichever is the biggest. For example,
+ * for 32-bit, 64-bit and 128-bit wide trace memory, the four
+ * LSBs must be 0s. For 256-bit wide trace memory, the five
+ * LSBs must be 0s.
+ */
+ switch (drvdata->memwidth) {
+ case TMC_MEM_INTF_WIDTH_32BITS:
+ case TMC_MEM_INTF_WIDTH_64BITS:
+ case TMC_MEM_INTF_WIDTH_128BITS:
+ mask = GENMASK(31, 4);
+ break;
+ case TMC_MEM_INTF_WIDTH_256BITS:
+ mask = GENMASK(31, 5);
+ break;
+ }
+
+ /*
+ * Make sure the new size is aligned in accordance with the
+ * requirement explained above.
+ */
+ to_read = handle->size & mask;
+ /* Move the RAM read pointer up */
+ read_ptr = (write_ptr + drvdata->size) - to_read;
+ /* Make sure we are still within our limits */
+ if (read_ptr > (drvdata->size - 1))
+ read_ptr -= drvdata->size;
+ /* Tell the HW */
+ tmc_write_rrp(drvdata, read_ptr);
+ lost = true;
+ }
+
+ if (lost)
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+
+ cur = buf->cur;
+ offset = buf->offset;
+ barrier = 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 && i < CORESIGHT_BARRIER_PKT_SIZE) {
+ *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 all we have to do is communicate to
+ * perf_aux_output_end() the address of the current head. In full
+ * trace mode the same function expects a size to move rb->aux_head
+ * forward.
+ */
+ if (buf->snapshot)
+ local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
+ else
+ local_add(to_read, &buf->data_size);
+
+ CS_LOCK(drvdata->base);
+}
+
+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,
+ .set_buffer = tmc_set_etf_buffer,
+ .reset_buffer = tmc_reset_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;
+ }
+
+ /* 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;
+ }
+
+ /* 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)
+ 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;
+}
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