[PATCH V4 17/18] coresight: tmc: implementing TMC-ETR AUX space API
Mathieu Poirier
mathieu.poirier at linaro.org
Tue Apr 26 15:10:33 PDT 2016
This patch implement the AUX area interfaces required to
use the TMC (configured as an ETR) from the Perf sub-system.
The ETR is configured to work with contiguous memory only.
Although not optimal, it allows the IP block to be used
while the scatter-gather mode of operation is being worked
on.
The heuristic is heavily borrowed from the ETB10 and TMC-ETF
implementation.
Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 6 +-
drivers/hwtracing/coresight/coresight-tmc-etr.c | 142 ++++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tmc.h | 3 +
3 files changed, 148 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index f00867869d20..465f92e9641e 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -365,9 +365,9 @@ static unsigned long tmc_reset_etf_buffer(struct coresight_device *csdev,
return size;
}
-static void tmc_update_etf_buffer(struct coresight_device *csdev,
- struct perf_output_handle *handle,
- void *sink_config)
+void tmc_update_etf_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
{
int i, cur;
u32 *buf_ptr;
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 847d1b5f2c13..0ff4b3983771 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -15,11 +15,30 @@
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/circ_buf.h>
#include <linux/coresight.h>
#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+
#include "coresight-priv.h"
#include "coresight-tmc.h"
+/**
+ * struct cs_etr_buffer - keep track of a recording session' specifics
+ * @tmc: generic portion of the TMC buffers
+ * @paddr: the physical address of a DMA'able contiguous memory area
+ * @vaddr: the virtual address associated to @paddr
+ * @size: how much memory we have, starting at @paddr
+ * @dev: the device @vaddr has been tied to
+ */
+struct cs_etr_buffers {
+ struct cs_buffers tmc;
+ dma_addr_t paddr;
+ void __iomem *vaddr;
+ u32 size;
+ struct device *dev;
+};
+
void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
{
u32 axictl;
@@ -235,9 +254,132 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
dev_info(drvdata->dev, "TMC-ETR disabled\n");
}
+static void *tmc_alloc_etr_buffer(struct coresight_device *csdev, int cpu,
+ void **pages, int nr_pages, bool overwrite)
+{
+ int node;
+ struct cs_etr_buffers *buf;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (cpu == -1)
+ cpu = smp_processor_id();
+ node = cpu_to_node(cpu);
+
+ /* Allocate memory structure for interaction with Perf */
+ buf = kzalloc_node(sizeof(struct cs_etr_buffers), GFP_KERNEL, node);
+ if (!buf)
+ return NULL;
+
+ buf->dev = drvdata->dev;
+ buf->size = drvdata->size;
+ buf->vaddr = dma_alloc_coherent(buf->dev, buf->size,
+ &buf->paddr, GFP_KERNEL);
+ if (!buf->vaddr) {
+ kfree(buf);
+ return NULL;
+ }
+
+ buf->tmc.snapshot = overwrite;
+ buf->tmc.nr_pages = nr_pages;
+ buf->tmc.data_pages = pages;
+
+ return buf;
+}
+
+static void tmc_free_etr_buffer(void *config)
+{
+ struct cs_etr_buffers *buf = config;
+
+ dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->paddr);
+ kfree(buf);
+}
+
+static int tmc_set_etr_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ int ret = 0;
+ unsigned long head;
+ struct cs_etr_buffers *buf = sink_config;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ /* wrap head around to the amount of space we have */
+ head = handle->head & ((buf->tmc.nr_pages << PAGE_SHIFT) - 1);
+
+ /* find the page to write to */
+ buf->tmc.cur = head / PAGE_SIZE;
+
+ /* and offset within that page */
+ buf->tmc.offset = head % PAGE_SIZE;
+
+ local_set(&buf->tmc.data_size, 0);
+
+ /* Tell the HW where to put the trace data */
+ drvdata->vaddr = buf->vaddr;
+ drvdata->paddr = buf->paddr;
+ memset(drvdata->vaddr, 0, drvdata->size);
+
+ return ret;
+}
+
+static unsigned long tmc_reset_etr_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config, bool *lost)
+{
+ long size = 0;
+ struct cs_etr_buffers *buf = sink_config;
+ struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ 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->tmc.snapshot) {
+ size = buf->tmc.nr_pages << PAGE_SHIFT;
+ handle->head = local_xchg(&buf->tmc.data_size, size);
+ }
+
+ /*
+ * 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_etr_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.
+ */
+ *lost = !!local_xchg(&buf->tmc.lost, 0);
+ size = local_xchg(&buf->tmc.data_size, 0);
+ }
+
+ /* Get ready for another run */
+ drvdata->vaddr = NULL;
+ drvdata->paddr = 0;
+
+ return size;
+}
+
+static void tmc_update_etr_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ struct cs_etr_buffers *buf = sink_config;
+
+ /*
+ * An ETR configured to work in contiguous memory mode works the same
+ * was as an ETB or ETF.
+ */
+ tmc_update_etf_buffer(csdev, handle, &buf->tmc);
+}
+
static const struct coresight_ops_sink tmc_etr_sink_ops = {
.enable = tmc_enable_etr_sink,
.disable = tmc_disable_etr_sink,
+ .alloc_buffer = tmc_alloc_etr_buffer,
+ .free_buffer = tmc_free_etr_buffer,
+ .set_buffer = tmc_set_etr_buffer,
+ .reset_buffer = tmc_reset_etr_buffer,
+ .update_buffer = tmc_update_etr_buffer,
};
const struct coresight_ops tmc_etr_cs_ops = {
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 5c5fe2ad2ca7..bc51cbe54873 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -130,6 +130,9 @@ void tmc_disable_hw(struct tmc_drvdata *drvdata);
/* ETB/ETF functions */
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata);
int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata);
+void tmc_update_etf_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config);
extern const struct coresight_ops tmc_etb_cs_ops;
extern const struct coresight_ops tmc_etf_cs_ops;
--
2.5.0
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