diff options
author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2017-08-02 10:21:57 -0600 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-28 16:05:47 +0200 |
commit | 0c3fc4d5fa26092853278145aca9b21fa52a3e93 (patch) | |
tree | 22445053dce96dc4922d04deb5f029a3aaec8c56 /drivers/hwtracing/coresight/coresight-tmc-etf.c | |
parent | 4f871a9f0f6fbb8ab023cca1f0099bf152a5d618 (diff) | |
download | op-kernel-dev-0c3fc4d5fa26092853278145aca9b21fa52a3e93.zip op-kernel-dev-0c3fc4d5fa26092853278145aca9b21fa52a3e93.tar.gz |
coresight: Add barrier packet for synchronisation
When a buffer overflow happens the synchronisation patckets usually
present at the beginning of the buffer are lost, a situation that
prevents the decoder from knowing the context of the traces being
decoded.
This patch adds a barrier packet to be used by sink IPs when a buffer
overflow condition is detected. These barrier packets are then used
by the decoding library as markers to force re-synchronisation.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-tmc-etf.c')
-rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etf.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 2e0fb5b..d189b28 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -43,17 +43,34 @@ static void tmc_etb_enable_hw(struct tmc_drvdata *drvdata) static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) { + bool lost = false; char *bufp; - u32 read_data; + const u32 *barrier; + u32 read_data, status; int i; + /* + * Get a hold of the status register and see if a wrap around + * has occurred. + */ + status = readl_relaxed(drvdata->base + TMC_STS); + if (status & TMC_STS_FULL) + lost = true; + bufp = drvdata->buf; drvdata->len = 0; + barrier = barrier_pkt; while (1) { for (i = 0; i < drvdata->memwidth; i++) { read_data = readl_relaxed(drvdata->base + TMC_RRD); if (read_data == 0xFFFFFFFF) return; + + if (lost && *barrier) { + read_data = *barrier; + barrier++; + } + memcpy(bufp, &read_data, 4); bufp += 4; drvdata->len += 4; @@ -371,6 +388,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, { bool lost = false; int i, cur; + const u32 *barrier; u32 *buf_ptr; u32 read_ptr, write_ptr; u32 status, to_read; @@ -451,12 +469,18 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, 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 && *barrier) { + *buf_ptr = *barrier; + barrier++; + } + offset += 4; if (offset >= PAGE_SIZE) { offset = 0; |