From 0c3fc4d5fa26092853278145aca9b21fa52a3e93 Mon Sep 17 00:00:00 2001 From: Mathieu Poirier Date: Wed, 2 Aug 2017 10:21:57 -0600 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etb10.c | 22 ++++++++++++++-- drivers/hwtracing/coresight/coresight-priv.h | 2 ++ .../hwtracing/coresight/coresight-tmc-etf.c | 26 ++++++++++++++++++- .../hwtracing/coresight/coresight-tmc-etr.c | 12 +++++++++ drivers/hwtracing/coresight/coresight.c | 8 ++++++ 5 files changed, 67 insertions(+), 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 50f4846e6271..42360306f049 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -200,8 +200,10 @@ static void etb_disable_hw(struct etb_drvdata *drvdata) static void etb_dump_hw(struct etb_drvdata *drvdata) { + bool lost = false; int i; u8 *buf_ptr; + const u32 *barrier; u32 read_data, depth; u32 read_ptr, write_ptr; u32 frame_off, frame_endoff; @@ -223,16 +225,24 @@ static void etb_dump_hw(struct etb_drvdata *drvdata) } if ((readl_relaxed(drvdata->base + ETB_STATUS_REG) - & ETB_STATUS_RAM_FULL) == 0) + & ETB_STATUS_RAM_FULL) == 0) { writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER); - else + } else { writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER); + lost = true; + } depth = drvdata->buffer_depth; buf_ptr = drvdata->buf; + barrier = barrier_pkt; for (i = 0; i < depth; i++) { read_data = readl_relaxed(drvdata->base + ETB_RAM_READ_DATA_REG); + if (lost && *barrier) { + read_data = *barrier; + barrier++; + } + *(u32 *)buf_ptr = read_data; buf_ptr += 4; } @@ -354,6 +364,7 @@ static void etb_update_buffer(struct coresight_device *csdev, bool lost = false; int i, cur; u8 *buf_ptr; + const u32 *barrier; u32 read_ptr, write_ptr, capacity; u32 status, read_data, to_read; unsigned long offset; @@ -438,10 +449,17 @@ static void etb_update_buffer(struct coresight_device *csdev, cur = buf->cur; offset = buf->offset; + barrier = barrier_pkt; + for (i = 0; i < to_read; i += 4) { buf_ptr = buf->data_pages[cur] + offset; read_data = readl_relaxed(drvdata->base + ETB_RAM_READ_DATA_REG); + if (lost && *barrier) { + read_data = *barrier; + barrier++; + } + *(u32 *)buf_ptr = read_data; buf_ptr += 4; diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 5f662d82052c..3e25b1dd1a1a 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -56,6 +56,8 @@ static ssize_t name##_show(struct device *_dev, \ } \ static DEVICE_ATTR_RO(name) +extern const u32 barrier_pkt[5]; + enum etm_addr_type { ETM_ADDR_TYPE_NONE, ETM_ADDR_TYPE_SINGLE, diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 2e0fb5b9372c..d189b28bd5c4 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; diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 5d312699b3b9..b8fb981de7b6 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -59,6 +59,8 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata) static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata) { + const u32 *barrier; + u32 *temp; u32 rwp, val; rwp = readl_relaxed(drvdata->base + TMC_RWP); @@ -71,6 +73,16 @@ static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata) if (val & TMC_STS_FULL) { drvdata->buf = drvdata->vaddr + rwp - drvdata->paddr; drvdata->len = drvdata->size; + + barrier = barrier_pkt; + temp = (u32 *)drvdata->buf; + + while (*barrier) { + *temp = *barrier; + temp++; + barrier++; + } + } else { drvdata->buf = drvdata->vaddr; drvdata->len = rwp - drvdata->paddr; diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 6a0202b7384f..b8091bef21dc 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -53,6 +53,14 @@ static DEFINE_PER_CPU(struct list_head *, tracer_path); */ static struct list_head *stm_path; +/* + * When losing synchronisation a new barrier packet needs to be inserted at the + * beginning of the data collected in a buffer. That way the decoder knows that + * it needs to look for another sync sequence. + */ +const u32 barrier_pkt[5] = {0x7fffffff, 0x7fffffff, + 0x7fffffff, 0x7fffffff, 0x0}; + static int coresight_id_match(struct device *dev, void *data) { int trace_id, i_trace_id;