coresight: tmc: adding mode of operation for link/sinks

Moving tmc_drvdata::enable to a local_t mode.  That way the
sink interface is aware of it's orgin and the foundation for
mutual exclusion between the sysFS and Perf interface can be
laid out.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 60edf4d..bc0efc1 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -111,6 +111,7 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
        int ret = 0;
        bool used = false;
        char *buf = NULL;
+       long val;
        unsigned long flags;
        struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -140,6 +141,15 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
                goto out;
        }
 
+       val = local_xchg(&drvdata->mode, mode);
+       /*
+        * 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 (val == 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.
@@ -157,7 +167,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
        }
 
        tmc_etb_enable_hw(drvdata);
-       drvdata->enable = true;
 out:
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
@@ -173,6 +182,7 @@ out:
 
 static void tmc_disable_etf_sink(struct coresight_device *csdev)
 {
+       long val;
        unsigned long flags;
        struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -182,8 +192,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
                return;
        }
 
-       tmc_etb_disable_hw(drvdata);
-       drvdata->enable = false;
+       val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
+       /* Disable the TMC only if it needs to */
+       if (val != CS_MODE_DISABLED)
+               tmc_etb_disable_hw(drvdata);
+
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        dev_info(drvdata->dev, "TMC-ETB/ETF disabled\n");
@@ -202,7 +215,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
        }
 
        tmc_etf_enable_hw(drvdata);
-       drvdata->enable = true;
+       local_set(&drvdata->mode, CS_MODE_SYSFS);
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -222,7 +235,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
        }
 
        tmc_etf_disable_hw(drvdata);
-       drvdata->enable = false;
+       local_set(&drvdata->mode, CS_MODE_DISABLED);
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        dev_info(drvdata->dev, "TMC disabled\n");
@@ -279,7 +292,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
        }
 
        /* Disable the TMC if need be */
-       if (drvdata->enable)
+       if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
                tmc_etb_disable_hw(drvdata);
 
        drvdata->reading = true;
@@ -310,7 +323,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
        }
 
        /* Re-enable the TMC if need be */
-       if (drvdata->enable) {
+       if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
                /*
                 * The trace run will continue with the same allocated trace
                 * buffer. As such zero-out the buffer so that we don't end

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index d6999b4..0c10781 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -86,6 +86,7 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
 {
        int ret = 0;
        bool used = false;
+       long val;
        unsigned long flags;
        void __iomem *vaddr = NULL;
        dma_addr_t paddr;
@@ -122,6 +123,15 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
                goto out;
        }
 
+       val = local_xchg(&drvdata->mode, mode);
+       /*
+        * 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 (val == CS_MODE_SYSFS)
+               goto out;
+
        /*
         * If drvdata::buf == NULL, use the memory allocated above.
         * Otherwise a buffer still exists from a previous session, so
@@ -137,7 +147,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
        memset(drvdata->vaddr, 0, drvdata->size);
 
        tmc_etr_enable_hw(drvdata);
-       drvdata->enable = true;
 out:
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
@@ -153,6 +162,7 @@ out:
 
 static void tmc_disable_etr_sink(struct coresight_device *csdev)
 {
+       long val;
        unsigned long flags;
        struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -162,8 +172,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
                return;
        }
 
-       tmc_etr_disable_hw(drvdata);
-       drvdata->enable = false;
+       val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
+       /* Disable the TMC only if it needs to */
+       if (val != CS_MODE_DISABLED)
+               tmc_etr_disable_hw(drvdata);
+
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        dev_info(drvdata->dev, "TMC-ETR disabled\n");
@@ -200,7 +213,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
        }
 
        /* Disable the TMC if need be */
-       if (drvdata->enable)
+       if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
                tmc_etr_disable_hw(drvdata);
 
        drvdata->reading = true;
@@ -223,7 +236,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
        spin_lock_irqsave(&drvdata->spinlock, flags);
 
        /* RE-enable the TMC if need be */
-       if (drvdata->enable) {
+       if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
                /*
                 * The trace run will continue with the same allocated trace
                 * buffer. As such zero-out the buffer so that we don't end

diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 592eb14..94bc034 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -98,7 +98,7 @@ enum tmc_mem_intf_width {
  * @paddr:     DMA start location in RAM.
  * @vaddr:     virtual representation of @paddr.
  * @size:      @buf size.
- * @enable:    this TMC is being used.
+ * @mode:      how this TMC is being used.
  * @config_type: TMC variant, must be of type @tmc_config_type.
  * @trigger_cntr: amount of words to store after a trigger.
  */
@@ -113,7 +113,7 @@ struct tmc_drvdata {
        dma_addr_t              paddr;
        void __iomem            *vaddr;
        u32                     size;
-       bool                    enable;
+       local_t                 mode;
        enum tmc_config_type    config_type;
        u32                     trigger_cntr;
 };