* GNU General Public License for more details.
*/
+#include <asm/local.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/coresight.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
+#include <linux/circ_buf.h>
+#include <linux/mm.h>
+#include <linux/perf_event.h>
+
+#include <asm/local.h>
#include "coresight-priv.h"
#define ETB_FFSR_BIT 1
#define ETB_FRAME_SIZE_WORDS 4
+/**
+ * struct cs_buffer - keep track of a recording session' specifics
+ * @cur: index of the current buffer
+ * @nr_pages: max number of pages granted to us
+ * @offset: offset within the current buffer
+ * @data_size: how much we collected in this run
+ * @lost: other than zero if we had a HW buffer wrap around
+ * @snapshot: is this run in snapshot mode
+ * @data_pages: a handle the ring buffer
+ */
+struct cs_buffers {
+ unsigned int cur;
+ unsigned int nr_pages;
+ unsigned long offset;
+ local_t data_size;
+ local_t lost;
+ bool snapshot;
+ void **data_pages;
+};
+
/**
* struct etb_drvdata - specifics associated to an ETB component
* @base: memory mapped base address for this component.
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.etb" entry.
* @spinlock: only one at a time pls.
- * @in_use: synchronise user space access to etb buffer.
+ * @reading: synchronise user space access to etb buffer.
+ * @mode: this ETB is being used.
* @buf: area of memory where ETB buffer content gets sent.
* @buffer_depth: size of @buf.
- * @enable: this ETB is being used.
* @trigger_cntr: amount of words to store after a trigger.
*/
struct etb_drvdata {
struct coresight_device *csdev;
struct miscdevice miscdev;
spinlock_t spinlock;
- atomic_t in_use;
+ local_t reading;
+ local_t mode;
u8 *buf;
u32 buffer_depth;
- bool enable;
u32 trigger_cntr;
};
CS_LOCK(drvdata->base);
}
-static int etb_enable(struct coresight_device *csdev)
+static int etb_enable(struct coresight_device *csdev, u32 mode)
{
- struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ u32 val;
unsigned long flags;
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
- pm_runtime_get_sync(drvdata->dev);
+ val = local_cmpxchg(&drvdata->mode,
+ CS_MODE_DISABLED, mode);
+ /*
+ * When accessing from Perf, a HW buffer can be handled
+ * by a single trace entity. In sysFS mode many tracers
+ * can be logging to the same HW buffer.
+ */
+ if (val == CS_MODE_PERF)
+ return -EBUSY;
+
+ /* Nothing to do, the tracer is already enabled. */
+ if (val == CS_MODE_SYSFS)
+ goto out;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_enable_hw(drvdata);
- drvdata->enable = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+out:
dev_info(drvdata->dev, "ETB enabled\n");
return 0;
}
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
- drvdata->enable = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- pm_runtime_put(drvdata->dev);
+ local_set(&drvdata->mode, CS_MODE_DISABLED);
dev_info(drvdata->dev, "ETB disabled\n");
}
+static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
+ void **pages, int nr_pages, bool overwrite)
+{
+ int node;
+ struct cs_buffers *buf;
+
+ if (cpu == -1)
+ cpu = smp_processor_id();
+ node = cpu_to_node(cpu);
+
+ 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 etb_free_buffer(void *config)
+{
+ struct cs_buffers *buf = config;
+
+ kfree(buf);
+}
+
+static int etb_set_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 etb_reset_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config, bool *lost)
+{
+ unsigned 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.
+ */
+ *lost = !!local_xchg(&buf->lost, 0);
+ size = local_xchg(&buf->data_size, 0);
+ }
+
+ return size;
+}
+
+static void etb_update_buffer(struct coresight_device *csdev,
+ struct perf_output_handle *handle,
+ void *sink_config)
+{
+ int i, cur;
+ u8 *buf_ptr;
+ u32 read_ptr, write_ptr, capacity;
+ u32 status, read_data, to_read;
+ unsigned long offset;
+ struct cs_buffers *buf = sink_config;
+ struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ if (!buf)
+ return;
+
+ capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
+
+ CS_UNLOCK(drvdata->base);
+ etb_disable_hw(drvdata);
+
+ /* unit is in words, not bytes */
+ read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
+ write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
+
+ /*
+ * Entries should be aligned to the frame size. If they are not
+ * go back to the last alignement point to give decoding tools a
+ * chance to fix things.
+ */
+ if (write_ptr % ETB_FRAME_SIZE_WORDS) {
+ dev_err(drvdata->dev,
+ "write_ptr: %lu not aligned to formatter frame size\n",
+ (unsigned long)write_ptr);
+
+ write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
+ local_inc(&buf->lost);
+ }
+
+ /*
+ * Get a hold of the status register and see if a wrap around
+ * has occurred. If so adjust things accordingly. Otherwise
+ * start at the beginning and go until the write pointer has
+ * been reached.
+ */
+ status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
+ if (status & ETB_STATUS_RAM_FULL) {
+ local_inc(&buf->lost);
+ to_read = capacity;
+ read_ptr = write_ptr;
+ } else {
+ to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
+ to_read *= ETB_FRAME_SIZE_WORDS;
+ }
+
+ /*
+ * Make sure we don't overwrite data that hasn't been consumed yet.
+ * It is entirely possible that the HW buffer has more data than the
+ * ring buffer can currently handle. If so adjust the start address
+ * to take only the last traces.
+ *
+ * In snapshot mode we are looking to get the latest traces only and as
+ * such, we don't care about not overwriting data that hasn't been
+ * processed by user space.
+ */
+ if (!buf->snapshot && to_read > handle->size) {
+ u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
+
+ /* The new read pointer must be frame size aligned */
+ to_read -= handle->size & mask;
+ /*
+ * Move the RAM read pointer up, keeping in mind that
+ * everything is in frame size units.
+ */
+ read_ptr = (write_ptr + drvdata->buffer_depth) -
+ to_read / ETB_FRAME_SIZE_WORDS;
+ /* Wrap around if need be*/
+ read_ptr &= ~(drvdata->buffer_depth - 1);
+ /* let the decoder know we've skipped ahead */
+ local_inc(&buf->lost);
+ }
+
+ /* finally tell HW where we want to start reading from */
+ writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
+
+ cur = buf->cur;
+ offset = buf->offset;
+ 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);
+ *buf_ptr++ = read_data >> 0;
+ *buf_ptr++ = read_data >> 8;
+ *buf_ptr++ = read_data >> 16;
+ *buf_ptr++ = read_data >> 24;
+
+ offset += 4;
+ if (offset >= PAGE_SIZE) {
+ offset = 0;
+ cur++;
+ /* wrap around at the end of the buffer */
+ cur &= buf->nr_pages - 1;
+ }
+ }
+
+ /* reset ETB buffer for next run */
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
+ writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
+
+ /*
+ * 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);
+
+ etb_enable_hw(drvdata);
+ CS_LOCK(drvdata->base);
+}
+
static const struct coresight_ops_sink etb_sink_ops = {
.enable = etb_enable,
.disable = etb_disable,
+ .alloc_buffer = etb_alloc_buffer,
+ .free_buffer = etb_free_buffer,
+ .set_buffer = etb_set_buffer,
+ .reset_buffer = etb_reset_buffer,
+ .update_buffer = etb_update_buffer,
};
static const struct coresight_ops etb_cs_ops = {
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
- if (drvdata->enable) {
+ if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
etb_enable_hw(drvdata);
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
- if (atomic_cmpxchg(&drvdata->in_use, 0, 1))
+ if (local_cmpxchg(&drvdata->reading, 0, 1))
return -EBUSY;
dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
- atomic_set(&drvdata->in_use, 0);
+ local_set(&drvdata->reading, 0);
dev_dbg(drvdata->dev, "%s: released\n", __func__);
return 0;
return ret;
}
-static int etb_remove(struct amba_device *adev)
-{
- struct etb_drvdata *drvdata = amba_get_drvdata(adev);
-
- misc_deregister(&drvdata->miscdev);
- coresight_unregister(drvdata->csdev);
- return 0;
-}
-
#ifdef CONFIG_PM
static int etb_runtime_suspend(struct device *dev)
{
.name = "coresight-etb10",
.owner = THIS_MODULE,
.pm = &etb_dev_pm_ops,
+ .suppress_bind_attrs = true,
},
.probe = etb_probe,
- .remove = etb_remove,
.id_table = etb_ids,
};
projects / firefly-linux-kernel-4.4.55.git / blobdiff