[PATCH 018/115] gpu: ion: Add explicit sync ioctl

John Stultz
2013-12-13T22:26:37Z

From: Rebecca Schultz Zavin <rebecca@android.com>

This is deprecated in favor of using the dma_buf api which will
automatically sync a buffer to memory when it is mapped to a device.
However, that functionality is not ready, so this patch adds the
ability to sync a buffer explicitly.

Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/staging/android/ion/ion.c | 38 ++++++++++++++++++++++++++++++++++++--
drivers/staging/android/ion/ion.h | 12 +++++++++++-
2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index bc9e922..d4e4c68 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -684,8 +684,7 @@ static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
struct dma_buf *dmabuf = attachment->dmabuf;
struct ion_buffer *buffer = dmabuf->priv;

- if (buffer->flags & ION_FLAG_CACHED)
- ion_buffer_sync_for_device(buffer, attachment->dev, direction);
+ ion_buffer_sync_for_device(buffer, attachment->dev, direction);
return buffer->sg_table;
}

@@ -721,6 +720,10 @@ static void ion_buffer_sync_for_device(struct ion_buffer *buffer,

pr_debug("%s: syncing for device %s\n", __func__,
dev ? dev_name(dev) : "null");
+
+ if (!(buffer->flags & ION_FLAG_CACHED))
+ return;
+
mutex_lock(&buffer->lock);
for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i) {
if (!test_bit(i, buffer->dirty))
@@ -958,6 +961,28 @@ end:
return handle;
}

+static int ion_sync_for_device(struct ion_client *client, int fd)
+{
+ struct dma_buf *dmabuf;
+ struct ion_buffer *buffer;
+
+ dmabuf = dma_buf_get(fd);
+ if (IS_ERR_OR_NULL(dmabuf))
+ return PTR_ERR(dmabuf);
+
+ /* if this memory came from ion */
+ if (dmabuf->ops != &dma_buf_ops) {
+ pr_err("%s: can not sync dmabuf from another exporter\n",
+ __func__);
+ dma_buf_put(dmabuf);
+ return -EINVAL;
+ }
+ buffer = dmabuf->priv;
+ ion_buffer_sync_for_device(buffer, NULL, DMA_BIDIRECTIONAL);
+ dma_buf_put(dmabuf);
+ return 0;
+}
+
static long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct ion_client *client = filp->private_data;
@@ -1022,6 +1047,15 @@ static long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return -EFAULT;
break;
}
+ case ION_IOC_SYNC:
+ {
+ struct ion_fd_data data;
+ if (copy_from_user(&data, (void __user *)arg,
+ sizeof(struct ion_fd_data)))
+ return -EFAULT;
+ ion_sync_for_device(client, data.fd);
+ break;
+ }
case ION_IOC_CUSTOM:
{
struct ion_device *dev = client->dev;
diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h
index 88b9a2f..83baa38 100644
--- a/drivers/staging/android/ion/ion.h
+++ b/drivers/staging/android/ion/ion.h
@@ -328,7 +328,17 @@ struct ion_custom_data {
* descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
* filed set to the corresponding opaque handle.
*/
-#define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, int)
+#define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
+
+/**
+ * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
+ *
+ * Deprecated in favor of using the dma_buf api's correctly (syncing
+ * will happend automatically when the buffer is mapped to a device).
+ * If necessary should be used after touching a cached buffer from the cpu,
+ * this will make the buffer in memory coherent.
+ */
+#define ION_IOC_SYNC _IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)

/**
* DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
--
1.8.3.2