gpu: ion: Add explicit sync ioctl

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index bc9e922bfbf82f512db7075020b14624756e4622..d4e4c686d09883af374589b750d7781c512bd52a 100644 (file)
--- 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 88b9a2f5f87eaadd524067c25bc7d2d504ec2e02..83baa3830fc6b232bc888b7ff6ed8b2a3f6408a4 100644 (file)
--- 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