rpmsg: omx: implement separate register ioctl for sgx buffers

This implements a new register ioctl specifically meant for sgx
buffers. rpmsg_omx clients are expected to call register ioctl
for the specific buffer type (ion or sgx) before sending a buffer
to .write for mapping. The registration allows the rpmsg_omx
driver to hold a reference to the ion buffers making up the sgx
buffer, thereby preventing the buffer(s) to be freed up from
under the remote processor.

The individual imported ion handles are expected to be passed
into the .write call.

When a client no longer expects remote processor to use the buffer,
client should call unregister ioctl. A separate unregister ioctl
for pvr buffers is not created, and the same ion unregister ioctl
is expected to be used for all the ion handles a sgx buffer is
comprised of.

Change-Id: I12d088851f259724e10bed642956bd263b19df1d
Signed-off-by: Tyler Luu <tluu@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>

2 files changed, 68 insertions, 53 deletions

diff --git a/drivers/rpmsg/rpmsg_omx.c b/drivers/rpmsg/rpmsg_omx.c
index 0af2367bf26d..728bdc79d06c 100644
--- a/drivers/rpmsg/rpmsg_omx.c
+++ b/drivers/rpmsg/rpmsg_omx.c
@@ -36,6 +36,7 @@
 #include <linux/rpmsg_omx.h>
 #include <linux/completion.h>
 #include <linux/remoteproc.h>
+#include <linux/fdtable.h>
 
 #ifdef CONFIG_ION_OMAP
 #include <linux/ion.h>
@@ -125,12 +126,11 @@ static int _rpmsg_pa_to_da(struct rpmsg_omx_instance *omx, u32 pa, u32 *da)
 #endif
 
 static int _rpmsg_omx_buffer_lookup(struct rpmsg_omx_instance *omx,
-					long buffer, u32 *va, u32 *va2)
+					long buffer, u32 *va)
 {
 	int ret = -EIO;
 
 	*va = 0;
-	*va2 = 0;
 
 #ifdef CONFIG_ION_OMAP
 	{
@@ -138,47 +138,12 @@ static int _rpmsg_omx_buffer_lookup(struct rpmsg_omx_instance *omx,
 		ion_phys_addr_t paddr;
 		size_t unused;
 
-		/* is it an ion handle? */
 		handle = (struct ion_handle *)buffer;
 		if (!ion_phys(omx->ion_client, handle, &paddr, &unused)) {
 			ret = _rpmsg_pa_to_da(omx, (phys_addr_t)paddr, va);
 			goto exit;
 		}
-
-		/* how about an sgx buffer wrapping an ion handle? */
-		{
-			int fd;
-			struct ion_handle *handles[2] = { NULL, NULL };
-			struct ion_client *pvr_ion_client;
-			ion_phys_addr_t paddr2;
-			int num_handles = 2;
-
-			fd = buffer;
-			if (omap_ion_fd_to_handles(fd, &pvr_ion_client,
-					handles, &num_handles) < 0)
-				goto nopvr;
-
-			/* Get the 1st buffer's da */
-			if ((handles[0]) && !ion_phys(pvr_ion_client,
-					handles[0], &paddr, &unused)) {
-				ret = _rpmsg_pa_to_da(omx,
-						(phys_addr_t)paddr, va);
-				if (ret)
-					goto exit;
-
-				/* Get the 2nd buffer's da in da2 */
-				if ((handles[1]) &&
-					!ion_phys(pvr_ion_client,
-					handles[1], &paddr2, &unused)) {
-					ret = _rpmsg_pa_to_da(omx,
-						(phys_addr_t)paddr2, va2);
-					goto exit;
-				} else
-					goto exit;
-			}
-		}
 	}
-nopvr:
 exit:
 #endif
 
@@ -194,7 +159,7 @@ static int _rpmsg_omx_map_buf(struct rpmsg_omx_instance *omx, char *packet)
 	long *buffer;
 	char *data;
 	enum rpc_omx_map_info_type maptype;
-	u32 da = 0 , da2 = 0;
+	u32 da = 0;
 
 	data = (char *)((struct omx_packet *)packet)->data;
 	maptype = *((enum rpc_omx_map_info_type *)data);
@@ -211,25 +176,18 @@ static int _rpmsg_omx_map_buf(struct rpmsg_omx_instance *omx, char *packet)
 	buffer = (long *)((int)data + offset);
 
 	/* Lookup for the da of 1st buffer */
-	ret = _rpmsg_omx_buffer_lookup(omx, *buffer, &da, &da2);
+	ret = _rpmsg_omx_buffer_lookup(omx, *buffer, &da);
 	if (!ret)
 		*buffer = da;
 
 	/* If 2 buffers, get the 2nd buffers da */
 	if (!ret && (maptype >= RPC_OMX_MAP_INFO_TWO_BUF)) {
 		buffer = (long *)((int)data + offset + sizeof(*buffer));
-
 		if (*buffer != 0) {
-			/* Use da2 if valid in case of NV12 contiguous bufs */
-			if (da2)
-				*buffer = da2;
-			/* If not, do the lookup for 2nd buf */
-			else {
-				ret = _rpmsg_omx_buffer_lookup(omx,
-						*buffer, &da, &da2);
-				if (!ret)
-					*buffer = da;
-			}
+			/* Lookup the da for 2nd buffer */
+			ret = _rpmsg_omx_buffer_lookup(omx, *buffer, &da);
+			if (!ret)
+				*buffer = da;
 		}
 	}
 
@@ -237,8 +195,7 @@ static int _rpmsg_omx_map_buf(struct rpmsg_omx_instance *omx, char *packet)
 	if (!ret && maptype >= RPC_OMX_MAP_INFO_THREE_BUF) {
 		buffer = (long *)((int)data + offset + 2*sizeof(*buffer));
 		if (*buffer != 0) {
-			ret = _rpmsg_omx_buffer_lookup(omx,
-					*buffer, &da, &da2);
+			ret = _rpmsg_omx_buffer_lookup(omx, *buffer, &da);
 			if (!ret)
 				*buffer = da;
 		}
@@ -404,6 +361,50 @@ long rpmsg_omx_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		}
 		break;
 	}
+	case OMX_IOCPVRREGISTER:
+	{
+		struct omx_pvr_data data;
+		struct ion_buffer *ion_bufs[2] = { NULL, NULL };
+		int num_handles = 2, i = 0;
+
+		if (copy_from_user(&data, (char __user *)arg, sizeof(data))) {
+			dev_err(omxserv->dev,
+				"%s: %d: copy_from_user fail: %d\n", __func__,
+				_IOC_NR(cmd), ret);
+			return -EFAULT;
+		}
+
+		if (!fcheck(data.fd)) {
+			dev_err(omxserv->dev,
+				"%s: %d: invalid fd: %d\n", __func__,
+				_IOC_NR(cmd), ret);
+			return -EBADF;
+		}
+
+		data.handles[0] = data.handles[1] = NULL;
+		if (!omap_ion_share_fd_to_buffers(data.fd, ion_bufs,
+						  &num_handles)) {
+			unsigned int size = ARRAY_SIZE(data.handles);
+			for (i = 0; (i < num_handles) && (i < size); i++) {
+				struct ion_handle *handle = NULL;
+
+				if (!IS_ERR_OR_NULL(ion_bufs[i]))
+					handle = ion_import(omx->ion_client,
+							   ion_bufs[i]);
+				if (!IS_ERR_OR_NULL(handle))
+					data.handles[i] = handle;
+			}
+		}
+		data.num_handles = i;
+
+		if (copy_to_user((char __user *)arg, &data, sizeof(data))) {
+			dev_err(omxserv->dev,
+				"%s: %d: copy_to_user fail: %d\n", __func__,
+				_IOC_NR(cmd), ret);
+			return -EFAULT;
+		}
+		break;
+	}
 	case OMX_IOCIONUNREGISTER:
 	{
 		struct ion_fd_data data;
diff --git a/include/linux/rpmsg_omx.h b/include/linux/rpmsg_omx.h
index 15503d5ee07d..3d5e42aca77f 100644
--- a/include/linux/rpmsg_omx.h
+++ b/include/linux/rpmsg_omx.h
@@ -35,13 +35,27 @@
 
 #include <linux/ioctl.h>
 
+/**
+ * struct omx_pvr_data - metadata passed to/from userspace for a pvr register
+ * @fd:           a file descriptor representing a pvr handle
+ * @num_handles:  field filled by driver. userspace uses this to determine
+ *                number of handles associated with fd
+ * @handles:      opaque pointers pointing to buffers
+ */
+struct omx_pvr_data {
+	int fd;
+	unsigned int num_handles;
+	void *handles[2];
+};
+
 #define OMX_IOC_MAGIC	'X'
 
 #define OMX_IOCCONNECT		_IOW(OMX_IOC_MAGIC, 1, char *)
 #define OMX_IOCIONREGISTER	_IOWR(OMX_IOC_MAGIC, 2, struct ion_fd_data)
 #define OMX_IOCIONUNREGISTER	_IOWR(OMX_IOC_MAGIC, 3, struct ion_fd_data)
+#define OMX_IOCPVRREGISTER	_IOWR(OMX_IOC_MAGIC, 4, struct omx_pvr_data)
 
-#define OMX_IOC_MAXNR	(3)
+#define OMX_IOC_MAXNR	(4)
 
 #ifdef __KERNEL__