[xferbuf] Generalise to handle umalloc()-based buffers

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/xferbuf.c

@@ -28,6 +28,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <errno.h>
 #include <ipxe/xfer.h>
 #include <ipxe/iobuf.h>
+#include <ipxe/umalloc.h>
+#include <ipxe/profile.h>
 #include <ipxe/xferbuf.h>
 
 /** @file
@@ -36,14 +38,26 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  *
  */
 
+/** Data delivery profiler */
+static struct profiler xferbuf_deliver_profiler __profiler =
+	{ .name = "xferbuf.deliver" };
+
+/** Data write profiler */
+static struct profiler xferbuf_write_profiler __profiler =
+	{ .name = "xferbuf.write" };
+
+/** Data read profiler */
+static struct profiler xferbuf_read_profiler __profiler =
+	{ .name = "xferbuf.read" };
+
 /**
- * Finish using data transfer buffer
+ * Free data transfer buffer
  *
  * @v xferbuf		Data transfer buffer
  */
-void xferbuf_done ( struct xfer_buffer *xferbuf ) {
-	free ( xferbuf->data );
-	xferbuf->data = NULL;
+void xferbuf_free ( struct xfer_buffer *xferbuf ) {
+
+	xferbuf->op->realloc ( xferbuf, 0 );
 	xferbuf->len = 0;
 	xferbuf->pos = 0;
 }
@@ -56,25 +70,77 @@ void xferbuf_done ( struct xfer_buffer *xferbuf ) {
  * @ret rc		Return status code
  */
 static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) {
-	void *new_data;
+	int rc;
 
 	/* If buffer is already large enough, do nothing */
 	if ( len <= xferbuf->len )
 		return 0;
 
 	/* Extend buffer */
-	new_data = realloc ( xferbuf->data, len );
-	if ( ! new_data ) {
+	if ( ( rc = xferbuf->op->realloc ( xferbuf, len ) ) != 0 ) {
 		DBGC ( xferbuf, "XFERBUF %p could not extend buffer to "
-		       "%zd bytes\n", xferbuf, len );
-		return -ENOSPC;
+		       "%zd bytes: %s\n", xferbuf, len, strerror ( rc ) );
+		return rc;
 	}
-	xferbuf->data = new_data;
 	xferbuf->len = len;
 
 	return 0;
 }
 
+/**
+ * Write to data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to write
+ * @v len		Length of data
+ */
+int xferbuf_write ( struct xfer_buffer *xferbuf, size_t offset,
+		    const void *data, size_t len ) {
+	size_t max_len;
+	int rc;
+
+	/* Check for overflow */
+	max_len = ( offset + len );
+	if ( max_len < offset )
+		return -EOVERFLOW;
+
+	/* Ensure buffer is large enough to contain this write */
+	if ( ( rc = xferbuf_ensure_size ( xferbuf, max_len ) ) != 0 )
+		return rc;
+
+	/* Copy data to buffer */
+	profile_start ( &xferbuf_write_profiler );
+	xferbuf->op->write ( xferbuf, offset, data, len );
+	profile_stop ( &xferbuf_write_profiler );
+
+	return 0;
+}
+
+/**
+ * Read from data transfer buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to write
+ * @v len		Length of data
+ */
+int xferbuf_read ( struct xfer_buffer *xferbuf, size_t offset,
+		   void *data, size_t len ) {
+
+	/* Check that read is within buffer range */
+	if ( ( offset > xferbuf->len ) ||
+	     ( len > ( xferbuf->len - offset ) ) )
+		return -ENOENT;
+
+	/* Copy data from buffer */
+	profile_start ( &xferbuf_read_profiler );
+	xferbuf->op->read ( xferbuf, offset, data, len );
+	profile_stop ( &xferbuf_read_profiler );
+
+	return 0;
+}
+
 /**
  * Add received data to data transfer buffer
  *
@@ -85,28 +151,135 @@ static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) {
  */
 int xferbuf_deliver ( struct xfer_buffer *xferbuf, struct io_buffer *iobuf,
 		      struct xfer_metadata *meta ) {
-	size_t len;
-	size_t max;
+	size_t len = iob_len ( iobuf );
+	size_t pos;
 	int rc;
 
-	/* Calculate new buffer position */
-	if ( meta->flags & XFER_FL_ABS_OFFSET )
-		xferbuf->pos = 0;
-	xferbuf->pos += meta->offset;
+	/* Start profiling */
+	profile_start ( &xferbuf_deliver_profiler );
 
-	/* Ensure that we have enough buffer space for this data */
-	len = iob_len ( iobuf );
-	max = ( xferbuf->pos + len );
-	if ( ( rc = xferbuf_ensure_size ( xferbuf, max ) ) != 0 )
+	/* Calculate new buffer position */
+	pos = xferbuf->pos;
+	if ( meta->flags & XFER_FL_ABS_OFFSET )
+		pos = 0;
+	pos += meta->offset;
+
+	/* Write data to buffer */
+	if ( ( rc = xferbuf_write ( xferbuf, pos, iobuf->data, len ) ) != 0 )
 		goto done;
 
-	/* Copy data to buffer */
-	memcpy ( ( xferbuf->data + xferbuf->pos ), iobuf->data, len );
-
 	/* Update current buffer position */
-	xferbuf->pos += len;
+	xferbuf->pos = ( pos + len );
 
  done:
 	free_iob ( iobuf );
+	profile_stop ( &xferbuf_deliver_profiler );
 	return rc;
 }
+
+/**
+ * Reallocate malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v len		New length (or zero to free buffer)
+ * @ret rc		Return status code
+ */
+static int xferbuf_malloc_realloc ( struct xfer_buffer *xferbuf, size_t len ) {
+	void *new_data;
+
+	new_data = realloc ( xferbuf->data, len );
+	if ( ! new_data )
+		return -ENOSPC;
+	xferbuf->data = new_data;
+	return 0;
+}
+
+/**
+ * Write data to malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to copy
+ * @v len		Length of data
+ */
+static void xferbuf_malloc_write ( struct xfer_buffer *xferbuf, size_t offset,
+				   const void *data, size_t len ) {
+
+	memcpy ( ( xferbuf->data + offset ), data, len );
+}
+
+/**
+ * Read data from malloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to read
+ * @v len		Length of data
+ */
+static void xferbuf_malloc_read ( struct xfer_buffer *xferbuf, size_t offset,
+				  void *data, size_t len ) {
+
+	memcpy ( data, ( xferbuf->data + offset ), len );
+}
+
+/** malloc()-based data buffer operations */
+struct xfer_buffer_operations xferbuf_malloc_operations = {
+	.realloc = xferbuf_malloc_realloc,
+	.write = xferbuf_malloc_write,
+	.read = xferbuf_malloc_read,
+};
+
+/**
+ * Reallocate umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v len		New length (or zero to free buffer)
+ * @ret rc		Return status code
+ */
+static int xferbuf_umalloc_realloc ( struct xfer_buffer *xferbuf, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+	userptr_t new_udata;
+
+	new_udata = urealloc ( *udata, len );
+	if ( ! new_udata )
+		return -ENOSPC;
+	*udata = new_udata;
+	return 0;
+}
+
+/**
+ * Write data to umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to copy
+ * @v len		Length of data
+ */
+static void xferbuf_umalloc_write ( struct xfer_buffer *xferbuf, size_t offset,
+				    const void *data, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+
+	copy_to_user ( *udata, offset, data, len );
+}
+
+/**
+ * Read data from umalloc()-based data buffer
+ *
+ * @v xferbuf		Data transfer buffer
+ * @v offset		Starting offset
+ * @v data		Data to read
+ * @v len		Length of data
+ */
+static void xferbuf_umalloc_read ( struct xfer_buffer *xferbuf, size_t offset,
+				   void *data, size_t len ) {
+	userptr_t *udata = xferbuf->data;
+
+	copy_from_user ( data, *udata, offset, len );
+}
+
+/** umalloc()-based data buffer operations */
+struct xfer_buffer_operations xferbuf_umalloc_operations = {
+	.realloc = xferbuf_umalloc_realloc,
+	.write = xferbuf_umalloc_write,
+	.read = xferbuf_umalloc_read,
+};