--- /dev/null
+/*
+ * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * @file
+ *
+ * Block device translator
+ *
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+#include <ipxe/blockdev.h>
+#include <ipxe/blocktrans.h>
+
+/**
+ * Reallocate block device translator data buffer
+ *
+ * @v xferbuf Data transfer buffer
+ * @v len New length (or zero to free buffer)
+ * @ret rc Return status code
+ */
+static int blktrans_xferbuf_realloc ( struct xfer_buffer *xferbuf,
+ size_t len ) {
+ struct block_translator *blktrans =
+ container_of ( xferbuf, struct block_translator, xferbuf );
+
+ /* Record length, if applicable */
+ if ( blktrans->buffer ) {
+
+ /* We have a (non-reallocatable) data buffer */
+ return -ENOTSUP;
+
+ } else {
+
+ /* Record length (for block device capacity) */
+ xferbuf->len = len;
+ return 0;
+ }
+}
+
+/**
+ * Write data to block device translator data buffer
+ *
+ * @v xferbuf Data transfer buffer
+ * @v offset Starting offset
+ * @v data Data to copy
+ * @v len Length of data
+ */
+static void blktrans_xferbuf_write ( struct xfer_buffer *xferbuf, size_t offset,
+ const void *data, size_t len ) {
+ struct block_translator *blktrans =
+ container_of ( xferbuf, struct block_translator, xferbuf );
+
+ /* Write data to buffer, if applicable */
+ if ( blktrans->buffer ) {
+
+ /* Write data to buffer */
+ copy_to_user ( blktrans->buffer, offset, data, len );
+
+ } else {
+
+ /* Sanity check */
+ assert ( len == 0 );
+ }
+}
+
+/**
+ * Read data from block device translator data buffer
+ *
+ * @v xferbuf Data transfer buffer
+ * @v offset Starting offset
+ * @v data Data to read
+ * @v len Length of data
+ */
+static void blktrans_xferbuf_read ( struct xfer_buffer *xferbuf, size_t offset,
+ void *data, size_t len ) {
+ struct block_translator *blktrans =
+ container_of ( xferbuf, struct block_translator, xferbuf );
+
+ /* Read data from buffer, if applicable */
+ if ( blktrans->buffer ) {
+
+ /* Read data from buffer */
+ copy_from_user ( data, blktrans->buffer, offset, len );
+
+ } else {
+
+ /* Sanity check */
+ assert ( len == 0 );
+ }
+}
+
+/** Block device translator data transfer buffer operations */
+static struct xfer_buffer_operations blktrans_xferbuf_operations = {
+ .realloc = blktrans_xferbuf_realloc,
+ .write = blktrans_xferbuf_write,
+ .read = blktrans_xferbuf_read,
+};
+
+/**
+ * Close block device translator
+ *
+ * @v blktrans Block device translator
+ * @v rc Reason for close
+ */
+static void blktrans_close ( struct block_translator *blktrans, int rc ) {
+ struct block_device_capacity capacity;
+
+ /* Report block device capacity, if applicable */
+ if ( ( rc == 0 ) && ( blktrans->blksize ) ) {
+
+ /* Construct block device capacity */
+ capacity.blocks =
+ ( blktrans->xferbuf.len / blktrans->blksize );
+ capacity.blksize = blktrans->blksize;
+ capacity.max_count = -1U;
+
+ /* Report block device capacity */
+ block_capacity ( &blktrans->block, &capacity );
+ }
+
+ /* Shut down interfaces */
+ intf_shutdown ( &blktrans->xfer, rc );
+ intf_shutdown ( &blktrans->block, rc );
+}
+
+/**
+ * Deliver data
+ *
+ * @v blktrans Block device translator
+ * @v iobuf I/O buffer
+ * @v meta Data transfer metadata
+ * @ret rc Return status code
+ */
+static int blktrans_deliver ( struct block_translator *blktrans,
+ struct io_buffer *iobuf,
+ struct xfer_metadata *meta ) {
+ int rc;
+
+ /* Deliver to buffer */
+ if ( ( rc = xferbuf_deliver ( &blktrans->xferbuf, iob_disown ( iobuf ),
+ meta ) ) != 0 ) {
+ DBGC ( blktrans, "BLKTRANS %p could not deliver: %s\n",
+ blktrans, strerror ( rc ) );
+ goto err;
+ }
+
+ return 0;
+
+ err:
+ blktrans_close ( blktrans, rc );
+ return rc;
+}
+
+/**
+ * Get underlying data transfer buffer
+ *
+ * @v blktrans Block device translator
+ * @ret xferbuf Data transfer buffer
+ */
+static struct xfer_buffer *
+blktrans_buffer ( struct block_translator *blktrans ) {
+
+ return &blktrans->xferbuf;
+}
+
+/** Block device translator block device interface operations */
+static struct interface_operation blktrans_block_operations[] = {
+ INTF_OP ( intf_close, struct block_translator *, blktrans_close ),
+};
+
+/** Block device translator block device interface descriptor */
+static struct interface_descriptor blktrans_block_desc =
+ INTF_DESC_PASSTHRU ( struct block_translator, block,
+ blktrans_block_operations, xfer );
+
+/** Block device translator data transfer interface operations */
+static struct interface_operation blktrans_xfer_operations[] = {
+ INTF_OP ( xfer_deliver, struct block_translator *, blktrans_deliver ),
+ INTF_OP ( xfer_buffer, struct block_translator *, blktrans_buffer ),
+ INTF_OP ( intf_close, struct block_translator *, blktrans_close ),
+};
+
+/** Block device translator data transfer interface descriptor */
+static struct interface_descriptor blktrans_xfer_desc =
+ INTF_DESC_PASSTHRU ( struct block_translator, xfer,
+ blktrans_xfer_operations, block );
+
+/**
+ * Insert block device translator
+ *
+ * @v block Block device interface
+ * @v buffer Data buffer (or UNULL)
+ * @v size Length of data buffer, or block size
+ * @ret rc Return status code
+ */
+int block_translate ( struct interface *block, userptr_t buffer, size_t size ) {
+ struct block_translator *blktrans;
+ int rc;
+
+ /* Allocate and initialise structure */
+ blktrans = zalloc ( sizeof ( *blktrans ) );
+ if ( ! blktrans ) {
+ rc = -ENOMEM;
+ goto err_alloc;
+ }
+ ref_init ( &blktrans->refcnt, NULL );
+ intf_init ( &blktrans->block, &blktrans_block_desc, &blktrans->refcnt );
+ intf_init ( &blktrans->xfer, &blktrans_xfer_desc, &blktrans->refcnt );
+ blktrans->xferbuf.op = &blktrans_xferbuf_operations;
+ blktrans->buffer = buffer;
+ if ( buffer ) {
+ blktrans->xferbuf.len = size;
+ } else {
+ blktrans->blksize = size;
+ }
+
+ /* Attach to interfaces, mortalise self, and return */
+ assert ( block->dest != &null_intf );
+ intf_plug_plug ( &blktrans->xfer, block->dest );
+ intf_plug_plug ( &blktrans->block, block );
+ ref_put ( &blktrans->refcnt );
+
+ DBGC2 ( blktrans, "BLKTRANS %p created", blktrans );
+ if ( buffer ) {
+ DBGC2 ( blktrans, " for %#lx+%#zx",
+ user_to_phys ( buffer, 0 ), size );
+ }
+ DBGC2 ( blktrans, "\n" );
+ return 0;
+
+ ref_put ( &blktrans->refcnt );
+ err_alloc:
+ return rc;
+}
Code Review / kvmfornfv.git / blobdiff