Add a scatter-gather list type and accessors (Avi Kivity)

Scatter-gather lists are used extensively in dma-capable devices; a
single data structure allows more code reuse later on.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6522 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 33 insertions, 0 deletions

diff --git a/dma.h b/dma.h
new file mode 100644
index 0000000000..16af50f1f7
--- /dev/null
+++ b/dma.h
@@ -0,0 +1,33 @@
+/*
+ * DMA helper functions
+ *
+ * Copyright (c) 2009 Red Hat
+ *
+ * This work is licensed under the terms of the GNU General Public License
+ * (GNU GPL), version 2 or later.
+ */
+
+#ifndef DMA_H
+#define DMA_H
+
+#include <stdio.h>
+#include "cpu.h"
+
+typedef struct {
+    target_phys_addr_t base;
+    target_phys_addr_t len;
+} ScatterGatherEntry;
+
+typedef struct {
+    ScatterGatherEntry *sg;
+    int nsg;
+    int nalloc;
+    target_phys_addr_t size;
+} QEMUSGList;
+
+void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint);
+void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
+                     target_phys_addr_t len);
+void qemu_sglist_destroy(QEMUSGList *qsg);
+
+#endif