From b3dc8992bbea0358752efdd8ca8803c8f150f083 Mon Sep 17 00:00:00 2001
From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 23 Oct 2012 18:26:51 +0100
Subject: [PATCH] dma: Define dma_context_memory and use by default

Define a new global dma_context_memory which is a DMAContext corresponding
to the global address_space_memory AddressSpace. This can be used by
sysbus peripherals like sysbus-ohci which need to do DMA.

[PC] Use this dma context by default if NULL is passed to the dma API for
DMAContext *dma

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---
 dma.h  |   17 +++++++++++++++++
 exec.c |    5 +++++
 2 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/dma.h b/dma.h
index 91ccdb5..defed50 100644
--- a/dma.h
+++ b/dma.h
@@ -68,6 +68,11 @@ struct DMAContext {
     DMAUnmapFunc *unmap;
 };
 
+/* A global DMA context corresponding to the address_space_memory
+ * AddressSpace, for sysbus devices which do DMA.
+ */
+extern DMAContext dma_context_memory;
+
 static inline void dma_barrier(DMAContext *dma, DMADirection dir)
 {
     /*
@@ -107,6 +112,9 @@ static inline bool dma_memory_valid(DMAContext *dma,
                                     dma_addr_t addr, dma_addr_t len,
                                     DMADirection dir)
 {
+    if (!dma) {
+        dma = &dma_context_memory;
+    }
     if (!dma_has_iommu(dma)) {
         return true;
     } else {
@@ -120,6 +128,9 @@ static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,
                                         void *buf, dma_addr_t len,
                                         DMADirection dir)
 {
+    if (!dma) {
+        dma = &dma_context_memory;
+    }
     if (!dma_has_iommu(dma)) {
         /* Fast-path for no IOMMU */
         address_space_rw(dma->as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
@@ -176,6 +187,9 @@ static inline void *dma_memory_map(DMAContext *dma,
                                    dma_addr_t addr, dma_addr_t *len,
                                    DMADirection dir)
 {
+    if (!dma) {
+        dma = &dma_context_memory;
+    }
     if (!dma_has_iommu(dma)) {
         hwaddr xlen = *len;
         void *p;
@@ -195,6 +209,9 @@ static inline void dma_memory_unmap(DMAContext *dma,
                                     void *buffer, dma_addr_t len,
                                     DMADirection dir, dma_addr_t access_len)
 {
+    if (!dma) {
+        dma = &dma_context_memory;
+    }
     if (!dma_has_iommu(dma)) {
         address_space_unmap(dma->as, buffer, (hwaddr)len,
                             dir == DMA_DIRECTION_FROM_DEVICE, access_len);
diff --git a/exec.c b/exec.c
index b0ed593..d2f6e79 100644
--- a/exec.c
+++ b/exec.c
@@ -34,6 +34,7 @@
 #include "hw/xen.h"
 #include "qemu-timer.h"
 #include "memory.h"
+#include "dma.h"
 #include "exec-memory.h"
 #if defined(CONFIG_USER_ONLY)
 #include <qemu.h>
@@ -103,6 +104,7 @@ static MemoryRegion *system_io;
 
 AddressSpace address_space_io;
 AddressSpace address_space_memory;
+DMAContext dma_context_memory;
 
 MemoryRegion io_mem_ram, io_mem_rom, io_mem_unassigned, io_mem_notdirty;
 static MemoryRegion io_mem_subpage_ram;
@@ -3276,6 +3278,9 @@ static void memory_map_init(void)
     memory_listener_register(&core_memory_listener, &address_space_memory);
     memory_listener_register(&io_memory_listener, &address_space_io);
     memory_listener_register(&tcg_memory_listener, &address_space_memory);
+
+    dma_context_init(&dma_context_memory, &address_space_memory,
+                     NULL, NULL, NULL);
 }
 
 MemoryRegion *get_system_memory(void)
-- 
1.7.0.4