[PATCH v2 1/2] exec/memory: Extract address_space_set() from dma_memory_set()

[Philippe Mathieu-Daudé]

dma_memory_set() does a DMA barrier, set the address space with
a constant value. The constant value filling code is not specific
to DMA and can be used for AddressSpace. Extract it as a new
helper: address_space_set().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/exec/memory.h | 16 ++++++++++++++++
 softmmu/dma-helpers.c | 16 +---------------
 softmmu/physmem.c     | 19 +++++++++++++++++++
 3 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 5728a681b27..192139af58e 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -2568,6 +2568,22 @@ address_space_write_cached(MemoryRegionCache *cache, 
hwaddr addr,
     }
 }
 
+/**
+ * address_space_set: Fill address space with a constant byte.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @c: constant byte to fill the memory
+ * @len: the number of bytes to fill with the constant byte
+ * @attrs: memory transaction attributes
+ */
+MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+                              uint8_t c, hwaddr len, MemTxAttrs attrs);
+
 #ifdef NEED_CPU_H
 /* enum device_endian to MemOp.  */
 static inline MemOp devend_memop(enum device_endian end)
diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c
index 7d766a5e89a..8e1e7ad5320 100644
--- a/softmmu/dma-helpers.c
+++ b/softmmu/dma-helpers.c
@@ -23,21 +23,7 @@ MemTxResult dma_memory_set(AddressSpace *as, dma_addr_t addr,
 {
     dma_barrier(as, DMA_DIRECTION_FROM_DEVICE);
 
-#define FILLBUF_SIZE 512
-    uint8_t fillbuf[FILLBUF_SIZE];
-    int l;
-    MemTxResult error = MEMTX_OK;
-
-    memset(fillbuf, c, FILLBUF_SIZE);
-    while (len > 0) {
-        l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
-        error |= address_space_write(as, addr, MEMTXATTRS_UNSPECIFIED,
-                                     fillbuf, l);
-        len -= l;
-        addr += l;
-    }
-
-    return error;
+    return address_space_set(as, addr, c, len, MEMTXATTRS_UNSPECIFIED);
 }
 
 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 85034d9c11e..c9117527ae7 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2891,6 +2891,25 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr 
addr, MemTxAttrs attrs,
     }
 }
 
+MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+                              uint8_t c, hwaddr len, MemTxAttrs attrs)
+{
+#define FILLBUF_SIZE 512
+    uint8_t fillbuf[FILLBUF_SIZE];
+    int l;
+    MemTxResult error = MEMTX_OK;
+
+    memset(fillbuf, c, FILLBUF_SIZE);
+    while (len > 0) {
+        l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
+        error |= address_space_write(as, addr, attrs, fillbuf, l);
+        len -= l;
+        addr += l;
+    }
+
+    return error;
+}
+
 void cpu_physical_memory_rw(hwaddr addr, void *buf,
                             hwaddr len, bool is_write)
 {
-- 
2.26.3