[QEMU][PATCH v3 3/7] softmmu: let qemu_map_ram_ptr() use qemu_ram_ptr_length()

[Vikram Garhwal]

From: Juergen Gross <jgross@suse.com>

qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so
modify qemu_ram_ptr_length() a little bit and use it for
qemu_map_ram_ptr(), too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 system/physmem.c | 56 ++++++++++++++++++++----------------------------
 1 file changed, 23 insertions(+), 33 deletions(-)

diff --git a/system/physmem.c b/system/physmem.c
index 84f3022099..949dcb20ba 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2163,43 +2163,17 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
 }
 #endif /* !_WIN32 */
 
-/* Return a host pointer to ram allocated with qemu_ram_alloc.
- * This should not be used for general purpose DMA.  Use address_space_map
- * or address_space_rw instead. For local memory (e.g. video ram) that the
- * device owns, use memory_region_get_ram_ptr.
- *
- * Called within RCU critical section.
- */
-void *qemu_map_ram_ptr(RAMBlock *block, ram_addr_t addr)
-{
-    if (block == NULL) {
-        block = qemu_get_ram_block(addr);
-        addr -= block->offset;
-    }
-
-    if (xen_enabled() && block->host == NULL) {
-        /* We need to check if the requested address is in the RAM
-         * because we don't want to map the entire memory in QEMU.
-         * In that case just map until the end of the page.
-         */
-        if (block->offset == 0) {
-            return xen_map_cache(addr, 0, 0, false);
-        }
-
-        block->host = xen_map_cache(block->offset, block->max_length, 1, 
false);
-    }
-    return ramblock_ptr(block, addr);
-}
-
-/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr
- * but takes a size argument.
+/*
+ * Return a host pointer to guest's ram.
  *
  * Called within RCU critical section.
  */
 static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr,
                                  hwaddr *size, bool lock)
 {
-    if (*size == 0) {
+    hwaddr len = 0;
+
+    if (size && *size == 0) {
         return NULL;
     }
 
@@ -2207,7 +2181,10 @@ static void *qemu_ram_ptr_length(RAMBlock *block, 
ram_addr_t addr,
         block = qemu_get_ram_block(addr);
         addr -= block->offset;
     }
-    *size = MIN(*size, block->max_length - addr);
+    if (size) {
+        *size = MIN(*size, block->max_length - addr);
+        len = *size;
+    }
 
     if (xen_enabled() && block->host == NULL) {
         /* We need to check if the requested address is in the RAM
@@ -2215,7 +2192,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, 
ram_addr_t addr,
          * In that case just map the requested area.
          */
         if (block->offset == 0) {
-            return xen_map_cache(addr, *size, lock, lock);
+            return xen_map_cache(addr, len, lock, lock);
         }
 
         block->host = xen_map_cache(block->offset, block->max_length, 1, lock);
@@ -2224,6 +2201,19 @@ static void *qemu_ram_ptr_length(RAMBlock *block, 
ram_addr_t addr,
     return ramblock_ptr(block, addr);
 }
 
+/*
+ * Return a host pointer to ram allocated with qemu_ram_alloc.
+ * This should not be used for general purpose DMA.  Use address_space_map
+ * or address_space_rw instead. For local memory (e.g. video ram) that the
+ * device owns, use memory_region_get_ram_ptr.
+ *
+ * Called within RCU critical section.
+ */
+void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
+{
+    return qemu_ram_ptr_length(ram_block, addr, NULL, false);
+}
+
 /* Return the offset of a hostpointer within a ramblock */
 ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
 {
-- 
2.17.1