exec: Eliminate qemu_ram_free_from_ptr()

Replace qemu_ram_free_from_ptr() with qemu_ram_free().

The only difference between qemu_ram_free_from_ptr() and
qemu_ram_free() is that g_free_rcu() is used instead of
call_rcu(reclaim_ramblock). We can safely replace it because:

* RAM blocks allocated by qemu_ram_alloc_from_ptr() always have
  RAM_PREALLOC set;
* reclaim_ramblock(block) will do nothing except g_free(block)
  if RAM_PREALLOC is set at block->flags.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1446844805-14492-2-git-send-email-ehabkost@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

exec.c

diff --git a/exec.c b/exec.c
index 0bf0a6e..d12cd42 100644
--- a/exec.c
+++ b/exec.c
@@ -1676,25 +1676,6 @@
     return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true, mr, errp);
 }
 
-void qemu_ram_free_from_ptr(ram_addr_t addr)
-{
-    RAMBlock *block;
-
-    qemu_mutex_lock_ramlist();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        if (addr == block->offset) {
-            QLIST_REMOVE_RCU(block, next);
-            ram_list.mru_block = NULL;
-            /* Write list before version */
-            smp_wmb();
-            ram_list.version++;
-            g_free_rcu(block, rcu);
-            break;
-        }
-    }
-    qemu_mutex_unlock_ramlist();
-}
-
 static void reclaim_ramblock(RAMBlock *block)
 {
     if (block->flags & RAM_PREALLOC) {

include/exec/ram_addr.h

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 7115154..d1d9963 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -75,7 +75,6 @@
 void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
 void *qemu_get_ram_ptr(ram_addr_t addr);
 void qemu_ram_free(ram_addr_t addr);
-void qemu_ram_free_from_ptr(ram_addr_t addr);
 
 int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp);
 

memory.c

diff --git a/memory.c b/memory.c
index e193658..cf5b05f 100644
--- a/memory.c
+++ b/memory.c
@@ -861,7 +861,7 @@
 
 static void memory_region_destructor_ram_from_ptr(MemoryRegion *mr)
 {
-    qemu_ram_free_from_ptr(mr->ram_addr);
+    qemu_ram_free(mr->ram_addr);
 }
 
 static void memory_region_destructor_rom_device(MemoryRegion *mr)