From 8871565764495cfe873b781f52e0d39ecbc3ddf6 Mon Sep 17 00:00:00 2001
From: aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Wed, 11 Feb 2009 15:20:58 +0000
Subject: [PATCH] qemu: add cpu_unregister_io_memory and make io mem table
 index dynamic (Marcelo Tosatti)

So drivers can clear their mem io table entries on exit back to unassigned
state.

Also make the io mem index allocation dynamic.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6601 c046a42c-6fe2-441c-8c8c-71466251a162
---
 cpu-all.h |  1 +
 exec.c    | 39 ++++++++++++++++++++++++++++++++++-----
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/cpu-all.h b/cpu-all.h
index 56a768add4..e0c3efd557 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -909,6 +909,7 @@ int cpu_register_io_memory(int io_index,
                            CPUReadMemoryFunc **mem_read,
                            CPUWriteMemoryFunc **mem_write,
                            void *opaque);
+void cpu_unregister_io_memory(int table_address);
 CPUWriteMemoryFunc **cpu_get_io_memory_write(int io_index);
 CPUReadMemoryFunc **cpu_get_io_memory_read(int io_index);
 
diff --git a/exec.c b/exec.c
index 9852bdcd31..7ed7e3ed32 100644
--- a/exec.c
+++ b/exec.c
@@ -179,7 +179,7 @@ static void io_mem_init(void);
 CPUWriteMemoryFunc *io_mem_write[IO_MEM_NB_ENTRIES][4];
 CPUReadMemoryFunc *io_mem_read[IO_MEM_NB_ENTRIES][4];
 void *io_mem_opaque[IO_MEM_NB_ENTRIES];
-static int io_mem_nb;
+char io_mem_used[IO_MEM_NB_ENTRIES];
 static int io_mem_watch;
 #endif
 
@@ -2799,12 +2799,28 @@ static void *subpage_init (target_phys_addr_t base, ram_addr_t *phys,
     return mmio;
 }
 
+static int get_free_io_mem_idx(void)
+{
+    int i;
+
+    for (i = 0; i<IO_MEM_NB_ENTRIES; i++)
+        if (!io_mem_used[i]) {
+            io_mem_used[i] = 1;
+            return i;
+        }
+
+    return -1;
+}
+
 static void io_mem_init(void)
 {
+    int i;
+
     cpu_register_io_memory(IO_MEM_ROM >> IO_MEM_SHIFT, error_mem_read, unassigned_mem_write, NULL);
     cpu_register_io_memory(IO_MEM_UNASSIGNED >> IO_MEM_SHIFT, unassigned_mem_read, unassigned_mem_write, NULL);
     cpu_register_io_memory(IO_MEM_NOTDIRTY >> IO_MEM_SHIFT, error_mem_read, notdirty_mem_write, NULL);
-    io_mem_nb = 5;
+    for (i=0; i<5; i++)
+        io_mem_used[i] = 1;
 
     io_mem_watch = cpu_register_io_memory(0, watch_mem_read,
                                           watch_mem_write, NULL);
@@ -2829,9 +2845,9 @@ int cpu_register_io_memory(int io_index,
     int i, subwidth = 0;
 
     if (io_index <= 0) {
-        if (io_mem_nb >= IO_MEM_NB_ENTRIES)
-            return -1;
-        io_index = io_mem_nb++;
+        io_index = get_free_io_mem_idx();
+        if (io_index == -1)
+            return io_index;
     } else {
         if (io_index >= IO_MEM_NB_ENTRIES)
             return -1;
@@ -2847,6 +2863,19 @@ int cpu_register_io_memory(int io_index,
     return (io_index << IO_MEM_SHIFT) | subwidth;
 }
 
+void cpu_unregister_io_memory(int io_table_address)
+{
+    int i;
+    int io_index = io_table_address >> IO_MEM_SHIFT;
+
+    for (i=0;i < 3; i++) {
+        io_mem_read[io_index][i] = unassigned_mem_read[i];
+        io_mem_write[io_index][i] = unassigned_mem_write[i];
+    }
+    io_mem_opaque[io_index] = NULL;
+    io_mem_used[io_index] = 0;
+}
+
 CPUWriteMemoryFunc **cpu_get_io_memory_write(int io_index)
 {
     return io_mem_write[io_index >> IO_MEM_SHIFT];