Add functions which allow i/o memory to be accessed without forcing a

memory barrier (needed for XFree86 4.0).

Approved by: jkh

2 files changed, 26 insertions, 5 deletions

diff --git a/lib/libio/bwx.c b/lib/libio/bwx.c
index bc3bbb3..dede881 100644
--- a/lib/libio/bwx.c
+++ b/lib/libio/bwx.c
@@ -206,21 +206,21 @@ static void
 bwx_writeb(void *handle, u_int32_t offset, u_int8_t val)
 {
     struct bwx_mem_handle *h = handle;
-    stb((vm_offset_t)h->virt1 + offset, val);
+    stb_nb((vm_offset_t)h->virt1 + offset, val);
 }
 
 static void
 bwx_writew(void *handle, u_int32_t offset, u_int16_t val)
 {
     struct bwx_mem_handle *h = handle;
-    stw((vm_offset_t)h->virt2 + offset, val);
+    stw_nb((vm_offset_t)h->virt2 + offset, val);
 }
 
 static void
 bwx_writel(void *handle, u_int32_t offset, u_int32_t val)
 {
     struct bwx_mem_handle *h = handle;
-    stl((vm_offset_t)h->virt4 + offset, val);
+    stl_nb((vm_offset_t)h->virt4 + offset, val);
 }
 
 struct io_ops bwx_io_ops = {
diff --git a/lib/libio/io.c b/lib/libio/io.c
index 7abfa36..3ccce2e 100644
--- a/lib/libio/io.c
+++ b/lib/libio/io.c
@@ -119,18 +119,39 @@ readl(void *handle, u_int32_t offset)
 void
 writeb(void *handle, u_int32_t offset, u_int8_t val)
 {
-    return ops->writeb(handle, offset, val);
+    ops->writeb(handle, offset, val);
+    __asm__ __volatile__ ("mb");
 }
 
 void
 writew(void *handle, u_int32_t offset, u_int16_t val)
 {
-    return ops->writew(handle, offset, val);
+    ops->writew(handle, offset, val);
+    __asm__ __volatile__ ("mb");
 }
 
 void
 writel(void *handle, u_int32_t offset, u_int32_t val)
 {
+    ops->writel(handle, offset, val);
+    __asm__ __volatile__ ("mb");
+}
+
+void
+writeb_nb(void *handle, u_int32_t offset, u_int8_t val)
+{
+    return ops->writeb(handle, offset, val);
+}
+
+void
+writew_nb(void *handle, u_int32_t offset, u_int16_t val)
+{
+    return ops->writew(handle, offset, val);
+}
+
+void
+writel_nb(void *handle, u_int32_t offset, u_int32_t val)
+{
     return ops->writel(handle, offset, val);
 }