[PATCH] uml: use host AIO support

This patch makes UML use host AIO support when it (and
/usr/include/linux/aio_abi.h) are present.  This is only the support, with no
consumers - a consumer is coming in the next patch.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 30 insertions, 11 deletions

diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 9f18061ef4c9..dcd814971995 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -31,7 +31,7 @@
 #include "kern_util.h"
 #include "irq_user.h"
 #include "irq_kern.h"
-
+#include "os.h"
 
 /*
  * Generic, controller-independent functions:
@@ -168,13 +168,32 @@ void __init init_IRQ(void)
         }
 }
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
+                                                             struct pt_regs *))
+{
+        int fds[2], err;
+
+        err = os_pipe(fds, 1, 1);
+        if(err){
+                printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
+                goto out;
+        }
+
+        err = um_request_irq(irq, fds[0], IRQ_READ, handler,
+                             SA_INTERRUPT | SA_SAMPLE_RANDOM, name,
+                             (void *) (long) fds[0]);
+        if(err){
+                printk("init_aio_irq - : um_request_irq failed, err = %d\n",
+                       err);
+                goto out_close;
+        }
+
+        err = fds[1];
+        goto out;
+
+ out_close:
+        os_close_file(fds[0]);
+        os_close_file(fds[1]);
+ out:
+        return(err);
+}