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Use atomic_ops(3) for ref counting.

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This commit is contained in:
jym 2011-05-15 07:24:15 +00:00
parent 2c52b012a9
commit 264d3132bf
1 changed files with 7 additions and 8 deletions
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15
sys/arch/xen/xen/xbdback_xenbus.c
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@ -1,4 +1,4 @@
/* $NetBSD: xbdback_xenbus.c,v 1.34 2011/04/29 22:58:46 jym Exp $ */ /* $NetBSD: xbdback_xenbus.c,v 1.35 2011/05/15 07:24:15 jym Exp $ */
/* /*
* Copyright (c) 2006 Manuel Bouyer. * Copyright (c) 2006 Manuel Bouyer.
@ -26,7 +26,7 @@
*/ */
#include <sys/cdefs.h> #include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.34 2011/04/29 22:58:46 jym Exp $"); __KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.35 2011/05/15 07:24:15 jym Exp $");
#include <sys/types.h> #include <sys/types.h>
#include <sys/param.h> #include <sys/param.h>
@ -34,6 +34,7 @@ __KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.34 2011/04/29 22:58:46 jym Exp
#include <sys/malloc.h> #include <sys/malloc.h>
#include <sys/queue.h> #include <sys/queue.h>
#include <sys/kernel.h> #include <sys/kernel.h>
#include <sys/atomic.h>
#include <sys/conf.h> #include <sys/conf.h>
#include <sys/disk.h> #include <sys/disk.h>
#include <sys/disklabel.h> #include <sys/disklabel.h>
@ -143,7 +144,7 @@ struct xbdback_instance {
grant_handle_t xbdi_ring_handle; /* to unmap the ring */ grant_handle_t xbdi_ring_handle; /* to unmap the ring */
vaddr_t xbdi_ring_va; /* to unmap the ring */ vaddr_t xbdi_ring_va; /* to unmap the ring */
/* disconnection must be postponed until all I/O is done */ /* disconnection must be postponed until all I/O is done */
volatile unsigned xbdi_refcnt; volatile unsigned int xbdi_refcnt;
/* /*
* State for I/O processing/coalescing follows; this has to * State for I/O processing/coalescing follows; this has to
* live here instead of on the stack because of the * live here instead of on the stack because of the
@ -167,13 +168,11 @@ struct xbdback_instance {
uint xbdi_pendingreqs; /* number of I/O in fly */ uint xbdi_pendingreqs; /* number of I/O in fly */
}; };
/* Manipulation of the above reference count. */ /* Manipulation of the above reference count. */
/* XXXjld@panix.com: not MP-safe, and move the i386 asm elsewhere. */ #define xbdi_get(xbdip) atomic_inc_uint(&(xbdip)->xbdi_refcnt)
#define xbdi_get(xbdip) (++(xbdip)->xbdi_refcnt)
#define xbdi_put(xbdip) \ #define xbdi_put(xbdip) \
do { \ do { \
__asm volatile("decl %0" \ atomic_dec_uint(&(xbdip)->xbdi_refcnt); \
: "=m"((xbdip)->xbdi_refcnt) : "m"((xbdip)->xbdi_refcnt)); \ if (0 == (xbdip)->xbdi_refcnt) \
if (0 == (xbdip)->xbdi_refcnt) \
xbdback_finish_disconnect(xbdip); \ xbdback_finish_disconnect(xbdip); \
} while (/* CONSTCOND */ 0) } while (/* CONSTCOND */ 0)