[src/trunk]: src/sys/net/npf NPF portmap: add a workaround for archs without ...

[rmind <rmind%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1dbaac97b4ce
branches:  trunk
changeset: 457845:1dbaac97b4ce
user:      rmind <rmind%NetBSD.org@localhost>
date:      Tue Jul 23 08:25:52 2019 +0000

description:
NPF portmap: add a workaround for archs without 64-bit CAS.

diffstat:

 sys/net/npf/npf_portmap.c |  37 +++++++++++++++++++++++++++++++------
 1 files changed, 31 insertions(+), 6 deletions(-)

diffs (107 lines):

diff -r 405ebbc6fd47 -r 1dbaac97b4ce sys/net/npf/npf_portmap.c
--- a/sys/net/npf/npf_portmap.c Tue Jul 23 07:52:53 2019 +0000
+++ b/sys/net/npf/npf_portmap.c Tue Jul 23 08:25:52 2019 +0000
@@ -35,7 +35,7 @@
 
 #ifdef _KERNEL
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: npf_portmap.c,v 1.1 2019/07/23 00:52:01 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: npf_portmap.c,v 1.2 2019/07/23 08:25:52 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -106,6 +106,8 @@
        int             max_port;
 } npf_portmap_params_t;
 
+static kmutex_t                        portmap_lock;
+
 void
 npf_portmap_init(npf_t *npf)
 {
@@ -130,6 +132,8 @@
        npf->portmap = kmem_zalloc(sizeof(npf_portmap_t), KM_SLEEP);
        mutex_init(&npf->portmap->list_lock, MUTEX_DEFAULT, IPL_SOFTNET);
        npf->portmap->addr_map = thmap_create(0, NULL, THMAP_NOCOPY);
+
+       mutex_init(&portmap_lock, MUTEX_DEFAULT, IPL_SOFTNET);
 }
 
 void
@@ -146,10 +150,31 @@
        thmap_destroy(pm->addr_map);
        mutex_destroy(&pm->list_lock);
        kmem_free(pm, sizeof(npf_portmap_t));
+
+       mutex_destroy(&portmap_lock);
 }
 
 /////////////////////////////////////////////////////////////////////////
 
+#if defined(_LP64)
+#define        __npf_atomic_cas_64     atomic_cas_64
+#else
+static uint64_t
+__npf_atomic_cas_64(volatile uint64_t *ptr, uint64_t old, uint64_t new)
+{
+       uint64_t prev;
+
+       mutex_enter(&portmap_lock);
+       prev = *ptr;
+       if (prev == old) {
+               *ptr = new;
+       }
+       mutex_exit(&portmap_lock);
+
+       return prev;
+}
+#endif
+
 /*
  * bitmap_word_isset: test whether the bit value is in the packed array.
  *
@@ -283,7 +308,7 @@
                 */
                if ((nval = bitmap_word_cax(bval, -1, chunk_bit)) != 0) {
                        KASSERT((nval & PORTMAP_L1_TAG) == 0);
-                       if (atomic_cas_64(&bm->bits0[i], bval, nval) != bval) {
+                       if (__npf_atomic_cas_64(&bm->bits0[i], bval, nval) != bval) {
                                goto again;
                        }
                        return true;
@@ -315,7 +340,7 @@
                bm1p = (uintptr_t)bm1;
                KASSERT((bm1p & PORTMAP_L1_TAG) == 0);
                bm1p |= PORTMAP_L1_TAG;
-               if (atomic_cas_64(&bm->bits0[i], bval, bm1p) != bval) {
+               if (__npf_atomic_cas_64(&bm->bits0[i], bval, bm1p) != bval) {
                        kmem_intr_free(bm1, sizeof(bitmap_l1_t));
                        goto again;
                }
@@ -332,7 +357,7 @@
                return false;
        }
        nval = oval | b;
-       if (atomic_cas_64(&bm1->bits1[i], oval, nval) != oval) {
+       if (__npf_atomic_cas_64(&bm1->bits1[i], oval, nval) != oval) {
                goto again;
        }
        return true;
@@ -356,7 +381,7 @@
                }
                nval = bitmap_word_cax(bval, chunk_bit, chunk_bit);
                KASSERT((nval & PORTMAP_L1_TAG) == 0);
-               if (atomic_cas_64(&bm->bits0[i], bval, nval) != bval) {
+               if (__npf_atomic_cas_64(&bm->bits0[i], bval, nval) != bval) {
                        goto again;
                }
                return true;
@@ -372,7 +397,7 @@
                return false;
        }
        nval = oval & ~b;
-       if (atomic_cas_64(&bm1->bits1[i], oval, nval) != oval) {
+       if (__npf_atomic_cas_64(&bm1->bits1[i], oval, nval) != oval) {
                goto again;
        }
        return true;