svn commit: r342749 - head/sys/net

[Matt Macy]

Author: mmacy
Date: Thu Jan  3 23:06:05 2019
New Revision: 342749
URL: https://svnweb.freebsd.org/changeset/base/342749

Log:
  mp_ring: avoid items offset difference between iflib and mp_ring
  on architectures without 64-bit atomics
  
  Reported by:	Augustin Cavalier <waddlesplash at gmail.com>

Modified:
  head/sys/net/mp_ring.c
  head/sys/net/mp_ring.h

Modified: head/sys/net/mp_ring.c
==============================================================================
--- head/sys/net/mp_ring.c	Thu Jan  3 22:51:14 2019	(r342748)
+++ head/sys/net/mp_ring.c	Thu Jan  3 23:06:05 2019	(r342749)
@@ -37,10 +37,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <machine/cpu.h>
 
-#if defined(__powerpc__) || defined(__mips__) || defined(__i386__)
-#define NO_64BIT_ATOMICS
-#endif
-
 #if defined(__i386__)
 #define atomic_cmpset_acq_64 atomic_cmpset_64
 #define atomic_cmpset_rel_64 atomic_cmpset_64
@@ -101,7 +97,7 @@ state_to_flags(union ring_state s, int abdicate)
 	return (BUSY);
 }
 
-#ifdef NO_64BIT_ATOMICS
+#ifdef MP_RING_NO_64BIT_ATOMICS
 static void
 drain_ring_locked(struct ifmp_ring *r, union ring_state os, uint16_t prev, int budget)
 {
@@ -291,7 +287,7 @@ ifmp_ring_alloc(struct ifmp_ring **pr, int size, void 
 	}
 
 	*pr = r;
-#ifdef NO_64BIT_ATOMICS
+#ifdef MP_RING_NO_64BIT_ATOMICS
 	mtx_init(&r->lock, "mp_ring lock", NULL, MTX_DEF);
 #endif
 	return (0);
@@ -325,7 +321,7 @@ ifmp_ring_free(struct ifmp_ring *r)
  *
  * Returns an errno.
  */
-#ifdef NO_64BIT_ATOMICS
+#ifdef MP_RING_NO_64BIT_ATOMICS
 int
 ifmp_ring_enqueue(struct ifmp_ring *r, void **items, int n, int budget, int abdicate)
 {
@@ -503,7 +499,7 @@ ifmp_ring_check_drainage(struct ifmp_ring *r, int budg
 	ns.flags = BUSY;
 
 
-#ifdef NO_64BIT_ATOMICS
+#ifdef MP_RING_NO_64BIT_ATOMICS
 	mtx_lock(&r->lock);
 	if (r->state != os.state) {
 		mtx_unlock(&r->lock);

Modified: head/sys/net/mp_ring.h
==============================================================================
--- head/sys/net/mp_ring.h	Thu Jan  3 22:51:14 2019	(r342748)
+++ head/sys/net/mp_ring.h	Thu Jan  3 23:06:05 2019	(r342749)
@@ -40,6 +40,10 @@ typedef u_int (*mp_ring_drain_t)(struct ifmp_ring *, u
 typedef u_int (*mp_ring_can_drain_t)(struct ifmp_ring *);
 typedef void (*mp_ring_serial_t)(struct ifmp_ring *);
 
+#if defined(__powerpc__) || defined(__mips__) || defined(__i386__)
+#define MP_RING_NO_64BIT_ATOMICS
+#endif
+
 struct ifmp_ring {
 	volatile uint64_t	state __aligned(CACHE_LINE_SIZE);
 
@@ -54,7 +58,7 @@ struct ifmp_ring {
 	counter_u64_t		stalls;
 	counter_u64_t		restarts;	/* recovered after stalling */
 	counter_u64_t		abdications;
-#ifdef NO_64BIT_ATOMICS
+#ifdef MP_RING_NO_64BIT_ATOMICS
 	struct mtx		lock;
 #endif
 	void * volatile		items[] __aligned(CACHE_LINE_SIZE);