First in a series of changes to remove the now-unused Giant compatibility

framework for non-MPSAFE network protocols:

- Remove debug_mpsafenet variable, sysctl, and tunable.
- Remove NET_NEEDS_GIANT() and associate SYSINITSs used by it to force
  debug.mpsafenet=0 if non-MPSAFE protocols are compiled into the kernel.
- Remove logic to automatically flag interrupt handlers as non-MPSAFE if
  debug.mpsafenet is set for an INTR_TYPE_NET handler.
- Remove logic to automatically flag netisr handlers as non-MPSAFE if
  debug.mpsafenet is set.
- Remove references in a few subsystems, including NFS and Cronyx drivers,
  which keyed off debug_mpsafenet to determine various aspects of their own
  locking behavior.
- Convert NET_LOCK_GIANT(), NET_UNLOCK_GIANT(), and NET_ASSERT_GIANT into
  no-op's, as their entire behavior was determined by the value in
  debug_mpsafenet.
- Alias NET_CALLOUT_MPSAFE to CALLOUT_MPSAFE.

Many remaining references to NET_.*_GIANT() and NET_CALLOUT_MPSAFE are still
present in subsystems, and will be removed in followup commits.

Reviewed by:	bz, jhb
Approved by:	re (kensmith)

1 files changed, 0 insertions, 92 deletions

diff --git a/sys/net/netisr.c b/sys/net/netisr.c
index b44b030..d4bf693 100644
--- a/sys/net/netisr.c
+++ b/sys/net/netisr.c
@@ -56,24 +56,6 @@
 #include <net/if_var.h>
 #include <net/netisr.h>
 
-/* 
- * debug_mpsafenet controls network subsystem-wide use of the Giant lock,
- * from system calls down to interrupt handlers.  It can be changed only via
- * a tunable at boot, not at run-time, due to the complexity of unwinding.
- * The compiled default is set via a kernel option; right now, the default
- * unless otherwise specified is to run the network stack without Giant.
- */
-#ifdef NET_WITH_GIANT
-int	debug_mpsafenet = 0;
-#else
-int	debug_mpsafenet = 1;
-#endif
-int	debug_mpsafenet_toolatetotwiddle = 0;
-
-TUNABLE_INT("debug.mpsafenet", &debug_mpsafenet);
-SYSCTL_INT(_debug, OID_AUTO, mpsafenet, CTLFLAG_RD, &debug_mpsafenet, 0,
-    "Enable/disable MPSAFE network support");
-
 volatile unsigned int	netisr;	/* scheduling bits for network */
 
 struct netisr {
@@ -84,78 +66,6 @@ struct netisr {
 
 static void *net_ih;
 
-/*
- * Not all network code is currently capable of running MPSAFE; however,
- * most of it is.  Since those sections that are not are generally optional
- * components not shipped with default kernels, we provide a basic way to
- * determine whether MPSAFE operation is permitted: based on a default of
- * yes, we permit non-MPSAFE components to use a registration call to
- * identify that they require Giant.  If the system is early in the boot
- * process still, then we change the debug_mpsafenet setting to choose a
- * non-MPSAFE execution mode (degraded).  If it's too late for that (since
- * the setting cannot be changed at run time), we generate a console warning
- * that the configuration may be unsafe.
- */
-static int mpsafe_warn_count;
-
-/*
- * Function call implementing registration of a non-MPSAFE network component.
- */
-void
-net_warn_not_mpsafe(const char *component)
-{
-
-	/*
-	 * If we're running with Giant over the network stack, there is no
-	 * problem.
-	 */
-	if (!debug_mpsafenet)
-		return;
-
-	/*
-	 * If it's not too late to change the MPSAFE setting for the network
-	 * stack, do so now.  This effectively suppresses warnings by
-	 * components registering later.
-	 */
-	if (!debug_mpsafenet_toolatetotwiddle) {
-		debug_mpsafenet = 0;
-		printf("WARNING: debug.mpsafenet forced to 0 as %s requires "
-		    "Giant\n", component);
-		return;
-	}
-
-	/*
-	 * We must run without Giant, so generate a console warning with some
-	 * information with what to do about it.  The system may be operating
-	 * unsafely, however.
-	 */
-	printf("WARNING: Network stack Giant-free, but %s requires Giant.\n",
-	    component);
-	if (mpsafe_warn_count == 0)
-		printf("    Consider adding 'options NET_WITH_GIANT' or "
-		    "setting debug.mpsafenet=0\n");
-	mpsafe_warn_count++;
-}
-
-/*
- * This sysinit is run after any pre-loaded or compiled-in components have
- * announced that they require Giant, but before any modules loaded at
- * run-time.
- */
-static void
-net_mpsafe_toolate(void *arg)
-{
-
-	debug_mpsafenet_toolatetotwiddle = 1;
-
-	if (!debug_mpsafenet)
-		printf("WARNING: MPSAFE network stack disabled, expect "
-		    "reduced performance.\n");
-}
-
-SYSINIT(net_mpsafe_toolate, SI_SUB_SETTINGS, SI_ORDER_ANY, net_mpsafe_toolate,
-    NULL);
-
 void
 legacy_setsoftnet(void)
 {
@@ -170,8 +80,6 @@ netisr_register(int num, netisr_t *handler, struct ifqueue *inq, int flags)
 	    ("bad isr %d", num));
 	netisrs[num].ni_handler = handler;
 	netisrs[num].ni_queue = inq;
-	if ((flags & NETISR_MPSAFE) && !debug_mpsafenet)
-		flags &= ~NETISR_MPSAFE;
 	netisrs[num].ni_flags = flags;
 }