Merge tag 'isci-for-3.5' into misc

isci update for 3.5

1/ Rework remote-node-context (RNC) handling for proper management of
   the silicon state machine in error handling and hot-plug conditions.
   Further details below, suffice to say if the RNC is mismanaged the
   silicon state machines may lock up.

2/ Refactor the initialization code to be reused for suspend/resume support

3/ Miscellaneous bug fixes to address discovery issues and hardware
   compatibility.

RNC rework details from Jeff Skirvin:

In the controller, devices as they appear on a SAS domain (or
direct-attached SATA devices) are represented by memory structures known
as "Remote Node Contexts" (RNCs).  These structures are transferred from
main memory to the controller using a set of register commands; these
commands include setting up the context ("posting"), removing the
context ("invalidating"), and commands to control the scheduling of
commands and connections to that remote device ("suspensions" and
"resumptions").  There is a similar path to control RNC scheduling from
the protocol engine, which interprets the results of command and data
transmission and reception.

In general, the controller chooses among non-suspended RNCs to find one
that has work requiring scheduling the transmission of command and data
frames to a target.  Likewise, when a target tries to return data back
to the initiator, the state of the RNC is used by the controller to
determine how to treat the incoming request. As an example, if the RNC
is in the state "TX/RX Suspended", incoming SSP connection requests from
the target will be rejected by the controller hardware.  When an RNC is
"TX Suspended", it will not be selected by the controller hardware to
start outgoing command or data operations (with certain priority-based
exceptions).

As mentioned above, there are two sources for management of the RNC
states: commands from driver software, and the result of transmission
and reception conditions of commands and data signaled by the controller
hardware.  As an example of the latter, if an outgoing SSP command ends
with a OPEN_REJECT(BAD_DESTINATION) status, the RNC state will
transition to the "TX Suspended" state, and this is signaled by the
controller hardware in the status to the completion of the pending
command as well as signaled in a controller hardware event.  Examples of
the former are included in the patch changelogs.

Driver software is required to suspend the RNC in a "TX/RX Suspended"
condition before any outstanding commands can be terminated.  Failure to
guarantee this can lead to a complete hardware hang condition.  Earlier
versions of the driver software did not guarantee that an RNC was
correctly managed before I/O termination, and so operated in an unsafe
way.

Further, the driver performed unnecessary contortions to preserve the
remote device command state and so was more complicated than it needed
to be.  A simplifying driver assumption is that once an I/O has entered
the error handler path without having completed in the target, the
requirement on the driver is that all use of the sas_task must end.
Beyond that, recovery of operation is dependent on libsas and other
components to reset, rediscover and reconfigure the device before normal
operation can restart.  In the driver, this simplifying assumption meant
that the RNC management could be reduced to entry into the suspended
state, terminating the targeted I/O request, and resuming the RNC as
needed for device-specific management such as an SSP Abort Task or LUN
Reset Management request.

1 files changed, 44 insertions, 27 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 3992e26a6039..bc4888d902b2 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -62,7 +62,7 @@
 #include <linux/sysctl.h>
 #endif
 
-static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,
+static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
 				    const struct in6_addr *dest);
 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
@@ -285,6 +285,10 @@ static void ip6_dst_destroy(struct dst_entry *dst)
 		rt->rt6i_idev = NULL;
 		in6_dev_put(idev);
 	}
+
+	if (!(rt->rt6i_flags & RTF_EXPIRES) && dst->from)
+		dst_release(dst->from);
+
 	if (peer) {
 		rt->rt6i_peer = NULL;
 		inet_putpeer(peer);
@@ -329,8 +333,17 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
 static __inline__ int rt6_check_expired(const struct rt6_info *rt)
 {
-	return (rt->rt6i_flags & RTF_EXPIRES) &&
-		time_after(jiffies, rt->dst.expires);
+	struct rt6_info *ort = NULL;
+
+	if (rt->rt6i_flags & RTF_EXPIRES) {
+		if (time_after(jiffies, rt->dst.expires))
+			return 1;
+	} else if (rt->dst.from) {
+		ort = (struct rt6_info *) rt->dst.from;
+		return (ort->rt6i_flags & RTF_EXPIRES) &&
+			time_after(jiffies, ort->dst.expires);
+	}
+	return 0;
 }
 
 static inline int rt6_need_strict(const struct in6_addr *daddr)
@@ -620,12 +633,11 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 				 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 
 	if (rt) {
-		if (!addrconf_finite_timeout(lifetime)) {
-			rt->rt6i_flags &= ~RTF_EXPIRES;
-		} else {
-			rt->dst.expires = jiffies + HZ * lifetime;
-			rt->rt6i_flags |= RTF_EXPIRES;
-		}
+		if (!addrconf_finite_timeout(lifetime))
+			rt6_clean_expires(rt);
+		else
+			rt6_set_expires(rt, jiffies + HZ * lifetime);
+
 		dst_release(&rt->dst);
 	}
 	return 0;
@@ -730,7 +742,7 @@ int ip6_ins_rt(struct rt6_info *rt)
 	return __ip6_ins_rt(rt, &info);
 }
 
-static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort,
+static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort,
 				      const struct in6_addr *daddr,
 				      const struct in6_addr *saddr)
 {
@@ -954,10 +966,10 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 		rt->rt6i_idev = ort->rt6i_idev;
 		if (rt->rt6i_idev)
 			in6_dev_hold(rt->rt6i_idev);
-		rt->dst.expires = 0;
 
 		rt->rt6i_gateway = ort->rt6i_gateway;
-		rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
+		rt->rt6i_flags = ort->rt6i_flags;
+		rt6_clean_expires(rt);
 		rt->rt6i_metric = 0;
 
 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
@@ -1019,10 +1031,9 @@ static void ip6_link_failure(struct sk_buff *skb)
 
 	rt = (struct rt6_info *) skb_dst(skb);
 	if (rt) {
-		if (rt->rt6i_flags & RTF_CACHE) {
-			dst_set_expires(&rt->dst, 0);
-			rt->rt6i_flags |= RTF_EXPIRES;
-		} else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
+		if (rt->rt6i_flags & RTF_CACHE)
+			rt6_update_expires(rt, 0);
+		else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
 			rt->rt6i_node->fn_sernum = -1;
 	}
 }
@@ -1289,9 +1300,12 @@ int ip6_route_add(struct fib6_config *cfg)
 	}
 
 	rt->dst.obsolete = -1;
-	rt->dst.expires = (cfg->fc_flags & RTF_EXPIRES) ?
-				jiffies + clock_t_to_jiffies(cfg->fc_expires) :
-				0;
+
+	if (cfg->fc_flags & RTF_EXPIRES)
+		rt6_set_expires(rt, jiffies +
+				clock_t_to_jiffies(cfg->fc_expires));
+	else
+		rt6_clean_expires(rt);
 
 	if (cfg->fc_protocol == RTPROT_UNSPEC)
 		cfg->fc_protocol = RTPROT_BOOT;
@@ -1736,8 +1750,8 @@ again:
 			features |= RTAX_FEATURE_ALLFRAG;
 			dst_metric_set(&rt->dst, RTAX_FEATURES, features);
 		}
-		dst_set_expires(&rt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires);
-		rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
+		rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
+		rt->rt6i_flags |= RTF_MODIFIED;
 		goto out;
 	}
 
@@ -1765,9 +1779,8 @@ again:
 		 * which is 10 mins. After 10 mins the decreased pmtu is expired
 		 * and detecting PMTU increase will be automatically happened.
 		 */
-		dst_set_expires(&nrt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires);
-		nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES;
-
+		rt6_update_expires(nrt, net->ipv6.sysctl.ip6_rt_mtu_expires);
+		nrt->rt6i_flags |= RTF_DYNAMIC;
 		ip6_ins_rt(nrt);
 	}
 out:
@@ -1799,7 +1812,7 @@ void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *sad
  *	Misc support functions
  */
 
-static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,
+static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
 				    const struct in6_addr *dest)
 {
 	struct net *net = dev_net(ort->dst.dev);
@@ -1819,10 +1832,14 @@ static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,
 		if (rt->rt6i_idev)
 			in6_dev_hold(rt->rt6i_idev);
 		rt->dst.lastuse = jiffies;
-		rt->dst.expires = 0;
 
 		rt->rt6i_gateway = ort->rt6i_gateway;
-		rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
+		rt->rt6i_flags = ort->rt6i_flags;
+		if ((ort->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ==
+		    (RTF_DEFAULT | RTF_ADDRCONF))
+			rt6_set_from(rt, ort);
+		else
+			rt6_clean_expires(rt);
 		rt->rt6i_metric = 0;
 
 #ifdef CONFIG_IPV6_SUBTREES