sgi-xpc: prevent false heartbeat failures

The heartbeat timeout functionality in sgi-xpc is currently not trained to
the connection time.  If a connection is made and the code is in the last
polling window prior to doing a timeout, the next polling window will see
the heartbeat as unchanged and initiate a no-heartbeat disconnect.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 62 deletions

diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 114444cfd496..da32bbe8caaf 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -90,18 +90,21 @@ struct xpc_rsvd_page {
         short max_npartitions;  /* value of XPC_MAX_PARTITIONS */
         u8 version;
         u8 pad1[3];             /* align to next u64 in 1st 64-byte cacheline */
+        unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
         union {
-                unsigned long vars_pa;  /* phys address of struct xpc_vars */
-                unsigned long activate_gru_mq_desc_gpa; /* phys addr of */
-                                                        /* activate mq's */
-                                                        /* gru mq descriptor */
+                struct {
+                        unsigned long vars_pa;  /* phys addr */
+                } sn2;
+                struct {
+                        unsigned long heartbeat_gpa; /* phys addr */
+                        unsigned long activate_gru_mq_desc_gpa; /* phys addr */
+                } uv;
         } sn;
-        unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
-        u64 pad2[10];           /* align to last u64 in 2nd 64-byte cacheline */
+        u64 pad2[9];            /* align to last u64 in 2nd 64-byte cacheline */
         u64 SAL_nasids_size;    /* SAL: size of each nasid mask in bytes */
 };
 
-#define XPC_RP_VERSION _XPC_VERSION(2, 0) /* version 2.0 of the reserved page */
+#define XPC_RP_VERSION _XPC_VERSION(3, 0) /* version 3.0 of the reserved page */
 
 /*
  * Define the structures by which XPC variables can be exported to other
@@ -182,6 +185,17 @@ struct xpc_vars_part_sn2 {
                                  (XPC_RP_MACH_NASIDS(_rp) + \
                                   xpc_nasid_mask_nlongs))
 
+
+/*
+ * The following structure describes the partition's heartbeat info which
+ * will be periodically read by other partitions to determine whether this
+ * XPC is still 'alive'.
+ */
+struct xpc_heartbeat_uv {
+        unsigned long value;
+        unsigned long offline;  /* if 0, heartbeat should be changing */
+};
+
 /*
  * Info pertinent to a GRU message queue using a watch list for irq generation.
  */
@@ -198,7 +212,7 @@ struct xpc_gru_mq_uv {
 
 /*
  * The activate_mq is used to send/receive GRU messages that affect XPC's
- * heartbeat, partition active state, and channel state. This is UV only.
+ * partition active state and channel state. This is uv only.
  */
 struct xpc_activate_mq_msghdr_uv {
         unsigned int gru_msg_hdr; /* FOR GRU INTERNAL USE ONLY */
@@ -210,33 +224,26 @@ struct xpc_activate_mq_msghdr_uv {
 
 /* activate_mq defined message types */
 #define XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV           0
-#define XPC_ACTIVATE_MQ_MSG_INC_HEARTBEAT_UV            1
-#define XPC_ACTIVATE_MQ_MSG_OFFLINE_HEARTBEAT_UV        2
-#define XPC_ACTIVATE_MQ_MSG_ONLINE_HEARTBEAT_UV         3
 
-#define XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV             4
-#define XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV           5
+#define XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV             1
+#define XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV           2
 
-#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV       6
-#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV         7
-#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV        8
-#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV          9
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV       3
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV         4
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV        5
+#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV          6
 
-#define XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV             10
-#define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV          11
+#define XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV             7
+#define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV          8
 
 struct xpc_activate_mq_msg_uv {
         struct xpc_activate_mq_msghdr_uv hdr;
 };
 
-struct xpc_activate_mq_msg_heartbeat_req_uv {
-        struct xpc_activate_mq_msghdr_uv hdr;
-        u64 heartbeat;
-};
-
 struct xpc_activate_mq_msg_activate_req_uv {
         struct xpc_activate_mq_msghdr_uv hdr;
         unsigned long rp_gpa;
+        unsigned long heartbeat_gpa;
         unsigned long activate_gru_mq_desc_gpa;
 };
 
@@ -687,6 +694,9 @@ struct xpc_partition_sn2 {
 };
 
 struct xpc_partition_uv {
+        unsigned long heartbeat_gpa; /* phys addr of partition's heartbeat */
+        struct xpc_heartbeat_uv cached_heartbeat; /* cached copy of */
+                                                  /* partition's heartbeat */
         unsigned long activate_gru_mq_desc_gpa; /* phys addr of parititon's */
                                                 /* activate mq's gru mq */
                                                 /* descriptor */
@@ -698,14 +708,12 @@ struct xpc_partition_uv {
         u8 remote_act_state;    /* remote partition's act_state */
         u8 act_state_req;       /* act_state request from remote partition */
         enum xp_retval reason;  /* reason for deactivate act_state request */
-        u64 heartbeat;          /* incremented by remote partition */
 };
 
 /* struct xpc_partition_uv flags */
 
-#define XPC_P_HEARTBEAT_OFFLINE_UV              0x00000001
+#define XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV    0x00000001
 #define XPC_P_ENGAGED_UV                        0x00000002
-#define XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV    0x00000004
 
 /* struct xpc_partition_uv act_state change requests */
 
@@ -807,7 +815,6 @@ extern int xpc_disengage_timedout;
 extern int xpc_activate_IRQ_rcvd;
 extern spinlock_t xpc_activate_IRQ_rcvd_lock;
 extern wait_queue_head_t xpc_activate_IRQ_wq;
-extern void *xpc_heartbeating_to_mask;
 extern void *xpc_kzalloc_cacheline_aligned(size_t, gfp_t, void **);
 extern void xpc_activate_partition(struct xpc_partition *);
 extern void xpc_activate_kthreads(struct xpc_channel *, int);
@@ -825,6 +832,9 @@ extern void (*xpc_increment_heartbeat) (void);
 extern void (*xpc_offline_heartbeat) (void);
 extern void (*xpc_online_heartbeat) (void);
 extern enum xp_retval (*xpc_get_remote_heartbeat) (struct xpc_partition *);
+extern void (*xpc_allow_hb) (short);
+extern void (*xpc_disallow_hb) (short);
+extern void (*xpc_disallow_all_hbs) (void);
 extern enum xp_retval (*xpc_make_first_contact) (struct xpc_partition *);
 extern u64 (*xpc_get_chctl_all_flags) (struct xpc_partition *);
 extern enum xp_retval (*xpc_setup_msg_structures) (struct xpc_channel *);
@@ -909,40 +919,6 @@ extern void xpc_disconnect_channel(const int, struct xpc_channel *,
 extern void xpc_disconnect_callout(struct xpc_channel *, enum xp_retval);
 extern void xpc_partition_going_down(struct xpc_partition *, enum xp_retval);
 
-static inline int
-xpc_hb_allowed(short partid, void *heartbeating_to_mask)
-{
-        return test_bit(partid, heartbeating_to_mask);
-}
-
-static inline int
-xpc_any_hbs_allowed(void)
-{
-        DBUG_ON(xpc_heartbeating_to_mask == NULL);
-        return !bitmap_empty(xpc_heartbeating_to_mask, xp_max_npartitions);
-}
-
-static inline void
-xpc_allow_hb(short partid)
-{
-        DBUG_ON(xpc_heartbeating_to_mask == NULL);
-        set_bit(partid, xpc_heartbeating_to_mask);
-}
-
-static inline void
-xpc_disallow_hb(short partid)
-{
-        DBUG_ON(xpc_heartbeating_to_mask == NULL);
-        clear_bit(partid, xpc_heartbeating_to_mask);
-}
-
-static inline void
-xpc_disallow_all_hbs(void)
-{
-        DBUG_ON(xpc_heartbeating_to_mask == NULL);
-        bitmap_zero(xpc_heartbeating_to_mask, xp_max_npartitions);
-}
-
 static inline void
 xpc_wakeup_channel_mgr(struct xpc_partition *part)
 {