* clear of the Timeout bit (as well) will free the resource. No reply will
* be sent (the hardware will only do one reply per message).
*/
-static void reply_to_message(struct msg_desc *mdp, struct bau_control *bcp)
+static void reply_to_message(struct msg_desc *mdp, struct bau_control *bcp,
+ int do_acknowledge)
{
unsigned long dw;
struct bau_pq_entry *msg;
msg = mdp->msg;
- if (!msg->canceled) {
+ if (!msg->canceled && do_acknowledge) {
dw = (msg->swack_vec << UV_SW_ACK_NPENDING) | msg->swack_vec;
write_mmr_sw_ack(dw);
}
if (mmr & (msg_res << UV_SW_ACK_NPENDING)) {
unsigned long mr;
/*
- * is the resource timed out?
- * make everyone ignore the cancelled message.
+ * Is the resource timed out?
+ * Make everyone ignore the cancelled message.
*/
msg2->canceled = 1;
stat->d_canceled++;
* Do all the things a cpu should do for a TLB shootdown message.
* Other cpu's may come here at the same time for this message.
*/
-static void bau_process_message(struct msg_desc *mdp,
- struct bau_control *bcp)
+static void bau_process_message(struct msg_desc *mdp, struct bau_control *bcp,
+ int do_acknowledge)
{
short socket_ack_count = 0;
short *sp;
if (msg_ack_count == bcp->cpus_in_uvhub) {
/*
* All cpus in uvhub saw it; reply
+ * (unless we are in the UV2 workaround)
*/
- reply_to_message(mdp, bcp);
+ reply_to_message(mdp, bcp, do_acknowledge);
}
}
/*
* UV2 has an extra bit of status in the ACTIVATION_STATUS_2 register.
*/
-static unsigned long uv2_read_status(unsigned long offset, int rshft, int cpu)
+static unsigned long uv2_read_status(unsigned long offset, int rshft, int desc)
{
unsigned long descriptor_status;
unsigned long descriptor_status2;
descriptor_status = ((read_lmmr(offset) >> rshft) & UV_ACT_STATUS_MASK);
- descriptor_status2 = (read_mmr_uv2_status() >> cpu) & 0x1UL;
+ descriptor_status2 = (read_mmr_uv2_status() >> desc) & 0x1UL;
descriptor_status = (descriptor_status << 1) | descriptor_status2;
return descriptor_status;
}
+/*
+ * Return whether the status of the descriptor that is normally used for this
+ * cpu (the one indexed by its hub-relative cpu number) is busy.
+ * The status of the original 32 descriptors is always reflected in the 64
+ * bits of UVH_LB_BAU_SB_ACTIVATION_STATUS_0.
+ * The bit provided by the activation_status_2 register is irrelevant to
+ * the status if it is only being tested for busy or not busy.
+ */
+int normal_busy(struct bau_control *bcp)
+{
+ int cpu = bcp->uvhub_cpu;
+ int mmr_offset;
+ int right_shift;
+
+ mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_0;
+ right_shift = cpu * UV_ACT_STATUS_SIZE;
+ return (((((read_lmmr(mmr_offset) >> right_shift) &
+ UV_ACT_STATUS_MASK)) << 1) == UV2H_DESC_BUSY);
+}
+
+/*
+ * Entered when a bau descriptor has gone into a permanent busy wait because
+ * of a hardware bug.
+ * Workaround the bug.
+ */
+int handle_uv2_busy(struct bau_control *bcp)
+{
+ int busy_one = bcp->using_desc;
+ int normal = bcp->uvhub_cpu;
+ int selected = -1;
+ int i;
+ unsigned long descriptor_status;
+ unsigned long status;
+ int mmr_offset;
+ struct bau_desc *bau_desc_old;
+ struct bau_desc *bau_desc_new;
+ struct bau_control *hmaster = bcp->uvhub_master;
+ struct ptc_stats *stat = bcp->statp;
+ cycles_t ttm;
+
+ stat->s_uv2_wars++;
+ spin_lock(&hmaster->uvhub_lock);
+ /* try for the original first */
+ if (busy_one != normal) {
+ if (!normal_busy(bcp))
+ selected = normal;
+ }
+ if (selected < 0) {
+ /* can't use the normal, select an alternate */
+ mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_1;
+ descriptor_status = read_lmmr(mmr_offset);
+
+ /* scan available descriptors 32-63 */
+ for (i = 0; i < UV_CPUS_PER_AS; i++) {
+ if ((hmaster->inuse_map & (1 << i)) == 0) {
+ status = ((descriptor_status >>
+ (i * UV_ACT_STATUS_SIZE)) &
+ UV_ACT_STATUS_MASK) << 1;
+ if (status != UV2H_DESC_BUSY) {
+ selected = i + UV_CPUS_PER_AS;
+ break;
+ }
+ }
+ }
+ }
+
+ if (busy_one != normal)
+ /* mark the busy alternate as not in-use */
+ hmaster->inuse_map &= ~(1 << (busy_one - UV_CPUS_PER_AS));
+
+ if (selected >= 0) {
+ /* switch to the selected descriptor */
+ if (selected != normal) {
+ /* set the selected alternate as in-use */
+ hmaster->inuse_map |=
+ (1 << (selected - UV_CPUS_PER_AS));
+ if (selected > stat->s_uv2_wars_hw)
+ stat->s_uv2_wars_hw = selected;
+ }
+ bau_desc_old = bcp->descriptor_base;
+ bau_desc_old += (ITEMS_PER_DESC * busy_one);
+ bcp->using_desc = selected;
+ bau_desc_new = bcp->descriptor_base;
+ bau_desc_new += (ITEMS_PER_DESC * selected);
+ *bau_desc_new = *bau_desc_old;
+ } else {
+ /*
+ * All are busy. Wait for the normal one for this cpu to
+ * free up.
+ */
+ stat->s_uv2_war_waits++;
+ spin_unlock(&hmaster->uvhub_lock);
+ ttm = get_cycles();
+ do {
+ cpu_relax();
+ } while (normal_busy(bcp));
+ spin_lock(&hmaster->uvhub_lock);
+ /* switch to the original descriptor */
+ bcp->using_desc = normal;
+ bau_desc_old = bcp->descriptor_base;
+ bau_desc_old += (ITEMS_PER_DESC * bcp->using_desc);
+ bcp->using_desc = (ITEMS_PER_DESC * normal);
+ bau_desc_new = bcp->descriptor_base;
+ bau_desc_new += (ITEMS_PER_DESC * normal);
+ *bau_desc_new = *bau_desc_old; /* copy the entire descriptor */
+ }
+ spin_unlock(&hmaster->uvhub_lock);
+ return FLUSH_RETRY_BUSYBUG;
+}
+
static int uv2_wait_completion(struct bau_desc *bau_desc,
unsigned long mmr_offset, int right_shift,
struct bau_control *bcp, long try)
{
unsigned long descriptor_stat;
cycles_t ttm;
- int cpu = bcp->uvhub_cpu;
+ int desc = bcp->using_desc;
+ long busy_reps = 0;
struct ptc_stats *stat = bcp->statp;
- descriptor_stat = uv2_read_status(mmr_offset, right_shift, cpu);
+ descriptor_stat = uv2_read_status(mmr_offset, right_shift, desc);
/* spin on the status MMR, waiting for it to go idle */
while (descriptor_stat != UV2H_DESC_IDLE) {
bcp->conseccompletes = 0;
return FLUSH_RETRY_TIMEOUT;
} else {
+ busy_reps++;
+ if (busy_reps > 1000000) {
+ /* not to hammer on the clock */
+ busy_reps = 0;
+ ttm = get_cycles();
+ if ((ttm - bcp->send_message) >
+ (bcp->clocks_per_100_usec)) {
+ return handle_uv2_busy(bcp);
+ }
+ }
/*
* descriptor_stat is still BUSY
*/
cpu_relax();
}
- descriptor_stat = uv2_read_status(mmr_offset, right_shift, cpu);
+ descriptor_stat = uv2_read_status(mmr_offset, right_shift,
+ desc);
}
bcp->conseccompletes++;
return FLUSH_COMPLETE;
{
int right_shift;
unsigned long mmr_offset;
- int cpu = bcp->uvhub_cpu;
+ int desc = bcp->using_desc;
- if (cpu < UV_CPUS_PER_AS) {
+ if (desc < UV_CPUS_PER_AS) {
mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_0;
- right_shift = cpu * UV_ACT_STATUS_SIZE;
+ right_shift = desc * UV_ACT_STATUS_SIZE;
} else {
mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_1;
- right_shift = ((cpu - UV_CPUS_PER_AS) * UV_ACT_STATUS_SIZE);
+ right_shift = ((desc - UV_CPUS_PER_AS) * UV_ACT_STATUS_SIZE);
}
if (bcp->uvhub_version == 1)
* Returns 1 if it gives up entirely and the original cpu mask is to be
* returned to the kernel.
*/
-int uv_flush_send_and_wait(struct bau_desc *bau_desc,
- struct cpumask *flush_mask, struct bau_control *bcp)
+int uv_flush_send_and_wait(struct cpumask *flush_mask, struct bau_control *bcp)
{
int seq_number = 0;
int completion_stat = 0;
struct bau_control *hmaster = bcp->uvhub_master;
struct uv1_bau_msg_header *uv1_hdr = NULL;
struct uv2_bau_msg_header *uv2_hdr = NULL;
+ struct bau_desc *bau_desc;
- if (bcp->uvhub_version == 1) {
- uv1 = 1;
+ if (bcp->uvhub_version == 1)
uv1_throttle(hmaster, stat);
- uv1_hdr = &bau_desc->header.uv1_hdr;
- } else
- uv2_hdr = &bau_desc->header.uv2_hdr;
while (hmaster->uvhub_quiesce)
cpu_relax();
time1 = get_cycles();
do {
- if (try == 0) {
+ bau_desc = bcp->descriptor_base;
+ bau_desc += (ITEMS_PER_DESC * bcp->using_desc);
+ if (bcp->uvhub_version == 1) {
+ uv1 = 1;
+ uv1_hdr = &bau_desc->header.uv1_hdr;
+ } else
+ uv2_hdr = &bau_desc->header.uv2_hdr;
+ if ((try == 0) || (completion_stat == FLUSH_RETRY_BUSYBUG)) {
if (uv1)
uv1_hdr->msg_type = MSG_REGULAR;
else
uv1_hdr->sequence = seq_number;
else
uv2_hdr->sequence = seq_number;
- index = (1UL << AS_PUSH_SHIFT) | bcp->uvhub_cpu;
+ index = (1UL << AS_PUSH_SHIFT) | bcp->using_desc;
bcp->send_message = get_cycles();
write_mmr_activation(index);
try++;
completion_stat = wait_completion(bau_desc, bcp, try);
+ /* UV2: wait_completion() may change the bcp->using_desc */
handle_cmplt(completion_stat, bau_desc, bcp, hmaster, stat);
}
cpu_relax();
} while ((completion_stat == FLUSH_RETRY_PLUGGED) ||
+ (completion_stat == FLUSH_RETRY_BUSYBUG) ||
(completion_stat == FLUSH_RETRY_TIMEOUT));
time2 = get_cycles();
record_send_stats(time1, time2, bcp, stat, completion_stat, try);
if (completion_stat == FLUSH_GIVEUP)
+ /* FLUSH_GIVEUP will fall back to using IPI's for tlb flush */
return 1;
return 0;
}
stat->s_ntargself++;
bau_desc = bcp->descriptor_base;
- bau_desc += (ITEMS_PER_DESC * bcp->uvhub_cpu);
+ bau_desc += (ITEMS_PER_DESC * bcp->using_desc);
bau_uvhubs_clear(&bau_desc->distribution, UV_DISTRIBUTION_SIZE);
if (set_distrib_bits(flush_mask, bcp, bau_desc, &locals, &remotes))
return NULL;
* uv_flush_send_and_wait returns 0 if all cpu's were messaged,
* or 1 if it gave up and the original cpumask should be returned.
*/
- if (!uv_flush_send_and_wait(bau_desc, flush_mask, bcp))
+ if (!uv_flush_send_and_wait(flush_mask, bcp))
return NULL;
else
return cpumask;
}
/*
+ * Search the message queue for any 'other' message with the same software
+ * acknowledge resource bit vector.
+ */
+struct bau_pq_entry *find_another_by_swack(struct bau_pq_entry *msg,
+ struct bau_control *bcp, unsigned char swack_vec)
+{
+ struct bau_pq_entry *msg_next = msg + 1;
+
+ if (msg_next > bcp->queue_last)
+ msg_next = bcp->queue_first;
+ while ((msg_next->swack_vec != 0) && (msg_next != msg)) {
+ if (msg_next->swack_vec == swack_vec)
+ return msg_next;
+ msg_next++;
+ if (msg_next > bcp->queue_last)
+ msg_next = bcp->queue_first;
+ }
+ return NULL;
+}
+
+/*
+ * UV2 needs to work around a bug in which an arriving message has not
+ * set a bit in the UVH_LB_BAU_INTD_SOFTWARE_ACKNOWLEDGE register.
+ * Such a message must be ignored.
+ */
+void process_uv2_message(struct msg_desc *mdp, struct bau_control *bcp)
+{
+ unsigned long mmr_image;
+ unsigned char swack_vec;
+ struct bau_pq_entry *msg = mdp->msg;
+ struct bau_pq_entry *other_msg;
+
+ mmr_image = read_mmr_sw_ack();
+ swack_vec = msg->swack_vec;
+
+ if ((swack_vec & mmr_image) == 0) {
+ /*
+ * This message was assigned a swack resource, but no
+ * reserved acknowlegment is pending.
+ * The bug has prevented this message from setting the MMR.
+ * And no other message has used the same sw_ack resource.
+ * Do the requested shootdown but do not reply to the msg.
+ * (the 0 means make no acknowledge)
+ */
+ bau_process_message(mdp, bcp, 0);
+ return;
+ }
+
+ /*
+ * Some message has set the MMR 'pending' bit; it might have been
+ * another message. Look for that message.
+ */
+ other_msg = find_another_by_swack(msg, bcp, msg->swack_vec);
+ if (other_msg) {
+ /* There is another. Do not ack the current one. */
+ bau_process_message(mdp, bcp, 0);
+ /*
+ * Let the natural processing of that message acknowledge
+ * it. Don't get the processing of sw_ack's out of order.
+ */
+ return;
+ }
+
+ /*
+ * There is no other message using this sw_ack, so it is safe to
+ * acknowledge it.
+ */
+ bau_process_message(mdp, bcp, 1);
+
+ return;
+}
+
+/*
* The BAU message interrupt comes here. (registered by set_intr_gate)
* See entry_64.S
*
count++;
msgdesc.msg_slot = msg - msgdesc.queue_first;
- msgdesc.swack_slot = ffs(msg->swack_vec) - 1;
msgdesc.msg = msg;
- bau_process_message(&msgdesc, bcp);
+ if (bcp->uvhub_version == 2)
+ process_uv2_message(&msgdesc, bcp);
+ else
+ bau_process_message(&msgdesc, bcp, 1);
msg++;
if (msg > msgdesc.queue_last)
seq_printf(file,
"all one mult none retry canc nocan reset rcan ");
seq_printf(file,
- "disable enable\n");
+ "disable enable wars warshw warwaits\n");
}
if (cpu < num_possible_cpus() && cpu_online(cpu)) {
stat = &per_cpu(ptcstats, cpu);
stat->d_nomsg, stat->d_retries, stat->d_canceled,
stat->d_nocanceled, stat->d_resets,
stat->d_rcanceled);
- seq_printf(file, "%ld %ld\n",
- stat->s_bau_disabled, stat->s_bau_reenabled);
+ seq_printf(file, "%ld %ld %ld %ld %ld\n",
+ stat->s_bau_disabled, stat->s_bau_reenabled,
+ stat->s_uv2_wars, stat->s_uv2_wars_hw,
+ stat->s_uv2_war_waits);
}
return 0;
}
write_mmr_payload_first(pnode, pn_first);
write_mmr_payload_tail(pnode, first);
write_mmr_payload_last(pnode, last);
+ write_gmmr_sw_ack(pnode, 0xffffUL);
/* in effect, all msg_type's are set to MSG_NOOP */
memset(pqp, 0, sizeof(struct bau_pq_entry) * DEST_Q_SIZE);
bcp->cong_response_us = congested_respns_us;
bcp->cong_reps = congested_reps;
bcp->cong_period = congested_period;
+ bcp->clocks_per_100_usec = usec_2_cycles(100);
}
}
}
bcp->uvhub_master = *hmasterp;
bcp->uvhub_cpu = uv_cpu_hub_info(cpu)->blade_processor_id;
+ bcp->using_desc = bcp->uvhub_cpu;
if (bcp->uvhub_cpu >= MAX_CPUS_PER_UVHUB) {
printk(KERN_EMERG "%d cpus per uvhub invalid\n",
bcp->uvhub_cpu);