+++ /dev/null
-From: Gerald Schaefer <geraldsc@de.ibm.com>
-Subject: qdio: rework inbound buffer acknowledgement
-References: bnc#458339
-
-Symptom: Inbound network traffic stall.
-Problem: Under high load the qdio buffer that specifies the acknowledge
- mode can be overwritten.
-Solution: Use automatic acknowledgement of incoming buffers in QEBSM mode
- to improve performance with QIOASSIST.
- Move ACK for non-QEBSM mode always to the newest buffer to prevent
- a race with qdio_stop_polling.
- Remove the polling spinlock, the upper layer drivers return new
- buffers in the same code path and could not run in parallel.
- Don't flood the error log in case of no-target-buffer-empty.
- In handle_inbound we check if we would overwrite an ACK'ed buffer,
- if so advance the pointer to the oldest ACK'ed buffer so we don't
- overwrite an empty buffer in qdio_stop_polling.
-
-Acked-by: John Jolly <jjolly@suse.de>
-
----
- drivers/s390/cio/qdio.h | 19 ++--
- drivers/s390/cio/qdio_debug.c | 7 +
- drivers/s390/cio/qdio_main.c | 181 ++++++++++++++++++++++++++--------------
- drivers/s390/cio/qdio_perf.c | 2
- drivers/s390/cio/qdio_perf.h | 1
- drivers/s390/cio/qdio_setup.c | 1
- drivers/s390/cio/qdio_thinint.c | 2
- 7 files changed, 139 insertions(+), 74 deletions(-)
-
-Index: linux-sles11/drivers/s390/cio/qdio.h
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio.h
-+++ linux-sles11/drivers/s390/cio/qdio.h
-@@ -112,12 +112,12 @@ static inline int do_sqbs(u64 token, uns
- }
-
- static inline int do_eqbs(u64 token, unsigned char *state, int queue,
-- int *start, int *count)
-+ int *start, int *count, int ack)
- {
- register unsigned long _ccq asm ("0") = *count;
- register unsigned long _token asm ("1") = token;
- unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
-- unsigned long _state = 0;
-+ unsigned long _state = (unsigned long)ack << 63;
-
- asm volatile(
- " .insn rrf,0xB99c0000,%1,%2,0,0"
-@@ -134,7 +134,7 @@ static inline int do_eqbs(u64 token, uns
- static inline int do_sqbs(u64 token, unsigned char state, int queue,
- int *start, int *count) { return 0; }
- static inline int do_eqbs(u64 token, unsigned char *state, int queue,
-- int *start, int *count) { return 0; }
-+ int *start, int *count, int ack) { return 0; }
- #endif /* CONFIG_64BIT */
-
- struct qdio_irq;
-@@ -187,11 +187,11 @@ struct qdio_input_q {
- /* input buffer acknowledgement flag */
- int polling;
-
-+ /* how much sbals are acknowledged with qebsm */
-+ int ack_count;
-+
- /* last time of noticing incoming data */
- u64 timestamp;
--
-- /* lock for clearing the acknowledgement */
-- spinlock_t lock;
- };
-
- struct qdio_output_q {
-@@ -348,10 +348,13 @@ static inline unsigned long long get_use
- ((bufnr + 1) & QDIO_MAX_BUFFERS_MASK)
- #define add_buf(bufnr, inc) \
- ((bufnr + inc) & QDIO_MAX_BUFFERS_MASK)
-+#define sub_buf(bufnr, dec) \
-+ ((bufnr - dec) & QDIO_MAX_BUFFERS_MASK)
-
- /* prototypes for thin interrupt */
- void qdio_sync_after_thinint(struct qdio_q *q);
--int get_buf_state(struct qdio_q *q, unsigned int bufnr, unsigned char *state);
-+int get_buf_state(struct qdio_q *q, unsigned int bufnr, unsigned char *state,
-+ int auto_ack);
- void qdio_check_outbound_after_thinint(struct qdio_q *q);
- int qdio_inbound_q_moved(struct qdio_q *q);
- void qdio_kick_inbound_handler(struct qdio_q *q);
-@@ -385,6 +388,8 @@ int qdio_setup_irq(struct qdio_initializ
- void qdio_print_subchannel_info(struct qdio_irq *irq_ptr,
- struct ccw_device *cdev);
- void qdio_release_memory(struct qdio_irq *irq_ptr);
-+int qdio_setup_create_sysfs(struct ccw_device *cdev);
-+void qdio_setup_destroy_sysfs(struct ccw_device *cdev);
- int qdio_setup_init(void);
- void qdio_setup_exit(void);
-
-Index: linux-sles11/drivers/s390/cio/qdio_debug.c
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_debug.c
-+++ linux-sles11/drivers/s390/cio/qdio_debug.c
-@@ -59,16 +59,18 @@ static int qstat_show(struct seq_file *m
- if (!q)
- return 0;
-
-- seq_printf(m, "device state indicator: %d\n", *q->irq_ptr->dsci);
-+ seq_printf(m, "device state indicator: %d\n", *(u32 *)q->irq_ptr->dsci);
- seq_printf(m, "nr_used: %d\n", atomic_read(&q->nr_buf_used));
- seq_printf(m, "ftc: %d\n", q->first_to_check);
- seq_printf(m, "last_move_ftc: %d\n", q->last_move_ftc);
- seq_printf(m, "polling: %d\n", q->u.in.polling);
-+ seq_printf(m, "ack count: %d\n", q->u.in.ack_count);
- seq_printf(m, "slsb buffer states:\n");
-+ seq_printf(m, "|0 |8 |16 |24 |32 |40 |48 |56 63|\n");
-
- qdio_siga_sync_q(q);
- for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++) {
-- get_buf_state(q, i, &state);
-+ get_buf_state(q, i, &state, 0);
- switch (state) {
- case SLSB_P_INPUT_NOT_INIT:
- case SLSB_P_OUTPUT_NOT_INIT:
-@@ -100,6 +102,7 @@ static int qstat_show(struct seq_file *m
- seq_printf(m, "\n");
- }
- seq_printf(m, "\n");
-+ seq_printf(m, "|64 |72 |80 |88 |96 |104 |112 | 127|\n");
- return 0;
- }
-
-Index: linux-sles11/drivers/s390/cio/qdio_main.c
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_main.c
-+++ linux-sles11/drivers/s390/cio/qdio_main.c
-@@ -112,12 +112,13 @@ static inline int qdio_check_ccq(struct
- * @state: state of the extracted buffers
- * @start: buffer number to start at
- * @count: count of buffers to examine
-+ * @auto_ack: automatically acknowledge buffers
- *
- * Returns the number of successfull extracted equal buffer states.
- * Stops processing if a state is different from the last buffers state.
- */
- static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
-- int start, int count)
-+ int start, int count, int auto_ack)
- {
- unsigned int ccq = 0;
- int tmp_count = count, tmp_start = start;
-@@ -129,7 +130,8 @@ static int qdio_do_eqbs(struct qdio_q *q
- if (!q->is_input_q)
- nr += q->irq_ptr->nr_input_qs;
- again:
-- ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
-+ ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
-+ auto_ack);
- rc = qdio_check_ccq(q, ccq);
-
- /* At least one buffer was processed, return and extract the remaining
-@@ -172,6 +174,9 @@ static int qdio_do_sqbs(struct qdio_q *q
- int nr = q->nr;
- int rc;
-
-+ if (!count)
-+ return 0;
-+
- BUG_ON(!q->irq_ptr->sch_token);
-
- if (!q->is_input_q)
-@@ -197,7 +202,8 @@ again:
-
- /* returns number of examined buffers and their common state in *state */
- static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
-- unsigned char *state, unsigned int count)
-+ unsigned char *state, unsigned int count,
-+ int auto_ack)
- {
- unsigned char __state = 0;
- int i;
-@@ -206,7 +212,7 @@ static inline int get_buf_states(struct
- BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);
-
- if (is_qebsm(q))
-- return qdio_do_eqbs(q, state, bufnr, count);
-+ return qdio_do_eqbs(q, state, bufnr, count, auto_ack);
-
- for (i = 0; i < count; i++) {
- if (!__state)
-@@ -220,9 +226,9 @@ static inline int get_buf_states(struct
- }
-
- inline int get_buf_state(struct qdio_q *q, unsigned int bufnr,
-- unsigned char *state)
-+ unsigned char *state, int auto_ack)
- {
-- return get_buf_states(q, bufnr, state, 1);
-+ return get_buf_states(q, bufnr, state, 1, auto_ack);
- }
-
- /* wrap-around safe setting of slsb states, returns number of changed buffers */
-@@ -367,29 +373,91 @@ void qdio_sync_after_thinint(struct qdio
-
- inline void qdio_stop_polling(struct qdio_q *q)
- {
-- spin_lock_bh(&q->u.in.lock);
-- if (!q->u.in.polling) {
-- spin_unlock_bh(&q->u.in.lock);
-+ if (!q->u.in.polling)
- return;
-- }
-+
- q->u.in.polling = 0;
- qdio_perf_stat_inc(&perf_stats.debug_stop_polling);
-
- /* show the card that we are not polling anymore */
-- set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
-- spin_unlock_bh(&q->u.in.lock);
-+ if (is_qebsm(q)) {
-+ set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
-+ q->u.in.ack_count);
-+ q->u.in.ack_count = 0;
-+ } else
-+ set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
- }
-
--static void announce_buffer_error(struct qdio_q *q)
-+static void announce_buffer_error(struct qdio_q *q, int count)
- {
-+ q->qdio_error = QDIO_ERROR_SLSB_STATE;
-+
-+ /* special handling for no target buffer empty */
-+ if ((!q->is_input_q &&
-+ (q->sbal[q->first_to_check]->element[15].flags & 0xff) == 0x10)) {
-+ qdio_perf_stat_inc(&perf_stats.outbound_target_full);
-+ DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%3d",
-+ q->first_to_check);
-+ return;
-+ }
-+
- DBF_ERROR("%4x BUF ERROR", SCH_NO(q));
- DBF_ERROR((q->is_input_q) ? "IN:%2d" : "OUT:%2d", q->nr);
-- DBF_ERROR("FTC:%3d", q->first_to_check);
-+ DBF_ERROR("FTC:%3d C:%3d", q->first_to_check, count);
- DBF_ERROR("F14:%2x F15:%2x",
- q->sbal[q->first_to_check]->element[14].flags & 0xff,
- q->sbal[q->first_to_check]->element[15].flags & 0xff);
-+}
-
-- q->qdio_error = QDIO_ERROR_SLSB_STATE;
-+static inline void inbound_primed(struct qdio_q *q, int count)
-+{
-+ int new;
-+
-+ DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim: %3d", count);
-+
-+ /* for QEBSM the ACK was already set by EQBS */
-+ if (is_qebsm(q)) {
-+ if (!q->u.in.polling) {
-+ q->u.in.polling = 1;
-+ q->u.in.ack_count = count;
-+ q->last_move_ftc = q->first_to_check;
-+ return;
-+ }
-+
-+ /* delete the previous ACK's */
-+ set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
-+ q->u.in.ack_count);
-+ q->u.in.ack_count = count;
-+ q->last_move_ftc = q->first_to_check;
-+ return;
-+ }
-+
-+ /*
-+ * ACK the newest buffer. The ACK will be removed in qdio_stop_polling
-+ * or by the next inbound run.
-+ */
-+ new = add_buf(q->first_to_check, count - 1);
-+ if (q->u.in.polling) {
-+ /* reset the previous ACK but first set the new one */
-+ set_buf_state(q, new, SLSB_P_INPUT_ACK);
-+ set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
-+ }
-+ else {
-+ q->u.in.polling = 1;
-+ set_buf_state(q, q->first_to_check, SLSB_P_INPUT_ACK);
-+ }
-+
-+ q->last_move_ftc = new;
-+ count--;
-+ if (!count)
-+ return;
-+
-+ /*
-+ * Need to change all PRIMED buffers to NOT_INIT, otherwise
-+ * we're loosing initiative in the thinint code.
-+ */
-+ set_buf_states(q, next_buf(q->first_to_check), SLSB_P_INPUT_NOT_INIT,
-+ count);
- }
-
- static int get_inbound_buffer_frontier(struct qdio_q *q)
-@@ -398,13 +466,6 @@ static int get_inbound_buffer_frontier(s
- unsigned char state;
-
- /*
-- * If we still poll don't update last_move_ftc, keep the
-- * previously ACK buffer there.
-- */
-- if (!q->u.in.polling)
-- q->last_move_ftc = q->first_to_check;
--
-- /*
- * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
- * would return 0.
- */
-@@ -424,34 +485,13 @@ check_next:
- if (q->first_to_check == stop)
- goto out;
-
-- count = get_buf_states(q, q->first_to_check, &state, count);
-+ count = get_buf_states(q, q->first_to_check, &state, count, 1);
- if (!count)
- goto out;
-
- switch (state) {
- case SLSB_P_INPUT_PRIMED:
-- DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim: %3d", count);
--
-- /*
-- * Only ACK the first buffer. The ACK will be removed in
-- * qdio_stop_polling.
-- */
-- if (q->u.in.polling)
-- state = SLSB_P_INPUT_NOT_INIT;
-- else {
-- q->u.in.polling = 1;
-- state = SLSB_P_INPUT_ACK;
-- }
-- set_buf_state(q, q->first_to_check, state);
--
-- /*
-- * Need to change all PRIMED buffers to NOT_INIT, otherwise
-- * we're loosing initiative in the thinint code.
-- */
-- if (count > 1)
-- set_buf_states(q, next_buf(q->first_to_check),
-- SLSB_P_INPUT_NOT_INIT, count - 1);
--
-+ inbound_primed(q, count);
- /*
- * No siga-sync needed for non-qebsm here, as the inbound queue
- * will be synced on the next siga-r, resp.
-@@ -461,7 +501,7 @@ check_next:
- atomic_sub(count, &q->nr_buf_used);
- goto check_next;
- case SLSB_P_INPUT_ERROR:
-- announce_buffer_error(q);
-+ announce_buffer_error(q, count);
- /* process the buffer, the upper layer will take care of it */
- q->first_to_check = add_buf(q->first_to_check, count);
- atomic_sub(count, &q->nr_buf_used);
-@@ -507,7 +547,7 @@ static int qdio_inbound_q_done(struct qd
- */
- qdio_siga_sync_q(q);
-
-- get_buf_state(q, q->first_to_check, &state);
-+ get_buf_state(q, q->first_to_check, &state, 0);
- if (state == SLSB_P_INPUT_PRIMED)
- /* we got something to do */
- return 0;
-@@ -610,7 +650,7 @@ check_next:
- if (q->first_to_check == stop)
- return q->first_to_check;
-
-- count = get_buf_states(q, q->first_to_check, &state, count);
-+ count = get_buf_states(q, q->first_to_check, &state, count, 0);
- if (!count)
- return q->first_to_check;
-
-@@ -629,7 +669,7 @@ check_next:
- break;
- goto check_next;
- case SLSB_P_OUTPUT_ERROR:
-- announce_buffer_error(q);
-+ announce_buffer_error(q, count);
- /* process the buffer, the upper layer will take care of it */
- q->first_to_check = add_buf(q->first_to_check, count);
- atomic_sub(count, &q->nr_buf_used);
-@@ -1441,23 +1481,38 @@ static inline int buf_in_between(int buf
- static void handle_inbound(struct qdio_q *q, unsigned int callflags,
- int bufnr, int count)
- {
-- unsigned long flags;
-- int used, rc;
-+ int used, rc, diff;
-
-- /*
-- * do_QDIO could run in parallel with the queue tasklet so the
-- * upper-layer programm could empty the ACK'ed buffer here.
-- * If that happens we must clear the polling flag, otherwise
-- * qdio_stop_polling() could set the buffer to NOT_INIT after
-- * it was set to EMPTY which would kill us.
-- */
-- spin_lock_irqsave(&q->u.in.lock, flags);
-- if (q->u.in.polling)
-- if (buf_in_between(q->last_move_ftc, bufnr, count))
-+ if (!q->u.in.polling)
-+ goto set;
-+
-+ /* protect against stop polling setting an ACK for an emptied slsb */
-+ if (count == QDIO_MAX_BUFFERS_PER_Q) {
-+ /* overwriting everything, just delete polling status */
-+ q->u.in.polling = 0;
-+ q->u.in.ack_count = 0;
-+ goto set;
-+ } else if (buf_in_between(q->last_move_ftc, bufnr, count)) {
-+ if (is_qebsm(q)) {
-+ /* partial overwrite, just update last_move_ftc */
-+ diff = add_buf(bufnr, count);
-+ diff = sub_buf(diff, q->last_move_ftc);
-+ q->u.in.ack_count -= diff;
-+ if (q->u.in.ack_count <= 0) {
-+ q->u.in.polling = 0;
-+ q->u.in.ack_count = 0;
-+ /* TODO: must we set last_move_ftc to something meaningful? */
-+ goto set;
-+ }
-+ q->last_move_ftc = add_buf(q->last_move_ftc, diff);
-+ }
-+ else
-+ /* the only ACK will be deleted, so stop polling */
- q->u.in.polling = 0;
-+ }
-
-+set:
- count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);
-- spin_unlock_irqrestore(&q->u.in.lock, flags);
-
- used = atomic_add_return(count, &q->nr_buf_used) - count;
- BUG_ON(used + count > QDIO_MAX_BUFFERS_PER_Q);
-@@ -1516,7 +1571,7 @@ static void handle_outbound(struct qdio_
- }
-
- /* try to fast requeue buffers */
-- get_buf_state(q, prev_buf(bufnr), &state);
-+ get_buf_state(q, prev_buf(bufnr), &state, 0);
- if (state != SLSB_CU_OUTPUT_PRIMED)
- qdio_kick_outbound_q(q);
- else {
-Index: linux-sles11/drivers/s390/cio/qdio_perf.c
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_perf.c
-+++ linux-sles11/drivers/s390/cio/qdio_perf.c
-@@ -74,6 +74,8 @@ static int qdio_perf_proc_show(struct se
- seq_printf(m, "\n");
- seq_printf(m, "Number of fast requeues (outg. SBAL w/o SIGA)\t: %li\n",
- (long)atomic_long_read(&perf_stats.fast_requeue));
-+ seq_printf(m, "Number of outbound target full condition\t: %li\n",
-+ (long)atomic_long_read(&perf_stats.outbound_target_full));
- seq_printf(m, "Number of outbound tasklet mod_timer calls\t: %li\n",
- (long)atomic_long_read(&perf_stats.debug_tl_out_timer));
- seq_printf(m, "Number of stop polling calls\t\t\t: %li\n",
-Index: linux-sles11/drivers/s390/cio/qdio_perf.h
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_perf.h
-+++ linux-sles11/drivers/s390/cio/qdio_perf.h
-@@ -36,6 +36,7 @@ struct qdio_perf_stats {
- atomic_long_t inbound_handler;
- atomic_long_t outbound_handler;
- atomic_long_t fast_requeue;
-+ atomic_long_t outbound_target_full;
-
- /* for debugging */
- atomic_long_t debug_tl_out_timer;
-Index: linux-sles11/drivers/s390/cio/qdio_setup.c
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_setup.c
-+++ linux-sles11/drivers/s390/cio/qdio_setup.c
-@@ -167,7 +167,6 @@ static void setup_queues(struct qdio_irq
- setup_queues_misc(q, irq_ptr, qdio_init->input_handler, i);
-
- q->is_input_q = 1;
-- spin_lock_init(&q->u.in.lock);
- setup_storage_lists(q, irq_ptr, input_sbal_array, i);
- input_sbal_array += QDIO_MAX_BUFFERS_PER_Q;
-
-Index: linux-sles11/drivers/s390/cio/qdio_thinint.c
-===================================================================
---- linux-sles11.orig/drivers/s390/cio/qdio_thinint.c
-+++ linux-sles11/drivers/s390/cio/qdio_thinint.c
-@@ -131,7 +131,7 @@ static inline int tiqdio_inbound_q_done(
- return 1;
-
- qdio_siga_sync_q(q);
-- get_buf_state(q, q->first_to_check, &state);
-+ get_buf_state(q, q->first_to_check, &state, 0);
-
- if (state == SLSB_P_INPUT_PRIMED)
- /* more work coming */
projects / people / pmueller / ipfire-2.x.git / blobdiff