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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
[S390] qdio: improve inbound buffer acknowledgement
- Use automatic acknowledgement of incoming buffers in QEBSM mode - 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 Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
22f9934767
commit
50f769df1c
7 changed files with 139 additions and 74 deletions
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@ -112,12 +112,12 @@ static inline int do_sqbs(u64 token, unsigned char state, int queue,
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}
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static inline int do_eqbs(u64 token, unsigned char *state, int queue,
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int *start, int *count)
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int *start, int *count, int ack)
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{
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register unsigned long _ccq asm ("0") = *count;
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register unsigned long _token asm ("1") = token;
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unsigned long _queuestart = ((unsigned long)queue << 32) | *start;
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unsigned long _state = 0;
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unsigned long _state = (unsigned long)ack << 63;
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asm volatile(
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" .insn rrf,0xB99c0000,%1,%2,0,0"
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@ -134,7 +134,7 @@ static inline int do_eqbs(u64 token, unsigned char *state, int queue,
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static inline int do_sqbs(u64 token, unsigned char state, int queue,
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int *start, int *count) { return 0; }
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static inline int do_eqbs(u64 token, unsigned char *state, int queue,
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int *start, int *count) { return 0; }
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int *start, int *count, int ack) { return 0; }
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#endif /* CONFIG_64BIT */
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struct qdio_irq;
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@ -187,11 +187,11 @@ struct qdio_input_q {
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/* input buffer acknowledgement flag */
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int polling;
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/* how much sbals are acknowledged with qebsm */
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int ack_count;
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/* last time of noticing incoming data */
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u64 timestamp;
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/* lock for clearing the acknowledgement */
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spinlock_t lock;
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};
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struct qdio_output_q {
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@ -351,10 +351,13 @@ static inline unsigned long long get_usecs(void)
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((bufnr + 1) & QDIO_MAX_BUFFERS_MASK)
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#define add_buf(bufnr, inc) \
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((bufnr + inc) & QDIO_MAX_BUFFERS_MASK)
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#define sub_buf(bufnr, dec) \
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((bufnr - dec) & QDIO_MAX_BUFFERS_MASK)
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/* prototypes for thin interrupt */
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void qdio_sync_after_thinint(struct qdio_q *q);
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int get_buf_state(struct qdio_q *q, unsigned int bufnr, unsigned char *state);
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int get_buf_state(struct qdio_q *q, unsigned int bufnr, unsigned char *state,
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int auto_ack);
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void qdio_check_outbound_after_thinint(struct qdio_q *q);
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int qdio_inbound_q_moved(struct qdio_q *q);
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void qdio_kick_inbound_handler(struct qdio_q *q);
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@ -388,6 +391,8 @@ int qdio_setup_irq(struct qdio_initialize *init_data);
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void qdio_print_subchannel_info(struct qdio_irq *irq_ptr,
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struct ccw_device *cdev);
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void qdio_release_memory(struct qdio_irq *irq_ptr);
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int qdio_setup_create_sysfs(struct ccw_device *cdev);
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void qdio_setup_destroy_sysfs(struct ccw_device *cdev);
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int qdio_setup_init(void);
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void qdio_setup_exit(void);
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@ -60,16 +60,18 @@ static int qstat_show(struct seq_file *m, void *v)
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if (!q)
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return 0;
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seq_printf(m, "device state indicator: %d\n", *q->irq_ptr->dsci);
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seq_printf(m, "device state indicator: %d\n", *(u32 *)q->irq_ptr->dsci);
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seq_printf(m, "nr_used: %d\n", atomic_read(&q->nr_buf_used));
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seq_printf(m, "ftc: %d\n", q->first_to_check);
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seq_printf(m, "last_move_ftc: %d\n", q->last_move_ftc);
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seq_printf(m, "polling: %d\n", q->u.in.polling);
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seq_printf(m, "ack count: %d\n", q->u.in.ack_count);
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seq_printf(m, "slsb buffer states:\n");
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seq_printf(m, "|0 |8 |16 |24 |32 |40 |48 |56 63|\n");
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qdio_siga_sync_q(q);
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for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++) {
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get_buf_state(q, i, &state);
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get_buf_state(q, i, &state, 0);
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switch (state) {
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case SLSB_P_INPUT_NOT_INIT:
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case SLSB_P_OUTPUT_NOT_INIT:
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@ -101,6 +103,7 @@ static int qstat_show(struct seq_file *m, void *v)
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seq_printf(m, "\n");
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}
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seq_printf(m, "\n");
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seq_printf(m, "|64 |72 |80 |88 |96 |104 |112 | 127|\n");
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return 0;
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}
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@ -112,12 +112,13 @@ static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
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* @state: state of the extracted buffers
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* @start: buffer number to start at
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* @count: count of buffers to examine
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* @auto_ack: automatically acknowledge buffers
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*
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* Returns the number of successfull extracted equal buffer states.
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* Stops processing if a state is different from the last buffers state.
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*/
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static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
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int start, int count)
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int start, int count, int auto_ack)
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{
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unsigned int ccq = 0;
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int tmp_count = count, tmp_start = start;
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@ -130,7 +131,8 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
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if (!q->is_input_q)
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nr += q->irq_ptr->nr_input_qs;
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again:
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ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
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ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
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auto_ack);
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rc = qdio_check_ccq(q, ccq);
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/* At least one buffer was processed, return and extract the remaining
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@ -176,6 +178,9 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
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int nr = q->nr;
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int rc;
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if (!count)
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return 0;
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BUG_ON(!q->irq_ptr->sch_token);
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qdio_perf_stat_inc(&perf_stats.debug_sqbs_all);
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@ -203,7 +208,8 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
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/* returns number of examined buffers and their common state in *state */
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static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
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unsigned char *state, unsigned int count)
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unsigned char *state, unsigned int count,
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int auto_ack)
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{
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unsigned char __state = 0;
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int i;
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@ -212,7 +218,7 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
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BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);
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if (is_qebsm(q))
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return qdio_do_eqbs(q, state, bufnr, count);
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return qdio_do_eqbs(q, state, bufnr, count, auto_ack);
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for (i = 0; i < count; i++) {
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if (!__state)
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@ -226,9 +232,9 @@ static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
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}
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inline int get_buf_state(struct qdio_q *q, unsigned int bufnr,
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unsigned char *state)
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unsigned char *state, int auto_ack)
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{
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return get_buf_states(q, bufnr, state, 1);
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return get_buf_states(q, bufnr, state, 1, auto_ack);
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}
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/* wrap-around safe setting of slsb states, returns number of changed buffers */
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@ -376,29 +382,91 @@ void qdio_sync_after_thinint(struct qdio_q *q)
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inline void qdio_stop_polling(struct qdio_q *q)
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{
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spin_lock_bh(&q->u.in.lock);
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if (!q->u.in.polling) {
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spin_unlock_bh(&q->u.in.lock);
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if (!q->u.in.polling)
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return;
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}
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q->u.in.polling = 0;
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qdio_perf_stat_inc(&perf_stats.debug_stop_polling);
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/* show the card that we are not polling anymore */
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set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
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spin_unlock_bh(&q->u.in.lock);
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if (is_qebsm(q)) {
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set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
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q->u.in.ack_count);
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q->u.in.ack_count = 0;
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} else
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set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
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}
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static void announce_buffer_error(struct qdio_q *q)
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static void announce_buffer_error(struct qdio_q *q, int count)
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{
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q->qdio_error = QDIO_ERROR_SLSB_STATE;
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/* special handling for no target buffer empty */
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if ((!q->is_input_q &&
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(q->sbal[q->first_to_check]->element[15].flags & 0xff) == 0x10)) {
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qdio_perf_stat_inc(&perf_stats.outbound_target_full);
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DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%3d",
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q->first_to_check);
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return;
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}
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DBF_ERROR("%4x BUF ERROR", SCH_NO(q));
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DBF_ERROR((q->is_input_q) ? "IN:%2d" : "OUT:%2d", q->nr);
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DBF_ERROR("FTC:%3d", q->first_to_check);
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DBF_ERROR("FTC:%3d C:%3d", q->first_to_check, count);
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DBF_ERROR("F14:%2x F15:%2x",
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q->sbal[q->first_to_check]->element[14].flags & 0xff,
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q->sbal[q->first_to_check]->element[15].flags & 0xff);
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}
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q->qdio_error = QDIO_ERROR_SLSB_STATE;
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static inline void inbound_primed(struct qdio_q *q, int count)
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{
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int new;
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DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim: %3d", count);
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/* for QEBSM the ACK was already set by EQBS */
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if (is_qebsm(q)) {
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if (!q->u.in.polling) {
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q->u.in.polling = 1;
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q->u.in.ack_count = count;
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q->last_move_ftc = q->first_to_check;
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return;
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}
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/* delete the previous ACK's */
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set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
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q->u.in.ack_count);
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q->u.in.ack_count = count;
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q->last_move_ftc = q->first_to_check;
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return;
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}
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/*
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* ACK the newest buffer. The ACK will be removed in qdio_stop_polling
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* or by the next inbound run.
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*/
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new = add_buf(q->first_to_check, count - 1);
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if (q->u.in.polling) {
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/* reset the previous ACK but first set the new one */
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set_buf_state(q, new, SLSB_P_INPUT_ACK);
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set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
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}
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else {
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q->u.in.polling = 1;
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set_buf_state(q, q->first_to_check, SLSB_P_INPUT_ACK);
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}
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q->last_move_ftc = new;
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count--;
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if (!count)
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return;
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/*
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* Need to change all PRIMED buffers to NOT_INIT, otherwise
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* we're loosing initiative in the thinint code.
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*/
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set_buf_states(q, next_buf(q->first_to_check), SLSB_P_INPUT_NOT_INIT,
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count);
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}
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static int get_inbound_buffer_frontier(struct qdio_q *q)
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@ -406,13 +474,6 @@ static int get_inbound_buffer_frontier(struct qdio_q *q)
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int count, stop;
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unsigned char state;
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/*
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* If we still poll don't update last_move_ftc, keep the
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* previously ACK buffer there.
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*/
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if (!q->u.in.polling)
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q->last_move_ftc = q->first_to_check;
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/*
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* Don't check 128 buffers, as otherwise qdio_inbound_q_moved
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* would return 0.
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@ -433,34 +494,13 @@ static int get_inbound_buffer_frontier(struct qdio_q *q)
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if (q->first_to_check == stop)
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goto out;
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count = get_buf_states(q, q->first_to_check, &state, count);
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count = get_buf_states(q, q->first_to_check, &state, count, 1);
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if (!count)
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goto out;
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switch (state) {
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case SLSB_P_INPUT_PRIMED:
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DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim: %3d", count);
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/*
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* Only ACK the first buffer. The ACK will be removed in
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* qdio_stop_polling.
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*/
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if (q->u.in.polling)
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state = SLSB_P_INPUT_NOT_INIT;
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else {
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q->u.in.polling = 1;
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state = SLSB_P_INPUT_ACK;
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}
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set_buf_state(q, q->first_to_check, state);
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/*
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* Need to change all PRIMED buffers to NOT_INIT, otherwise
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* we're loosing initiative in the thinint code.
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*/
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if (count > 1)
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set_buf_states(q, next_buf(q->first_to_check),
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SLSB_P_INPUT_NOT_INIT, count - 1);
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inbound_primed(q, count);
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/*
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* No siga-sync needed for non-qebsm here, as the inbound queue
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* will be synced on the next siga-r, resp.
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@ -470,7 +510,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q)
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atomic_sub(count, &q->nr_buf_used);
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goto check_next;
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case SLSB_P_INPUT_ERROR:
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announce_buffer_error(q);
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announce_buffer_error(q, count);
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/* process the buffer, the upper layer will take care of it */
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q->first_to_check = add_buf(q->first_to_check, count);
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atomic_sub(count, &q->nr_buf_used);
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@ -516,7 +556,7 @@ static int qdio_inbound_q_done(struct qdio_q *q)
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*/
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qdio_siga_sync_q(q);
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get_buf_state(q, q->first_to_check, &state);
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get_buf_state(q, q->first_to_check, &state, 0);
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if (state == SLSB_P_INPUT_PRIMED)
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/* we got something to do */
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return 0;
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@ -619,7 +659,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
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if (q->first_to_check == stop)
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return q->first_to_check;
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count = get_buf_states(q, q->first_to_check, &state, count);
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count = get_buf_states(q, q->first_to_check, &state, count, 0);
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if (!count)
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return q->first_to_check;
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@ -638,7 +678,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q)
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break;
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goto check_next;
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case SLSB_P_OUTPUT_ERROR:
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announce_buffer_error(q);
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announce_buffer_error(q, count);
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/* process the buffer, the upper layer will take care of it */
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q->first_to_check = add_buf(q->first_to_check, count);
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atomic_sub(count, &q->nr_buf_used);
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@ -1451,23 +1491,38 @@ static inline int buf_in_between(int bufnr, int start, int count)
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static void handle_inbound(struct qdio_q *q, unsigned int callflags,
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int bufnr, int count)
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{
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unsigned long flags;
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int used, rc;
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int used, rc, diff;
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/*
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* do_QDIO could run in parallel with the queue tasklet so the
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* upper-layer programm could empty the ACK'ed buffer here.
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* If that happens we must clear the polling flag, otherwise
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* qdio_stop_polling() could set the buffer to NOT_INIT after
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* it was set to EMPTY which would kill us.
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*/
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spin_lock_irqsave(&q->u.in.lock, flags);
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if (q->u.in.polling)
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if (buf_in_between(q->last_move_ftc, bufnr, count))
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if (!q->u.in.polling)
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goto set;
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/* protect against stop polling setting an ACK for an emptied slsb */
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if (count == QDIO_MAX_BUFFERS_PER_Q) {
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/* overwriting everything, just delete polling status */
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q->u.in.polling = 0;
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q->u.in.ack_count = 0;
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goto set;
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} else if (buf_in_between(q->last_move_ftc, bufnr, count)) {
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if (is_qebsm(q)) {
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/* partial overwrite, just update last_move_ftc */
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diff = add_buf(bufnr, count);
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diff = sub_buf(diff, q->last_move_ftc);
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q->u.in.ack_count -= diff;
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if (q->u.in.ack_count <= 0) {
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q->u.in.polling = 0;
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q->u.in.ack_count = 0;
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/* 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);
|
||||
|
@ -1535,7 +1590,7 @@ static void handle_outbound(struct qdio_q *q, unsigned int callflags,
|
|||
}
|
||||
|
||||
/* 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 {
|
||||
|
|
|
@ -74,6 +74,8 @@ static int qdio_perf_proc_show(struct seq_file *m, void *v)
|
|||
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",
|
||||
|
|
|
@ -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;
|
||||
|
|
|
@ -167,7 +167,6 @@ static void setup_queues(struct qdio_irq *irq_ptr,
|
|||
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;
|
||||
|
||||
|
|
|
@ -131,7 +131,7 @@ static inline int tiqdio_inbound_q_done(struct qdio_q *q)
|
|||
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 */
|
||||
|
|
Loading…
Reference in a new issue