src/patches/suse-2.6.27.31/patches.arch/s390-11-09-qdio_ack_newest_and_seperate_polling.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: qdio: move ACK to newest buffer for devices without QEBSM
   3 References: bnc#484767,LTC#52208
   4
   5 Symptom:     Lower performance of non-QEBSM qdio devices under heavy traffic
   6 Problem:     The ACKnowledgement state is set on the first SBAL so in case of
   7              multiple PRIMED buffers the firmware has to scan all buffers.
   8 Solution:    The ACKnowledgement state is set on the newest SBAL so an
   9              adapter interrupt surpression check needs to scan fewer SBALs.
  10
  11 Acked-by: John Jolly <jjolly@suse.de>
  12 ---
  13  drivers/s390/cio/qdio.h       |    5 ++++-
  14  drivers/s390/cio/qdio_debug.c |    3 ++-
  15  drivers/s390/cio/qdio_main.c  |   41 ++++++++++++++++++++---------------------
  16  3 files changed, 26 insertions(+), 23 deletions(-)
  17
  18 Index: linux-sles11/drivers/s390/cio/qdio.h
  19 ===================================================================
  20 --- linux-sles11.orig/drivers/s390/cio/qdio.h
  21 +++ linux-sles11/drivers/s390/cio/qdio.h
  22 @@ -186,6 +186,9 @@ struct qdio_input_q {
  23         /* input buffer acknowledgement flag */
  24         int polling;
  25
  26 +       /* first ACK'ed buffer */
  27 +       int ack_start;
  28 +
  29         /* how much sbals are acknowledged with qebsm */
  30         int ack_count;
  31
  32 @@ -231,7 +234,7 @@ struct qdio_q {
  33         int first_to_check;
  34
  35         /* first_to_check of the last time */
  36 -       int last_move_ftc;
  37 +       int last_move;
  38
  39         /* beginning position for calling the program */
  40         int first_to_kick;
  41 Index: linux-sles11/drivers/s390/cio/qdio_debug.c
  42 ===================================================================
  43 --- linux-sles11.orig/drivers/s390/cio/qdio_debug.c
  44 +++ linux-sles11/drivers/s390/cio/qdio_debug.c
  45 @@ -62,8 +62,9 @@ static int qstat_show(struct seq_file *m
  46         seq_printf(m, "device state indicator: %d\n", *(u32 *)q->irq_ptr->dsci);
  47         seq_printf(m, "nr_used: %d\n", atomic_read(&q->nr_buf_used));
  48         seq_printf(m, "ftc: %d\n", q->first_to_check);
  49 -       seq_printf(m, "last_move_ftc: %d\n", q->last_move_ftc);
  50 +       seq_printf(m, "last_move: %d\n", q->last_move);
  51         seq_printf(m, "polling: %d\n", q->u.in.polling);
  52 +       seq_printf(m, "ack start: %d\n", q->u.in.ack_start);
  53         seq_printf(m, "ack count: %d\n", q->u.in.ack_count);
  54         seq_printf(m, "slsb buffer states:\n");
  55         seq_printf(m, "|0      |8      |16     |24     |32     |40     |48     |56  63|\n");
  56 Index: linux-sles11/drivers/s390/cio/qdio_main.c
  57 ===================================================================
  58 --- linux-sles11.orig/drivers/s390/cio/qdio_main.c
  59 +++ linux-sles11/drivers/s390/cio/qdio_main.c
  60 @@ -371,11 +371,11 @@ inline void qdio_stop_polling(struct qdi
  61
  62         /* show the card that we are not polling anymore */
  63         if (is_qebsm(q)) {
  64 -               set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
  65 +               set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
  66                                q->u.in.ack_count);
  67                 q->u.in.ack_count = 0;
  68         } else
  69 -               set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
  70 +               set_buf_state(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT);
  71  }
  72
  73  static void announce_buffer_error(struct qdio_q *q, int count)
  74 @@ -410,15 +410,15 @@ static inline void inbound_primed(struct
  75                 if (!q->u.in.polling) {
  76                         q->u.in.polling = 1;
  77                         q->u.in.ack_count = count;
  78 -                       q->last_move_ftc = q->first_to_check;
  79 +                       q->u.in.ack_start = q->first_to_check;
  80                         return;
  81                 }
  82
  83                 /* delete the previous ACK's */
  84 -               set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
  85 +               set_buf_states(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT,
  86                                q->u.in.ack_count);
  87                 q->u.in.ack_count = count;
  88 -               q->last_move_ftc = q->first_to_check;
  89 +               q->u.in.ack_start = q->first_to_check;
  90                 return;
  91         }
  92
  93 @@ -430,14 +430,13 @@ static inline void inbound_primed(struct
  94         if (q->u.in.polling) {
  95                 /* reset the previous ACK but first set the new one */
  96                 set_buf_state(q, new, SLSB_P_INPUT_ACK);
  97 -               set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
  98 -       }
  99 -       else {
 100 +               set_buf_state(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT);
 101 +       } else {
 102                 q->u.in.polling = 1;
 103 -               set_buf_state(q, q->first_to_check, SLSB_P_INPUT_ACK);
 104 +               set_buf_state(q, new, SLSB_P_INPUT_ACK);
 105         }
 106
 107 -       q->last_move_ftc = new;
 108 +       q->u.in.ack_start = new;
 109         count--;
 110         if (!count)
 111                 return;
 112 @@ -446,7 +445,7 @@ static inline void inbound_primed(struct
 113          * Need to change all PRIMED buffers to NOT_INIT, otherwise
 114          * we're loosing initiative in the thinint code.
 115          */
 116 -       set_buf_states(q, next_buf(q->first_to_check), SLSB_P_INPUT_NOT_INIT,
 117 +       set_buf_states(q, q->first_to_check, SLSB_P_INPUT_NOT_INIT,
 118                        count);
 119  }
 120
 121 @@ -514,7 +513,8 @@ int qdio_inbound_q_moved(struct qdio_q *
 122
 123         bufnr = get_inbound_buffer_frontier(q);
 124
 125 -       if ((bufnr != q->last_move_ftc) || q->qdio_error) {
 126 +       if ((bufnr != q->last_move) || q->qdio_error) {
 127 +               q->last_move = bufnr;
 128                 if (!need_siga_sync(q) && !pci_out_supported(q))
 129                         q->u.in.timestamp = get_usecs();
 130
 131 @@ -689,8 +689,8 @@ static inline int qdio_outbound_q_moved(
 132
 133         bufnr = get_outbound_buffer_frontier(q);
 134
 135 -       if ((bufnr != q->last_move_ftc) || q->qdio_error) {
 136 -               q->last_move_ftc = bufnr;
 137 +       if ((bufnr != q->last_move) || q->qdio_error) {
 138 +               q->last_move = bufnr;
 139                 DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
 140                 return 1;
 141         } else
 142 @@ -732,7 +732,7 @@ static void qdio_kick_outbound_handler(s
 143         int start, end, count;
 144
 145         start = q->first_to_kick;
 146 -       end = q->last_move_ftc;
 147 +       end = q->last_move;
 148         if (end >= start)
 149                 count = end - start;
 150         else
 151 @@ -748,7 +748,7 @@ static void qdio_kick_outbound_handler(s
 152                    q->irq_ptr->int_parm);
 153
 154         /* for the next time: */
 155 -       q->first_to_kick = q->last_move_ftc;
 156 +       q->first_to_kick = q->last_move;
 157         q->qdio_error = 0;
 158  }
 159
 160 @@ -1453,19 +1453,18 @@ static int handle_inbound(struct qdio_q
 161                 q->u.in.polling = 0;
 162                 q->u.in.ack_count = 0;
 163                 goto set;
 164 -       } else if (buf_in_between(q->last_move_ftc, bufnr, count)) {
 165 +       } else if (buf_in_between(q->u.in.ack_start, bufnr, count)) {
 166                 if (is_qebsm(q)) {
 167 -                       /* partial overwrite, just update last_move_ftc */
 168 +                       /* partial overwrite, just update ack_start */
 169                         diff = add_buf(bufnr, count);
 170 -                       diff = sub_buf(diff, q->last_move_ftc);
 171 +                       diff = sub_buf(diff, q->u.in.ack_start);
 172                         q->u.in.ack_count -= diff;
 173                         if (q->u.in.ack_count <= 0) {
 174                                 q->u.in.polling = 0;
 175                                 q->u.in.ack_count = 0;
 176 -                               /* TODO: must we set last_move_ftc to something meaningful? */
 177                                 goto set;
 178                         }
 179 -                       q->last_move_ftc = add_buf(q->last_move_ftc, diff);
 180 +                       q->u.in.ack_start = add_buf(q->u.in.ack_start, diff);
 181                 }
 182                 else
 183                         /* the only ACK will be deleted, so stop polling */