drivers/net/ethernet/amd/pds_core/adminq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 2023 Advanced Micro Devices, Inc */
   3
   4 #include <linux/dynamic_debug.h>
   5
   6 #include "core.h"
   7
   8 struct pdsc_wait_context {
   9         struct pdsc_qcq *qcq;
  10         struct completion wait_completion;
  11 };
  12
  13 static int pdsc_process_notifyq(struct pdsc_qcq *qcq)
  14 {
  15         union pds_core_notifyq_comp *comp;
  16         struct pdsc *pdsc = qcq->pdsc;
  17         struct pdsc_cq *cq = &qcq->cq;
  18         struct pdsc_cq_info *cq_info;
  19         int nq_work = 0;
  20         u64 eid;
  21
  22         cq_info = &cq->info[cq->tail_idx];
  23         comp = cq_info->comp;
  24         eid = le64_to_cpu(comp->event.eid);
  25         while (eid > pdsc->last_eid) {
  26                 u16 ecode = le16_to_cpu(comp->event.ecode);
  27
  28                 switch (ecode) {
  29                 case PDS_EVENT_LINK_CHANGE:
  30                         dev_info(pdsc->dev, "NotifyQ LINK_CHANGE ecode %d eid %lld\n",
  31                                  ecode, eid);
  32                         pdsc_notify(PDS_EVENT_LINK_CHANGE, comp);
  33                         break;
  34
  35                 case PDS_EVENT_RESET:
  36                         dev_info(pdsc->dev, "NotifyQ RESET ecode %d eid %lld\n",
  37                                  ecode, eid);
  38                         pdsc_notify(PDS_EVENT_RESET, comp);
  39                         break;
  40
  41                 case PDS_EVENT_XCVR:
  42                         dev_info(pdsc->dev, "NotifyQ XCVR ecode %d eid %lld\n",
  43                                  ecode, eid);
  44                         break;
  45
  46                 default:
  47                         dev_info(pdsc->dev, "NotifyQ ecode %d eid %lld\n",
  48                                  ecode, eid);
  49                         break;
  50                 }
  51
  52                 pdsc->last_eid = eid;
  53                 cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
  54                 cq_info = &cq->info[cq->tail_idx];
  55                 comp = cq_info->comp;
  56                 eid = le64_to_cpu(comp->event.eid);
  57
  58                 nq_work++;
  59         }
  60
  61         qcq->accum_work += nq_work;
  62
  63         return nq_work;
  64 }
  65
  66 static bool pdsc_adminq_inc_if_up(struct pdsc *pdsc)
  67 {
  68         if (pdsc->state & BIT_ULL(PDSC_S_STOPPING_DRIVER) ||
  69             pdsc->state & BIT_ULL(PDSC_S_FW_DEAD))
  70                 return false;
  71
  72         return refcount_inc_not_zero(&pdsc->adminq_refcnt);
  73 }
  74
  75 void pdsc_process_adminq(struct pdsc_qcq *qcq)
  76 {
  77         union pds_core_adminq_comp *comp;
  78         struct pdsc_queue *q = &qcq->q;
  79         struct pdsc *pdsc = qcq->pdsc;
  80         struct pdsc_cq *cq = &qcq->cq;
  81         struct pdsc_q_info *q_info;
  82         unsigned long irqflags;
  83         int nq_work = 0;
  84         int aq_work = 0;
  85
  86         /* Don't process AdminQ when it's not up */
  87         if (!pdsc_adminq_inc_if_up(pdsc)) {
  88                 dev_err(pdsc->dev, "%s: called while adminq is unavailable\n",
  89                         __func__);
  90                 return;
  91         }
  92
  93         /* Check for NotifyQ event */
  94         nq_work = pdsc_process_notifyq(&pdsc->notifyqcq);
  95
  96         /* Check for empty queue, which can happen if the interrupt was
  97          * for a NotifyQ event and there are no new AdminQ completions.
  98          */
  99         if (q->tail_idx == q->head_idx)
 100                 goto credits;
 101
 102         /* Find the first completion to clean,
 103          * run the callback in the related q_info,
 104          * and continue while we still match done color
 105          */
 106         spin_lock_irqsave(&pdsc->adminq_lock, irqflags);
 107         comp = cq->info[cq->tail_idx].comp;
 108         while (pdsc_color_match(comp->color, cq->done_color)) {
 109                 q_info = &q->info[q->tail_idx];
 110                 q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
 111
 112                 /* Copy out the completion data */
 113                 memcpy(q_info->dest, comp, sizeof(*comp));
 114
 115                 complete_all(&q_info->wc->wait_completion);
 116
 117                 if (cq->tail_idx == cq->num_descs - 1)
 118                         cq->done_color = !cq->done_color;
 119                 cq->tail_idx = (cq->tail_idx + 1) & (cq->num_descs - 1);
 120                 comp = cq->info[cq->tail_idx].comp;
 121
 122                 aq_work++;
 123         }
 124         spin_unlock_irqrestore(&pdsc->adminq_lock, irqflags);
 125
 126         qcq->accum_work += aq_work;
 127
 128 credits:
 129         /* Return the interrupt credits, one for each completion */
 130         pds_core_intr_credits(&pdsc->intr_ctrl[qcq->intx],
 131                               nq_work + aq_work,
 132                               PDS_CORE_INTR_CRED_REARM);
 133         refcount_dec(&pdsc->adminq_refcnt);
 134 }
 135
 136 void pdsc_work_thread(struct work_struct *work)
 137 {
 138         struct pdsc_qcq *qcq = container_of(work, struct pdsc_qcq, work);
 139
 140         pdsc_process_adminq(qcq);
 141 }
 142
 143 irqreturn_t pdsc_adminq_isr(int irq, void *data)
 144 {
 145         struct pdsc *pdsc = data;
 146         struct pdsc_qcq *qcq;
 147
 148         /* Don't process AdminQ when it's not up */
 149         if (!pdsc_adminq_inc_if_up(pdsc)) {
 150                 dev_err(pdsc->dev, "%s: called while adminq is unavailable\n",
 151                         __func__);
 152                 return IRQ_HANDLED;
 153         }
 154
 155         qcq = &pdsc->adminqcq;
 156         queue_work(pdsc->wq, &qcq->work);
 157         refcount_dec(&pdsc->adminq_refcnt);
 158
 159         return IRQ_HANDLED;
 160 }
 161
 162 static int __pdsc_adminq_post(struct pdsc *pdsc,
 163                               struct pdsc_qcq *qcq,
 164                               union pds_core_adminq_cmd *cmd,
 165                               union pds_core_adminq_comp *comp,
 166                               struct pdsc_wait_context *wc)
 167 {
 168         struct pdsc_queue *q = &qcq->q;
 169         struct pdsc_q_info *q_info;
 170         unsigned long irqflags;
 171         unsigned int avail;
 172         int index;
 173         int ret;
 174
 175         spin_lock_irqsave(&pdsc->adminq_lock, irqflags);
 176
 177         /* Check for space in the queue */
 178         avail = q->tail_idx;
 179         if (q->head_idx >= avail)
 180                 avail += q->num_descs - q->head_idx - 1;
 181         else
 182                 avail -= q->head_idx + 1;
 183         if (!avail) {
 184                 ret = -ENOSPC;
 185                 goto err_out_unlock;
 186         }
 187
 188         /* Check that the FW is running */
 189         if (!pdsc_is_fw_running(pdsc)) {
 190                 if (pdsc->info_regs) {
 191                         u8 fw_status =
 192                                 ioread8(&pdsc->info_regs->fw_status);
 193
 194                         dev_info(pdsc->dev, "%s: post failed - fw not running %#02x:\n",
 195                                  __func__, fw_status);
 196                 } else {
 197                         dev_info(pdsc->dev, "%s: post failed - BARs not setup\n",
 198                                  __func__);
 199                 }
 200                 ret = -ENXIO;
 201
 202                 goto err_out_unlock;
 203         }
 204
 205         /* Post the request */
 206         index = q->head_idx;
 207         q_info = &q->info[index];
 208         q_info->wc = wc;
 209         q_info->dest = comp;
 210         memcpy(q_info->desc, cmd, sizeof(*cmd));
 211
 212         dev_dbg(pdsc->dev, "head_idx %d tail_idx %d\n",
 213                 q->head_idx, q->tail_idx);
 214         dev_dbg(pdsc->dev, "post admin queue command:\n");
 215         dynamic_hex_dump("cmd ", DUMP_PREFIX_OFFSET, 16, 1,
 216                          cmd, sizeof(*cmd), true);
 217
 218         q->head_idx = (q->head_idx + 1) & (q->num_descs - 1);
 219
 220         pds_core_dbell_ring(pdsc->kern_dbpage,
 221                             q->hw_type, q->dbval | q->head_idx);
 222         ret = index;
 223
 224 err_out_unlock:
 225         spin_unlock_irqrestore(&pdsc->adminq_lock, irqflags);
 226         return ret;
 227 }
 228
 229 int pdsc_adminq_post(struct pdsc *pdsc,
 230                      union pds_core_adminq_cmd *cmd,
 231                      union pds_core_adminq_comp *comp,
 232                      bool fast_poll)
 233 {
 234         struct pdsc_wait_context wc = {
 235                 .wait_completion =
 236                         COMPLETION_INITIALIZER_ONSTACK(wc.wait_completion),
 237         };
 238         unsigned long poll_interval = 1;
 239         unsigned long poll_jiffies;
 240         unsigned long time_limit;
 241         unsigned long time_start;
 242         unsigned long time_done;
 243         unsigned long remaining;
 244         int err = 0;
 245         int index;
 246
 247         if (!pdsc_adminq_inc_if_up(pdsc)) {
 248                 dev_dbg(pdsc->dev, "%s: preventing adminq cmd %u\n",
 249                         __func__, cmd->opcode);
 250                 return -ENXIO;
 251         }
 252
 253         wc.qcq = &pdsc->adminqcq;
 254         index = __pdsc_adminq_post(pdsc, &pdsc->adminqcq, cmd, comp, &wc);
 255         if (index < 0) {
 256                 err = index;
 257                 goto err_out;
 258         }
 259
 260         time_start = jiffies;
 261         time_limit = time_start + HZ * pdsc->devcmd_timeout;
 262         do {
 263                 /* Timeslice the actual wait to catch IO errors etc early */
 264                 poll_jiffies = msecs_to_jiffies(poll_interval);
 265                 remaining = wait_for_completion_timeout(&wc.wait_completion,
 266                                                         poll_jiffies);
 267                 if (remaining)
 268                         break;
 269
 270                 if (!pdsc_is_fw_running(pdsc)) {
 271                         if (pdsc->info_regs) {
 272                                 u8 fw_status =
 273                                         ioread8(&pdsc->info_regs->fw_status);
 274
 275                                 dev_dbg(pdsc->dev, "%s: post wait failed - fw not running %#02x:\n",
 276                                         __func__, fw_status);
 277                         } else {
 278                                 dev_dbg(pdsc->dev, "%s: post wait failed - BARs not setup\n",
 279                                         __func__);
 280                         }
 281                         err = -ENXIO;
 282                         break;
 283                 }
 284
 285                 /* When fast_poll is not requested, prevent aggressive polling
 286                  * on failures due to timeouts by doing exponential back off.
 287                  */
 288                 if (!fast_poll && poll_interval < PDSC_ADMINQ_MAX_POLL_INTERVAL)
 289                         poll_interval <<= 1;
 290         } while (time_before(jiffies, time_limit));
 291         time_done = jiffies;
 292         dev_dbg(pdsc->dev, "%s: elapsed %d msecs\n",
 293                 __func__, jiffies_to_msecs(time_done - time_start));
 294
 295         /* Check the results */
 296         if (time_after_eq(time_done, time_limit))
 297                 err = -ETIMEDOUT;
 298
 299         dev_dbg(pdsc->dev, "read admin queue completion idx %d:\n", index);
 300         dynamic_hex_dump("comp ", DUMP_PREFIX_OFFSET, 16, 1,
 301                          comp, sizeof(*comp), true);
 302
 303         if (remaining && comp->status)
 304                 err = pdsc_err_to_errno(comp->status);
 305
 306 err_out:
 307         if (err) {
 308                 dev_dbg(pdsc->dev, "%s: opcode %d status %d err %pe\n",
 309                         __func__, cmd->opcode, comp->status, ERR_PTR(err));
 310                 if (err == -ENXIO || err == -ETIMEDOUT)
 311                         queue_work(pdsc->wq, &pdsc->health_work);
 312         }
 313
 314         refcount_dec(&pdsc->adminq_refcnt);
 315
 316         return err;
 317 }
 318 EXPORT_SYMBOL_GPL(pdsc_adminq_post);