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   1 /* pci_msi.c: Sparc64 MSI support common layer.
   2  *
   3  * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/interrupt.h>
   7 #include <linux/irq.h>
   8
   9 #include "pci_impl.h"
  10
  11 static irqreturn_t sparc64_msiq_interrupt(int irq, void *cookie)
  12 {
  13         struct sparc64_msiq_cookie *msiq_cookie = cookie;
  14         struct pci_pbm_info *pbm = msiq_cookie->pbm;
  15         unsigned long msiqid = msiq_cookie->msiqid;
  16         const struct sparc64_msiq_ops *ops;
  17         unsigned long orig_head, head;
  18         int err;
  19
  20         ops = pbm->msi_ops;
  21
  22         err = ops->get_head(pbm, msiqid, &head);
  23         if (unlikely(err < 0))
  24                 goto err_get_head;
  25
  26         orig_head = head;
  27         for (;;) {
  28                 unsigned long msi;
  29
  30                 err = ops->dequeue_msi(pbm, msiqid, &head, &msi);
  31                 if (likely(err > 0)) {
  32                         struct irq_desc *desc;
  33                         unsigned int virt_irq;
  34
  35                         virt_irq = pbm->msi_irq_table[msi - pbm->msi_first];
  36                         desc = irq_desc + virt_irq;
  37
  38                         desc->handle_irq(virt_irq, desc);
  39                 }
  40
  41                 if (unlikely(err < 0))
  42                         goto err_dequeue;
  43
  44                 if (err == 0)
  45                         break;
  46         }
  47         if (likely(head != orig_head)) {
  48                 err = ops->set_head(pbm, msiqid, head);
  49                 if (unlikely(err < 0))
  50                         goto err_set_head;
  51         }
  52         return IRQ_HANDLED;
  53
  54 err_get_head:
  55         printk(KERN_EMERG "MSI: Get head on msiqid[%lu] gives error %d\n",
  56                msiqid, err);
  57         goto err_out;
  58
  59 err_dequeue:
  60         printk(KERN_EMERG "MSI: Dequeue head[%lu] from msiqid[%lu] "
  61                "gives error %d\n",
  62                head, msiqid, err);
  63         goto err_out;
  64
  65 err_set_head:
  66         printk(KERN_EMERG "MSI: Set head[%lu] on msiqid[%lu] "
  67                "gives error %d\n",
  68                head, msiqid, err);
  69         goto err_out;
  70
  71 err_out:
  72         return IRQ_NONE;
  73 }
  74
  75 static u32 pick_msiq(struct pci_pbm_info *pbm)
  76 {
  77         static DEFINE_SPINLOCK(rotor_lock);
  78         unsigned long flags;
  79         u32 ret, rotor;
  80
  81         spin_lock_irqsave(&rotor_lock, flags);
  82
  83         rotor = pbm->msiq_rotor;
  84         ret = pbm->msiq_first + rotor;
  85
  86         if (++rotor >= pbm->msiq_num)
  87                 rotor = 0;
  88         pbm->msiq_rotor = rotor;
  89
  90         spin_unlock_irqrestore(&rotor_lock, flags);
  91
  92         return ret;
  93 }
  94
  95
  96 static int alloc_msi(struct pci_pbm_info *pbm)
  97 {
  98         int i;
  99
 100         for (i = 0; i < pbm->msi_num; i++) {
 101                 if (!test_and_set_bit(i, pbm->msi_bitmap))
 102                         return i + pbm->msi_first;
 103         }
 104
 105         return -ENOENT;
 106 }
 107
 108 static void free_msi(struct pci_pbm_info *pbm, int msi_num)
 109 {
 110         msi_num -= pbm->msi_first;
 111         clear_bit(msi_num, pbm->msi_bitmap);
 112 }
 113
 114 static struct irq_chip msi_irq = {
 115         .typename       = "PCI-MSI",
 116         .mask           = mask_msi_irq,
 117         .unmask         = unmask_msi_irq,
 118         .enable         = unmask_msi_irq,
 119         .disable        = mask_msi_irq,
 120         /* XXX affinity XXX */
 121 };
 122
 123 int sparc64_setup_msi_irq(unsigned int *virt_irq_p,
 124                           struct pci_dev *pdev,
 125                           struct msi_desc *entry)
 126 {
 127         struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
 128         const struct sparc64_msiq_ops *ops = pbm->msi_ops;
 129         struct msi_msg msg;
 130         int msi, err;
 131         u32 msiqid;
 132
 133         *virt_irq_p = virt_irq_alloc(0, 0);
 134         err = -ENOMEM;
 135         if (!*virt_irq_p)
 136                 goto out_err;
 137
 138         set_irq_chip_and_handler_name(*virt_irq_p, &msi_irq,
 139                                       handle_simple_irq, "MSI");
 140
 141         err = alloc_msi(pbm);
 142         if (unlikely(err < 0))
 143                 goto out_virt_irq_free;
 144
 145         msi = err;
 146
 147         msiqid = pick_msiq(pbm);
 148
 149         err = ops->msi_setup(pbm, msiqid, msi,
 150                              (entry->msi_attrib.is_64 ? 1 : 0));
 151         if (err)
 152                 goto out_msi_free;
 153
 154         pbm->msi_irq_table[msi - pbm->msi_first] = *virt_irq_p;
 155
 156         if (entry->msi_attrib.is_64) {
 157                 msg.address_hi = pbm->msi64_start >> 32;
 158                 msg.address_lo = pbm->msi64_start & 0xffffffff;
 159         } else {
 160                 msg.address_hi = 0;
 161                 msg.address_lo = pbm->msi32_start;
 162         }
 163         msg.data = msi;
 164
 165         set_irq_msi(*virt_irq_p, entry);
 166         write_msi_msg(*virt_irq_p, &msg);
 167
 168         return 0;
 169
 170 out_msi_free:
 171         free_msi(pbm, msi);
 172
 173 out_virt_irq_free:
 174         set_irq_chip(*virt_irq_p, NULL);
 175         virt_irq_free(*virt_irq_p);
 176         *virt_irq_p = 0;
 177
 178 out_err:
 179         return err;
 180 }
 181
 182 void sparc64_teardown_msi_irq(unsigned int virt_irq,
 183                               struct pci_dev *pdev)
 184 {
 185         struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
 186         const struct sparc64_msiq_ops *ops = pbm->msi_ops;
 187         unsigned int msi_num;
 188         int i, err;
 189
 190         for (i = 0; i < pbm->msi_num; i++) {
 191                 if (pbm->msi_irq_table[i] == virt_irq)
 192                         break;
 193         }
 194         if (i >= pbm->msi_num) {
 195                 printk(KERN_ERR "%s: teardown: No MSI for irq %u\n",
 196                        pbm->name, virt_irq);
 197                 return;
 198         }
 199
 200         msi_num = pbm->msi_first + i;
 201         pbm->msi_irq_table[i] = ~0U;
 202
 203         err = ops->msi_teardown(pbm, msi_num);
 204         if (err) {
 205                 printk(KERN_ERR "%s: teardown: ops->teardown() on MSI %u, "
 206                        "irq %u, gives error %d\n",
 207                        pbm->name, msi_num, virt_irq, err);
 208                 return;
 209         }
 210
 211         free_msi(pbm, msi_num);
 212
 213         set_irq_chip(virt_irq, NULL);
 214         virt_irq_free(virt_irq);
 215 }
 216
 217 static int msi_bitmap_alloc(struct pci_pbm_info *pbm)
 218 {
 219         unsigned long size, bits_per_ulong;
 220
 221         bits_per_ulong = sizeof(unsigned long) * 8;
 222         size = (pbm->msi_num + (bits_per_ulong - 1)) & ~(bits_per_ulong - 1);
 223         size /= 8;
 224         BUG_ON(size % sizeof(unsigned long));
 225
 226         pbm->msi_bitmap = kzalloc(size, GFP_KERNEL);
 227         if (!pbm->msi_bitmap)
 228                 return -ENOMEM;
 229
 230         return 0;
 231 }
 232
 233 static void msi_bitmap_free(struct pci_pbm_info *pbm)
 234 {
 235         kfree(pbm->msi_bitmap);
 236         pbm->msi_bitmap = NULL;
 237 }
 238
 239 static int msi_table_alloc(struct pci_pbm_info *pbm)
 240 {
 241         int size, i;
 242
 243         size = pbm->msiq_num * sizeof(struct sparc64_msiq_cookie);
 244         pbm->msiq_irq_cookies = kzalloc(size, GFP_KERNEL);
 245         if (!pbm->msiq_irq_cookies)
 246                 return -ENOMEM;
 247
 248         for (i = 0; i < pbm->msiq_num; i++) {
 249                 struct sparc64_msiq_cookie *p;
 250
 251                 p = &pbm->msiq_irq_cookies[i];
 252                 p->pbm = pbm;
 253                 p->msiqid = pbm->msiq_first + i;
 254         }
 255
 256         size = pbm->msi_num * sizeof(unsigned int);
 257         pbm->msi_irq_table = kzalloc(size, GFP_KERNEL);
 258         if (!pbm->msi_irq_table) {
 259                 kfree(pbm->msiq_irq_cookies);
 260                 pbm->msiq_irq_cookies = NULL;
 261                 return -ENOMEM;
 262         }
 263
 264         return 0;
 265 }
 266
 267 static void msi_table_free(struct pci_pbm_info *pbm)
 268 {
 269         kfree(pbm->msiq_irq_cookies);
 270         pbm->msiq_irq_cookies = NULL;
 271
 272         kfree(pbm->msi_irq_table);
 273         pbm->msi_irq_table = NULL;
 274 }
 275
 276 static int bringup_one_msi_queue(struct pci_pbm_info *pbm,
 277                                  const struct sparc64_msiq_ops *ops,
 278                                  unsigned long msiqid,
 279                                  unsigned long devino)
 280 {
 281         int irq = ops->msiq_build_irq(pbm, msiqid, devino);
 282         int err;
 283
 284         if (irq < 0)
 285                 return irq;
 286
 287         err = request_irq(irq, sparc64_msiq_interrupt, 0,
 288                           "MSIQ",
 289                           &pbm->msiq_irq_cookies[msiqid - pbm->msiq_first]);
 290         if (err)
 291                 return err;
 292
 293         return 0;
 294 }
 295
 296 static int sparc64_bringup_msi_queues(struct pci_pbm_info *pbm,
 297                                       const struct sparc64_msiq_ops *ops)
 298 {
 299         int i;
 300
 301         for (i = 0; i < pbm->msiq_num; i++) {
 302                 unsigned long msiqid = i + pbm->msiq_first;
 303                 unsigned long devino = i + pbm->msiq_first_devino;
 304                 int err;
 305
 306                 err = bringup_one_msi_queue(pbm, ops, msiqid, devino);
 307                 if (err)
 308                         return err;
 309         }
 310
 311         return 0;
 312 }
 313
 314 void sparc64_pbm_msi_init(struct pci_pbm_info *pbm,
 315                           const struct sparc64_msiq_ops *ops)
 316 {
 317         const u32 *val;
 318         int len;
 319
 320         val = of_get_property(pbm->prom_node, "#msi-eqs", &len);
 321         if (!val || len != 4)
 322                 goto no_msi;
 323         pbm->msiq_num = *val;
 324         if (pbm->msiq_num) {
 325                 const struct msiq_prop {
 326                         u32 first_msiq;
 327                         u32 num_msiq;
 328                         u32 first_devino;
 329                 } *mqp;
 330                 const struct msi_range_prop {
 331                         u32 first_msi;
 332                         u32 num_msi;
 333                 } *mrng;
 334                 const struct addr_range_prop {
 335                         u32 msi32_high;
 336                         u32 msi32_low;
 337                         u32 msi32_len;
 338                         u32 msi64_high;
 339                         u32 msi64_low;
 340                         u32 msi64_len;
 341                 } *arng;
 342
 343                 val = of_get_property(pbm->prom_node, "msi-eq-size", &len);
 344                 if (!val || len != 4)
 345                         goto no_msi;
 346
 347                 pbm->msiq_ent_count = *val;
 348
 349                 mqp = of_get_property(pbm->prom_node,
 350                                       "msi-eq-to-devino", &len);
 351                 if (!mqp)
 352                         mqp = of_get_property(pbm->prom_node,
 353                                               "msi-eq-devino", &len);
 354                 if (!mqp || len != sizeof(struct msiq_prop))
 355                         goto no_msi;
 356
 357                 pbm->msiq_first = mqp->first_msiq;
 358                 pbm->msiq_first_devino = mqp->first_devino;
 359
 360                 val = of_get_property(pbm->prom_node, "#msi", &len);
 361                 if (!val || len != 4)
 362                         goto no_msi;
 363                 pbm->msi_num = *val;
 364
 365                 mrng = of_get_property(pbm->prom_node, "msi-ranges", &len);
 366                 if (!mrng || len != sizeof(struct msi_range_prop))
 367                         goto no_msi;
 368                 pbm->msi_first = mrng->first_msi;
 369
 370                 val = of_get_property(pbm->prom_node, "msi-data-mask", &len);
 371                 if (!val || len != 4)
 372                         goto no_msi;
 373                 pbm->msi_data_mask = *val;
 374
 375                 val = of_get_property(pbm->prom_node, "msix-data-width", &len);
 376                 if (!val || len != 4)
 377                         goto no_msi;
 378                 pbm->msix_data_width = *val;
 379
 380                 arng = of_get_property(pbm->prom_node, "msi-address-ranges",
 381                                        &len);
 382                 if (!arng || len != sizeof(struct addr_range_prop))
 383                         goto no_msi;
 384                 pbm->msi32_start = ((u64)arng->msi32_high << 32) |
 385                         (u64) arng->msi32_low;
 386                 pbm->msi64_start = ((u64)arng->msi64_high << 32) |
 387                         (u64) arng->msi64_low;
 388                 pbm->msi32_len = arng->msi32_len;
 389                 pbm->msi64_len = arng->msi64_len;
 390
 391                 if (msi_bitmap_alloc(pbm))
 392                         goto no_msi;
 393
 394                 if (msi_table_alloc(pbm)) {
 395                         msi_bitmap_free(pbm);
 396                         goto no_msi;
 397                 }
 398
 399                 if (ops->msiq_alloc(pbm)) {
 400                         msi_table_free(pbm);
 401                         msi_bitmap_free(pbm);
 402                         goto no_msi;
 403                 }
 404
 405                 if (sparc64_bringup_msi_queues(pbm, ops)) {
 406                         ops->msiq_free(pbm);
 407                         msi_table_free(pbm);
 408                         msi_bitmap_free(pbm);
 409                         goto no_msi;
 410                 }
 411
 412                 printk(KERN_INFO "%s: MSI Queue first[%u] num[%u] count[%u] "
 413                        "devino[0x%x]\n",
 414                        pbm->name,
 415                        pbm->msiq_first, pbm->msiq_num,
 416                        pbm->msiq_ent_count,
 417                        pbm->msiq_first_devino);
 418                 printk(KERN_INFO "%s: MSI first[%u] num[%u] mask[0x%x] "
 419                        "width[%u]\n",
 420                        pbm->name,
 421                        pbm->msi_first, pbm->msi_num, pbm->msi_data_mask,
 422                        pbm->msix_data_width);
 423                 printk(KERN_INFO "%s: MSI addr32[0x%lx:0x%x] "
 424                        "addr64[0x%lx:0x%x]\n",
 425                        pbm->name,
 426                        pbm->msi32_start, pbm->msi32_len,
 427                        pbm->msi64_start, pbm->msi64_len);
 428                 printk(KERN_INFO "%s: MSI queues at RA [%016lx]\n",
 429                        pbm->name,
 430                        __pa(pbm->msi_queues));
 431
 432                 pbm->msi_ops = ops;
 433                 pbm->setup_msi_irq = sparc64_setup_msi_irq;
 434                 pbm->teardown_msi_irq = sparc64_teardown_msi_irq;
 435         }
 436         return;
 437
 438 no_msi:
 439         pbm->msiq_num = 0;
 440         printk(KERN_INFO "%s: No MSI support.\n", pbm->name);
 441 }