linux/arch/sparc/kernel/pci_msi.c
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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/slab.h>
   8#include <linux/irq.h>
   9
  10#include "pci_impl.h"
  11
  12static irqreturn_t sparc64_msiq_interrupt(int irq, void *cookie)
  13{
  14        struct sparc64_msiq_cookie *msiq_cookie = cookie;
  15        struct pci_pbm_info *pbm = msiq_cookie->pbm;
  16        unsigned long msiqid = msiq_cookie->msiqid;
  17        const struct sparc64_msiq_ops *ops;
  18        unsigned long orig_head, head;
  19        int err;
  20
  21        ops = pbm->msi_ops;
  22
  23        err = ops->get_head(pbm, msiqid, &head);
  24        if (unlikely(err < 0))
  25                goto err_get_head;
  26
  27        orig_head = head;
  28        for (;;) {
  29                unsigned long msi;
  30
  31                err = ops->dequeue_msi(pbm, msiqid, &head, &msi);
  32                if (likely(err > 0)) {
  33                        unsigned int irq;
  34
  35                        irq = pbm->msi_irq_table[msi - pbm->msi_first];
  36                        generic_handle_irq(irq);
  37                }
  38
  39                if (unlikely(err < 0))
  40                        goto err_dequeue;
  41
  42                if (err == 0)
  43                        break;
  44        }
  45        if (likely(head != orig_head)) {
  46                err = ops->set_head(pbm, msiqid, head);
  47                if (unlikely(err < 0))
  48                        goto err_set_head;
  49        }
  50        return IRQ_HANDLED;
  51
  52err_get_head:
  53        printk(KERN_EMERG "MSI: Get head on msiqid[%lu] gives error %d\n",
  54               msiqid, err);
  55        goto err_out;
  56
  57err_dequeue:
  58        printk(KERN_EMERG "MSI: Dequeue head[%lu] from msiqid[%lu] "
  59               "gives error %d\n",
  60               head, msiqid, err);
  61        goto err_out;
  62
  63err_set_head:
  64        printk(KERN_EMERG "MSI: Set head[%lu] on msiqid[%lu] "
  65               "gives error %d\n",
  66               head, msiqid, err);
  67        goto err_out;
  68
  69err_out:
  70        return IRQ_NONE;
  71}
  72
  73static u32 pick_msiq(struct pci_pbm_info *pbm)
  74{
  75        static DEFINE_SPINLOCK(rotor_lock);
  76        unsigned long flags;
  77        u32 ret, rotor;
  78
  79        spin_lock_irqsave(&rotor_lock, flags);
  80
  81        rotor = pbm->msiq_rotor;
  82        ret = pbm->msiq_first + rotor;
  83
  84        if (++rotor >= pbm->msiq_num)
  85                rotor = 0;
  86        pbm->msiq_rotor = rotor;
  87
  88        spin_unlock_irqrestore(&rotor_lock, flags);
  89
  90        return ret;
  91}
  92
  93
  94static int alloc_msi(struct pci_pbm_info *pbm)
  95{
  96        int i;
  97
  98        for (i = 0; i < pbm->msi_num; i++) {
  99                if (!test_and_set_bit(i, pbm->msi_bitmap))
 100                        return i + pbm->msi_first;
 101        }
 102
 103        return -ENOENT;
 104}
 105
 106static void free_msi(struct pci_pbm_info *pbm, int msi_num)
 107{
 108        msi_num -= pbm->msi_first;
 109        clear_bit(msi_num, pbm->msi_bitmap);
 110}
 111
 112static struct irq_chip msi_irq = {
 113        .name           = "PCI-MSI",
 114        .irq_mask       = mask_msi_irq,
 115        .irq_unmask     = unmask_msi_irq,
 116        .irq_enable     = unmask_msi_irq,
 117        .irq_disable    = mask_msi_irq,
 118        /* XXX affinity XXX */
 119};
 120
 121static int sparc64_setup_msi_irq(unsigned int *irq_p,
 122                                 struct pci_dev *pdev,
 123                                 struct msi_desc *entry)
 124{
 125        struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
 126        const struct sparc64_msiq_ops *ops = pbm->msi_ops;
 127        struct msi_msg msg;
 128        int msi, err;
 129        u32 msiqid;
 130
 131        *irq_p = irq_alloc(0, 0);
 132        err = -ENOMEM;
 133        if (!*irq_p)
 134                goto out_err;
 135
 136        irq_set_chip_and_handler_name(*irq_p, &msi_irq, handle_simple_irq,
 137                                      "MSI");
 138
 139        err = alloc_msi(pbm);
 140        if (unlikely(err < 0))
 141                goto out_irq_free;
 142
 143        msi = err;
 144
 145        msiqid = pick_msiq(pbm);
 146
 147        err = ops->msi_setup(pbm, msiqid, msi,
 148                             (entry->msi_attrib.is_64 ? 1 : 0));
 149        if (err)
 150                goto out_msi_free;
 151
 152        pbm->msi_irq_table[msi - pbm->msi_first] = *irq_p;
 153
 154        if (entry->msi_attrib.is_64) {
 155                msg.address_hi = pbm->msi64_start >> 32;
 156                msg.address_lo = pbm->msi64_start & 0xffffffff;
 157        } else {
 158                msg.address_hi = 0;
 159                msg.address_lo = pbm->msi32_start;
 160        }
 161        msg.data = msi;
 162
 163        irq_set_msi_desc(*irq_p, entry);
 164        write_msi_msg(*irq_p, &msg);
 165
 166        return 0;
 167
 168out_msi_free:
 169        free_msi(pbm, msi);
 170
 171out_irq_free:
 172        irq_set_chip(*irq_p, NULL);
 173        irq_free(*irq_p);
 174        *irq_p = 0;
 175
 176out_err:
 177        return err;
 178}
 179
 180static void sparc64_teardown_msi_irq(unsigned int irq,
 181                                     struct pci_dev *pdev)
 182{
 183        struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
 184        const struct sparc64_msiq_ops *ops = pbm->msi_ops;
 185        unsigned int msi_num;
 186        int i, err;
 187
 188        for (i = 0; i < pbm->msi_num; i++) {
 189                if (pbm->msi_irq_table[i] == irq)
 190                        break;
 191        }
 192        if (i >= pbm->msi_num) {
 193                printk(KERN_ERR "%s: teardown: No MSI for irq %u\n",
 194                       pbm->name, irq);
 195                return;
 196        }
 197
 198        msi_num = pbm->msi_first + i;
 199        pbm->msi_irq_table[i] = ~0U;
 200
 201        err = ops->msi_teardown(pbm, msi_num);
 202        if (err) {
 203                printk(KERN_ERR "%s: teardown: ops->teardown() on MSI %u, "
 204                       "irq %u, gives error %d\n",
 205                       pbm->name, msi_num, irq, err);
 206                return;
 207        }
 208
 209        free_msi(pbm, msi_num);
 210
 211        irq_set_chip(irq, NULL);
 212        irq_free(irq);
 213}
 214
 215static int msi_bitmap_alloc(struct pci_pbm_info *pbm)
 216{
 217        unsigned long size, bits_per_ulong;
 218
 219        bits_per_ulong = sizeof(unsigned long) * 8;
 220        size = (pbm->msi_num + (bits_per_ulong - 1)) & ~(bits_per_ulong - 1);
 221        size /= 8;
 222        BUG_ON(size % sizeof(unsigned long));
 223
 224        pbm->msi_bitmap = kzalloc(size, GFP_KERNEL);
 225        if (!pbm->msi_bitmap)
 226                return -ENOMEM;
 227
 228        return 0;
 229}
 230
 231static void msi_bitmap_free(struct pci_pbm_info *pbm)
 232{
 233        kfree(pbm->msi_bitmap);
 234        pbm->msi_bitmap = NULL;
 235}
 236
 237static int msi_table_alloc(struct pci_pbm_info *pbm)
 238{
 239        int size, i;
 240
 241        size = pbm->msiq_num * sizeof(struct sparc64_msiq_cookie);
 242        pbm->msiq_irq_cookies = kzalloc(size, GFP_KERNEL);
 243        if (!pbm->msiq_irq_cookies)
 244                return -ENOMEM;
 245
 246        for (i = 0; i < pbm->msiq_num; i++) {
 247                struct sparc64_msiq_cookie *p;
 248
 249                p = &pbm->msiq_irq_cookies[i];
 250                p->pbm = pbm;
 251                p->msiqid = pbm->msiq_first + i;
 252        }
 253
 254        size = pbm->msi_num * sizeof(unsigned int);
 255        pbm->msi_irq_table = kzalloc(size, GFP_KERNEL);
 256        if (!pbm->msi_irq_table) {
 257                kfree(pbm->msiq_irq_cookies);
 258                pbm->msiq_irq_cookies = NULL;
 259                return -ENOMEM;
 260        }
 261
 262        return 0;
 263}
 264
 265static void msi_table_free(struct pci_pbm_info *pbm)
 266{
 267        kfree(pbm->msiq_irq_cookies);
 268        pbm->msiq_irq_cookies = NULL;
 269
 270        kfree(pbm->msi_irq_table);
 271        pbm->msi_irq_table = NULL;
 272}
 273
 274static int bringup_one_msi_queue(struct pci_pbm_info *pbm,
 275                                 const struct sparc64_msiq_ops *ops,
 276                                 unsigned long msiqid,
 277                                 unsigned long devino)
 278{
 279        int irq = ops->msiq_build_irq(pbm, msiqid, devino);
 280        int err, nid;
 281
 282        if (irq < 0)
 283                return irq;
 284
 285        nid = pbm->numa_node;
 286        if (nid != -1) {
 287                cpumask_t numa_mask;
 288
 289                cpumask_copy(&numa_mask, cpumask_of_node(nid));
 290                irq_set_affinity(irq, &numa_mask);
 291        }
 292        err = request_irq(irq, sparc64_msiq_interrupt, 0,
 293                          "MSIQ",
 294                          &pbm->msiq_irq_cookies[msiqid - pbm->msiq_first]);
 295        if (err)
 296                return err;
 297
 298        return 0;
 299}
 300
 301static int sparc64_bringup_msi_queues(struct pci_pbm_info *pbm,
 302                                      const struct sparc64_msiq_ops *ops)
 303{
 304        int i;
 305
 306        for (i = 0; i < pbm->msiq_num; i++) {
 307                unsigned long msiqid = i + pbm->msiq_first;
 308                unsigned long devino = i + pbm->msiq_first_devino;
 309                int err;
 310
 311                err = bringup_one_msi_queue(pbm, ops, msiqid, devino);
 312                if (err)
 313                        return err;
 314        }
 315
 316        return 0;
 317}
 318
 319void sparc64_pbm_msi_init(struct pci_pbm_info *pbm,
 320                          const struct sparc64_msiq_ops *ops)
 321{
 322        const u32 *val;
 323        int len;
 324
 325        val = of_get_property(pbm->op->dev.of_node, "#msi-eqs", &len);
 326        if (!val || len != 4)
 327                goto no_msi;
 328        pbm->msiq_num = *val;
 329        if (pbm->msiq_num) {
 330                const struct msiq_prop {
 331                        u32 first_msiq;
 332                        u32 num_msiq;
 333                        u32 first_devino;
 334                } *mqp;
 335                const struct msi_range_prop {
 336                        u32 first_msi;
 337                        u32 num_msi;
 338                } *mrng;
 339                const struct addr_range_prop {
 340                        u32 msi32_high;
 341                        u32 msi32_low;
 342                        u32 msi32_len;
 343                        u32 msi64_high;
 344                        u32 msi64_low;
 345                        u32 msi64_len;
 346                } *arng;
 347
 348                val = of_get_property(pbm->op->dev.of_node, "msi-eq-size", &len);
 349                if (!val || len != 4)
 350                        goto no_msi;
 351
 352                pbm->msiq_ent_count = *val;
 353
 354                mqp = of_get_property(pbm->op->dev.of_node,
 355                                      "msi-eq-to-devino", &len);
 356                if (!mqp)
 357                        mqp = of_get_property(pbm->op->dev.of_node,
 358                                              "msi-eq-devino", &len);
 359                if (!mqp || len != sizeof(struct msiq_prop))
 360                        goto no_msi;
 361
 362                pbm->msiq_first = mqp->first_msiq;
 363                pbm->msiq_first_devino = mqp->first_devino;
 364
 365                val = of_get_property(pbm->op->dev.of_node, "#msi", &len);
 366                if (!val || len != 4)
 367                        goto no_msi;
 368                pbm->msi_num = *val;
 369
 370                mrng = of_get_property(pbm->op->dev.of_node, "msi-ranges", &len);
 371                if (!mrng || len != sizeof(struct msi_range_prop))
 372                        goto no_msi;
 373                pbm->msi_first = mrng->first_msi;
 374
 375                val = of_get_property(pbm->op->dev.of_node, "msi-data-mask", &len);
 376                if (!val || len != 4)
 377                        goto no_msi;
 378                pbm->msi_data_mask = *val;
 379
 380                val = of_get_property(pbm->op->dev.of_node, "msix-data-width", &len);
 381                if (!val || len != 4)
 382                        goto no_msi;
 383                pbm->msix_data_width = *val;
 384
 385                arng = of_get_property(pbm->op->dev.of_node, "msi-address-ranges",
 386                                       &len);
 387                if (!arng || len != sizeof(struct addr_range_prop))
 388                        goto no_msi;
 389                pbm->msi32_start = ((u64)arng->msi32_high << 32) |
 390                        (u64) arng->msi32_low;
 391                pbm->msi64_start = ((u64)arng->msi64_high << 32) |
 392                        (u64) arng->msi64_low;
 393                pbm->msi32_len = arng->msi32_len;
 394                pbm->msi64_len = arng->msi64_len;
 395
 396                if (msi_bitmap_alloc(pbm))
 397                        goto no_msi;
 398
 399                if (msi_table_alloc(pbm)) {
 400                        msi_bitmap_free(pbm);
 401                        goto no_msi;
 402                }
 403
 404                if (ops->msiq_alloc(pbm)) {
 405                        msi_table_free(pbm);
 406                        msi_bitmap_free(pbm);
 407                        goto no_msi;
 408                }
 409
 410                if (sparc64_bringup_msi_queues(pbm, ops)) {
 411                        ops->msiq_free(pbm);
 412                        msi_table_free(pbm);
 413                        msi_bitmap_free(pbm);
 414                        goto no_msi;
 415                }
 416
 417                printk(KERN_INFO "%s: MSI Queue first[%u] num[%u] count[%u] "
 418                       "devino[0x%x]\n",
 419                       pbm->name,
 420                       pbm->msiq_first, pbm->msiq_num,
 421                       pbm->msiq_ent_count,
 422                       pbm->msiq_first_devino);
 423                printk(KERN_INFO "%s: MSI first[%u] num[%u] mask[0x%x] "
 424                       "width[%u]\n",
 425                       pbm->name,
 426                       pbm->msi_first, pbm->msi_num, pbm->msi_data_mask,
 427                       pbm->msix_data_width);
 428                printk(KERN_INFO "%s: MSI addr32[0x%llx:0x%x] "
 429                       "addr64[0x%llx:0x%x]\n",
 430                       pbm->name,
 431                       pbm->msi32_start, pbm->msi32_len,
 432                       pbm->msi64_start, pbm->msi64_len);
 433                printk(KERN_INFO "%s: MSI queues at RA [%016lx]\n",
 434                       pbm->name,
 435                       __pa(pbm->msi_queues));
 436
 437                pbm->msi_ops = ops;
 438                pbm->setup_msi_irq = sparc64_setup_msi_irq;
 439                pbm->teardown_msi_irq = sparc64_teardown_msi_irq;
 440        }
 441        return;
 442
 443no_msi:
 444        pbm->msiq_num = 0;
 445        printk(KERN_INFO "%s: No MSI support.\n", pbm->name);
 446}
 447