platforms/pseries/msi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
0004  * Copyright 2006-2007 Michael Ellerman, IBM Corp.
0005  */
0006
0007 #include <linux/crash_dump.h>
0008 #include <linux/device.h>
0009 #include <linux/irq.h>
0010 #include <linux/irqdomain.h>
0011 #include <linux/msi.h>
0012
0013 #include <asm/rtas.h>
0014 #include <asm/hw_irq.h>
0015 #include <asm/ppc-pci.h>
0016 #include <asm/machdep.h>
0017 #include <asm/xive.h>
0018
0019 #include "pseries.h"
0020
0021 static int query_token, change_token;
0022
0023 #define RTAS_QUERY_FN       0
0024 #define RTAS_CHANGE_FN      1
0025 #define RTAS_RESET_FN       2
0026 #define RTAS_CHANGE_MSI_FN  3
0027 #define RTAS_CHANGE_MSIX_FN 4
0028 #define RTAS_CHANGE_32MSI_FN    5
0029
0030 /* RTAS Helpers */
0031
0032 static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
0033 {
0034     u32 addr, seq_num, rtas_ret[3];
0035     unsigned long buid;
0036     int rc;
0037
0038     addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
0039     buid = pdn->phb->buid;
0040
0041     seq_num = 1;
0042     do {
0043         if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
0044             func == RTAS_CHANGE_32MSI_FN)
0045             rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
0046                     BUID_HI(buid), BUID_LO(buid),
0047                     func, num_irqs, seq_num);
0048         else
0049             rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
0050                     BUID_HI(buid), BUID_LO(buid),
0051                     func, num_irqs, seq_num);
0052
0053         seq_num = rtas_ret[1];
0054     } while (rtas_busy_delay(rc));
0055
0056     /*
0057      * If the RTAS call succeeded, return the number of irqs allocated.
0058      * If not, make sure we return a negative error code.
0059      */
0060     if (rc == 0)
0061         rc = rtas_ret[0];
0062     else if (rc > 0)
0063         rc = -rc;
0064
0065     pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
0066          func, num_irqs, rtas_ret[0], rc);
0067
0068     return rc;
0069 }
0070
0071 static void rtas_disable_msi(struct pci_dev *pdev)
0072 {
0073     struct pci_dn *pdn;
0074
0075     pdn = pci_get_pdn(pdev);
0076     if (!pdn)
0077         return;
0078
0079     /*
0080      * disabling MSI with the explicit interface also disables MSI-X
0081      */
0082     if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
0083         /*
0084          * may have failed because explicit interface is not
0085          * present
0086          */
0087         if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
0088             pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
0089         }
0090     }
0091 }
0092
0093 static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
0094 {
0095     u32 addr, rtas_ret[2];
0096     unsigned long buid;
0097     int rc;
0098
0099     addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
0100     buid = pdn->phb->buid;
0101
0102     do {
0103         rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
0104                    BUID_HI(buid), BUID_LO(buid), offset);
0105     } while (rtas_busy_delay(rc));
0106
0107     if (rc) {
0108         pr_debug("rtas_msi: error (%d) querying source number\n", rc);
0109         return rc;
0110     }
0111
0112     return rtas_ret[0];
0113 }
0114
0115 static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
0116 {
0117     struct device_node *dn;
0118     const __be32 *p;
0119     u32 req_msi;
0120
0121     dn = pci_device_to_OF_node(pdev);
0122
0123     p = of_get_property(dn, prop_name, NULL);
0124     if (!p) {
0125         pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn);
0126         return -ENOENT;
0127     }
0128
0129     req_msi = be32_to_cpup(p);
0130     if (req_msi < nvec) {
0131         pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
0132
0133         if (req_msi == 0) /* Be paranoid */
0134             return -ENOSPC;
0135
0136         return req_msi;
0137     }
0138
0139     return 0;
0140 }
0141
0142 static int check_req_msi(struct pci_dev *pdev, int nvec)
0143 {
0144     return check_req(pdev, nvec, "ibm,req#msi");
0145 }
0146
0147 static int check_req_msix(struct pci_dev *pdev, int nvec)
0148 {
0149     return check_req(pdev, nvec, "ibm,req#msi-x");
0150 }
0151
0152 /* Quota calculation */
0153
0154 static struct device_node *__find_pe_total_msi(struct device_node *node, int *total)
0155 {
0156     struct device_node *dn;
0157     const __be32 *p;
0158
0159     dn = of_node_get(node);
0160     while (dn) {
0161         p = of_get_property(dn, "ibm,pe-total-#msi", NULL);
0162         if (p) {
0163             pr_debug("rtas_msi: found prop on dn %pOF\n",
0164                 dn);
0165             *total = be32_to_cpup(p);
0166             return dn;
0167         }
0168
0169         dn = of_get_next_parent(dn);
0170     }
0171
0172     return NULL;
0173 }
0174
0175 static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total)
0176 {
0177     return __find_pe_total_msi(pci_device_to_OF_node(dev), total);
0178 }
0179
0180 static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
0181 {
0182     struct device_node *dn;
0183     struct eeh_dev *edev;
0184
0185     /* Found our PE and assume 8 at that point. */
0186
0187     dn = pci_device_to_OF_node(dev);
0188     if (!dn)
0189         return NULL;
0190
0191     /* Get the top level device in the PE */
0192     edev = pdn_to_eeh_dev(PCI_DN(dn));
0193     if (edev->pe)
0194         edev = list_first_entry(&edev->pe->edevs, struct eeh_dev,
0195                     entry);
0196     dn = pci_device_to_OF_node(edev->pdev);
0197     if (!dn)
0198         return NULL;
0199
0200     /* We actually want the parent */
0201     dn = of_get_parent(dn);
0202     if (!dn)
0203         return NULL;
0204
0205     /* Hardcode of 8 for old firmwares */
0206     *total = 8;
0207     pr_debug("rtas_msi: using PE dn %pOF\n", dn);
0208
0209     return dn;
0210 }
0211
0212 struct msi_counts {
0213     struct device_node *requestor;
0214     int num_devices;
0215     int request;
0216     int quota;
0217     int spare;
0218     int over_quota;
0219 };
0220
0221 static void *count_non_bridge_devices(struct device_node *dn, void *data)
0222 {
0223     struct msi_counts *counts = data;
0224     const __be32 *p;
0225     u32 class;
0226
0227     pr_debug("rtas_msi: counting %pOF\n", dn);
0228
0229     p = of_get_property(dn, "class-code", NULL);
0230     class = p ? be32_to_cpup(p) : 0;
0231
0232     if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
0233         counts->num_devices++;
0234
0235     return NULL;
0236 }
0237
0238 static void *count_spare_msis(struct device_node *dn, void *data)
0239 {
0240     struct msi_counts *counts = data;
0241     const __be32 *p;
0242     int req;
0243
0244     if (dn == counts->requestor)
0245         req = counts->request;
0246     else {
0247         /* We don't know if a driver will try to use MSI or MSI-X,
0248          * so we just have to punt and use the larger of the two. */
0249         req = 0;
0250         p = of_get_property(dn, "ibm,req#msi", NULL);
0251         if (p)
0252             req = be32_to_cpup(p);
0253
0254         p = of_get_property(dn, "ibm,req#msi-x", NULL);
0255         if (p)
0256             req = max(req, (int)be32_to_cpup(p));
0257     }
0258
0259     if (req < counts->quota)
0260         counts->spare += counts->quota - req;
0261     else if (req > counts->quota)
0262         counts->over_quota++;
0263
0264     return NULL;
0265 }
0266
0267 static int msi_quota_for_device(struct pci_dev *dev, int request)
0268 {
0269     struct device_node *pe_dn;
0270     struct msi_counts counts;
0271     int total;
0272
0273     pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
0274           request);
0275
0276     pe_dn = find_pe_total_msi(dev, &total);
0277     if (!pe_dn)
0278         pe_dn = find_pe_dn(dev, &total);
0279
0280     if (!pe_dn) {
0281         pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
0282         goto out;
0283     }
0284
0285     pr_debug("rtas_msi: found PE %pOF\n", pe_dn);
0286
0287     memset(&counts, 0, sizeof(struct msi_counts));
0288
0289     /* Work out how many devices we have below this PE */
0290     pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts);
0291
0292     if (counts.num_devices == 0) {
0293         pr_err("rtas_msi: found 0 devices under PE for %s\n",
0294             pci_name(dev));
0295         goto out;
0296     }
0297
0298     counts.quota = total / counts.num_devices;
0299     if (request <= counts.quota)
0300         goto out;
0301
0302     /* else, we have some more calculating to do */
0303     counts.requestor = pci_device_to_OF_node(dev);
0304     counts.request = request;
0305     pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts);
0306
0307     /* If the quota isn't an integer multiple of the total, we can
0308      * use the remainder as spare MSIs for anyone that wants them. */
0309     counts.spare += total % counts.num_devices;
0310
0311     /* Divide any spare by the number of over-quota requestors */
0312     if (counts.over_quota)
0313         counts.quota += counts.spare / counts.over_quota;
0314
0315     /* And finally clamp the request to the possibly adjusted quota */
0316     request = min(counts.quota, request);
0317
0318     pr_debug("rtas_msi: request clamped to quota %d\n", request);
0319 out:
0320     of_node_put(pe_dn);
0321
0322     return request;
0323 }
0324
0325 static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
0326 {
0327     u32 addr_hi, addr_lo;
0328
0329     /*
0330      * We should only get in here for IODA1 configs. This is based on the
0331      * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
0332      * support, and we are in a PCIe Gen2 slot.
0333      */
0334     dev_info(&pdev->dev,
0335          "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
0336     pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
0337     addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
0338     pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
0339     pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
0340 }
0341
0342 static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int nvec_in, int type,
0343                  msi_alloc_info_t *arg)
0344 {
0345     struct pci_dn *pdn;
0346     int quota, rc;
0347     int nvec = nvec_in;
0348     int use_32bit_msi_hack = 0;
0349
0350     if (type == PCI_CAP_ID_MSIX)
0351         rc = check_req_msix(pdev, nvec);
0352     else
0353         rc = check_req_msi(pdev, nvec);
0354
0355     if (rc)
0356         return rc;
0357
0358     quota = msi_quota_for_device(pdev, nvec);
0359
0360     if (quota && quota < nvec)
0361         return quota;
0362
0363     /*
0364      * Firmware currently refuse any non power of two allocation
0365      * so we round up if the quota will allow it.
0366      */
0367     if (type == PCI_CAP_ID_MSIX) {
0368         int m = roundup_pow_of_two(nvec);
0369         quota = msi_quota_for_device(pdev, m);
0370
0371         if (quota >= m)
0372             nvec = m;
0373     }
0374
0375     pdn = pci_get_pdn(pdev);
0376
0377     /*
0378      * Try the new more explicit firmware interface, if that fails fall
0379      * back to the old interface. The old interface is known to never
0380      * return MSI-Xs.
0381      */
0382 again:
0383     if (type == PCI_CAP_ID_MSI) {
0384         if (pdev->no_64bit_msi) {
0385             rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
0386             if (rc < 0) {
0387                 /*
0388                  * We only want to run the 32 bit MSI hack below if
0389                  * the max bus speed is Gen2 speed
0390                  */
0391                 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
0392                     return rc;
0393
0394                 use_32bit_msi_hack = 1;
0395             }
0396         } else
0397             rc = -1;
0398
0399         if (rc < 0)
0400             rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
0401
0402         if (rc < 0) {
0403             pr_debug("rtas_msi: trying the old firmware call.\n");
0404             rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
0405         }
0406
0407         if (use_32bit_msi_hack && rc > 0)
0408             rtas_hack_32bit_msi_gen2(pdev);
0409     } else
0410         rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
0411
0412     if (rc != nvec) {
0413         if (nvec != nvec_in) {
0414             nvec = nvec_in;
0415             goto again;
0416         }
0417         pr_debug("rtas_msi: rtas_change_msi() failed\n");
0418         return rc;
0419     }
0420
0421     return 0;
0422 }
0423
0424 static int pseries_msi_ops_prepare(struct irq_domain *domain, struct device *dev,
0425                    int nvec, msi_alloc_info_t *arg)
0426 {
0427     struct pci_dev *pdev = to_pci_dev(dev);
0428     int type = pdev->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI;
0429
0430     return rtas_prepare_msi_irqs(pdev, nvec, type, arg);
0431 }
0432
0433 /*
0434  * ->msi_free() is called before irq_domain_free_irqs_top() when the
0435  * handler data is still available. Use that to clear the XIVE
0436  * controller data.
0437  */
0438 static void pseries_msi_ops_msi_free(struct irq_domain *domain,
0439                      struct msi_domain_info *info,
0440                      unsigned int irq)
0441 {
0442     if (xive_enabled())
0443         xive_irq_free_data(irq);
0444 }
0445
0446 /*
0447  * RTAS can not disable one MSI at a time. It's all or nothing. Do it
0448  * at the end after all IRQs have been freed.
0449  */
0450 static void pseries_msi_domain_free_irqs(struct irq_domain *domain,
0451                      struct device *dev)
0452 {
0453     if (WARN_ON_ONCE(!dev_is_pci(dev)))
0454         return;
0455
0456     __msi_domain_free_irqs(domain, dev);
0457
0458     rtas_disable_msi(to_pci_dev(dev));
0459 }
0460
0461 static struct msi_domain_ops pseries_pci_msi_domain_ops = {
0462     .msi_prepare    = pseries_msi_ops_prepare,
0463     .msi_free   = pseries_msi_ops_msi_free,
0464     .domain_free_irqs = pseries_msi_domain_free_irqs,
0465 };
0466
0467 static void pseries_msi_shutdown(struct irq_data *d)
0468 {
0469     d = d->parent_data;
0470     if (d->chip->irq_shutdown)
0471         d->chip->irq_shutdown(d);
0472 }
0473
0474 static void pseries_msi_mask(struct irq_data *d)
0475 {
0476     pci_msi_mask_irq(d);
0477     irq_chip_mask_parent(d);
0478 }
0479
0480 static void pseries_msi_unmask(struct irq_data *d)
0481 {
0482     pci_msi_unmask_irq(d);
0483     irq_chip_unmask_parent(d);
0484 }
0485
0486 static void pseries_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
0487 {
0488     struct msi_desc *entry = irq_data_get_msi_desc(data);
0489
0490     /*
0491      * Do not update the MSIx vector table. It's not strictly necessary
0492      * because the table is initialized by the underlying hypervisor, PowerVM
0493      * or QEMU/KVM. However, if the MSIx vector entry is cleared, any further
0494      * activation will fail. This can happen in some drivers (eg. IPR) which
0495      * deactivate an IRQ used for testing MSI support.
0496      */
0497     entry->msg = *msg;
0498 }
0499
0500 static struct irq_chip pseries_pci_msi_irq_chip = {
0501     .name       = "pSeries-PCI-MSI",
0502     .irq_shutdown   = pseries_msi_shutdown,
0503     .irq_mask   = pseries_msi_mask,
0504     .irq_unmask = pseries_msi_unmask,
0505     .irq_eoi    = irq_chip_eoi_parent,
0506     .irq_write_msi_msg  = pseries_msi_write_msg,
0507 };
0508
0509
0510 /*
0511  * Set MSI_FLAG_MSIX_CONTIGUOUS as there is no way to express to
0512  * firmware to request a discontiguous or non-zero based range of
0513  * MSI-X entries. Core code will reject such setup attempts.
0514  */
0515 static struct msi_domain_info pseries_msi_domain_info = {
0516     .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
0517           MSI_FLAG_MULTI_PCI_MSI  | MSI_FLAG_PCI_MSIX |
0518           MSI_FLAG_MSIX_CONTIGUOUS),
0519     .ops   = &pseries_pci_msi_domain_ops,
0520     .chip  = &pseries_pci_msi_irq_chip,
0521 };
0522
0523 static void pseries_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
0524 {
0525     __pci_read_msi_msg(irq_data_get_msi_desc(data), msg);
0526 }
0527
0528 static struct irq_chip pseries_msi_irq_chip = {
0529     .name           = "pSeries-MSI",
0530     .irq_shutdown       = pseries_msi_shutdown,
0531     .irq_mask       = irq_chip_mask_parent,
0532     .irq_unmask     = irq_chip_unmask_parent,
0533     .irq_eoi        = irq_chip_eoi_parent,
0534     .irq_set_affinity   = irq_chip_set_affinity_parent,
0535     .irq_compose_msi_msg    = pseries_msi_compose_msg,
0536 };
0537
0538 static int pseries_irq_parent_domain_alloc(struct irq_domain *domain, unsigned int virq,
0539                        irq_hw_number_t hwirq)
0540 {
0541     struct irq_fwspec parent_fwspec;
0542     int ret;
0543
0544     parent_fwspec.fwnode = domain->parent->fwnode;
0545     parent_fwspec.param_count = 2;
0546     parent_fwspec.param[0] = hwirq;
0547     parent_fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
0548
0549     ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
0550     if (ret)
0551         return ret;
0552
0553     return 0;
0554 }
0555
0556 static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
0557                     unsigned int nr_irqs, void *arg)
0558 {
0559     struct pci_controller *phb = domain->host_data;
0560     msi_alloc_info_t *info = arg;
0561     struct msi_desc *desc = info->desc;
0562     struct pci_dev *pdev = msi_desc_to_pci_dev(desc);
0563     int hwirq;
0564     int i, ret;
0565
0566     hwirq = rtas_query_irq_number(pci_get_pdn(pdev), desc->msi_index);
0567     if (hwirq < 0) {
0568         dev_err(&pdev->dev, "Failed to query HW IRQ: %d\n", hwirq);
0569         return hwirq;
0570     }
0571
0572     dev_dbg(&pdev->dev, "%s bridge %pOF %d/%x #%d\n", __func__,
0573         phb->dn, virq, hwirq, nr_irqs);
0574
0575     for (i = 0; i < nr_irqs; i++) {
0576         ret = pseries_irq_parent_domain_alloc(domain, virq + i, hwirq + i);
0577         if (ret)
0578             goto out;
0579
0580         irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
0581                           &pseries_msi_irq_chip, domain->host_data);
0582     }
0583
0584     return 0;
0585
0586 out:
0587     /* TODO: handle RTAS cleanup in ->msi_finish() ? */
0588     irq_domain_free_irqs_parent(domain, virq, i - 1);
0589     return ret;
0590 }
0591
0592 static void pseries_irq_domain_free(struct irq_domain *domain, unsigned int virq,
0593                     unsigned int nr_irqs)
0594 {
0595     struct irq_data *d = irq_domain_get_irq_data(domain, virq);
0596     struct pci_controller *phb = irq_data_get_irq_chip_data(d);
0597
0598     pr_debug("%s bridge %pOF %d #%d\n", __func__, phb->dn, virq, nr_irqs);
0599
0600     /* XIVE domain data is cleared through ->msi_free() */
0601 }
0602
0603 static const struct irq_domain_ops pseries_irq_domain_ops = {
0604     .alloc  = pseries_irq_domain_alloc,
0605     .free   = pseries_irq_domain_free,
0606 };
0607
0608 static int __pseries_msi_allocate_domains(struct pci_controller *phb,
0609                       unsigned int count)
0610 {
0611     struct irq_domain *parent = irq_get_default_host();
0612
0613     phb->fwnode = irq_domain_alloc_named_id_fwnode("pSeries-MSI",
0614                                phb->global_number);
0615     if (!phb->fwnode)
0616         return -ENOMEM;
0617
0618     phb->dev_domain = irq_domain_create_hierarchy(parent, 0, count,
0619                               phb->fwnode,
0620                               &pseries_irq_domain_ops, phb);
0621     if (!phb->dev_domain) {
0622         pr_err("PCI: failed to create IRQ domain bridge %pOF (domain %d)\n",
0623                phb->dn, phb->global_number);
0624         irq_domain_free_fwnode(phb->fwnode);
0625         return -ENOMEM;
0626     }
0627
0628     phb->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(phb->dn),
0629                             &pseries_msi_domain_info,
0630                             phb->dev_domain);
0631     if (!phb->msi_domain) {
0632         pr_err("PCI: failed to create MSI IRQ domain bridge %pOF (domain %d)\n",
0633                phb->dn, phb->global_number);
0634         irq_domain_free_fwnode(phb->fwnode);
0635         irq_domain_remove(phb->dev_domain);
0636         return -ENOMEM;
0637     }
0638
0639     return 0;
0640 }
0641
0642 int pseries_msi_allocate_domains(struct pci_controller *phb)
0643 {
0644     int count;
0645
0646     if (!__find_pe_total_msi(phb->dn, &count)) {
0647         pr_err("PCI: failed to find MSIs for bridge %pOF (domain %d)\n",
0648                phb->dn, phb->global_number);
0649         return -ENOSPC;
0650     }
0651
0652     return __pseries_msi_allocate_domains(phb, count);
0653 }
0654
0655 void pseries_msi_free_domains(struct pci_controller *phb)
0656 {
0657     if (phb->msi_domain)
0658         irq_domain_remove(phb->msi_domain);
0659     if (phb->dev_domain)
0660         irq_domain_remove(phb->dev_domain);
0661     if (phb->fwnode)
0662         irq_domain_free_fwnode(phb->fwnode);
0663 }
0664
0665 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
0666 {
0667     /* No LSI -> leave MSIs (if any) configured */
0668     if (!pdev->irq) {
0669         dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
0670         return;
0671     }
0672
0673     /* No MSI -> MSIs can't have been assigned by fw, leave LSI */
0674     if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) {
0675         dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
0676         return;
0677     }
0678
0679     dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
0680     rtas_disable_msi(pdev);
0681 }
0682
0683 static int rtas_msi_init(void)
0684 {
0685     query_token  = rtas_token("ibm,query-interrupt-source-number");
0686     change_token = rtas_token("ibm,change-msi");
0687
0688     if ((query_token == RTAS_UNKNOWN_SERVICE) ||
0689             (change_token == RTAS_UNKNOWN_SERVICE)) {
0690         pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
0691         return -1;
0692     }
0693
0694     pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
0695
0696     WARN_ON(ppc_md.pci_irq_fixup);
0697     ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
0698
0699     return 0;
0700 }
0701 machine_arch_initcall(pseries, rtas_msi_init);