| /* |
| * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. |
| * Copyright 2006-2007 Michael Ellerman, IBM Corp. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; version 2 of the |
| * License. |
| * |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/irq.h> |
| #include <linux/msi.h> |
| |
| #include <asm/rtas.h> |
| #include <asm/hw_irq.h> |
| #include <asm/ppc-pci.h> |
| |
| static int query_token, change_token; |
| |
| #define RTAS_QUERY_FN 0 |
| #define RTAS_CHANGE_FN 1 |
| #define RTAS_RESET_FN 2 |
| #define RTAS_CHANGE_MSI_FN 3 |
| #define RTAS_CHANGE_MSIX_FN 4 |
| #define RTAS_CHANGE_32MSI_FN 5 |
| |
| /* RTAS Helpers */ |
| |
| static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) |
| { |
| u32 addr, seq_num, rtas_ret[3]; |
| unsigned long buid; |
| int rc; |
| |
| addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); |
| buid = pdn->phb->buid; |
| |
| seq_num = 1; |
| do { |
| if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN || |
| func == RTAS_CHANGE_32MSI_FN) |
| rc = rtas_call(change_token, 6, 4, rtas_ret, addr, |
| BUID_HI(buid), BUID_LO(buid), |
| func, num_irqs, seq_num); |
| else |
| rc = rtas_call(change_token, 6, 3, rtas_ret, addr, |
| BUID_HI(buid), BUID_LO(buid), |
| func, num_irqs, seq_num); |
| |
| seq_num = rtas_ret[1]; |
| } while (rtas_busy_delay(rc)); |
| |
| /* |
| * If the RTAS call succeeded, return the number of irqs allocated. |
| * If not, make sure we return a negative error code. |
| */ |
| if (rc == 0) |
| rc = rtas_ret[0]; |
| else if (rc > 0) |
| rc = -rc; |
| |
| pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", |
| func, num_irqs, rtas_ret[0], rc); |
| |
| return rc; |
| } |
| |
| static void rtas_disable_msi(struct pci_dev *pdev) |
| { |
| struct pci_dn *pdn; |
| |
| pdn = pci_get_pdn(pdev); |
| if (!pdn) |
| return; |
| |
| /* |
| * disabling MSI with the explicit interface also disables MSI-X |
| */ |
| if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) { |
| /* |
| * may have failed because explicit interface is not |
| * present |
| */ |
| if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) { |
| pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); |
| } |
| } |
| } |
| |
| static int rtas_query_irq_number(struct pci_dn *pdn, int offset) |
| { |
| u32 addr, rtas_ret[2]; |
| unsigned long buid; |
| int rc; |
| |
| addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); |
| buid = pdn->phb->buid; |
| |
| do { |
| rc = rtas_call(query_token, 4, 3, rtas_ret, addr, |
| BUID_HI(buid), BUID_LO(buid), offset); |
| } while (rtas_busy_delay(rc)); |
| |
| if (rc) { |
| pr_debug("rtas_msi: error (%d) querying source number\n", rc); |
| return rc; |
| } |
| |
| return rtas_ret[0]; |
| } |
| |
| static void rtas_teardown_msi_irqs(struct pci_dev *pdev) |
| { |
| struct msi_desc *entry; |
| |
| list_for_each_entry(entry, &pdev->msi_list, list) { |
| if (entry->irq == NO_IRQ) |
| continue; |
| |
| irq_set_msi_desc(entry->irq, NULL); |
| irq_dispose_mapping(entry->irq); |
| } |
| |
| rtas_disable_msi(pdev); |
| } |
| |
| static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) |
| { |
| struct device_node *dn; |
| struct pci_dn *pdn; |
| const u32 *req_msi; |
| |
| pdn = pci_get_pdn(pdev); |
| if (!pdn) |
| return -ENODEV; |
| |
| dn = pdn->node; |
| |
| req_msi = of_get_property(dn, prop_name, NULL); |
| if (!req_msi) { |
| pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name); |
| return -ENOENT; |
| } |
| |
| if (*req_msi < nvec) { |
| pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); |
| |
| if (*req_msi == 0) /* Be paranoid */ |
| return -ENOSPC; |
| |
| return *req_msi; |
| } |
| |
| return 0; |
| } |
| |
| static int check_req_msi(struct pci_dev *pdev, int nvec) |
| { |
| return check_req(pdev, nvec, "ibm,req#msi"); |
| } |
| |
| static int check_req_msix(struct pci_dev *pdev, int nvec) |
| { |
| return check_req(pdev, nvec, "ibm,req#msi-x"); |
| } |
| |
| /* Quota calculation */ |
| |
| static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) |
| { |
| struct device_node *dn; |
| const u32 *p; |
| |
| dn = of_node_get(pci_device_to_OF_node(dev)); |
| while (dn) { |
| p = of_get_property(dn, "ibm,pe-total-#msi", NULL); |
| if (p) { |
| pr_debug("rtas_msi: found prop on dn %s\n", |
| dn->full_name); |
| *total = *p; |
| return dn; |
| } |
| |
| dn = of_get_next_parent(dn); |
| } |
| |
| return NULL; |
| } |
| |
| static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) |
| { |
| struct device_node *dn; |
| struct eeh_dev *edev; |
| |
| /* Found our PE and assume 8 at that point. */ |
| |
| dn = pci_device_to_OF_node(dev); |
| if (!dn) |
| return NULL; |
| |
| /* Get the top level device in the PE */ |
| edev = of_node_to_eeh_dev(dn); |
| if (edev->pe) |
| edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list); |
| dn = eeh_dev_to_of_node(edev); |
| if (!dn) |
| return NULL; |
| |
| /* We actually want the parent */ |
| dn = of_get_parent(dn); |
| if (!dn) |
| return NULL; |
| |
| /* Hardcode of 8 for old firmwares */ |
| *total = 8; |
| pr_debug("rtas_msi: using PE dn %s\n", dn->full_name); |
| |
| return dn; |
| } |
| |
| struct msi_counts { |
| struct device_node *requestor; |
| int num_devices; |
| int request; |
| int quota; |
| int spare; |
| int over_quota; |
| }; |
| |
| static void *count_non_bridge_devices(struct device_node *dn, void *data) |
| { |
| struct msi_counts *counts = data; |
| const u32 *p; |
| u32 class; |
| |
| pr_debug("rtas_msi: counting %s\n", dn->full_name); |
| |
| p = of_get_property(dn, "class-code", NULL); |
| class = p ? *p : 0; |
| |
| if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) |
| counts->num_devices++; |
| |
| return NULL; |
| } |
| |
| static void *count_spare_msis(struct device_node *dn, void *data) |
| { |
| struct msi_counts *counts = data; |
| const u32 *p; |
| int req; |
| |
| if (dn == counts->requestor) |
| req = counts->request; |
| else { |
| /* We don't know if a driver will try to use MSI or MSI-X, |
| * so we just have to punt and use the larger of the two. */ |
| req = 0; |
| p = of_get_property(dn, "ibm,req#msi", NULL); |
| if (p) |
| req = *p; |
| |
| p = of_get_property(dn, "ibm,req#msi-x", NULL); |
| if (p) |
| req = max(req, (int)*p); |
| } |
| |
| if (req < counts->quota) |
| counts->spare += counts->quota - req; |
| else if (req > counts->quota) |
| counts->over_quota++; |
| |
| return NULL; |
| } |
| |
| static int msi_quota_for_device(struct pci_dev *dev, int request) |
| { |
| struct device_node *pe_dn; |
| struct msi_counts counts; |
| int total; |
| |
| pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), |
| request); |
| |
| pe_dn = find_pe_total_msi(dev, &total); |
| if (!pe_dn) |
| pe_dn = find_pe_dn(dev, &total); |
| |
| if (!pe_dn) { |
| pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); |
| goto out; |
| } |
| |
| pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name); |
| |
| memset(&counts, 0, sizeof(struct msi_counts)); |
| |
| /* Work out how many devices we have below this PE */ |
| traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts); |
| |
| if (counts.num_devices == 0) { |
| pr_err("rtas_msi: found 0 devices under PE for %s\n", |
| pci_name(dev)); |
| goto out; |
| } |
| |
| counts.quota = total / counts.num_devices; |
| if (request <= counts.quota) |
| goto out; |
| |
| /* else, we have some more calculating to do */ |
| counts.requestor = pci_device_to_OF_node(dev); |
| counts.request = request; |
| traverse_pci_devices(pe_dn, count_spare_msis, &counts); |
| |
| /* If the quota isn't an integer multiple of the total, we can |
| * use the remainder as spare MSIs for anyone that wants them. */ |
| counts.spare += total % counts.num_devices; |
| |
| /* Divide any spare by the number of over-quota requestors */ |
| if (counts.over_quota) |
| counts.quota += counts.spare / counts.over_quota; |
| |
| /* And finally clamp the request to the possibly adjusted quota */ |
| request = min(counts.quota, request); |
| |
| pr_debug("rtas_msi: request clamped to quota %d\n", request); |
| out: |
| of_node_put(pe_dn); |
| |
| return request; |
| } |
| |
| static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type) |
| { |
| int quota, rc; |
| |
| if (type == PCI_CAP_ID_MSIX) |
| rc = check_req_msix(pdev, nvec); |
| else |
| rc = check_req_msi(pdev, nvec); |
| |
| if (rc) |
| return rc; |
| |
| quota = msi_quota_for_device(pdev, nvec); |
| |
| if (quota && quota < nvec) |
| return quota; |
| |
| return 0; |
| } |
| |
| static int check_msix_entries(struct pci_dev *pdev) |
| { |
| struct msi_desc *entry; |
| int expected; |
| |
| /* There's no way for us to express to firmware that we want |
| * a discontiguous, or non-zero based, range of MSI-X entries. |
| * So we must reject such requests. */ |
| |
| expected = 0; |
| list_for_each_entry(entry, &pdev->msi_list, list) { |
| if (entry->msi_attrib.entry_nr != expected) { |
| pr_debug("rtas_msi: bad MSI-X entries.\n"); |
| return -EINVAL; |
| } |
| expected++; |
| } |
| |
| return 0; |
| } |
| |
| static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) |
| { |
| u32 addr_hi, addr_lo; |
| |
| /* |
| * We should only get in here for IODA1 configs. This is based on the |
| * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS |
| * support, and we are in a PCIe Gen2 slot. |
| */ |
| dev_info(&pdev->dev, |
| "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); |
| pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); |
| addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); |
| pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); |
| pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); |
| } |
| |
| static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) |
| { |
| struct pci_dn *pdn; |
| int hwirq, virq, i, rc; |
| struct msi_desc *entry; |
| struct msi_msg msg; |
| int nvec = nvec_in; |
| int use_32bit_msi_hack = 0; |
| |
| pdn = pci_get_pdn(pdev); |
| if (!pdn) |
| return -ENODEV; |
| |
| if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) |
| return -EINVAL; |
| |
| /* |
| * Firmware currently refuse any non power of two allocation |
| * so we round up if the quota will allow it. |
| */ |
| if (type == PCI_CAP_ID_MSIX) { |
| int m = roundup_pow_of_two(nvec); |
| int quota = msi_quota_for_device(pdev, m); |
| |
| if (quota >= m) |
| nvec = m; |
| } |
| |
| /* |
| * Try the new more explicit firmware interface, if that fails fall |
| * back to the old interface. The old interface is known to never |
| * return MSI-Xs. |
| */ |
| again: |
| if (type == PCI_CAP_ID_MSI) { |
| if (pdn->force_32bit_msi) { |
| rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); |
| if (rc < 0) { |
| /* |
| * We only want to run the 32 bit MSI hack below if |
| * the max bus speed is Gen2 speed |
| */ |
| if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) |
| return rc; |
| |
| use_32bit_msi_hack = 1; |
| } |
| } else |
| rc = -1; |
| |
| if (rc < 0) |
| rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); |
| |
| if (rc < 0) { |
| pr_debug("rtas_msi: trying the old firmware call.\n"); |
| rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); |
| } |
| |
| if (use_32bit_msi_hack && rc > 0) |
| rtas_hack_32bit_msi_gen2(pdev); |
| } else |
| rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); |
| |
| if (rc != nvec) { |
| if (nvec != nvec_in) { |
| nvec = nvec_in; |
| goto again; |
| } |
| pr_debug("rtas_msi: rtas_change_msi() failed\n"); |
| return rc; |
| } |
| |
| i = 0; |
| list_for_each_entry(entry, &pdev->msi_list, list) { |
| hwirq = rtas_query_irq_number(pdn, i++); |
| if (hwirq < 0) { |
| pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); |
| return hwirq; |
| } |
| |
| virq = irq_create_mapping(NULL, hwirq); |
| |
| if (virq == NO_IRQ) { |
| pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); |
| return -ENOSPC; |
| } |
| |
| dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); |
| irq_set_msi_desc(virq, entry); |
| |
| /* Read config space back so we can restore after reset */ |
| read_msi_msg(virq, &msg); |
| entry->msg = msg; |
| } |
| |
| return 0; |
| } |
| |
| static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) |
| { |
| /* No LSI -> leave MSIs (if any) configured */ |
| if (pdev->irq == NO_IRQ) { |
| dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); |
| return; |
| } |
| |
| /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ |
| if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { |
| dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); |
| return; |
| } |
| |
| dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); |
| rtas_disable_msi(pdev); |
| } |
| |
| static int rtas_msi_init(void) |
| { |
| query_token = rtas_token("ibm,query-interrupt-source-number"); |
| change_token = rtas_token("ibm,change-msi"); |
| |
| if ((query_token == RTAS_UNKNOWN_SERVICE) || |
| (change_token == RTAS_UNKNOWN_SERVICE)) { |
| pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); |
| return -1; |
| } |
| |
| pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); |
| |
| WARN_ON(ppc_md.setup_msi_irqs); |
| ppc_md.setup_msi_irqs = rtas_setup_msi_irqs; |
| ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs; |
| ppc_md.msi_check_device = rtas_msi_check_device; |
| |
| WARN_ON(ppc_md.pci_irq_fixup); |
| ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; |
| |
| return 0; |
| } |
| arch_initcall(rtas_msi_init); |
| |