1/* 2 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. 3 * Copyright 2006-2007 Michael Ellerman, IBM Corp. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; version 2 of the 8 * License. 9 * 10 */ 11 12#include <linux/device.h> 13#include <linux/irq.h> 14#include <linux/msi.h> 15 16#include <asm/rtas.h> 17#include <asm/hw_irq.h> 18#include <asm/ppc-pci.h> 19 20static int query_token, change_token; 21 22#define RTAS_QUERY_FN 0 23#define RTAS_CHANGE_FN 1 24#define RTAS_RESET_FN 2 25#define RTAS_CHANGE_MSI_FN 3 26#define RTAS_CHANGE_MSIX_FN 4 27 28static struct pci_dn *get_pdn(struct pci_dev *pdev) 29{ 30 struct device_node *dn; 31 struct pci_dn *pdn; 32 33 dn = pci_device_to_OF_node(pdev); 34 if (!dn) { 35 dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n"); 36 return NULL; 37 } 38 39 pdn = PCI_DN(dn); 40 if (!pdn) { 41 dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n"); 42 return NULL; 43 } 44 45 return pdn; 46} 47 48/* RTAS Helpers */ 49 50static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) 51{ 52 u32 addr, seq_num, rtas_ret[3]; 53 unsigned long buid; 54 int rc; 55 56 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); 57 buid = pdn->phb->buid; 58 59 seq_num = 1; 60 do { 61 if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN) 62 rc = rtas_call(change_token, 6, 4, rtas_ret, addr, 63 BUID_HI(buid), BUID_LO(buid), 64 func, num_irqs, seq_num); 65 else 66 rc = rtas_call(change_token, 6, 3, rtas_ret, addr, 67 BUID_HI(buid), BUID_LO(buid), 68 func, num_irqs, seq_num); 69 70 seq_num = rtas_ret[1]; 71 } while (rtas_busy_delay(rc)); 72 73 if (rc == 0) /* Success */ 74 rc = rtas_ret[0]; 75 76 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d) = (%d)\n", 77 func, num_irqs, rc); 78 79 return rc; 80} 81 82static void rtas_disable_msi(struct pci_dev *pdev) 83{ 84 struct pci_dn *pdn; 85 86 pdn = get_pdn(pdev); 87 if (!pdn) 88 return; 89 90 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) 91 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); 92} 93 94static int rtas_query_irq_number(struct pci_dn *pdn, int offset) 95{ 96 u32 addr, rtas_ret[2]; 97 unsigned long buid; 98 int rc; 99 100 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); 101 buid = pdn->phb->buid; 102 103 do { 104 rc = rtas_call(query_token, 4, 3, rtas_ret, addr, 105 BUID_HI(buid), BUID_LO(buid), offset); 106 } while (rtas_busy_delay(rc)); 107 108 if (rc) { 109 pr_debug("rtas_msi: error (%d) querying source number\n", rc); 110 return rc; 111 } 112 113 return rtas_ret[0]; 114} 115 116static void rtas_teardown_msi_irqs(struct pci_dev *pdev) 117{ 118 struct msi_desc *entry; 119 120 list_for_each_entry(entry, &pdev->msi_list, list) { 121 if (entry->irq == NO_IRQ) 122 continue; 123 124 set_irq_msi(entry->irq, NULL); 125 irq_dispose_mapping(entry->irq); 126 } 127 128 rtas_disable_msi(pdev); 129} 130 131static int check_req_msi(struct pci_dev *pdev, int nvec) 132{ 133 struct device_node *dn; 134 struct pci_dn *pdn; 135 const u32 *req_msi; 136 137 pdn = get_pdn(pdev); 138 if (!pdn) 139 return -ENODEV; 140 141 dn = pdn->node; 142 143 req_msi = of_get_property(dn, "ibm,req#msi", NULL); 144 if (!req_msi) { 145 pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name); 146 return -ENOENT; 147 } 148 149 if (*req_msi < nvec) { 150 pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec); 151 return -ENOSPC; 152 } 153 154 return 0; 155} 156 157static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type) 158{ 159 if (type == PCI_CAP_ID_MSIX) 160 pr_debug("rtas_msi: MSI-X untested, trying anyway.\n"); 161 162 return check_req_msi(pdev, nvec); 163} 164 165static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) 166{ 167 struct pci_dn *pdn; 168 int hwirq, virq, i, rc; 169 struct msi_desc *entry; 170 171 pdn = get_pdn(pdev); 172 if (!pdn) 173 return -ENODEV; 174 175 /* 176 * Try the new more explicit firmware interface, if that fails fall 177 * back to the old interface. The old interface is known to never 178 * return MSI-Xs. 179 */ 180 if (type == PCI_CAP_ID_MSI) { 181 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); 182 183 if (rc != nvec) { 184 pr_debug("rtas_msi: trying the old firmware call.\n"); 185 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); 186 } 187 } else 188 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); 189 190 if (rc != nvec) { 191 pr_debug("rtas_msi: rtas_change_msi() failed\n"); 192 193 /* 194 * In case of an error it's not clear whether the device is 195 * left with MSI enabled or not, so we explicitly disable. 196 */ 197 goto out_free; 198 } 199 200 i = 0; 201 list_for_each_entry(entry, &pdev->msi_list, list) { 202 hwirq = rtas_query_irq_number(pdn, i); 203 if (hwirq < 0) { 204 rc = hwirq; 205 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); 206 goto out_free; 207 } 208 209 virq = irq_create_mapping(NULL, hwirq); 210 211 if (virq == NO_IRQ) { 212 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); 213 rc = -ENOSPC; 214 goto out_free; 215 } 216 217 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); 218 set_irq_msi(virq, entry); 219 unmask_msi_irq(virq); 220 } 221 222 return 0; 223 224 out_free: 225 rtas_teardown_msi_irqs(pdev); 226 return rc; 227} 228 229static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) 230{ 231 /* No LSI -> leave MSIs (if any) configured */ 232 if (pdev->irq == NO_IRQ) { 233 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); 234 return; 235 } 236 237 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ 238 if (check_req_msi(pdev, 1)) { 239 dev_dbg(&pdev->dev, "rtas_msi: no req#msi, nothing to do.\n"); 240 return; 241 } 242 243 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); 244 rtas_disable_msi(pdev); 245} 246 247static int rtas_msi_init(void) 248{ 249 query_token = rtas_token("ibm,query-interrupt-source-number"); 250 change_token = rtas_token("ibm,change-msi"); 251 252 if ((query_token == RTAS_UNKNOWN_SERVICE) || 253 (change_token == RTAS_UNKNOWN_SERVICE)) { 254 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); 255 return -1; 256 } 257 258 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); 259 260 WARN_ON(ppc_md.setup_msi_irqs); 261 ppc_md.setup_msi_irqs = rtas_setup_msi_irqs; 262 ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs; 263 ppc_md.msi_check_device = rtas_msi_check_device; 264 265 WARN_ON(ppc_md.pci_irq_fixup); 266 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; 267 268 return 0; 269} 270arch_initcall(rtas_msi_init); 271