2 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
3 * Copyright 2006-2007 Michael Ellerman, IBM Corp.
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
12 #include <linux/device.h>
13 #include <linux/irq.h>
14 #include <linux/msi.h>
17 #include <asm/hw_irq.h>
18 #include <asm/ppc-pci.h>
20 static int query_token, change_token;
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
28 static struct pci_dn *get_pdn(struct pci_dev *pdev)
30 struct device_node *dn;
33 dn = pci_device_to_OF_node(pdev);
35 dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n");
41 dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n");
50 static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
52 u32 addr, seq_num, rtas_ret[3];
56 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
57 buid = pdn->phb->buid;
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);
66 rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
67 BUID_HI(buid), BUID_LO(buid),
68 func, num_irqs, seq_num);
70 seq_num = rtas_ret[1];
71 } while (rtas_busy_delay(rc));
73 if (rc == 0) /* Success */
76 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d) = (%d)\n",
82 static void rtas_disable_msi(struct pci_dev *pdev)
90 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0)
91 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
94 static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
96 u32 addr, rtas_ret[2];
100 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
101 buid = pdn->phb->buid;
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));
109 pr_debug("rtas_msi: error (%d) querying source number\n", rc);
116 static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
118 struct msi_desc *entry;
120 list_for_each_entry(entry, &pdev->msi_list, list) {
121 if (entry->irq == NO_IRQ)
124 set_irq_msi(entry->irq, NULL);
125 irq_dispose_mapping(entry->irq);
128 rtas_disable_msi(pdev);
131 static int check_req_msi(struct pci_dev *pdev, int nvec)
133 struct device_node *dn;
143 req_msi = of_get_property(dn, "ibm,req#msi", NULL);
145 pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name);
149 if (*req_msi < nvec) {
150 pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec);
157 static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
159 if (type == PCI_CAP_ID_MSIX)
160 pr_debug("rtas_msi: MSI-X untested, trying anyway.\n");
162 return check_req_msi(pdev, nvec);
165 static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
168 int hwirq, virq, i, rc;
169 struct msi_desc *entry;
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
180 if (type == PCI_CAP_ID_MSI) {
181 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
184 pr_debug("rtas_msi: trying the old firmware call.\n");
185 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
188 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
191 pr_debug("rtas_msi: rtas_change_msi() failed\n");
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.
201 list_for_each_entry(entry, &pdev->msi_list, list) {
202 hwirq = rtas_query_irq_number(pdn, i);
205 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
209 virq = irq_create_mapping(NULL, hwirq);
211 if (virq == NO_IRQ) {
212 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
217 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
218 set_irq_msi(virq, entry);
219 unmask_msi_irq(virq);
225 rtas_teardown_msi_irqs(pdev);
229 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
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");
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");
243 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
244 rtas_disable_msi(pdev);
247 static int rtas_msi_init(void)
249 query_token = rtas_token("ibm,query-interrupt-source-number");
250 change_token = rtas_token("ibm,change-msi");
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");
258 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
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;
265 WARN_ON(ppc_md.pci_irq_fixup);
266 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
270 arch_initcall(rtas_msi_init);