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>
19 #include <asm/machdep.h>
23 static int query_token, change_token;
25 #define RTAS_QUERY_FN 0
26 #define RTAS_CHANGE_FN 1
27 #define RTAS_RESET_FN 2
28 #define RTAS_CHANGE_MSI_FN 3
29 #define RTAS_CHANGE_MSIX_FN 4
30 #define RTAS_CHANGE_32MSI_FN 5
34 static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
36 u32 addr, seq_num, rtas_ret[3];
40 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
41 buid = pdn->phb->buid;
45 if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
46 func == RTAS_CHANGE_32MSI_FN)
47 rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
48 BUID_HI(buid), BUID_LO(buid),
49 func, num_irqs, seq_num);
51 rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
52 BUID_HI(buid), BUID_LO(buid),
53 func, num_irqs, seq_num);
55 seq_num = rtas_ret[1];
56 } while (rtas_busy_delay(rc));
59 * If the RTAS call succeeded, return the number of irqs allocated.
60 * If not, make sure we return a negative error code.
67 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
68 func, num_irqs, rtas_ret[0], rc);
73 static void rtas_disable_msi(struct pci_dev *pdev)
77 pdn = pci_get_pdn(pdev);
82 * disabling MSI with the explicit interface also disables MSI-X
84 if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
86 * may have failed because explicit interface is not
89 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
90 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
95 static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
97 u32 addr, rtas_ret[2];
101 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
102 buid = pdn->phb->buid;
105 rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
106 BUID_HI(buid), BUID_LO(buid), offset);
107 } while (rtas_busy_delay(rc));
110 pr_debug("rtas_msi: error (%d) querying source number\n", rc);
117 static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
119 struct msi_desc *entry;
121 for_each_pci_msi_entry(entry, pdev) {
125 irq_set_msi_desc(entry->irq, NULL);
126 irq_dispose_mapping(entry->irq);
129 rtas_disable_msi(pdev);
132 static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
134 struct device_node *dn;
138 dn = pci_device_to_OF_node(pdev);
140 p = of_get_property(dn, prop_name, NULL);
142 pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn);
146 req_msi = be32_to_cpup(p);
147 if (req_msi < nvec) {
148 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
150 if (req_msi == 0) /* Be paranoid */
159 static int check_req_msi(struct pci_dev *pdev, int nvec)
161 return check_req(pdev, nvec, "ibm,req#msi");
164 static int check_req_msix(struct pci_dev *pdev, int nvec)
166 return check_req(pdev, nvec, "ibm,req#msi-x");
169 /* Quota calculation */
171 static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total)
173 struct device_node *dn;
176 dn = of_node_get(pci_device_to_OF_node(dev));
178 p = of_get_property(dn, "ibm,pe-total-#msi", NULL);
180 pr_debug("rtas_msi: found prop on dn %pOF\n",
182 *total = be32_to_cpup(p);
186 dn = of_get_next_parent(dn);
192 static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
194 struct device_node *dn;
195 struct eeh_dev *edev;
197 /* Found our PE and assume 8 at that point. */
199 dn = pci_device_to_OF_node(dev);
203 /* Get the top level device in the PE */
204 edev = pdn_to_eeh_dev(PCI_DN(dn));
206 edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list);
207 dn = pci_device_to_OF_node(edev->pdev);
211 /* We actually want the parent */
212 dn = of_get_parent(dn);
216 /* Hardcode of 8 for old firmwares */
218 pr_debug("rtas_msi: using PE dn %pOF\n", dn);
224 struct device_node *requestor;
232 static void *count_non_bridge_devices(struct device_node *dn, void *data)
234 struct msi_counts *counts = data;
238 pr_debug("rtas_msi: counting %pOF\n", dn);
240 p = of_get_property(dn, "class-code", NULL);
241 class = p ? be32_to_cpup(p) : 0;
243 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI)
244 counts->num_devices++;
249 static void *count_spare_msis(struct device_node *dn, void *data)
251 struct msi_counts *counts = data;
255 if (dn == counts->requestor)
256 req = counts->request;
258 /* We don't know if a driver will try to use MSI or MSI-X,
259 * so we just have to punt and use the larger of the two. */
261 p = of_get_property(dn, "ibm,req#msi", NULL);
263 req = be32_to_cpup(p);
265 p = of_get_property(dn, "ibm,req#msi-x", NULL);
267 req = max(req, (int)be32_to_cpup(p));
270 if (req < counts->quota)
271 counts->spare += counts->quota - req;
272 else if (req > counts->quota)
273 counts->over_quota++;
278 static int msi_quota_for_device(struct pci_dev *dev, int request)
280 struct device_node *pe_dn;
281 struct msi_counts counts;
284 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev),
287 pe_dn = find_pe_total_msi(dev, &total);
289 pe_dn = find_pe_dn(dev, &total);
292 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev));
296 pr_debug("rtas_msi: found PE %pOF\n", pe_dn);
298 memset(&counts, 0, sizeof(struct msi_counts));
300 /* Work out how many devices we have below this PE */
301 pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts);
303 if (counts.num_devices == 0) {
304 pr_err("rtas_msi: found 0 devices under PE for %s\n",
309 counts.quota = total / counts.num_devices;
310 if (request <= counts.quota)
313 /* else, we have some more calculating to do */
314 counts.requestor = pci_device_to_OF_node(dev);
315 counts.request = request;
316 pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts);
318 /* If the quota isn't an integer multiple of the total, we can
319 * use the remainder as spare MSIs for anyone that wants them. */
320 counts.spare += total % counts.num_devices;
322 /* Divide any spare by the number of over-quota requestors */
323 if (counts.over_quota)
324 counts.quota += counts.spare / counts.over_quota;
326 /* And finally clamp the request to the possibly adjusted quota */
327 request = min(counts.quota, request);
329 pr_debug("rtas_msi: request clamped to quota %d\n", request);
336 static int check_msix_entries(struct pci_dev *pdev)
338 struct msi_desc *entry;
341 /* There's no way for us to express to firmware that we want
342 * a discontiguous, or non-zero based, range of MSI-X entries.
343 * So we must reject such requests. */
346 for_each_pci_msi_entry(entry, pdev) {
347 if (entry->msi_attrib.entry_nr != expected) {
348 pr_debug("rtas_msi: bad MSI-X entries.\n");
357 static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
359 u32 addr_hi, addr_lo;
362 * We should only get in here for IODA1 configs. This is based on the
363 * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
364 * support, and we are in a PCIe Gen2 slot.
367 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
368 pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
369 addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
370 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
371 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
374 static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
377 int hwirq, virq, i, quota, rc;
378 struct msi_desc *entry;
381 int use_32bit_msi_hack = 0;
383 if (type == PCI_CAP_ID_MSIX)
384 rc = check_req_msix(pdev, nvec);
386 rc = check_req_msi(pdev, nvec);
391 quota = msi_quota_for_device(pdev, nvec);
393 if (quota && quota < nvec)
396 if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev))
400 * Firmware currently refuse any non power of two allocation
401 * so we round up if the quota will allow it.
403 if (type == PCI_CAP_ID_MSIX) {
404 int m = roundup_pow_of_two(nvec);
405 quota = msi_quota_for_device(pdev, m);
411 pdn = pci_get_pdn(pdev);
414 * Try the new more explicit firmware interface, if that fails fall
415 * back to the old interface. The old interface is known to never
419 if (type == PCI_CAP_ID_MSI) {
420 if (pdev->no_64bit_msi) {
421 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
424 * We only want to run the 32 bit MSI hack below if
425 * the max bus speed is Gen2 speed
427 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
430 use_32bit_msi_hack = 1;
436 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
439 pr_debug("rtas_msi: trying the old firmware call.\n");
440 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
443 if (use_32bit_msi_hack && rc > 0)
444 rtas_hack_32bit_msi_gen2(pdev);
446 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
449 if (nvec != nvec_in) {
453 pr_debug("rtas_msi: rtas_change_msi() failed\n");
458 for_each_pci_msi_entry(entry, pdev) {
459 hwirq = rtas_query_irq_number(pdn, i++);
461 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
465 virq = irq_create_mapping(NULL, hwirq);
468 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
472 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
473 irq_set_msi_desc(virq, entry);
475 /* Read config space back so we can restore after reset */
476 __pci_read_msi_msg(entry, &msg);
483 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
485 /* No LSI -> leave MSIs (if any) configured */
487 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
491 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */
492 if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) {
493 dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n");
497 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
498 rtas_disable_msi(pdev);
501 static int rtas_msi_init(void)
503 struct pci_controller *phb;
505 query_token = rtas_token("ibm,query-interrupt-source-number");
506 change_token = rtas_token("ibm,change-msi");
508 if ((query_token == RTAS_UNKNOWN_SERVICE) ||
509 (change_token == RTAS_UNKNOWN_SERVICE)) {
510 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
514 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
516 WARN_ON(pseries_pci_controller_ops.setup_msi_irqs);
517 pseries_pci_controller_ops.setup_msi_irqs = rtas_setup_msi_irqs;
518 pseries_pci_controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs;
520 list_for_each_entry(phb, &hose_list, list_node) {
521 WARN_ON(phb->controller_ops.setup_msi_irqs);
522 phb->controller_ops.setup_msi_irqs = rtas_setup_msi_irqs;
523 phb->controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs;
526 WARN_ON(ppc_md.pci_irq_fixup);
527 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
531 machine_arch_initcall(pseries, rtas_msi_init);