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
));
74 * If the RTAS call succeeded, return the number of irqs allocated.
75 * If not, make sure we return a negative error code.
82 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
83 func
, num_irqs
, rtas_ret
[0], rc
);
88 static void rtas_disable_msi(struct pci_dev
*pdev
)
96 if (rtas_change_msi(pdn
, RTAS_CHANGE_FN
, 0) != 0)
97 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
100 static int rtas_query_irq_number(struct pci_dn
*pdn
, int offset
)
102 u32 addr
, rtas_ret
[2];
106 addr
= rtas_config_addr(pdn
->busno
, pdn
->devfn
, 0);
107 buid
= pdn
->phb
->buid
;
110 rc
= rtas_call(query_token
, 4, 3, rtas_ret
, addr
,
111 BUID_HI(buid
), BUID_LO(buid
), offset
);
112 } while (rtas_busy_delay(rc
));
115 pr_debug("rtas_msi: error (%d) querying source number\n", rc
);
122 static void rtas_teardown_msi_irqs(struct pci_dev
*pdev
)
124 struct msi_desc
*entry
;
126 list_for_each_entry(entry
, &pdev
->msi_list
, list
) {
127 if (entry
->irq
== NO_IRQ
)
130 set_irq_msi(entry
->irq
, NULL
);
131 irq_dispose_mapping(entry
->irq
);
134 rtas_disable_msi(pdev
);
137 static int check_req(struct pci_dev
*pdev
, int nvec
, char *prop_name
)
139 struct device_node
*dn
;
149 req_msi
= of_get_property(dn
, prop_name
, NULL
);
151 pr_debug("rtas_msi: No %s on %s\n", prop_name
, dn
->full_name
);
155 if (*req_msi
< nvec
) {
156 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name
, nvec
);
158 if (*req_msi
== 0) /* Be paranoid */
167 static int check_req_msi(struct pci_dev
*pdev
, int nvec
)
169 return check_req(pdev
, nvec
, "ibm,req#msi");
172 static int check_req_msix(struct pci_dev
*pdev
, int nvec
)
174 return check_req(pdev
, nvec
, "ibm,req#msi-x");
177 /* Quota calculation */
179 static struct device_node
*find_pe_total_msi(struct pci_dev
*dev
, int *total
)
181 struct device_node
*dn
;
184 dn
= of_node_get(pci_device_to_OF_node(dev
));
186 p
= of_get_property(dn
, "ibm,pe-total-#msi", NULL
);
188 pr_debug("rtas_msi: found prop on dn %s\n",
194 dn
= of_get_next_parent(dn
);
200 static struct device_node
*find_pe_dn(struct pci_dev
*dev
, int *total
)
202 struct device_node
*dn
;
204 /* Found our PE and assume 8 at that point. */
206 dn
= pci_device_to_OF_node(dev
);
210 dn
= find_device_pe(dn
);
214 /* We actually want the parent */
215 dn
= of_get_parent(dn
);
219 /* Hardcode of 8 for old firmwares */
221 pr_debug("rtas_msi: using PE dn %s\n", dn
->full_name
);
227 struct device_node
*requestor
;
235 static void *count_non_bridge_devices(struct device_node
*dn
, void *data
)
237 struct msi_counts
*counts
= data
;
241 pr_debug("rtas_msi: counting %s\n", dn
->full_name
);
243 p
= of_get_property(dn
, "class-code", NULL
);
246 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI
)
247 counts
->num_devices
++;
252 static void *count_spare_msis(struct device_node
*dn
, void *data
)
254 struct msi_counts
*counts
= data
;
258 if (dn
== counts
->requestor
)
259 req
= counts
->request
;
261 /* We don't know if a driver will try to use MSI or MSI-X,
262 * so we just have to punt and use the larger of the two. */
264 p
= of_get_property(dn
, "ibm,req#msi", NULL
);
268 p
= of_get_property(dn
, "ibm,req#msi-x", NULL
);
270 req
= max(req
, (int)*p
);
273 if (req
< counts
->quota
)
274 counts
->spare
+= counts
->quota
- req
;
275 else if (req
> counts
->quota
)
276 counts
->over_quota
++;
281 static int msi_quota_for_device(struct pci_dev
*dev
, int request
)
283 struct device_node
*pe_dn
;
284 struct msi_counts counts
;
287 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev
),
290 pe_dn
= find_pe_total_msi(dev
, &total
);
292 pe_dn
= find_pe_dn(dev
, &total
);
295 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev
));
299 pr_debug("rtas_msi: found PE %s\n", pe_dn
->full_name
);
301 memset(&counts
, 0, sizeof(struct msi_counts
));
303 /* Work out how many devices we have below this PE */
304 traverse_pci_devices(pe_dn
, count_non_bridge_devices
, &counts
);
306 if (counts
.num_devices
== 0) {
307 pr_err("rtas_msi: found 0 devices under PE for %s\n",
312 counts
.quota
= total
/ counts
.num_devices
;
313 if (request
<= counts
.quota
)
316 /* else, we have some more calculating to do */
317 counts
.requestor
= pci_device_to_OF_node(dev
);
318 counts
.request
= request
;
319 traverse_pci_devices(pe_dn
, count_spare_msis
, &counts
);
321 /* If the quota isn't an integer multiple of the total, we can
322 * use the remainder as spare MSIs for anyone that wants them. */
323 counts
.spare
+= total
% counts
.num_devices
;
325 /* Divide any spare by the number of over-quota requestors */
326 if (counts
.over_quota
)
327 counts
.quota
+= counts
.spare
/ counts
.over_quota
;
329 /* And finally clamp the request to the possibly adjusted quota */
330 request
= min(counts
.quota
, request
);
332 pr_debug("rtas_msi: request clamped to quota %d\n", request
);
339 static int rtas_msi_check_device(struct pci_dev
*pdev
, int nvec
, int type
)
343 if (type
== PCI_CAP_ID_MSIX
)
344 rc
= check_req_msix(pdev
, nvec
);
346 rc
= check_req_msi(pdev
, nvec
);
351 quota
= msi_quota_for_device(pdev
, nvec
);
353 if (quota
&& quota
< nvec
)
359 static int check_msix_entries(struct pci_dev
*pdev
)
361 struct msi_desc
*entry
;
364 /* There's no way for us to express to firmware that we want
365 * a discontiguous, or non-zero based, range of MSI-X entries.
366 * So we must reject such requests. */
369 list_for_each_entry(entry
, &pdev
->msi_list
, list
) {
370 if (entry
->msi_attrib
.entry_nr
!= expected
) {
371 pr_debug("rtas_msi: bad MSI-X entries.\n");
380 static int rtas_setup_msi_irqs(struct pci_dev
*pdev
, int nvec
, int type
)
383 int hwirq
, virq
, i
, rc
;
384 struct msi_desc
*entry
;
391 if (type
== PCI_CAP_ID_MSIX
&& check_msix_entries(pdev
))
395 * Try the new more explicit firmware interface, if that fails fall
396 * back to the old interface. The old interface is known to never
399 if (type
== PCI_CAP_ID_MSI
) {
400 rc
= rtas_change_msi(pdn
, RTAS_CHANGE_MSI_FN
, nvec
);
403 pr_debug("rtas_msi: trying the old firmware call.\n");
404 rc
= rtas_change_msi(pdn
, RTAS_CHANGE_FN
, nvec
);
407 rc
= rtas_change_msi(pdn
, RTAS_CHANGE_MSIX_FN
, nvec
);
410 pr_debug("rtas_msi: rtas_change_msi() failed\n");
415 list_for_each_entry(entry
, &pdev
->msi_list
, list
) {
416 hwirq
= rtas_query_irq_number(pdn
, i
++);
418 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc
);
422 virq
= irq_create_mapping(NULL
, hwirq
);
424 if (virq
== NO_IRQ
) {
425 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq
);
429 dev_dbg(&pdev
->dev
, "rtas_msi: allocated virq %d\n", virq
);
430 set_irq_msi(virq
, entry
);
432 /* Read config space back so we can restore after reset */
433 read_msi_msg(virq
, &msg
);
440 static void rtas_msi_pci_irq_fixup(struct pci_dev
*pdev
)
442 /* No LSI -> leave MSIs (if any) configured */
443 if (pdev
->irq
== NO_IRQ
) {
444 dev_dbg(&pdev
->dev
, "rtas_msi: no LSI, nothing to do.\n");
448 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */
449 if (check_req_msi(pdev
, 1) && check_req_msix(pdev
, 1)) {
450 dev_dbg(&pdev
->dev
, "rtas_msi: no req#msi/x, nothing to do.\n");
454 dev_dbg(&pdev
->dev
, "rtas_msi: disabling existing MSI.\n");
455 rtas_disable_msi(pdev
);
458 static int rtas_msi_init(void)
460 query_token
= rtas_token("ibm,query-interrupt-source-number");
461 change_token
= rtas_token("ibm,change-msi");
463 if ((query_token
== RTAS_UNKNOWN_SERVICE
) ||
464 (change_token
== RTAS_UNKNOWN_SERVICE
)) {
465 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
469 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
471 WARN_ON(ppc_md
.setup_msi_irqs
);
472 ppc_md
.setup_msi_irqs
= rtas_setup_msi_irqs
;
473 ppc_md
.teardown_msi_irqs
= rtas_teardown_msi_irqs
;
474 ppc_md
.msi_check_device
= rtas_msi_check_device
;
476 WARN_ON(ppc_md
.pci_irq_fixup
);
477 ppc_md
.pci_irq_fixup
= rtas_msi_pci_irq_fixup
;
481 arch_initcall(rtas_msi_init
);
This page took 0.039766 seconds and 5 git commands to generate.