powerpc: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc
[linux-2.6-block.git] / arch / powerpc / platforms / cell / axon_msi.c
CommitLineData
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1/*
2 * Copyright 2007, Michael Ellerman, IBM Corporation.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10
11#include <linux/interrupt.h>
12#include <linux/irq.h>
13#include <linux/kernel.h>
14#include <linux/pci.h>
15#include <linux/msi.h>
66b15db6 16#include <linux/export.h>
e4347dfb 17#include <linux/of_platform.h>
72cac213 18#include <linux/debugfs.h>
5a0e3ad6 19#include <linux/slab.h>
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20
21#include <asm/dcr.h>
22#include <asm/machdep.h>
23#include <asm/prom.h>
24
7e3d6c5a 25#include "cell.h"
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26
27/*
28 * MSIC registers, specified as offsets from dcr_base
29 */
30#define MSIC_CTRL_REG 0x0
31
32/* Base Address registers specify FIFO location in BE memory */
33#define MSIC_BASE_ADDR_HI_REG 0x3
34#define MSIC_BASE_ADDR_LO_REG 0x4
35
36/* Hold the read/write offsets into the FIFO */
37#define MSIC_READ_OFFSET_REG 0x5
38#define MSIC_WRITE_OFFSET_REG 0x6
39
40
41/* MSIC control register flags */
42#define MSIC_CTRL_ENABLE 0x0001
43#define MSIC_CTRL_FIFO_FULL_ENABLE 0x0002
44#define MSIC_CTRL_IRQ_ENABLE 0x0008
45#define MSIC_CTRL_FULL_STOP_ENABLE 0x0010
46
47/*
48 * The MSIC can be configured to use a FIFO of 32KB, 64KB, 128KB or 256KB.
49 * Currently we're using a 64KB FIFO size.
50 */
51#define MSIC_FIFO_SIZE_SHIFT 16
52#define MSIC_FIFO_SIZE_BYTES (1 << MSIC_FIFO_SIZE_SHIFT)
53
54/*
55 * To configure the FIFO size as (1 << n) bytes, we write (n - 15) into bits
56 * 8-9 of the MSIC control reg.
57 */
58#define MSIC_CTRL_FIFO_SIZE (((MSIC_FIFO_SIZE_SHIFT - 15) << 8) & 0x300)
59
60/*
61 * We need to mask the read/write offsets to make sure they stay within
62 * the bounds of the FIFO. Also they should always be 16-byte aligned.
63 */
64#define MSIC_FIFO_SIZE_MASK ((MSIC_FIFO_SIZE_BYTES - 1) & ~0xFu)
65
66/* Each entry in the FIFO is 16 bytes, the first 4 bytes hold the irq # */
67#define MSIC_FIFO_ENTRY_SIZE 0x10
68
69
70struct axon_msic {
bae1d8f1 71 struct irq_domain *irq_domain;
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72 __le32 *fifo_virt;
73 dma_addr_t fifo_phys;
ce21b3c9 74 dcr_host_t dcr_host;
ce21b3c9 75 u32 read_offset;
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76#ifdef DEBUG
77 u32 __iomem *trigger;
78#endif
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79};
80
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81#ifdef DEBUG
82void axon_msi_debug_setup(struct device_node *dn, struct axon_msic *msic);
83#else
84static inline void axon_msi_debug_setup(struct device_node *dn,
85 struct axon_msic *msic) { }
86#endif
87
88
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89static void msic_dcr_write(struct axon_msic *msic, unsigned int dcr_n, u32 val)
90{
33875f03 91 pr_devel("axon_msi: dcr_write(0x%x, 0x%x)\n", val, dcr_n);
ce21b3c9 92
83f34df4 93 dcr_write(msic->dcr_host, dcr_n, val);
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94}
95
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96static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
97{
ec775d0e 98 struct irq_chip *chip = irq_desc_get_chip(desc);
c1231a78 99 struct axon_msic *msic = irq_desc_get_handler_data(desc);
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100 u32 write_offset, msi;
101 int idx;
d015fe99 102 int retry = 0;
ce21b3c9 103
2843e7f7 104 write_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG);
33875f03 105 pr_devel("axon_msi: original write_offset 0x%x\n", write_offset);
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106
107 /* write_offset doesn't wrap properly, so we have to mask it */
108 write_offset &= MSIC_FIFO_SIZE_MASK;
109
d015fe99 110 while (msic->read_offset != write_offset && retry < 100) {
ce21b3c9 111 idx = msic->read_offset / sizeof(__le32);
de4c928b 112 msi = le32_to_cpu(msic->fifo_virt[idx]);
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113 msi &= 0xFFFF;
114
33875f03 115 pr_devel("axon_msi: woff %x roff %x msi %x\n",
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116 write_offset, msic->read_offset, msi);
117
4013369f 118 if (msi < nr_irqs && irq_get_chip_data(msi) == msic) {
d015fe99
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119 generic_handle_irq(msi);
120 msic->fifo_virt[idx] = cpu_to_le32(0xffffffff);
121 } else {
122 /*
123 * Reading the MSIC_WRITE_OFFSET_REG does not
124 * reliably flush the outstanding DMA to the
125 * FIFO buffer. Here we were reading stale
126 * data, so we need to retry.
127 */
128 udelay(1);
129 retry++;
33875f03 130 pr_devel("axon_msi: invalid irq 0x%x!\n", msi);
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131 continue;
132 }
133
134 if (retry) {
33875f03 135 pr_devel("axon_msi: late irq 0x%x, retry %d\n",
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136 msi, retry);
137 retry = 0;
138 }
139
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140 msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
141 msic->read_offset &= MSIC_FIFO_SIZE_MASK;
d015fe99 142 }
ce21b3c9 143
d015fe99
AB
144 if (retry) {
145 printk(KERN_WARNING "axon_msi: irq timed out\n");
146
147 msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
148 msic->read_offset &= MSIC_FIFO_SIZE_MASK;
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149 }
150
d1ae63d4 151 chip->irq_eoi(&desc->irq_data);
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152}
153
154static struct axon_msic *find_msi_translator(struct pci_dev *dev)
155{
bae1d8f1 156 struct irq_domain *irq_domain;
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157 struct device_node *dn, *tmp;
158 const phandle *ph;
159 struct axon_msic *msic = NULL;
160
db220b23 161 dn = of_node_get(pci_device_to_OF_node(dev));
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162 if (!dn) {
163 dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
164 return NULL;
165 }
166
988479eb 167 for (; dn; dn = of_get_next_parent(dn)) {
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168 ph = of_get_property(dn, "msi-translator", NULL);
169 if (ph)
170 break;
171 }
172
173 if (!ph) {
174 dev_dbg(&dev->dev,
175 "axon_msi: no msi-translator property found\n");
176 goto out_error;
177 }
178
179 tmp = dn;
180 dn = of_find_node_by_phandle(*ph);
c6d01179 181 of_node_put(tmp);
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182 if (!dn) {
183 dev_dbg(&dev->dev,
184 "axon_msi: msi-translator doesn't point to a node\n");
185 goto out_error;
186 }
187
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GL
188 irq_domain = irq_find_host(dn);
189 if (!irq_domain) {
190 dev_dbg(&dev->dev, "axon_msi: no irq_domain found for node %s\n",
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191 dn->full_name);
192 goto out_error;
193 }
194
bae1d8f1 195 msic = irq_domain->host_data;
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196
197out_error:
198 of_node_put(dn);
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199
200 return msic;
201}
202
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203static int setup_msi_msg_address(struct pci_dev *dev, struct msi_msg *msg)
204{
988479eb 205 struct device_node *dn;
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206 struct msi_desc *entry;
207 int len;
208 const u32 *prop;
209
db220b23 210 dn = of_node_get(pci_device_to_OF_node(dev));
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211 if (!dn) {
212 dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
213 return -ENODEV;
214 }
215
216 entry = list_first_entry(&dev->msi_list, struct msi_desc, list);
217
988479eb 218 for (; dn; dn = of_get_next_parent(dn)) {
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219 if (entry->msi_attrib.is_64) {
220 prop = of_get_property(dn, "msi-address-64", &len);
221 if (prop)
222 break;
223 }
224
225 prop = of_get_property(dn, "msi-address-32", &len);
226 if (prop)
227 break;
228 }
229
230 if (!prop) {
231 dev_dbg(&dev->dev,
232 "axon_msi: no msi-address-(32|64) properties found\n");
233 return -ENOENT;
234 }
235
236 switch (len) {
237 case 8:
238 msg->address_hi = prop[0];
239 msg->address_lo = prop[1];
240 break;
241 case 4:
242 msg->address_hi = 0;
243 msg->address_lo = prop[0];
244 break;
245 default:
246 dev_dbg(&dev->dev,
247 "axon_msi: malformed msi-address-(32|64) property\n");
248 of_node_put(dn);
249 return -EINVAL;
250 }
251
252 of_node_put(dn);
253
254 return 0;
255}
256
257static int axon_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
258{
259 unsigned int virq, rc;
260 struct msi_desc *entry;
261 struct msi_msg msg;
262 struct axon_msic *msic;
263
264 msic = find_msi_translator(dev);
265 if (!msic)
266 return -ENODEV;
267
268 rc = setup_msi_msg_address(dev, &msg);
269 if (rc)
270 return rc;
271
ce21b3c9 272 list_for_each_entry(entry, &dev->msi_list, list) {
bae1d8f1 273 virq = irq_create_direct_mapping(msic->irq_domain);
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274 if (virq == NO_IRQ) {
275 dev_warn(&dev->dev,
276 "axon_msi: virq allocation failed!\n");
277 return -1;
278 }
279 dev_dbg(&dev->dev, "axon_msi: allocated virq 0x%x\n", virq);
280
ec775d0e 281 irq_set_msi_desc(virq, entry);
ce21b3c9 282 msg.data = virq;
83a18912 283 pci_write_msi_msg(virq, &msg);
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284 }
285
286 return 0;
287}
288
289static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
290{
291 struct msi_desc *entry;
292
293 dev_dbg(&dev->dev, "axon_msi: tearing down msi irqs\n");
294
295 list_for_each_entry(entry, &dev->msi_list, list) {
296 if (entry->irq == NO_IRQ)
297 continue;
298
ec775d0e 299 irq_set_msi_desc(entry->irq, NULL);
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300 irq_dispose_mapping(entry->irq);
301 }
302}
303
304static struct irq_chip msic_irq_chip = {
280510f1
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305 .irq_mask = pci_msi_mask_irq,
306 .irq_unmask = pci_msi_unmask_irq,
307 .irq_shutdown = pci_msi_mask_irq,
b27df672 308 .name = "AXON-MSI",
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309};
310
bae1d8f1 311static int msic_host_map(struct irq_domain *h, unsigned int virq,
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312 irq_hw_number_t hw)
313{
95533614 314 irq_set_chip_data(virq, h->host_data);
ec775d0e 315 irq_set_chip_and_handler(virq, &msic_irq_chip, handle_simple_irq);
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316
317 return 0;
318}
319
9f70b8eb 320static const struct irq_domain_ops msic_host_ops = {
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321 .map = msic_host_map,
322};
323
00006124 324static void axon_msi_shutdown(struct platform_device *device)
ce21b3c9 325{
86c27656 326 struct axon_msic *msic = dev_get_drvdata(&device->dev);
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327 u32 tmp;
328
33875f03 329 pr_devel("axon_msi: disabling %s\n",
bae1d8f1 330 msic->irq_domain->of_node->full_name);
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331 tmp = dcr_read(msic->dcr_host, MSIC_CTRL_REG);
332 tmp &= ~MSIC_CTRL_ENABLE & ~MSIC_CTRL_IRQ_ENABLE;
333 msic_dcr_write(msic, MSIC_CTRL_REG, tmp);
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334}
335
00006124 336static int axon_msi_probe(struct platform_device *device)
ce21b3c9 337{
61c7a080 338 struct device_node *dn = device->dev.of_node;
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339 struct axon_msic *msic;
340 unsigned int virq;
4acb8896 341 int dcr_base, dcr_len;
ce21b3c9 342
33875f03 343 pr_devel("axon_msi: setting up dn %s\n", dn->full_name);
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344
345 msic = kzalloc(sizeof(struct axon_msic), GFP_KERNEL);
346 if (!msic) {
347 printk(KERN_ERR "axon_msi: couldn't allocate msic for %s\n",
348 dn->full_name);
349 goto out;
350 }
351
4acb8896 352 dcr_base = dcr_resource_start(dn, 0);
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353 dcr_len = dcr_resource_len(dn, 0);
354
4acb8896 355 if (dcr_base == 0 || dcr_len == 0) {
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356 printk(KERN_ERR
357 "axon_msi: couldn't parse dcr properties on %s\n",
358 dn->full_name);
aee7a283 359 goto out_free_msic;
ce21b3c9
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360 }
361
4acb8896 362 msic->dcr_host = dcr_map(dn, dcr_base, dcr_len);
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363 if (!DCR_MAP_OK(msic->dcr_host)) {
364 printk(KERN_ERR "axon_msi: dcr_map failed for %s\n",
365 dn->full_name);
366 goto out_free_msic;
367 }
368
de4c928b
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369 msic->fifo_virt = dma_alloc_coherent(&device->dev, MSIC_FIFO_SIZE_BYTES,
370 &msic->fifo_phys, GFP_KERNEL);
371 if (!msic->fifo_virt) {
ce21b3c9
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372 printk(KERN_ERR "axon_msi: couldn't allocate fifo for %s\n",
373 dn->full_name);
374 goto out_free_msic;
375 }
376
997526db
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377 virq = irq_of_parse_and_map(dn, 0);
378 if (virq == NO_IRQ) {
379 printk(KERN_ERR "axon_msi: irq parse and map failed for %s\n",
380 dn->full_name);
381 goto out_free_fifo;
382 }
d015fe99 383 memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
997526db 384
4013369f
GL
385 /* We rely on being able to stash a virq in a u16, so limit irqs to < 65536 */
386 msic->irq_domain = irq_domain_add_nomap(dn, 65536, &msic_host_ops, msic);
bae1d8f1
GL
387 if (!msic->irq_domain) {
388 printk(KERN_ERR "axon_msi: couldn't allocate irq_domain for %s\n",
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389 dn->full_name);
390 goto out_free_fifo;
391 }
392
ec775d0e
TG
393 irq_set_handler_data(virq, msic);
394 irq_set_chained_handler(virq, axon_msi_cascade);
33875f03 395 pr_devel("axon_msi: irq 0x%x setup for axon_msi\n", virq);
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396
397 /* Enable the MSIC hardware */
de4c928b 398 msic_dcr_write(msic, MSIC_BASE_ADDR_HI_REG, msic->fifo_phys >> 32);
ce21b3c9 399 msic_dcr_write(msic, MSIC_BASE_ADDR_LO_REG,
de4c928b 400 msic->fifo_phys & 0xFFFFFFFF);
ce21b3c9
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401 msic_dcr_write(msic, MSIC_CTRL_REG,
402 MSIC_CTRL_IRQ_ENABLE | MSIC_CTRL_ENABLE |
403 MSIC_CTRL_FIFO_SIZE);
404
23e0e8af
AB
405 msic->read_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG)
406 & MSIC_FIFO_SIZE_MASK;
407
86c27656 408 dev_set_drvdata(&device->dev, msic);
e4347dfb 409
7e3d6c5a
DA
410 cell_pci_controller_ops.setup_msi_irqs = axon_msi_setup_msi_irqs;
411 cell_pci_controller_ops.teardown_msi_irqs = axon_msi_teardown_msi_irqs;
ce21b3c9 412
72cac213
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413 axon_msi_debug_setup(dn, msic);
414
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415 printk(KERN_DEBUG "axon_msi: setup MSIC on %s\n", dn->full_name);
416
417 return 0;
418
ce21b3c9 419out_free_fifo:
de4c928b
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420 dma_free_coherent(&device->dev, MSIC_FIFO_SIZE_BYTES, msic->fifo_virt,
421 msic->fifo_phys);
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422out_free_msic:
423 kfree(msic);
424out:
425
426 return -1;
427}
428
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429static const struct of_device_id axon_msi_device_id[] = {
430 {
431 .compatible = "ibm,axon-msic"
432 },
433 {}
434};
ce21b3c9 435
00006124 436static struct platform_driver axon_msi_driver = {
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437 .probe = axon_msi_probe,
438 .shutdown = axon_msi_shutdown,
4018294b
GL
439 .driver = {
440 .name = "axon-msi",
4018294b 441 .of_match_table = axon_msi_device_id,
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442 },
443};
ce21b3c9 444
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445static int __init axon_msi_init(void)
446{
00006124 447 return platform_driver_register(&axon_msi_driver);
ce21b3c9 448}
e4347dfb 449subsys_initcall(axon_msi_init);
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450
451
452#ifdef DEBUG
453static int msic_set(void *data, u64 val)
454{
455 struct axon_msic *msic = data;
456 out_le32(msic->trigger, val);
457 return 0;
458}
459
460static int msic_get(void *data, u64 *val)
461{
462 *val = 0;
463 return 0;
464}
465
466DEFINE_SIMPLE_ATTRIBUTE(fops_msic, msic_get, msic_set, "%llu\n");
467
468void axon_msi_debug_setup(struct device_node *dn, struct axon_msic *msic)
469{
470 char name[8];
471 u64 addr;
472
473 addr = of_translate_address(dn, of_get_property(dn, "reg", NULL));
474 if (addr == OF_BAD_ADDR) {
33875f03 475 pr_devel("axon_msi: couldn't translate reg property\n");
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476 return;
477 }
478
479 msic->trigger = ioremap(addr, 0x4);
480 if (!msic->trigger) {
33875f03 481 pr_devel("axon_msi: ioremap failed\n");
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482 return;
483 }
484
485 snprintf(name, sizeof(name), "msic_%d", of_node_to_nid(dn));
486
487 if (!debugfs_create_file(name, 0600, powerpc_debugfs_root,
488 msic, &fops_msic)) {
33875f03 489 pr_devel("axon_msi: debugfs_create_file failed!\n");
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490 return;
491 }
492}
493#endif /* DEBUG */