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8286ae03 JH |
1 | /* |
2 | * Bus driver for MIPS Common Device Memory Map (CDMM). | |
3 | * | |
4 | * Copyright (C) 2014-2015 Imagination Technologies Ltd. | |
5 | * | |
6 | * This file is subject to the terms and conditions of the GNU General Public | |
7 | * License. See the file "COPYING" in the main directory of this archive | |
8 | * for more details. | |
9 | */ | |
10 | ||
11 | #include <linux/atomic.h> | |
12 | #include <linux/err.h> | |
13 | #include <linux/cpu.h> | |
14 | #include <linux/cpumask.h> | |
15 | #include <linux/io.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/smp.h> | |
19 | #include <asm/cdmm.h> | |
20 | #include <asm/hazards.h> | |
21 | #include <asm/mipsregs.h> | |
22 | ||
23 | /* Access control and status register fields */ | |
24 | #define CDMM_ACSR_DEVTYPE_SHIFT 24 | |
25 | #define CDMM_ACSR_DEVTYPE (255ul << CDMM_ACSR_DEVTYPE_SHIFT) | |
26 | #define CDMM_ACSR_DEVSIZE_SHIFT 16 | |
27 | #define CDMM_ACSR_DEVSIZE (31ul << CDMM_ACSR_DEVSIZE_SHIFT) | |
28 | #define CDMM_ACSR_DEVREV_SHIFT 12 | |
29 | #define CDMM_ACSR_DEVREV (15ul << CDMM_ACSR_DEVREV_SHIFT) | |
30 | #define CDMM_ACSR_UW (1ul << 3) | |
31 | #define CDMM_ACSR_UR (1ul << 2) | |
32 | #define CDMM_ACSR_SW (1ul << 1) | |
33 | #define CDMM_ACSR_SR (1ul << 0) | |
34 | ||
35 | /* Each block of device registers is 64 bytes */ | |
36 | #define CDMM_DRB_SIZE 64 | |
37 | ||
38 | #define to_mips_cdmm_driver(d) container_of(d, struct mips_cdmm_driver, drv) | |
39 | ||
40 | /* Default physical base address */ | |
41 | static phys_addr_t mips_cdmm_default_base; | |
42 | ||
43 | /* Bus operations */ | |
44 | ||
45 | static const struct mips_cdmm_device_id * | |
46 | mips_cdmm_lookup(const struct mips_cdmm_device_id *table, | |
47 | struct mips_cdmm_device *dev) | |
48 | { | |
49 | int ret = 0; | |
50 | ||
51 | for (; table->type; ++table) { | |
52 | ret = (dev->type == table->type); | |
53 | if (ret) | |
54 | break; | |
55 | } | |
56 | ||
57 | return ret ? table : NULL; | |
58 | } | |
59 | ||
60 | static int mips_cdmm_match(struct device *dev, struct device_driver *drv) | |
61 | { | |
62 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
63 | struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(drv); | |
64 | ||
65 | return mips_cdmm_lookup(cdrv->id_table, cdev) != NULL; | |
66 | } | |
67 | ||
68 | static int mips_cdmm_uevent(struct device *dev, struct kobj_uevent_env *env) | |
69 | { | |
70 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
71 | int retval = 0; | |
72 | ||
73 | retval = add_uevent_var(env, "CDMM_CPU=%u", cdev->cpu); | |
74 | if (retval) | |
75 | return retval; | |
76 | ||
77 | retval = add_uevent_var(env, "CDMM_TYPE=0x%02x", cdev->type); | |
78 | if (retval) | |
79 | return retval; | |
80 | ||
81 | retval = add_uevent_var(env, "CDMM_REV=%u", cdev->rev); | |
82 | if (retval) | |
83 | return retval; | |
84 | ||
85 | retval = add_uevent_var(env, "MODALIAS=mipscdmm:t%02X", cdev->type); | |
86 | return retval; | |
87 | } | |
88 | ||
89 | /* Device attributes */ | |
90 | ||
91 | #define CDMM_ATTR(name, fmt, arg...) \ | |
92 | static ssize_t name##_show(struct device *_dev, \ | |
93 | struct device_attribute *attr, char *buf) \ | |
94 | { \ | |
95 | struct mips_cdmm_device *dev = to_mips_cdmm_device(_dev); \ | |
96 | return sprintf(buf, fmt, arg); \ | |
97 | } \ | |
98 | static DEVICE_ATTR_RO(name); | |
99 | ||
100 | CDMM_ATTR(cpu, "%u\n", dev->cpu); | |
101 | CDMM_ATTR(type, "0x%02x\n", dev->type); | |
102 | CDMM_ATTR(revision, "%u\n", dev->rev); | |
103 | CDMM_ATTR(modalias, "mipscdmm:t%02X\n", dev->type); | |
104 | CDMM_ATTR(resource, "\t%016llx\t%016llx\t%016lx\n", | |
105 | (unsigned long long)dev->res.start, | |
106 | (unsigned long long)dev->res.end, | |
107 | dev->res.flags); | |
108 | ||
109 | static struct attribute *mips_cdmm_dev_attrs[] = { | |
110 | &dev_attr_cpu.attr, | |
111 | &dev_attr_type.attr, | |
112 | &dev_attr_revision.attr, | |
113 | &dev_attr_modalias.attr, | |
114 | &dev_attr_resource.attr, | |
115 | NULL, | |
116 | }; | |
117 | ATTRIBUTE_GROUPS(mips_cdmm_dev); | |
118 | ||
119 | struct bus_type mips_cdmm_bustype = { | |
120 | .name = "cdmm", | |
121 | .dev_groups = mips_cdmm_dev_groups, | |
122 | .match = mips_cdmm_match, | |
123 | .uevent = mips_cdmm_uevent, | |
124 | }; | |
125 | EXPORT_SYMBOL_GPL(mips_cdmm_bustype); | |
126 | ||
127 | /* | |
128 | * Standard driver callback helpers. | |
129 | * | |
130 | * All the CDMM driver callbacks need to be executed on the appropriate CPU from | |
131 | * workqueues. For the standard driver callbacks we need a work function | |
132 | * (mips_cdmm_{void,int}_work()) to do the actual call from the right CPU, and a | |
133 | * wrapper function (generated with BUILD_PERCPU_HELPER) to arrange for the work | |
134 | * function to be called on that CPU. | |
135 | */ | |
136 | ||
137 | /** | |
138 | * struct mips_cdmm_work_dev - Data for per-device call work. | |
139 | * @fn: CDMM driver callback function to call for the device. | |
140 | * @dev: CDMM device to pass to @fn. | |
141 | */ | |
142 | struct mips_cdmm_work_dev { | |
143 | void *fn; | |
144 | struct mips_cdmm_device *dev; | |
145 | }; | |
146 | ||
147 | /** | |
148 | * mips_cdmm_void_work() - Call a void returning CDMM driver callback. | |
149 | * @data: struct mips_cdmm_work_dev pointer. | |
150 | * | |
151 | * A work_on_cpu() callback function to call an arbitrary CDMM driver callback | |
152 | * function which doesn't return a value. | |
153 | */ | |
154 | static long mips_cdmm_void_work(void *data) | |
155 | { | |
156 | struct mips_cdmm_work_dev *work = data; | |
157 | void (*fn)(struct mips_cdmm_device *) = work->fn; | |
158 | ||
159 | fn(work->dev); | |
160 | return 0; | |
161 | } | |
162 | ||
163 | /** | |
164 | * mips_cdmm_int_work() - Call an int returning CDMM driver callback. | |
165 | * @data: struct mips_cdmm_work_dev pointer. | |
166 | * | |
167 | * A work_on_cpu() callback function to call an arbitrary CDMM driver callback | |
168 | * function which returns an int. | |
169 | */ | |
170 | static long mips_cdmm_int_work(void *data) | |
171 | { | |
172 | struct mips_cdmm_work_dev *work = data; | |
173 | int (*fn)(struct mips_cdmm_device *) = work->fn; | |
174 | ||
175 | return fn(work->dev); | |
176 | } | |
177 | ||
178 | #define _BUILD_RET_void | |
179 | #define _BUILD_RET_int return | |
180 | ||
181 | /** | |
182 | * BUILD_PERCPU_HELPER() - Helper to call a CDMM driver callback on right CPU. | |
183 | * @_ret: Return type (void or int). | |
184 | * @_name: Name of CDMM driver callback function. | |
185 | * | |
186 | * Generates a specific device callback function to call a CDMM driver callback | |
187 | * function on the appropriate CPU for the device, and if applicable return the | |
188 | * result. | |
189 | */ | |
190 | #define BUILD_PERCPU_HELPER(_ret, _name) \ | |
191 | static _ret mips_cdmm_##_name(struct device *dev) \ | |
192 | { \ | |
193 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); \ | |
194 | struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(dev->driver); \ | |
195 | struct mips_cdmm_work_dev work = { \ | |
196 | .fn = cdrv->_name, \ | |
197 | .dev = cdev, \ | |
198 | }; \ | |
199 | \ | |
200 | _BUILD_RET_##_ret work_on_cpu(cdev->cpu, \ | |
201 | mips_cdmm_##_ret##_work, &work); \ | |
202 | } | |
203 | ||
204 | /* Driver callback functions */ | |
205 | BUILD_PERCPU_HELPER(int, probe) /* int mips_cdmm_probe(struct device) */ | |
206 | BUILD_PERCPU_HELPER(int, remove) /* int mips_cdmm_remove(struct device) */ | |
207 | BUILD_PERCPU_HELPER(void, shutdown) /* void mips_cdmm_shutdown(struct device) */ | |
208 | ||
209 | ||
210 | /* Driver registration */ | |
211 | ||
212 | /** | |
213 | * mips_cdmm_driver_register() - Register a CDMM driver. | |
214 | * @drv: CDMM driver information. | |
215 | * | |
216 | * Register a CDMM driver with the CDMM subsystem. The driver will be informed | |
217 | * of matching devices which are discovered. | |
218 | * | |
219 | * Returns: 0 on success. | |
220 | */ | |
221 | int mips_cdmm_driver_register(struct mips_cdmm_driver *drv) | |
222 | { | |
223 | drv->drv.bus = &mips_cdmm_bustype; | |
224 | ||
225 | if (drv->probe) | |
226 | drv->drv.probe = mips_cdmm_probe; | |
227 | if (drv->remove) | |
228 | drv->drv.remove = mips_cdmm_remove; | |
229 | if (drv->shutdown) | |
230 | drv->drv.shutdown = mips_cdmm_shutdown; | |
231 | ||
232 | return driver_register(&drv->drv); | |
233 | } | |
234 | EXPORT_SYMBOL_GPL(mips_cdmm_driver_register); | |
235 | ||
236 | /** | |
237 | * mips_cdmm_driver_unregister() - Unregister a CDMM driver. | |
238 | * @drv: CDMM driver information. | |
239 | * | |
240 | * Unregister a CDMM driver from the CDMM subsystem. | |
241 | */ | |
242 | void mips_cdmm_driver_unregister(struct mips_cdmm_driver *drv) | |
243 | { | |
244 | driver_unregister(&drv->drv); | |
245 | } | |
246 | EXPORT_SYMBOL_GPL(mips_cdmm_driver_unregister); | |
247 | ||
248 | ||
249 | /* CDMM initialisation and bus discovery */ | |
250 | ||
251 | /** | |
252 | * struct mips_cdmm_bus - Info about CDMM bus. | |
253 | * @phys: Physical address at which it is mapped. | |
254 | * @regs: Virtual address where registers can be accessed. | |
255 | * @drbs: Total number of DRBs. | |
256 | * @drbs_reserved: Number of DRBs reserved. | |
257 | * @discovered: Whether the devices on the bus have been discovered yet. | |
258 | * @offline: Whether the CDMM bus is going offline (or very early | |
259 | * coming back online), in which case it should be | |
260 | * reconfigured each time. | |
261 | */ | |
262 | struct mips_cdmm_bus { | |
263 | phys_addr_t phys; | |
264 | void __iomem *regs; | |
265 | unsigned int drbs; | |
266 | unsigned int drbs_reserved; | |
267 | bool discovered; | |
268 | bool offline; | |
269 | }; | |
270 | ||
271 | static struct mips_cdmm_bus mips_cdmm_boot_bus; | |
272 | static DEFINE_PER_CPU(struct mips_cdmm_bus *, mips_cdmm_buses); | |
273 | static atomic_t mips_cdmm_next_id = ATOMIC_INIT(-1); | |
274 | ||
275 | /** | |
276 | * mips_cdmm_get_bus() - Get the per-CPU CDMM bus information. | |
277 | * | |
278 | * Get information about the per-CPU CDMM bus, if the bus is present. | |
279 | * | |
280 | * The caller must prevent migration to another CPU, either by disabling | |
281 | * pre-emption or by running from a pinned kernel thread. | |
282 | * | |
283 | * Returns: Pointer to CDMM bus information for the current CPU. | |
284 | * May return ERR_PTR(-errno) in case of error, so check with | |
285 | * IS_ERR(). | |
286 | */ | |
287 | static struct mips_cdmm_bus *mips_cdmm_get_bus(void) | |
288 | { | |
289 | struct mips_cdmm_bus *bus, **bus_p; | |
290 | unsigned long flags; | |
291 | unsigned int cpu; | |
292 | ||
293 | if (!cpu_has_cdmm) | |
294 | return ERR_PTR(-ENODEV); | |
295 | ||
296 | cpu = smp_processor_id(); | |
297 | /* Avoid early use of per-cpu primitives before initialised */ | |
298 | if (cpu == 0) | |
299 | return &mips_cdmm_boot_bus; | |
300 | ||
301 | /* Get bus pointer */ | |
302 | bus_p = per_cpu_ptr(&mips_cdmm_buses, cpu); | |
303 | local_irq_save(flags); | |
304 | bus = *bus_p; | |
305 | /* Attempt allocation if NULL */ | |
306 | if (unlikely(!bus)) { | |
307 | bus = kzalloc(sizeof(*bus), GFP_ATOMIC); | |
308 | if (unlikely(!bus)) | |
309 | bus = ERR_PTR(-ENOMEM); | |
310 | else | |
311 | *bus_p = bus; | |
312 | } | |
313 | local_irq_restore(flags); | |
314 | return bus; | |
315 | } | |
316 | ||
317 | /** | |
318 | * mips_cdmm_cur_base() - Find current physical base address of CDMM region. | |
319 | * | |
320 | * Returns: Physical base address of CDMM region according to cdmmbase CP0 | |
321 | * register, or 0 if the CDMM region is disabled. | |
322 | */ | |
323 | static phys_addr_t mips_cdmm_cur_base(void) | |
324 | { | |
325 | unsigned long cdmmbase = read_c0_cdmmbase(); | |
326 | ||
327 | if (!(cdmmbase & MIPS_CDMMBASE_EN)) | |
328 | return 0; | |
329 | ||
330 | return (cdmmbase >> MIPS_CDMMBASE_ADDR_SHIFT) | |
331 | << MIPS_CDMMBASE_ADDR_START; | |
332 | } | |
333 | ||
e1d97497 BH |
334 | /** |
335 | * mips_cdmm_phys_base() - Choose a physical base address for CDMM region. | |
336 | * | |
337 | * Picking a suitable physical address at which to map the CDMM region is | |
338 | * platform specific, so this weak function can be overridden by platform | |
339 | * code to pick a suitable value if none is configured by the bootloader. | |
340 | */ | |
341 | phys_addr_t __weak mips_cdmm_phys_base(void) | |
342 | { | |
343 | return 0; | |
344 | } | |
345 | ||
8286ae03 JH |
346 | /** |
347 | * mips_cdmm_setup() - Ensure the CDMM bus is initialised and usable. | |
348 | * @bus: Pointer to bus information for current CPU. | |
349 | * IS_ERR(bus) is checked, so no need for caller to check. | |
350 | * | |
351 | * The caller must prevent migration to another CPU, either by disabling | |
352 | * pre-emption or by running from a pinned kernel thread. | |
353 | * | |
354 | * Returns 0 on success, -errno on failure. | |
355 | */ | |
356 | static int mips_cdmm_setup(struct mips_cdmm_bus *bus) | |
357 | { | |
358 | unsigned long cdmmbase, flags; | |
359 | int ret = 0; | |
360 | ||
361 | if (IS_ERR(bus)) | |
362 | return PTR_ERR(bus); | |
363 | ||
364 | local_irq_save(flags); | |
365 | /* Don't set up bus a second time unless marked offline */ | |
366 | if (bus->offline) { | |
367 | /* If CDMM region is still set up, nothing to do */ | |
368 | if (bus->phys == mips_cdmm_cur_base()) | |
369 | goto out; | |
370 | /* | |
371 | * The CDMM region isn't set up as expected, so it needs | |
372 | * reconfiguring, but then we can stop checking it. | |
373 | */ | |
374 | bus->offline = false; | |
375 | } else if (bus->phys > 1) { | |
376 | goto out; | |
377 | } | |
378 | ||
379 | /* If the CDMM region is already configured, inherit that setup */ | |
380 | if (!bus->phys) | |
381 | bus->phys = mips_cdmm_cur_base(); | |
382 | /* Otherwise, ask platform code for suggestions */ | |
e1d97497 | 383 | if (!bus->phys) |
8286ae03 JH |
384 | bus->phys = mips_cdmm_phys_base(); |
385 | /* Otherwise, copy what other CPUs have done */ | |
386 | if (!bus->phys) | |
387 | bus->phys = mips_cdmm_default_base; | |
388 | /* Otherwise, complain once */ | |
389 | if (!bus->phys) { | |
390 | bus->phys = 1; | |
391 | /* | |
392 | * If you hit this, either your bootloader needs to set up the | |
393 | * CDMM on the boot CPU, or else you need to implement | |
394 | * mips_cdmm_phys_base() for your platform (see asm/cdmm.h). | |
395 | */ | |
396 | pr_err("cdmm%u: Failed to choose a physical base\n", | |
397 | smp_processor_id()); | |
398 | } | |
399 | /* Already complained? */ | |
400 | if (bus->phys == 1) { | |
401 | ret = -ENOMEM; | |
402 | goto out; | |
403 | } | |
404 | /* Record our success for other CPUs to copy */ | |
405 | mips_cdmm_default_base = bus->phys; | |
406 | ||
407 | pr_debug("cdmm%u: Enabling CDMM region at %pa\n", | |
408 | smp_processor_id(), &bus->phys); | |
409 | ||
410 | /* Enable CDMM */ | |
411 | cdmmbase = read_c0_cdmmbase(); | |
412 | cdmmbase &= (1ul << MIPS_CDMMBASE_ADDR_SHIFT) - 1; | |
413 | cdmmbase |= (bus->phys >> MIPS_CDMMBASE_ADDR_START) | |
414 | << MIPS_CDMMBASE_ADDR_SHIFT; | |
415 | cdmmbase |= MIPS_CDMMBASE_EN; | |
416 | write_c0_cdmmbase(cdmmbase); | |
417 | tlbw_use_hazard(); | |
418 | ||
419 | bus->regs = (void __iomem *)CKSEG1ADDR(bus->phys); | |
420 | bus->drbs = 1 + ((cdmmbase & MIPS_CDMMBASE_SIZE) >> | |
421 | MIPS_CDMMBASE_SIZE_SHIFT); | |
422 | bus->drbs_reserved = !!(cdmmbase & MIPS_CDMMBASE_CI); | |
423 | ||
424 | out: | |
425 | local_irq_restore(flags); | |
426 | return ret; | |
427 | } | |
428 | ||
429 | /** | |
430 | * mips_cdmm_early_probe() - Minimally probe for a specific device on CDMM. | |
431 | * @dev_type: CDMM type code to look for. | |
432 | * | |
433 | * Minimally configure the in-CPU Common Device Memory Map (CDMM) and look for a | |
434 | * specific device. This can be used to find a device very early in boot for | |
435 | * example to configure an early FDC console device. | |
436 | * | |
437 | * The caller must prevent migration to another CPU, either by disabling | |
438 | * pre-emption or by running from a pinned kernel thread. | |
439 | * | |
440 | * Returns: MMIO pointer to device memory. The caller can read the ACSR | |
441 | * register to find more information about the device (such as the | |
442 | * version number or the number of blocks). | |
443 | * May return IOMEM_ERR_PTR(-errno) in case of error, so check with | |
444 | * IS_ERR(). | |
445 | */ | |
446 | void __iomem *mips_cdmm_early_probe(unsigned int dev_type) | |
447 | { | |
448 | struct mips_cdmm_bus *bus; | |
449 | void __iomem *cdmm; | |
450 | u32 acsr; | |
451 | unsigned int drb, type, size; | |
452 | int err; | |
453 | ||
454 | if (WARN_ON(!dev_type)) | |
455 | return IOMEM_ERR_PTR(-ENODEV); | |
456 | ||
457 | bus = mips_cdmm_get_bus(); | |
458 | err = mips_cdmm_setup(bus); | |
459 | if (err) | |
460 | return IOMEM_ERR_PTR(err); | |
461 | ||
462 | /* Skip the first block if it's reserved for more registers */ | |
463 | drb = bus->drbs_reserved; | |
464 | cdmm = bus->regs; | |
465 | ||
466 | /* Look for a specific device type */ | |
467 | for (; drb < bus->drbs; drb += size + 1) { | |
e21422de | 468 | acsr = __raw_readl(cdmm + drb * CDMM_DRB_SIZE); |
8286ae03 JH |
469 | type = (acsr & CDMM_ACSR_DEVTYPE) >> CDMM_ACSR_DEVTYPE_SHIFT; |
470 | if (type == dev_type) | |
471 | return cdmm + drb * CDMM_DRB_SIZE; | |
472 | size = (acsr & CDMM_ACSR_DEVSIZE) >> CDMM_ACSR_DEVSIZE_SHIFT; | |
473 | } | |
474 | ||
475 | return IOMEM_ERR_PTR(-ENODEV); | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(mips_cdmm_early_probe); | |
478 | ||
479 | /** | |
480 | * mips_cdmm_release() - Release a removed CDMM device. | |
481 | * @dev: Device object | |
482 | * | |
483 | * Clean up the struct mips_cdmm_device for an unused CDMM device. This is | |
484 | * called automatically by the driver core when a device is removed. | |
485 | */ | |
486 | static void mips_cdmm_release(struct device *dev) | |
487 | { | |
488 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
489 | ||
490 | kfree(cdev); | |
491 | } | |
492 | ||
493 | /** | |
494 | * mips_cdmm_bus_discover() - Discover the devices on the CDMM bus. | |
495 | * @bus: CDMM bus information, must already be set up. | |
496 | */ | |
497 | static void mips_cdmm_bus_discover(struct mips_cdmm_bus *bus) | |
498 | { | |
499 | void __iomem *cdmm; | |
500 | u32 acsr; | |
501 | unsigned int drb, type, size, rev; | |
502 | struct mips_cdmm_device *dev; | |
503 | unsigned int cpu = smp_processor_id(); | |
504 | int ret = 0; | |
505 | int id = 0; | |
506 | ||
507 | /* Skip the first block if it's reserved for more registers */ | |
508 | drb = bus->drbs_reserved; | |
509 | cdmm = bus->regs; | |
510 | ||
511 | /* Discover devices */ | |
512 | bus->discovered = true; | |
513 | pr_info("cdmm%u discovery (%u blocks)\n", cpu, bus->drbs); | |
514 | for (; drb < bus->drbs; drb += size + 1) { | |
e21422de | 515 | acsr = __raw_readl(cdmm + drb * CDMM_DRB_SIZE); |
8286ae03 JH |
516 | type = (acsr & CDMM_ACSR_DEVTYPE) >> CDMM_ACSR_DEVTYPE_SHIFT; |
517 | size = (acsr & CDMM_ACSR_DEVSIZE) >> CDMM_ACSR_DEVSIZE_SHIFT; | |
518 | rev = (acsr & CDMM_ACSR_DEVREV) >> CDMM_ACSR_DEVREV_SHIFT; | |
519 | ||
520 | if (!type) | |
521 | continue; | |
522 | ||
523 | pr_info("cdmm%u-%u: @%u (%#x..%#x), type 0x%02x, rev %u\n", | |
524 | cpu, id, drb, drb * CDMM_DRB_SIZE, | |
525 | (drb + size + 1) * CDMM_DRB_SIZE - 1, | |
526 | type, rev); | |
527 | ||
528 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
529 | if (!dev) | |
530 | break; | |
531 | ||
532 | dev->cpu = cpu; | |
533 | dev->res.start = bus->phys + drb * CDMM_DRB_SIZE; | |
534 | dev->res.end = bus->phys + | |
535 | (drb + size + 1) * CDMM_DRB_SIZE - 1; | |
536 | dev->res.flags = IORESOURCE_MEM; | |
537 | dev->type = type; | |
538 | dev->rev = rev; | |
539 | dev->dev.parent = get_cpu_device(cpu); | |
540 | dev->dev.bus = &mips_cdmm_bustype; | |
541 | dev->dev.id = atomic_inc_return(&mips_cdmm_next_id); | |
542 | dev->dev.release = mips_cdmm_release; | |
543 | ||
544 | dev_set_name(&dev->dev, "cdmm%u-%u", cpu, id); | |
545 | ++id; | |
546 | ret = device_register(&dev->dev); | |
547 | if (ret) { | |
548 | put_device(&dev->dev); | |
549 | kfree(dev); | |
550 | } | |
551 | } | |
552 | } | |
553 | ||
554 | ||
555 | /* | |
556 | * CPU hotplug and initialisation | |
557 | * | |
558 | * All the CDMM driver callbacks need to be executed on the appropriate CPU from | |
559 | * workqueues. For the CPU callbacks, they need to be called for all devices on | |
560 | * that CPU, so the work function calls bus_for_each_dev, using a helper | |
561 | * (generated with BUILD_PERDEV_HELPER) to call the driver callback if the | |
562 | * device's CPU matches. | |
563 | */ | |
564 | ||
565 | /** | |
566 | * BUILD_PERDEV_HELPER() - Helper to call a CDMM driver callback if CPU matches. | |
567 | * @_name: Name of CDMM driver callback function. | |
568 | * | |
569 | * Generates a bus_for_each_dev callback function to call a specific CDMM driver | |
570 | * callback function for the device if the device's CPU matches that pointed to | |
571 | * by the data argument. | |
572 | * | |
573 | * This is used for informing drivers for all devices on a given CPU of some | |
574 | * event (such as the CPU going online/offline). | |
575 | * | |
576 | * It is expected to already be called from the appropriate CPU. | |
577 | */ | |
578 | #define BUILD_PERDEV_HELPER(_name) \ | |
579 | static int mips_cdmm_##_name##_helper(struct device *dev, void *data) \ | |
580 | { \ | |
581 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); \ | |
582 | struct mips_cdmm_driver *cdrv; \ | |
583 | unsigned int cpu = *(unsigned int *)data; \ | |
584 | \ | |
585 | if (cdev->cpu != cpu || !dev->driver) \ | |
586 | return 0; \ | |
587 | \ | |
588 | cdrv = to_mips_cdmm_driver(dev->driver); \ | |
589 | if (!cdrv->_name) \ | |
590 | return 0; \ | |
591 | return cdrv->_name(cdev); \ | |
592 | } | |
593 | ||
594 | /* bus_for_each_dev callback helper functions */ | |
595 | BUILD_PERDEV_HELPER(cpu_down) /* int mips_cdmm_cpu_down_helper(...) */ | |
596 | BUILD_PERDEV_HELPER(cpu_up) /* int mips_cdmm_cpu_up_helper(...) */ | |
597 | ||
598 | /** | |
e8483b57 SAS |
599 | * mips_cdmm_cpu_down_prep() - Callback for CPUHP DOWN_PREP: |
600 | * Tear down the CDMM bus. | |
601 | * @cpu: unsigned int CPU number. | |
8286ae03 | 602 | * |
015aa05f AMG |
603 | * This function is executed on the hotplugged CPU and calls the CDMM |
604 | * driver cpu_down callback for all devices on that CPU. | |
8286ae03 | 605 | */ |
e8483b57 | 606 | static int mips_cdmm_cpu_down_prep(unsigned int cpu) |
8286ae03 JH |
607 | { |
608 | struct mips_cdmm_bus *bus; | |
609 | long ret; | |
610 | ||
611 | /* Inform all the devices on the bus */ | |
e8483b57 | 612 | ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, |
8286ae03 JH |
613 | mips_cdmm_cpu_down_helper); |
614 | ||
615 | /* | |
616 | * While bus is offline, each use of it should reconfigure it just in | |
617 | * case it is first use when coming back online again. | |
618 | */ | |
619 | bus = mips_cdmm_get_bus(); | |
620 | if (!IS_ERR(bus)) | |
621 | bus->offline = true; | |
622 | ||
623 | return ret; | |
624 | } | |
625 | ||
626 | /** | |
e8483b57 SAS |
627 | * mips_cdmm_cpu_online() - Callback for CPUHP ONLINE: Bring up the CDMM bus. |
628 | * @cpu: unsigned int CPU number. | |
8286ae03 JH |
629 | * |
630 | * This work_on_cpu callback function is executed on a given CPU to discover | |
631 | * CDMM devices on that CPU, or to call the CDMM driver cpu_up callback for all | |
632 | * devices already discovered on that CPU. | |
633 | * | |
015aa05f AMG |
634 | * It is used as work_on_cpu callback function during |
635 | * initialisation. When CPUs are brought online the function is | |
636 | * invoked directly on the hotplugged CPU. | |
8286ae03 | 637 | */ |
e8483b57 | 638 | static int mips_cdmm_cpu_online(unsigned int cpu) |
8286ae03 JH |
639 | { |
640 | struct mips_cdmm_bus *bus; | |
641 | long ret; | |
642 | ||
643 | bus = mips_cdmm_get_bus(); | |
644 | ret = mips_cdmm_setup(bus); | |
645 | if (ret) | |
646 | return ret; | |
647 | ||
648 | /* Bus now set up, so we can drop the offline flag if still set */ | |
649 | bus->offline = false; | |
650 | ||
651 | if (!bus->discovered) | |
652 | mips_cdmm_bus_discover(bus); | |
653 | else | |
654 | /* Inform all the devices on the bus */ | |
e8483b57 | 655 | ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, |
8286ae03 JH |
656 | mips_cdmm_cpu_up_helper); |
657 | ||
658 | return ret; | |
659 | } | |
660 | ||
8286ae03 JH |
661 | /** |
662 | * mips_cdmm_init() - Initialise CDMM bus. | |
663 | * | |
664 | * Initialise CDMM bus, discover CDMM devices for online CPUs, and arrange for | |
665 | * hotplug notifications so the CDMM drivers can be kept up to date. | |
666 | */ | |
667 | static int __init mips_cdmm_init(void) | |
668 | { | |
8286ae03 JH |
669 | int ret; |
670 | ||
671 | /* Register the bus */ | |
672 | ret = bus_register(&mips_cdmm_bustype); | |
673 | if (ret) | |
674 | return ret; | |
675 | ||
676 | /* We want to be notified about new CPUs */ | |
e8483b57 SAS |
677 | ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "bus/cdmm:online", |
678 | mips_cdmm_cpu_online, mips_cdmm_cpu_down_prep); | |
679 | if (ret < 0) | |
8286ae03 | 680 | pr_warn("cdmm: Failed to register CPU notifier\n"); |
8286ae03 | 681 | |
8286ae03 JH |
682 | return ret; |
683 | } | |
684 | subsys_initcall(mips_cdmm_init); |