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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> | |
2121aa3e SS |
16 | #include <linux/of_address.h> |
17 | #include <linux/of.h> | |
8286ae03 JH |
18 | #include <linux/platform_device.h> |
19 | #include <linux/slab.h> | |
20 | #include <linux/smp.h> | |
21 | #include <asm/cdmm.h> | |
22 | #include <asm/hazards.h> | |
23 | #include <asm/mipsregs.h> | |
24 | ||
25 | /* Access control and status register fields */ | |
26 | #define CDMM_ACSR_DEVTYPE_SHIFT 24 | |
27 | #define CDMM_ACSR_DEVTYPE (255ul << CDMM_ACSR_DEVTYPE_SHIFT) | |
28 | #define CDMM_ACSR_DEVSIZE_SHIFT 16 | |
29 | #define CDMM_ACSR_DEVSIZE (31ul << CDMM_ACSR_DEVSIZE_SHIFT) | |
30 | #define CDMM_ACSR_DEVREV_SHIFT 12 | |
31 | #define CDMM_ACSR_DEVREV (15ul << CDMM_ACSR_DEVREV_SHIFT) | |
32 | #define CDMM_ACSR_UW (1ul << 3) | |
33 | #define CDMM_ACSR_UR (1ul << 2) | |
34 | #define CDMM_ACSR_SW (1ul << 1) | |
35 | #define CDMM_ACSR_SR (1ul << 0) | |
36 | ||
37 | /* Each block of device registers is 64 bytes */ | |
38 | #define CDMM_DRB_SIZE 64 | |
39 | ||
40 | #define to_mips_cdmm_driver(d) container_of(d, struct mips_cdmm_driver, drv) | |
41 | ||
42 | /* Default physical base address */ | |
43 | static phys_addr_t mips_cdmm_default_base; | |
44 | ||
45 | /* Bus operations */ | |
46 | ||
47 | static const struct mips_cdmm_device_id * | |
48 | mips_cdmm_lookup(const struct mips_cdmm_device_id *table, | |
49 | struct mips_cdmm_device *dev) | |
50 | { | |
51 | int ret = 0; | |
52 | ||
53 | for (; table->type; ++table) { | |
54 | ret = (dev->type == table->type); | |
55 | if (ret) | |
56 | break; | |
57 | } | |
58 | ||
59 | return ret ? table : NULL; | |
60 | } | |
61 | ||
62 | static int mips_cdmm_match(struct device *dev, struct device_driver *drv) | |
63 | { | |
64 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
65 | struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(drv); | |
66 | ||
67 | return mips_cdmm_lookup(cdrv->id_table, cdev) != NULL; | |
68 | } | |
69 | ||
70 | static int mips_cdmm_uevent(struct device *dev, struct kobj_uevent_env *env) | |
71 | { | |
72 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
73 | int retval = 0; | |
74 | ||
75 | retval = add_uevent_var(env, "CDMM_CPU=%u", cdev->cpu); | |
76 | if (retval) | |
77 | return retval; | |
78 | ||
79 | retval = add_uevent_var(env, "CDMM_TYPE=0x%02x", cdev->type); | |
80 | if (retval) | |
81 | return retval; | |
82 | ||
83 | retval = add_uevent_var(env, "CDMM_REV=%u", cdev->rev); | |
84 | if (retval) | |
85 | return retval; | |
86 | ||
87 | retval = add_uevent_var(env, "MODALIAS=mipscdmm:t%02X", cdev->type); | |
88 | return retval; | |
89 | } | |
90 | ||
91 | /* Device attributes */ | |
92 | ||
93 | #define CDMM_ATTR(name, fmt, arg...) \ | |
94 | static ssize_t name##_show(struct device *_dev, \ | |
95 | struct device_attribute *attr, char *buf) \ | |
96 | { \ | |
97 | struct mips_cdmm_device *dev = to_mips_cdmm_device(_dev); \ | |
98 | return sprintf(buf, fmt, arg); \ | |
99 | } \ | |
100 | static DEVICE_ATTR_RO(name); | |
101 | ||
102 | CDMM_ATTR(cpu, "%u\n", dev->cpu); | |
103 | CDMM_ATTR(type, "0x%02x\n", dev->type); | |
104 | CDMM_ATTR(revision, "%u\n", dev->rev); | |
105 | CDMM_ATTR(modalias, "mipscdmm:t%02X\n", dev->type); | |
106 | CDMM_ATTR(resource, "\t%016llx\t%016llx\t%016lx\n", | |
107 | (unsigned long long)dev->res.start, | |
108 | (unsigned long long)dev->res.end, | |
109 | dev->res.flags); | |
110 | ||
111 | static struct attribute *mips_cdmm_dev_attrs[] = { | |
112 | &dev_attr_cpu.attr, | |
113 | &dev_attr_type.attr, | |
114 | &dev_attr_revision.attr, | |
115 | &dev_attr_modalias.attr, | |
116 | &dev_attr_resource.attr, | |
117 | NULL, | |
118 | }; | |
119 | ATTRIBUTE_GROUPS(mips_cdmm_dev); | |
120 | ||
121 | struct bus_type mips_cdmm_bustype = { | |
122 | .name = "cdmm", | |
123 | .dev_groups = mips_cdmm_dev_groups, | |
124 | .match = mips_cdmm_match, | |
125 | .uevent = mips_cdmm_uevent, | |
126 | }; | |
127 | EXPORT_SYMBOL_GPL(mips_cdmm_bustype); | |
128 | ||
129 | /* | |
130 | * Standard driver callback helpers. | |
131 | * | |
132 | * All the CDMM driver callbacks need to be executed on the appropriate CPU from | |
133 | * workqueues. For the standard driver callbacks we need a work function | |
134 | * (mips_cdmm_{void,int}_work()) to do the actual call from the right CPU, and a | |
135 | * wrapper function (generated with BUILD_PERCPU_HELPER) to arrange for the work | |
136 | * function to be called on that CPU. | |
137 | */ | |
138 | ||
139 | /** | |
140 | * struct mips_cdmm_work_dev - Data for per-device call work. | |
141 | * @fn: CDMM driver callback function to call for the device. | |
142 | * @dev: CDMM device to pass to @fn. | |
143 | */ | |
144 | struct mips_cdmm_work_dev { | |
145 | void *fn; | |
146 | struct mips_cdmm_device *dev; | |
147 | }; | |
148 | ||
149 | /** | |
150 | * mips_cdmm_void_work() - Call a void returning CDMM driver callback. | |
151 | * @data: struct mips_cdmm_work_dev pointer. | |
152 | * | |
153 | * A work_on_cpu() callback function to call an arbitrary CDMM driver callback | |
154 | * function which doesn't return a value. | |
155 | */ | |
156 | static long mips_cdmm_void_work(void *data) | |
157 | { | |
158 | struct mips_cdmm_work_dev *work = data; | |
159 | void (*fn)(struct mips_cdmm_device *) = work->fn; | |
160 | ||
161 | fn(work->dev); | |
162 | return 0; | |
163 | } | |
164 | ||
165 | /** | |
166 | * mips_cdmm_int_work() - Call an int returning CDMM driver callback. | |
167 | * @data: struct mips_cdmm_work_dev pointer. | |
168 | * | |
169 | * A work_on_cpu() callback function to call an arbitrary CDMM driver callback | |
170 | * function which returns an int. | |
171 | */ | |
172 | static long mips_cdmm_int_work(void *data) | |
173 | { | |
174 | struct mips_cdmm_work_dev *work = data; | |
175 | int (*fn)(struct mips_cdmm_device *) = work->fn; | |
176 | ||
177 | return fn(work->dev); | |
178 | } | |
179 | ||
180 | #define _BUILD_RET_void | |
181 | #define _BUILD_RET_int return | |
182 | ||
183 | /** | |
184 | * BUILD_PERCPU_HELPER() - Helper to call a CDMM driver callback on right CPU. | |
185 | * @_ret: Return type (void or int). | |
186 | * @_name: Name of CDMM driver callback function. | |
187 | * | |
188 | * Generates a specific device callback function to call a CDMM driver callback | |
189 | * function on the appropriate CPU for the device, and if applicable return the | |
190 | * result. | |
191 | */ | |
192 | #define BUILD_PERCPU_HELPER(_ret, _name) \ | |
193 | static _ret mips_cdmm_##_name(struct device *dev) \ | |
194 | { \ | |
195 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); \ | |
196 | struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(dev->driver); \ | |
197 | struct mips_cdmm_work_dev work = { \ | |
198 | .fn = cdrv->_name, \ | |
199 | .dev = cdev, \ | |
200 | }; \ | |
201 | \ | |
202 | _BUILD_RET_##_ret work_on_cpu(cdev->cpu, \ | |
203 | mips_cdmm_##_ret##_work, &work); \ | |
204 | } | |
205 | ||
206 | /* Driver callback functions */ | |
207 | BUILD_PERCPU_HELPER(int, probe) /* int mips_cdmm_probe(struct device) */ | |
208 | BUILD_PERCPU_HELPER(int, remove) /* int mips_cdmm_remove(struct device) */ | |
209 | BUILD_PERCPU_HELPER(void, shutdown) /* void mips_cdmm_shutdown(struct device) */ | |
210 | ||
211 | ||
212 | /* Driver registration */ | |
213 | ||
214 | /** | |
215 | * mips_cdmm_driver_register() - Register a CDMM driver. | |
216 | * @drv: CDMM driver information. | |
217 | * | |
218 | * Register a CDMM driver with the CDMM subsystem. The driver will be informed | |
219 | * of matching devices which are discovered. | |
220 | * | |
221 | * Returns: 0 on success. | |
222 | */ | |
223 | int mips_cdmm_driver_register(struct mips_cdmm_driver *drv) | |
224 | { | |
225 | drv->drv.bus = &mips_cdmm_bustype; | |
226 | ||
227 | if (drv->probe) | |
228 | drv->drv.probe = mips_cdmm_probe; | |
229 | if (drv->remove) | |
230 | drv->drv.remove = mips_cdmm_remove; | |
231 | if (drv->shutdown) | |
232 | drv->drv.shutdown = mips_cdmm_shutdown; | |
233 | ||
234 | return driver_register(&drv->drv); | |
235 | } | |
236 | EXPORT_SYMBOL_GPL(mips_cdmm_driver_register); | |
237 | ||
238 | /** | |
239 | * mips_cdmm_driver_unregister() - Unregister a CDMM driver. | |
240 | * @drv: CDMM driver information. | |
241 | * | |
242 | * Unregister a CDMM driver from the CDMM subsystem. | |
243 | */ | |
244 | void mips_cdmm_driver_unregister(struct mips_cdmm_driver *drv) | |
245 | { | |
246 | driver_unregister(&drv->drv); | |
247 | } | |
248 | EXPORT_SYMBOL_GPL(mips_cdmm_driver_unregister); | |
249 | ||
250 | ||
251 | /* CDMM initialisation and bus discovery */ | |
252 | ||
253 | /** | |
254 | * struct mips_cdmm_bus - Info about CDMM bus. | |
255 | * @phys: Physical address at which it is mapped. | |
256 | * @regs: Virtual address where registers can be accessed. | |
257 | * @drbs: Total number of DRBs. | |
258 | * @drbs_reserved: Number of DRBs reserved. | |
259 | * @discovered: Whether the devices on the bus have been discovered yet. | |
260 | * @offline: Whether the CDMM bus is going offline (or very early | |
261 | * coming back online), in which case it should be | |
262 | * reconfigured each time. | |
263 | */ | |
264 | struct mips_cdmm_bus { | |
265 | phys_addr_t phys; | |
266 | void __iomem *regs; | |
267 | unsigned int drbs; | |
268 | unsigned int drbs_reserved; | |
269 | bool discovered; | |
270 | bool offline; | |
271 | }; | |
272 | ||
273 | static struct mips_cdmm_bus mips_cdmm_boot_bus; | |
274 | static DEFINE_PER_CPU(struct mips_cdmm_bus *, mips_cdmm_buses); | |
275 | static atomic_t mips_cdmm_next_id = ATOMIC_INIT(-1); | |
276 | ||
277 | /** | |
278 | * mips_cdmm_get_bus() - Get the per-CPU CDMM bus information. | |
279 | * | |
280 | * Get information about the per-CPU CDMM bus, if the bus is present. | |
281 | * | |
282 | * The caller must prevent migration to another CPU, either by disabling | |
283 | * pre-emption or by running from a pinned kernel thread. | |
284 | * | |
285 | * Returns: Pointer to CDMM bus information for the current CPU. | |
286 | * May return ERR_PTR(-errno) in case of error, so check with | |
287 | * IS_ERR(). | |
288 | */ | |
289 | static struct mips_cdmm_bus *mips_cdmm_get_bus(void) | |
290 | { | |
291 | struct mips_cdmm_bus *bus, **bus_p; | |
292 | unsigned long flags; | |
293 | unsigned int cpu; | |
294 | ||
295 | if (!cpu_has_cdmm) | |
296 | return ERR_PTR(-ENODEV); | |
297 | ||
298 | cpu = smp_processor_id(); | |
299 | /* Avoid early use of per-cpu primitives before initialised */ | |
300 | if (cpu == 0) | |
301 | return &mips_cdmm_boot_bus; | |
302 | ||
303 | /* Get bus pointer */ | |
304 | bus_p = per_cpu_ptr(&mips_cdmm_buses, cpu); | |
305 | local_irq_save(flags); | |
306 | bus = *bus_p; | |
307 | /* Attempt allocation if NULL */ | |
308 | if (unlikely(!bus)) { | |
309 | bus = kzalloc(sizeof(*bus), GFP_ATOMIC); | |
310 | if (unlikely(!bus)) | |
311 | bus = ERR_PTR(-ENOMEM); | |
312 | else | |
313 | *bus_p = bus; | |
314 | } | |
315 | local_irq_restore(flags); | |
316 | return bus; | |
317 | } | |
318 | ||
319 | /** | |
320 | * mips_cdmm_cur_base() - Find current physical base address of CDMM region. | |
321 | * | |
322 | * Returns: Physical base address of CDMM region according to cdmmbase CP0 | |
323 | * register, or 0 if the CDMM region is disabled. | |
324 | */ | |
325 | static phys_addr_t mips_cdmm_cur_base(void) | |
326 | { | |
327 | unsigned long cdmmbase = read_c0_cdmmbase(); | |
328 | ||
329 | if (!(cdmmbase & MIPS_CDMMBASE_EN)) | |
330 | return 0; | |
331 | ||
332 | return (cdmmbase >> MIPS_CDMMBASE_ADDR_SHIFT) | |
333 | << MIPS_CDMMBASE_ADDR_START; | |
334 | } | |
335 | ||
e1d97497 BH |
336 | /** |
337 | * mips_cdmm_phys_base() - Choose a physical base address for CDMM region. | |
338 | * | |
339 | * Picking a suitable physical address at which to map the CDMM region is | |
340 | * platform specific, so this weak function can be overridden by platform | |
341 | * code to pick a suitable value if none is configured by the bootloader. | |
2121aa3e SS |
342 | * By default this method tries to find a CDMM-specific node in the system |
343 | * dtb. Note that this won't work for early serial console. | |
e1d97497 BH |
344 | */ |
345 | phys_addr_t __weak mips_cdmm_phys_base(void) | |
346 | { | |
2121aa3e SS |
347 | struct device_node *np; |
348 | struct resource res; | |
349 | int err; | |
350 | ||
351 | np = of_find_compatible_node(NULL, NULL, "mti,mips-cdmm"); | |
352 | if (np) { | |
353 | err = of_address_to_resource(np, 0, &res); | |
4528668c | 354 | of_node_put(np); |
2121aa3e SS |
355 | if (!err) |
356 | return res.start; | |
357 | } | |
358 | ||
e1d97497 BH |
359 | return 0; |
360 | } | |
361 | ||
8286ae03 JH |
362 | /** |
363 | * mips_cdmm_setup() - Ensure the CDMM bus is initialised and usable. | |
364 | * @bus: Pointer to bus information for current CPU. | |
365 | * IS_ERR(bus) is checked, so no need for caller to check. | |
366 | * | |
367 | * The caller must prevent migration to another CPU, either by disabling | |
368 | * pre-emption or by running from a pinned kernel thread. | |
369 | * | |
370 | * Returns 0 on success, -errno on failure. | |
371 | */ | |
372 | static int mips_cdmm_setup(struct mips_cdmm_bus *bus) | |
373 | { | |
374 | unsigned long cdmmbase, flags; | |
375 | int ret = 0; | |
376 | ||
377 | if (IS_ERR(bus)) | |
378 | return PTR_ERR(bus); | |
379 | ||
380 | local_irq_save(flags); | |
381 | /* Don't set up bus a second time unless marked offline */ | |
382 | if (bus->offline) { | |
383 | /* If CDMM region is still set up, nothing to do */ | |
384 | if (bus->phys == mips_cdmm_cur_base()) | |
385 | goto out; | |
386 | /* | |
387 | * The CDMM region isn't set up as expected, so it needs | |
388 | * reconfiguring, but then we can stop checking it. | |
389 | */ | |
390 | bus->offline = false; | |
391 | } else if (bus->phys > 1) { | |
392 | goto out; | |
393 | } | |
394 | ||
395 | /* If the CDMM region is already configured, inherit that setup */ | |
396 | if (!bus->phys) | |
397 | bus->phys = mips_cdmm_cur_base(); | |
398 | /* Otherwise, ask platform code for suggestions */ | |
e1d97497 | 399 | if (!bus->phys) |
8286ae03 JH |
400 | bus->phys = mips_cdmm_phys_base(); |
401 | /* Otherwise, copy what other CPUs have done */ | |
402 | if (!bus->phys) | |
403 | bus->phys = mips_cdmm_default_base; | |
404 | /* Otherwise, complain once */ | |
405 | if (!bus->phys) { | |
406 | bus->phys = 1; | |
407 | /* | |
408 | * If you hit this, either your bootloader needs to set up the | |
409 | * CDMM on the boot CPU, or else you need to implement | |
410 | * mips_cdmm_phys_base() for your platform (see asm/cdmm.h). | |
411 | */ | |
412 | pr_err("cdmm%u: Failed to choose a physical base\n", | |
413 | smp_processor_id()); | |
414 | } | |
415 | /* Already complained? */ | |
416 | if (bus->phys == 1) { | |
417 | ret = -ENOMEM; | |
418 | goto out; | |
419 | } | |
420 | /* Record our success for other CPUs to copy */ | |
421 | mips_cdmm_default_base = bus->phys; | |
422 | ||
423 | pr_debug("cdmm%u: Enabling CDMM region at %pa\n", | |
424 | smp_processor_id(), &bus->phys); | |
425 | ||
426 | /* Enable CDMM */ | |
427 | cdmmbase = read_c0_cdmmbase(); | |
428 | cdmmbase &= (1ul << MIPS_CDMMBASE_ADDR_SHIFT) - 1; | |
429 | cdmmbase |= (bus->phys >> MIPS_CDMMBASE_ADDR_START) | |
430 | << MIPS_CDMMBASE_ADDR_SHIFT; | |
431 | cdmmbase |= MIPS_CDMMBASE_EN; | |
432 | write_c0_cdmmbase(cdmmbase); | |
433 | tlbw_use_hazard(); | |
434 | ||
435 | bus->regs = (void __iomem *)CKSEG1ADDR(bus->phys); | |
436 | bus->drbs = 1 + ((cdmmbase & MIPS_CDMMBASE_SIZE) >> | |
437 | MIPS_CDMMBASE_SIZE_SHIFT); | |
438 | bus->drbs_reserved = !!(cdmmbase & MIPS_CDMMBASE_CI); | |
439 | ||
440 | out: | |
441 | local_irq_restore(flags); | |
442 | return ret; | |
443 | } | |
444 | ||
445 | /** | |
446 | * mips_cdmm_early_probe() - Minimally probe for a specific device on CDMM. | |
447 | * @dev_type: CDMM type code to look for. | |
448 | * | |
449 | * Minimally configure the in-CPU Common Device Memory Map (CDMM) and look for a | |
450 | * specific device. This can be used to find a device very early in boot for | |
451 | * example to configure an early FDC console device. | |
452 | * | |
453 | * The caller must prevent migration to another CPU, either by disabling | |
454 | * pre-emption or by running from a pinned kernel thread. | |
455 | * | |
456 | * Returns: MMIO pointer to device memory. The caller can read the ACSR | |
457 | * register to find more information about the device (such as the | |
458 | * version number or the number of blocks). | |
459 | * May return IOMEM_ERR_PTR(-errno) in case of error, so check with | |
460 | * IS_ERR(). | |
461 | */ | |
462 | void __iomem *mips_cdmm_early_probe(unsigned int dev_type) | |
463 | { | |
464 | struct mips_cdmm_bus *bus; | |
465 | void __iomem *cdmm; | |
466 | u32 acsr; | |
467 | unsigned int drb, type, size; | |
468 | int err; | |
469 | ||
470 | if (WARN_ON(!dev_type)) | |
471 | return IOMEM_ERR_PTR(-ENODEV); | |
472 | ||
473 | bus = mips_cdmm_get_bus(); | |
474 | err = mips_cdmm_setup(bus); | |
475 | if (err) | |
476 | return IOMEM_ERR_PTR(err); | |
477 | ||
478 | /* Skip the first block if it's reserved for more registers */ | |
479 | drb = bus->drbs_reserved; | |
480 | cdmm = bus->regs; | |
481 | ||
482 | /* Look for a specific device type */ | |
483 | for (; drb < bus->drbs; drb += size + 1) { | |
e21422de | 484 | acsr = __raw_readl(cdmm + drb * CDMM_DRB_SIZE); |
8286ae03 JH |
485 | type = (acsr & CDMM_ACSR_DEVTYPE) >> CDMM_ACSR_DEVTYPE_SHIFT; |
486 | if (type == dev_type) | |
487 | return cdmm + drb * CDMM_DRB_SIZE; | |
488 | size = (acsr & CDMM_ACSR_DEVSIZE) >> CDMM_ACSR_DEVSIZE_SHIFT; | |
489 | } | |
490 | ||
491 | return IOMEM_ERR_PTR(-ENODEV); | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(mips_cdmm_early_probe); | |
494 | ||
495 | /** | |
496 | * mips_cdmm_release() - Release a removed CDMM device. | |
497 | * @dev: Device object | |
498 | * | |
499 | * Clean up the struct mips_cdmm_device for an unused CDMM device. This is | |
500 | * called automatically by the driver core when a device is removed. | |
501 | */ | |
502 | static void mips_cdmm_release(struct device *dev) | |
503 | { | |
504 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); | |
505 | ||
506 | kfree(cdev); | |
507 | } | |
508 | ||
509 | /** | |
510 | * mips_cdmm_bus_discover() - Discover the devices on the CDMM bus. | |
511 | * @bus: CDMM bus information, must already be set up. | |
512 | */ | |
513 | static void mips_cdmm_bus_discover(struct mips_cdmm_bus *bus) | |
514 | { | |
515 | void __iomem *cdmm; | |
516 | u32 acsr; | |
517 | unsigned int drb, type, size, rev; | |
518 | struct mips_cdmm_device *dev; | |
519 | unsigned int cpu = smp_processor_id(); | |
520 | int ret = 0; | |
521 | int id = 0; | |
522 | ||
523 | /* Skip the first block if it's reserved for more registers */ | |
524 | drb = bus->drbs_reserved; | |
525 | cdmm = bus->regs; | |
526 | ||
527 | /* Discover devices */ | |
528 | bus->discovered = true; | |
529 | pr_info("cdmm%u discovery (%u blocks)\n", cpu, bus->drbs); | |
530 | for (; drb < bus->drbs; drb += size + 1) { | |
e21422de | 531 | acsr = __raw_readl(cdmm + drb * CDMM_DRB_SIZE); |
8286ae03 JH |
532 | type = (acsr & CDMM_ACSR_DEVTYPE) >> CDMM_ACSR_DEVTYPE_SHIFT; |
533 | size = (acsr & CDMM_ACSR_DEVSIZE) >> CDMM_ACSR_DEVSIZE_SHIFT; | |
534 | rev = (acsr & CDMM_ACSR_DEVREV) >> CDMM_ACSR_DEVREV_SHIFT; | |
535 | ||
536 | if (!type) | |
537 | continue; | |
538 | ||
539 | pr_info("cdmm%u-%u: @%u (%#x..%#x), type 0x%02x, rev %u\n", | |
540 | cpu, id, drb, drb * CDMM_DRB_SIZE, | |
541 | (drb + size + 1) * CDMM_DRB_SIZE - 1, | |
542 | type, rev); | |
543 | ||
544 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
545 | if (!dev) | |
546 | break; | |
547 | ||
548 | dev->cpu = cpu; | |
549 | dev->res.start = bus->phys + drb * CDMM_DRB_SIZE; | |
550 | dev->res.end = bus->phys + | |
551 | (drb + size + 1) * CDMM_DRB_SIZE - 1; | |
552 | dev->res.flags = IORESOURCE_MEM; | |
553 | dev->type = type; | |
554 | dev->rev = rev; | |
555 | dev->dev.parent = get_cpu_device(cpu); | |
556 | dev->dev.bus = &mips_cdmm_bustype; | |
557 | dev->dev.id = atomic_inc_return(&mips_cdmm_next_id); | |
558 | dev->dev.release = mips_cdmm_release; | |
559 | ||
560 | dev_set_name(&dev->dev, "cdmm%u-%u", cpu, id); | |
561 | ++id; | |
562 | ret = device_register(&dev->dev); | |
f0e82242 | 563 | if (ret) |
8286ae03 | 564 | put_device(&dev->dev); |
8286ae03 JH |
565 | } |
566 | } | |
567 | ||
568 | ||
569 | /* | |
570 | * CPU hotplug and initialisation | |
571 | * | |
572 | * All the CDMM driver callbacks need to be executed on the appropriate CPU from | |
573 | * workqueues. For the CPU callbacks, they need to be called for all devices on | |
574 | * that CPU, so the work function calls bus_for_each_dev, using a helper | |
575 | * (generated with BUILD_PERDEV_HELPER) to call the driver callback if the | |
576 | * device's CPU matches. | |
577 | */ | |
578 | ||
579 | /** | |
580 | * BUILD_PERDEV_HELPER() - Helper to call a CDMM driver callback if CPU matches. | |
581 | * @_name: Name of CDMM driver callback function. | |
582 | * | |
583 | * Generates a bus_for_each_dev callback function to call a specific CDMM driver | |
584 | * callback function for the device if the device's CPU matches that pointed to | |
585 | * by the data argument. | |
586 | * | |
587 | * This is used for informing drivers for all devices on a given CPU of some | |
588 | * event (such as the CPU going online/offline). | |
589 | * | |
590 | * It is expected to already be called from the appropriate CPU. | |
591 | */ | |
592 | #define BUILD_PERDEV_HELPER(_name) \ | |
593 | static int mips_cdmm_##_name##_helper(struct device *dev, void *data) \ | |
594 | { \ | |
595 | struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev); \ | |
596 | struct mips_cdmm_driver *cdrv; \ | |
597 | unsigned int cpu = *(unsigned int *)data; \ | |
598 | \ | |
599 | if (cdev->cpu != cpu || !dev->driver) \ | |
600 | return 0; \ | |
601 | \ | |
602 | cdrv = to_mips_cdmm_driver(dev->driver); \ | |
603 | if (!cdrv->_name) \ | |
604 | return 0; \ | |
605 | return cdrv->_name(cdev); \ | |
606 | } | |
607 | ||
608 | /* bus_for_each_dev callback helper functions */ | |
609 | BUILD_PERDEV_HELPER(cpu_down) /* int mips_cdmm_cpu_down_helper(...) */ | |
610 | BUILD_PERDEV_HELPER(cpu_up) /* int mips_cdmm_cpu_up_helper(...) */ | |
611 | ||
612 | /** | |
e8483b57 SAS |
613 | * mips_cdmm_cpu_down_prep() - Callback for CPUHP DOWN_PREP: |
614 | * Tear down the CDMM bus. | |
615 | * @cpu: unsigned int CPU number. | |
8286ae03 | 616 | * |
015aa05f AMG |
617 | * This function is executed on the hotplugged CPU and calls the CDMM |
618 | * driver cpu_down callback for all devices on that CPU. | |
8286ae03 | 619 | */ |
e8483b57 | 620 | static int mips_cdmm_cpu_down_prep(unsigned int cpu) |
8286ae03 JH |
621 | { |
622 | struct mips_cdmm_bus *bus; | |
623 | long ret; | |
624 | ||
625 | /* Inform all the devices on the bus */ | |
e8483b57 | 626 | ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, |
8286ae03 JH |
627 | mips_cdmm_cpu_down_helper); |
628 | ||
629 | /* | |
630 | * While bus is offline, each use of it should reconfigure it just in | |
631 | * case it is first use when coming back online again. | |
632 | */ | |
633 | bus = mips_cdmm_get_bus(); | |
634 | if (!IS_ERR(bus)) | |
635 | bus->offline = true; | |
636 | ||
637 | return ret; | |
638 | } | |
639 | ||
640 | /** | |
e8483b57 SAS |
641 | * mips_cdmm_cpu_online() - Callback for CPUHP ONLINE: Bring up the CDMM bus. |
642 | * @cpu: unsigned int CPU number. | |
8286ae03 JH |
643 | * |
644 | * This work_on_cpu callback function is executed on a given CPU to discover | |
645 | * CDMM devices on that CPU, or to call the CDMM driver cpu_up callback for all | |
646 | * devices already discovered on that CPU. | |
647 | * | |
015aa05f AMG |
648 | * It is used as work_on_cpu callback function during |
649 | * initialisation. When CPUs are brought online the function is | |
650 | * invoked directly on the hotplugged CPU. | |
8286ae03 | 651 | */ |
e8483b57 | 652 | static int mips_cdmm_cpu_online(unsigned int cpu) |
8286ae03 JH |
653 | { |
654 | struct mips_cdmm_bus *bus; | |
655 | long ret; | |
656 | ||
657 | bus = mips_cdmm_get_bus(); | |
658 | ret = mips_cdmm_setup(bus); | |
659 | if (ret) | |
660 | return ret; | |
661 | ||
662 | /* Bus now set up, so we can drop the offline flag if still set */ | |
663 | bus->offline = false; | |
664 | ||
665 | if (!bus->discovered) | |
666 | mips_cdmm_bus_discover(bus); | |
667 | else | |
668 | /* Inform all the devices on the bus */ | |
e8483b57 | 669 | ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, |
8286ae03 JH |
670 | mips_cdmm_cpu_up_helper); |
671 | ||
672 | return ret; | |
673 | } | |
674 | ||
8286ae03 JH |
675 | /** |
676 | * mips_cdmm_init() - Initialise CDMM bus. | |
677 | * | |
678 | * Initialise CDMM bus, discover CDMM devices for online CPUs, and arrange for | |
679 | * hotplug notifications so the CDMM drivers can be kept up to date. | |
680 | */ | |
681 | static int __init mips_cdmm_init(void) | |
682 | { | |
8286ae03 JH |
683 | int ret; |
684 | ||
685 | /* Register the bus */ | |
686 | ret = bus_register(&mips_cdmm_bustype); | |
687 | if (ret) | |
688 | return ret; | |
689 | ||
690 | /* We want to be notified about new CPUs */ | |
e8483b57 SAS |
691 | ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "bus/cdmm:online", |
692 | mips_cdmm_cpu_online, mips_cdmm_cpu_down_prep); | |
693 | if (ret < 0) | |
8286ae03 | 694 | pr_warn("cdmm: Failed to register CPU notifier\n"); |
8286ae03 | 695 | |
8286ae03 JH |
696 | return ret; |
697 | } | |
698 | subsys_initcall(mips_cdmm_init); |