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ed69bdd8 LP |
1 | /* |
2 | * CCI cache coherent interconnect driver | |
3 | * | |
4 | * Copyright (C) 2013 ARM Ltd. | |
5 | * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
12 | * kind, whether express or implied; without even the implied warranty | |
13 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/arm-cci.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/of_address.h> | |
21 | #include <linux/slab.h> | |
22 | ||
23 | #include <asm/cacheflush.h> | |
24 | #include <asm/smp_plat.h> | |
25 | ||
26 | #define CCI_PORT_CTRL 0x0 | |
27 | #define CCI_CTRL_STATUS 0xc | |
28 | ||
29 | #define CCI_ENABLE_SNOOP_REQ 0x1 | |
30 | #define CCI_ENABLE_DVM_REQ 0x2 | |
31 | #define CCI_ENABLE_REQ (CCI_ENABLE_SNOOP_REQ | CCI_ENABLE_DVM_REQ) | |
32 | ||
33 | struct cci_nb_ports { | |
34 | unsigned int nb_ace; | |
35 | unsigned int nb_ace_lite; | |
36 | }; | |
37 | ||
38 | enum cci_ace_port_type { | |
39 | ACE_INVALID_PORT = 0x0, | |
40 | ACE_PORT, | |
41 | ACE_LITE_PORT, | |
42 | }; | |
43 | ||
44 | struct cci_ace_port { | |
45 | void __iomem *base; | |
62158f81 | 46 | unsigned long phys; |
ed69bdd8 LP |
47 | enum cci_ace_port_type type; |
48 | struct device_node *dn; | |
49 | }; | |
50 | ||
51 | static struct cci_ace_port *ports; | |
52 | static unsigned int nb_cci_ports; | |
53 | ||
54 | static void __iomem *cci_ctrl_base; | |
62158f81 | 55 | static unsigned long cci_ctrl_phys; |
ed69bdd8 LP |
56 | |
57 | struct cpu_port { | |
58 | u64 mpidr; | |
59 | u32 port; | |
60 | }; | |
62158f81 | 61 | |
ed69bdd8 LP |
62 | /* |
63 | * Use the port MSB as valid flag, shift can be made dynamic | |
64 | * by computing number of bits required for port indexes. | |
65 | * Code disabling CCI cpu ports runs with D-cache invalidated | |
66 | * and SCTLR bit clear so data accesses must be kept to a minimum | |
67 | * to improve performance; for now shift is left static to | |
68 | * avoid one more data access while disabling the CCI port. | |
69 | */ | |
70 | #define PORT_VALID_SHIFT 31 | |
71 | #define PORT_VALID (0x1 << PORT_VALID_SHIFT) | |
72 | ||
73 | static inline void init_cpu_port(struct cpu_port *port, u32 index, u64 mpidr) | |
74 | { | |
75 | port->port = PORT_VALID | index; | |
76 | port->mpidr = mpidr; | |
77 | } | |
78 | ||
79 | static inline bool cpu_port_is_valid(struct cpu_port *port) | |
80 | { | |
81 | return !!(port->port & PORT_VALID); | |
82 | } | |
83 | ||
84 | static inline bool cpu_port_match(struct cpu_port *port, u64 mpidr) | |
85 | { | |
86 | return port->mpidr == (mpidr & MPIDR_HWID_BITMASK); | |
87 | } | |
88 | ||
89 | static struct cpu_port cpu_port[NR_CPUS]; | |
90 | ||
91 | /** | |
92 | * __cci_ace_get_port - Function to retrieve the port index connected to | |
93 | * a cpu or device. | |
94 | * | |
95 | * @dn: device node of the device to look-up | |
96 | * @type: port type | |
97 | * | |
98 | * Return value: | |
99 | * - CCI port index if success | |
100 | * - -ENODEV if failure | |
101 | */ | |
102 | static int __cci_ace_get_port(struct device_node *dn, int type) | |
103 | { | |
104 | int i; | |
105 | bool ace_match; | |
106 | struct device_node *cci_portn; | |
107 | ||
108 | cci_portn = of_parse_phandle(dn, "cci-control-port", 0); | |
109 | for (i = 0; i < nb_cci_ports; i++) { | |
110 | ace_match = ports[i].type == type; | |
111 | if (ace_match && cci_portn == ports[i].dn) | |
112 | return i; | |
113 | } | |
114 | return -ENODEV; | |
115 | } | |
116 | ||
117 | int cci_ace_get_port(struct device_node *dn) | |
118 | { | |
119 | return __cci_ace_get_port(dn, ACE_LITE_PORT); | |
120 | } | |
121 | EXPORT_SYMBOL_GPL(cci_ace_get_port); | |
122 | ||
123 | static void __init cci_ace_init_ports(void) | |
124 | { | |
78b4d6e0 SK |
125 | int port, cpu; |
126 | struct device_node *cpun; | |
ed69bdd8 LP |
127 | |
128 | /* | |
129 | * Port index look-up speeds up the function disabling ports by CPU, | |
130 | * since the logical to port index mapping is done once and does | |
131 | * not change after system boot. | |
132 | * The stashed index array is initialized for all possible CPUs | |
133 | * at probe time. | |
134 | */ | |
78b4d6e0 SK |
135 | for_each_possible_cpu(cpu) { |
136 | /* too early to use cpu->of_node */ | |
137 | cpun = of_get_cpu_node(cpu, NULL); | |
ed69bdd8 | 138 | |
78b4d6e0 | 139 | if (WARN(!cpun, "Missing cpu device node\n")) |
ed69bdd8 | 140 | continue; |
78b4d6e0 | 141 | |
ed69bdd8 LP |
142 | port = __cci_ace_get_port(cpun, ACE_PORT); |
143 | if (port < 0) | |
144 | continue; | |
145 | ||
146 | init_cpu_port(&cpu_port[cpu], port, cpu_logical_map(cpu)); | |
147 | } | |
148 | ||
149 | for_each_possible_cpu(cpu) { | |
150 | WARN(!cpu_port_is_valid(&cpu_port[cpu]), | |
151 | "CPU %u does not have an associated CCI port\n", | |
152 | cpu); | |
153 | } | |
154 | } | |
155 | /* | |
156 | * Functions to enable/disable a CCI interconnect slave port | |
157 | * | |
158 | * They are called by low-level power management code to disable slave | |
159 | * interfaces snoops and DVM broadcast. | |
160 | * Since they may execute with cache data allocation disabled and | |
161 | * after the caches have been cleaned and invalidated the functions provide | |
162 | * no explicit locking since they may run with D-cache disabled, so normal | |
163 | * cacheable kernel locks based on ldrex/strex may not work. | |
164 | * Locking has to be provided by BSP implementations to ensure proper | |
165 | * operations. | |
166 | */ | |
167 | ||
168 | /** | |
169 | * cci_port_control() - function to control a CCI port | |
170 | * | |
171 | * @port: index of the port to setup | |
172 | * @enable: if true enables the port, if false disables it | |
173 | */ | |
174 | static void notrace cci_port_control(unsigned int port, bool enable) | |
175 | { | |
176 | void __iomem *base = ports[port].base; | |
177 | ||
178 | writel_relaxed(enable ? CCI_ENABLE_REQ : 0, base + CCI_PORT_CTRL); | |
179 | /* | |
180 | * This function is called from power down procedures | |
181 | * and must not execute any instruction that might | |
182 | * cause the processor to be put in a quiescent state | |
183 | * (eg wfi). Hence, cpu_relax() can not be added to this | |
184 | * read loop to optimize power, since it might hide possibly | |
185 | * disruptive operations. | |
186 | */ | |
187 | while (readl_relaxed(cci_ctrl_base + CCI_CTRL_STATUS) & 0x1) | |
188 | ; | |
189 | } | |
190 | ||
191 | /** | |
192 | * cci_disable_port_by_cpu() - function to disable a CCI port by CPU | |
193 | * reference | |
194 | * | |
195 | * @mpidr: mpidr of the CPU whose CCI port should be disabled | |
196 | * | |
197 | * Disabling a CCI port for a CPU implies disabling the CCI port | |
198 | * controlling that CPU cluster. Code disabling CPU CCI ports | |
199 | * must make sure that the CPU running the code is the last active CPU | |
200 | * in the cluster ie all other CPUs are quiescent in a low power state. | |
201 | * | |
202 | * Return: | |
203 | * 0 on success | |
204 | * -ENODEV on port look-up failure | |
205 | */ | |
206 | int notrace cci_disable_port_by_cpu(u64 mpidr) | |
207 | { | |
208 | int cpu; | |
209 | bool is_valid; | |
210 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) { | |
211 | is_valid = cpu_port_is_valid(&cpu_port[cpu]); | |
212 | if (is_valid && cpu_port_match(&cpu_port[cpu], mpidr)) { | |
213 | cci_port_control(cpu_port[cpu].port, false); | |
214 | return 0; | |
215 | } | |
216 | } | |
217 | return -ENODEV; | |
218 | } | |
219 | EXPORT_SYMBOL_GPL(cci_disable_port_by_cpu); | |
220 | ||
62158f81 NP |
221 | /** |
222 | * cci_enable_port_for_self() - enable a CCI port for calling CPU | |
223 | * | |
224 | * Enabling a CCI port for the calling CPU implies enabling the CCI | |
225 | * port controlling that CPU's cluster. Caller must make sure that the | |
226 | * CPU running the code is the first active CPU in the cluster and all | |
227 | * other CPUs are quiescent in a low power state or waiting for this CPU | |
228 | * to complete the CCI initialization. | |
229 | * | |
230 | * Because this is called when the MMU is still off and with no stack, | |
231 | * the code must be position independent and ideally rely on callee | |
232 | * clobbered registers only. To achieve this we must code this function | |
233 | * entirely in assembler. | |
234 | * | |
235 | * On success this returns with the proper CCI port enabled. In case of | |
236 | * any failure this never returns as the inability to enable the CCI is | |
237 | * fatal and there is no possible recovery at this stage. | |
238 | */ | |
239 | asmlinkage void __naked cci_enable_port_for_self(void) | |
240 | { | |
241 | asm volatile ("\n" | |
f4902492 | 242 | " .arch armv7-a\n" |
62158f81 NP |
243 | " mrc p15, 0, r0, c0, c0, 5 @ get MPIDR value \n" |
244 | " and r0, r0, #"__stringify(MPIDR_HWID_BITMASK)" \n" | |
245 | " adr r1, 5f \n" | |
246 | " ldr r2, [r1] \n" | |
247 | " add r1, r1, r2 @ &cpu_port \n" | |
248 | " add ip, r1, %[sizeof_cpu_port] \n" | |
249 | ||
250 | /* Loop over the cpu_port array looking for a matching MPIDR */ | |
251 | "1: ldr r2, [r1, %[offsetof_cpu_port_mpidr_lsb]] \n" | |
252 | " cmp r2, r0 @ compare MPIDR \n" | |
253 | " bne 2f \n" | |
254 | ||
255 | /* Found a match, now test port validity */ | |
256 | " ldr r3, [r1, %[offsetof_cpu_port_port]] \n" | |
257 | " tst r3, #"__stringify(PORT_VALID)" \n" | |
258 | " bne 3f \n" | |
259 | ||
260 | /* no match, loop with the next cpu_port entry */ | |
261 | "2: add r1, r1, %[sizeof_struct_cpu_port] \n" | |
262 | " cmp r1, ip @ done? \n" | |
263 | " blo 1b \n" | |
264 | ||
265 | /* CCI port not found -- cheaply try to stall this CPU */ | |
266 | "cci_port_not_found: \n" | |
267 | " wfi \n" | |
268 | " wfe \n" | |
269 | " b cci_port_not_found \n" | |
270 | ||
271 | /* Use matched port index to look up the corresponding ports entry */ | |
272 | "3: bic r3, r3, #"__stringify(PORT_VALID)" \n" | |
273 | " adr r0, 6f \n" | |
274 | " ldmia r0, {r1, r2} \n" | |
275 | " sub r1, r1, r0 @ virt - phys \n" | |
276 | " ldr r0, [r0, r2] @ *(&ports) \n" | |
277 | " mov r2, %[sizeof_struct_ace_port] \n" | |
278 | " mla r0, r2, r3, r0 @ &ports[index] \n" | |
279 | " sub r0, r0, r1 @ virt_to_phys() \n" | |
280 | ||
281 | /* Enable the CCI port */ | |
282 | " ldr r0, [r0, %[offsetof_port_phys]] \n" | |
283 | " mov r3, #"__stringify(CCI_ENABLE_REQ)" \n" | |
284 | " str r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n" | |
285 | ||
286 | /* poll the status reg for completion */ | |
287 | " adr r1, 7f \n" | |
288 | " ldr r0, [r1] \n" | |
289 | " ldr r0, [r0, r1] @ cci_ctrl_base \n" | |
290 | "4: ldr r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n" | |
291 | " tst r1, #1 \n" | |
292 | " bne 4b \n" | |
293 | ||
294 | " mov r0, #0 \n" | |
295 | " bx lr \n" | |
296 | ||
297 | " .align 2 \n" | |
298 | "5: .word cpu_port - . \n" | |
299 | "6: .word . \n" | |
300 | " .word ports - 6b \n" | |
301 | "7: .word cci_ctrl_phys - . \n" | |
302 | : : | |
303 | [sizeof_cpu_port] "i" (sizeof(cpu_port)), | |
304 | #ifndef __ARMEB__ | |
305 | [offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)), | |
306 | #else | |
307 | [offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)+4), | |
308 | #endif | |
309 | [offsetof_cpu_port_port] "i" (offsetof(struct cpu_port, port)), | |
310 | [sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)), | |
311 | [sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)), | |
312 | [offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) ); | |
313 | ||
314 | unreachable(); | |
315 | } | |
316 | ||
ed69bdd8 LP |
317 | /** |
318 | * __cci_control_port_by_device() - function to control a CCI port by device | |
319 | * reference | |
320 | * | |
321 | * @dn: device node pointer of the device whose CCI port should be | |
322 | * controlled | |
323 | * @enable: if true enables the port, if false disables it | |
324 | * | |
325 | * Return: | |
326 | * 0 on success | |
327 | * -ENODEV on port look-up failure | |
328 | */ | |
329 | int notrace __cci_control_port_by_device(struct device_node *dn, bool enable) | |
330 | { | |
331 | int port; | |
332 | ||
333 | if (!dn) | |
334 | return -ENODEV; | |
335 | ||
336 | port = __cci_ace_get_port(dn, ACE_LITE_PORT); | |
337 | if (WARN_ONCE(port < 0, "node %s ACE lite port look-up failure\n", | |
338 | dn->full_name)) | |
339 | return -ENODEV; | |
340 | cci_port_control(port, enable); | |
341 | return 0; | |
342 | } | |
343 | EXPORT_SYMBOL_GPL(__cci_control_port_by_device); | |
344 | ||
345 | /** | |
346 | * __cci_control_port_by_index() - function to control a CCI port by port index | |
347 | * | |
348 | * @port: port index previously retrieved with cci_ace_get_port() | |
349 | * @enable: if true enables the port, if false disables it | |
350 | * | |
351 | * Return: | |
352 | * 0 on success | |
353 | * -ENODEV on port index out of range | |
354 | * -EPERM if operation carried out on an ACE PORT | |
355 | */ | |
356 | int notrace __cci_control_port_by_index(u32 port, bool enable) | |
357 | { | |
358 | if (port >= nb_cci_ports || ports[port].type == ACE_INVALID_PORT) | |
359 | return -ENODEV; | |
360 | /* | |
361 | * CCI control for ports connected to CPUS is extremely fragile | |
362 | * and must be made to go through a specific and controlled | |
363 | * interface (ie cci_disable_port_by_cpu(); control by general purpose | |
364 | * indexing is therefore disabled for ACE ports. | |
365 | */ | |
366 | if (ports[port].type == ACE_PORT) | |
367 | return -EPERM; | |
368 | ||
369 | cci_port_control(port, enable); | |
370 | return 0; | |
371 | } | |
372 | EXPORT_SYMBOL_GPL(__cci_control_port_by_index); | |
373 | ||
374 | static const struct cci_nb_ports cci400_ports = { | |
375 | .nb_ace = 2, | |
376 | .nb_ace_lite = 3 | |
377 | }; | |
378 | ||
379 | static const struct of_device_id arm_cci_matches[] = { | |
380 | {.compatible = "arm,cci-400", .data = &cci400_ports }, | |
381 | {}, | |
382 | }; | |
383 | ||
384 | static const struct of_device_id arm_cci_ctrl_if_matches[] = { | |
385 | {.compatible = "arm,cci-400-ctrl-if", }, | |
386 | {}, | |
387 | }; | |
388 | ||
389 | static int __init cci_probe(void) | |
390 | { | |
391 | struct cci_nb_ports const *cci_config; | |
392 | int ret, i, nb_ace = 0, nb_ace_lite = 0; | |
393 | struct device_node *np, *cp; | |
62158f81 | 394 | struct resource res; |
ed69bdd8 LP |
395 | const char *match_str; |
396 | bool is_ace; | |
397 | ||
398 | np = of_find_matching_node(NULL, arm_cci_matches); | |
399 | if (!np) | |
400 | return -ENODEV; | |
401 | ||
402 | cci_config = of_match_node(arm_cci_matches, np)->data; | |
403 | if (!cci_config) | |
404 | return -ENODEV; | |
405 | ||
406 | nb_cci_ports = cci_config->nb_ace + cci_config->nb_ace_lite; | |
407 | ||
408 | ports = kcalloc(sizeof(*ports), nb_cci_ports, GFP_KERNEL); | |
409 | if (!ports) | |
410 | return -ENOMEM; | |
411 | ||
62158f81 NP |
412 | ret = of_address_to_resource(np, 0, &res); |
413 | if (!ret) { | |
414 | cci_ctrl_base = ioremap(res.start, resource_size(&res)); | |
415 | cci_ctrl_phys = res.start; | |
416 | } | |
417 | if (ret || !cci_ctrl_base) { | |
ed69bdd8 LP |
418 | WARN(1, "unable to ioremap CCI ctrl\n"); |
419 | ret = -ENXIO; | |
420 | goto memalloc_err; | |
421 | } | |
422 | ||
423 | for_each_child_of_node(np, cp) { | |
424 | if (!of_match_node(arm_cci_ctrl_if_matches, cp)) | |
425 | continue; | |
426 | ||
427 | i = nb_ace + nb_ace_lite; | |
428 | ||
429 | if (i >= nb_cci_ports) | |
430 | break; | |
431 | ||
432 | if (of_property_read_string(cp, "interface-type", | |
433 | &match_str)) { | |
434 | WARN(1, "node %s missing interface-type property\n", | |
435 | cp->full_name); | |
436 | continue; | |
437 | } | |
438 | is_ace = strcmp(match_str, "ace") == 0; | |
439 | if (!is_ace && strcmp(match_str, "ace-lite")) { | |
440 | WARN(1, "node %s containing invalid interface-type property, skipping it\n", | |
441 | cp->full_name); | |
442 | continue; | |
443 | } | |
444 | ||
62158f81 NP |
445 | ret = of_address_to_resource(cp, 0, &res); |
446 | if (!ret) { | |
447 | ports[i].base = ioremap(res.start, resource_size(&res)); | |
448 | ports[i].phys = res.start; | |
449 | } | |
450 | if (ret || !ports[i].base) { | |
ed69bdd8 LP |
451 | WARN(1, "unable to ioremap CCI port %d\n", i); |
452 | continue; | |
453 | } | |
454 | ||
455 | if (is_ace) { | |
456 | if (WARN_ON(nb_ace >= cci_config->nb_ace)) | |
457 | continue; | |
458 | ports[i].type = ACE_PORT; | |
459 | ++nb_ace; | |
460 | } else { | |
461 | if (WARN_ON(nb_ace_lite >= cci_config->nb_ace_lite)) | |
462 | continue; | |
463 | ports[i].type = ACE_LITE_PORT; | |
464 | ++nb_ace_lite; | |
465 | } | |
466 | ports[i].dn = cp; | |
467 | } | |
468 | ||
469 | /* initialize a stashed array of ACE ports to speed-up look-up */ | |
470 | cci_ace_init_ports(); | |
471 | ||
472 | /* | |
473 | * Multi-cluster systems may need this data when non-coherent, during | |
474 | * cluster power-up/power-down. Make sure it reaches main memory. | |
475 | */ | |
476 | sync_cache_w(&cci_ctrl_base); | |
62158f81 | 477 | sync_cache_w(&cci_ctrl_phys); |
ed69bdd8 LP |
478 | sync_cache_w(&ports); |
479 | sync_cache_w(&cpu_port); | |
480 | __sync_cache_range_w(ports, sizeof(*ports) * nb_cci_ports); | |
481 | pr_info("ARM CCI driver probed\n"); | |
482 | return 0; | |
483 | ||
484 | memalloc_err: | |
485 | ||
486 | kfree(ports); | |
487 | return ret; | |
488 | } | |
489 | ||
490 | static int cci_init_status = -EAGAIN; | |
491 | static DEFINE_MUTEX(cci_probing); | |
492 | ||
493 | static int __init cci_init(void) | |
494 | { | |
495 | if (cci_init_status != -EAGAIN) | |
496 | return cci_init_status; | |
497 | ||
498 | mutex_lock(&cci_probing); | |
499 | if (cci_init_status == -EAGAIN) | |
500 | cci_init_status = cci_probe(); | |
501 | mutex_unlock(&cci_probing); | |
502 | return cci_init_status; | |
503 | } | |
504 | ||
505 | /* | |
506 | * To sort out early init calls ordering a helper function is provided to | |
507 | * check if the CCI driver has beed initialized. Function check if the driver | |
508 | * has been initialized, if not it calls the init function that probes | |
509 | * the driver and updates the return value. | |
510 | */ | |
511 | bool __init cci_probed(void) | |
512 | { | |
513 | return cci_init() == 0; | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(cci_probed); | |
516 | ||
517 | early_initcall(cci_init); | |
518 | MODULE_LICENSE("GPL"); | |
519 | MODULE_DESCRIPTION("ARM CCI support"); |