1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
4 *
5 * Copyright (C) 2012 Marvell
6 *
7 * Yehuda Yitschak <yehuday@marvell.com>
8 * Gregory Clement <gregory.clement@free-electrons.com>
9 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
10 *
11 * The Armada 370 and Armada XP SOCs have a power management service
12 * unit which is responsible for powering down and waking up CPUs and
13 * other SOC units
14 */
15
16#define pr_fmt(fmt) "mvebu-pmsu: " fmt
17
18#include <linux/clk.h>
19#include <linux/cpu_pm.h>
20#include <linux/delay.h>
21#include <linux/init.h>
22#include <linux/io.h>
23#include <linux/kernel.h>
24#include <linux/mbus.h>
25#include <linux/mvebu-pmsu.h>
26#include <linux/of.h>
27#include <linux/of_address.h>
28#include <linux/platform_device.h>
29#include <linux/resource.h>
30#include <linux/slab.h>
31#include <linux/smp.h>
32#include <asm/cacheflush.h>
33#include <asm/cp15.h>
34#include <asm/smp_scu.h>
35#include <asm/smp_plat.h>
36#include <asm/suspend.h>
37#include <asm/tlbflush.h>
38#include "common.h"
39#include "pmsu.h"
40
41#define PMSU_BASE_OFFSET 0x100
42#define PMSU_REG_SIZE 0x1000
43
44/* PMSU MP registers */
45#define PMSU_CONTROL_AND_CONFIG(cpu) ((cpu * 0x100) + 0x104)
46#define PMSU_CONTROL_AND_CONFIG_DFS_REQ BIT(18)
47#define PMSU_CONTROL_AND_CONFIG_PWDDN_REQ BIT(16)
48#define PMSU_CONTROL_AND_CONFIG_L2_PWDDN BIT(20)
49
50#define PMSU_CPU_POWER_DOWN_CONTROL(cpu) ((cpu * 0x100) + 0x108)
51
52#define PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP BIT(0)
53
54#define PMSU_STATUS_AND_MASK(cpu) ((cpu * 0x100) + 0x10c)
55#define PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT BIT(16)
56#define PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT BIT(17)
57#define PMSU_STATUS_AND_MASK_IRQ_WAKEUP BIT(20)
58#define PMSU_STATUS_AND_MASK_FIQ_WAKEUP BIT(21)
59#define PMSU_STATUS_AND_MASK_DBG_WAKEUP BIT(22)
60#define PMSU_STATUS_AND_MASK_IRQ_MASK BIT(24)
61#define PMSU_STATUS_AND_MASK_FIQ_MASK BIT(25)
62
63#define PMSU_EVENT_STATUS_AND_MASK(cpu) ((cpu * 0x100) + 0x120)
64#define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE BIT(1)
65#define PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK BIT(17)
66
67#define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x124)
68
69/* PMSU fabric registers */
70#define L2C_NFABRIC_PM_CTL 0x4
71#define L2C_NFABRIC_PM_CTL_PWR_DOWN BIT(20)
72
73/* PMSU delay registers */
74#define PMSU_POWERDOWN_DELAY 0xF04
75#define PMSU_POWERDOWN_DELAY_PMU BIT(1)
76#define PMSU_POWERDOWN_DELAY_MASK 0xFFFE
77#define PMSU_DFLT_ARMADA38X_DELAY 0x64
78
79/* CA9 MPcore SoC Control registers */
80
81#define MPCORE_RESET_CTL 0x64
82#define MPCORE_RESET_CTL_L2 BIT(0)
83#define MPCORE_RESET_CTL_DEBUG BIT(16)
84
85#define SRAM_PHYS_BASE 0xFFFF0000
86#define BOOTROM_BASE 0xFFF00000
87#define BOOTROM_SIZE 0x100000
88
89#define ARMADA_370_CRYPT0_ENG_TARGET 0x9
90#define ARMADA_370_CRYPT0_ENG_ATTR 0x1
91
92extern void ll_disable_coherency(void);
93extern void ll_enable_coherency(void);
94
95extern void armada_370_xp_cpu_resume(void);
96extern void armada_38x_cpu_resume(void);
97
98static phys_addr_t pmsu_mp_phys_base;
99static void __iomem *pmsu_mp_base;
100
101static void *mvebu_cpu_resume;
102
103static const struct of_device_id of_pmsu_table[] = {
104 { .compatible = "marvell,armada-370-pmsu", },
105 { .compatible = "marvell,armada-370-xp-pmsu", },
106 { .compatible = "marvell,armada-380-pmsu", },
107 { /* end of list */ },
108};
109
110void mvebu_pmsu_set_cpu_boot_addr(int hw_cpu, void *boot_addr)
111{
112 writel(__pa_symbol(boot_addr), addr: pmsu_mp_base +
113 PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
114}
115
116extern unsigned char mvebu_boot_wa_start[];
117extern unsigned char mvebu_boot_wa_end[];
118
119/*
120 * This function sets up the boot address workaround needed for SMP
121 * boot on Armada 375 Z1 and cpuidle on Armada 370. It unmaps the
122 * BootROM Mbus window, and instead remaps a crypto SRAM into which a
123 * custom piece of code is copied to replace the problematic BootROM.
124 */
125int mvebu_setup_boot_addr_wa(unsigned int crypto_eng_target,
126 unsigned int crypto_eng_attribute,
127 phys_addr_t resume_addr_reg)
128{
129 void __iomem *sram_virt_base;
130 u32 code_len = mvebu_boot_wa_end - mvebu_boot_wa_start;
131
132 mvebu_mbus_del_window(BOOTROM_BASE, BOOTROM_SIZE);
133 mvebu_mbus_add_window_by_id(crypto_eng_target, crypto_eng_attribute,
134 SRAM_PHYS_BASE, SZ_64K);
135
136 sram_virt_base = ioremap(SRAM_PHYS_BASE, SZ_64K);
137 if (!sram_virt_base) {
138 pr_err("Unable to map SRAM to setup the boot address WA\n");
139 return -ENOMEM;
140 }
141
142 memcpy(sram_virt_base, &mvebu_boot_wa_start, code_len);
143
144 /*
145 * The last word of the code copied in SRAM must contain the
146 * physical base address of the PMSU register. We
147 * intentionally store this address in the native endianness
148 * of the system.
149 */
150 __raw_writel(val: (unsigned long)resume_addr_reg,
151 addr: sram_virt_base + code_len - 4);
152
153 iounmap(addr: sram_virt_base);
154
155 return 0;
156}
157
158static int __init mvebu_v7_pmsu_init(void)
159{
160 struct device_node *np;
161 struct resource res;
162 int ret = 0;
163
164 np = of_find_matching_node(NULL, matches: of_pmsu_table);
165 if (!np)
166 return 0;
167
168 pr_info("Initializing Power Management Service Unit\n");
169
170 if (of_address_to_resource(dev: np, index: 0, r: &res)) {
171 pr_err("unable to get resource\n");
172 ret = -ENOENT;
173 goto out;
174 }
175
176 if (of_device_is_compatible(device: np, "marvell,armada-370-xp-pmsu")) {
177 pr_warn(FW_WARN "deprecated pmsu binding\n");
178 res.start = res.start - PMSU_BASE_OFFSET;
179 res.end = res.start + PMSU_REG_SIZE - 1;
180 }
181
182 if (!request_mem_region(res.start, resource_size(&res),
183 np->full_name)) {
184 pr_err("unable to request region\n");
185 ret = -EBUSY;
186 goto out;
187 }
188
189 pmsu_mp_phys_base = res.start;
190
191 pmsu_mp_base = ioremap(offset: res.start, size: resource_size(res: &res));
192 if (!pmsu_mp_base) {
193 pr_err("unable to map registers\n");
194 release_mem_region(res.start, resource_size(&res));
195 ret = -ENOMEM;
196 goto out;
197 }
198
199 out:
200 of_node_put(node: np);
201 return ret;
202}
203
204static void mvebu_v7_pmsu_enable_l2_powerdown_onidle(void)
205{
206 u32 reg;
207
208 if (pmsu_mp_base == NULL)
209 return;
210
211 /* Enable L2 & Fabric powerdown in Deep-Idle mode - Fabric */
212 reg = readl(addr: pmsu_mp_base + L2C_NFABRIC_PM_CTL);
213 reg |= L2C_NFABRIC_PM_CTL_PWR_DOWN;
214 writel(val: reg, addr: pmsu_mp_base + L2C_NFABRIC_PM_CTL);
215}
216
217enum pmsu_idle_prepare_flags {
218 PMSU_PREPARE_NORMAL = 0,
219 PMSU_PREPARE_DEEP_IDLE = BIT(0),
220 PMSU_PREPARE_SNOOP_DISABLE = BIT(1),
221};
222
223/* No locking is needed because we only access per-CPU registers */
224static int mvebu_v7_pmsu_idle_prepare(unsigned long flags)
225{
226 unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
227 u32 reg;
228
229 if (pmsu_mp_base == NULL)
230 return -EINVAL;
231
232 /*
233 * Adjust the PMSU configuration to wait for WFI signal, enable
234 * IRQ and FIQ as wakeup events, set wait for snoop queue empty
235 * indication and mask IRQ and FIQ from CPU
236 */
237 reg = readl(addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
238 reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT |
239 PMSU_STATUS_AND_MASK_IRQ_WAKEUP |
240 PMSU_STATUS_AND_MASK_FIQ_WAKEUP |
241 PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT |
242 PMSU_STATUS_AND_MASK_IRQ_MASK |
243 PMSU_STATUS_AND_MASK_FIQ_MASK;
244 writel(val: reg, addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
245
246 reg = readl(addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
247 /* ask HW to power down the L2 Cache if needed */
248 if (flags & PMSU_PREPARE_DEEP_IDLE)
249 reg |= PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
250
251 /* request power down */
252 reg |= PMSU_CONTROL_AND_CONFIG_PWDDN_REQ;
253 writel(val: reg, addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
254
255 if (flags & PMSU_PREPARE_SNOOP_DISABLE) {
256 /* Disable snoop disable by HW - SW is taking care of it */
257 reg = readl(addr: pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
258 reg |= PMSU_CPU_POWER_DOWN_DIS_SNP_Q_SKIP;
259 writel(val: reg, addr: pmsu_mp_base + PMSU_CPU_POWER_DOWN_CONTROL(hw_cpu));
260 }
261
262 return 0;
263}
264
265int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
266{
267 unsigned long flags = PMSU_PREPARE_SNOOP_DISABLE;
268 int ret;
269
270 if (deepidle)
271 flags |= PMSU_PREPARE_DEEP_IDLE;
272
273 ret = mvebu_v7_pmsu_idle_prepare(flags);
274 if (ret)
275 return ret;
276
277 v7_exit_coherency_flush(all);
278
279 ll_disable_coherency();
280
281 dsb();
282
283 wfi();
284
285 /* If we are here, wfi failed. As processors run out of
286 * coherency for some time, tlbs might be stale, so flush them
287 */
288 local_flush_tlb_all();
289
290 ll_enable_coherency();
291
292 /* Test the CR_C bit and set it if it was cleared */
293 asm volatile(
294 ".arch armv7-a\n\t"
295 "mrc p15, 0, r0, c1, c0, 0 \n\t"
296 "tst r0, %0 \n\t"
297 "orreq r0, r0, #(1 << 2) \n\t"
298 "mcreq p15, 0, r0, c1, c0, 0 \n\t"
299 "isb "
300 : : "Ir" (CR_C) : "r0");
301
302 pr_debug("Failed to suspend the system\n");
303
304 return 0;
305}
306
307static int armada_370_xp_cpu_suspend(unsigned long deepidle)
308{
309 return cpu_suspend(deepidle, armada_370_xp_pmsu_idle_enter);
310}
311
312int armada_38x_do_cpu_suspend(unsigned long deepidle)
313{
314 unsigned long flags = 0;
315
316 if (deepidle)
317 flags |= PMSU_PREPARE_DEEP_IDLE;
318
319 mvebu_v7_pmsu_idle_prepare(flags);
320 /*
321 * Already flushed cache, but do it again as the outer cache
322 * functions dirty the cache with spinlocks
323 */
324 v7_exit_coherency_flush(louis);
325
326 scu_power_mode(mvebu_get_scu_base(), SCU_PM_POWEROFF);
327
328 cpu_do_idle();
329
330 return 1;
331}
332
333static int armada_38x_cpu_suspend(unsigned long deepidle)
334{
335 return cpu_suspend(false, armada_38x_do_cpu_suspend);
336}
337
338/* No locking is needed because we only access per-CPU registers */
339void mvebu_v7_pmsu_idle_exit(void)
340{
341 unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
342 u32 reg;
343
344 if (pmsu_mp_base == NULL)
345 return;
346 /* cancel ask HW to power down the L2 Cache if possible */
347 reg = readl(addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
348 reg &= ~PMSU_CONTROL_AND_CONFIG_L2_PWDDN;
349 writel(val: reg, addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(hw_cpu));
350
351 /* cancel Enable wakeup events and mask interrupts */
352 reg = readl(addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
353 reg &= ~(PMSU_STATUS_AND_MASK_IRQ_WAKEUP | PMSU_STATUS_AND_MASK_FIQ_WAKEUP);
354 reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
355 reg &= ~PMSU_STATUS_AND_MASK_SNP_Q_EMPTY_WAIT;
356 reg &= ~(PMSU_STATUS_AND_MASK_IRQ_MASK | PMSU_STATUS_AND_MASK_FIQ_MASK);
357 writel(val: reg, addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(hw_cpu));
358}
359
360static int mvebu_v7_cpu_pm_notify(struct notifier_block *self,
361 unsigned long action, void *hcpu)
362{
363 if (action == CPU_PM_ENTER) {
364 unsigned int hw_cpu = cpu_logical_map(smp_processor_id());
365 mvebu_pmsu_set_cpu_boot_addr(hw_cpu, boot_addr: mvebu_cpu_resume);
366 } else if (action == CPU_PM_EXIT) {
367 mvebu_v7_pmsu_idle_exit();
368 }
369
370 return NOTIFY_OK;
371}
372
373static struct notifier_block mvebu_v7_cpu_pm_notifier = {
374 .notifier_call = mvebu_v7_cpu_pm_notify,
375};
376
377static struct platform_device mvebu_v7_cpuidle_device;
378
379static int broken_idle(struct device_node *np)
380{
381 if (of_property_read_bool(np, propname: "broken-idle")) {
382 pr_warn("CPU idle is currently broken: disabling\n");
383 return 1;
384 }
385
386 return 0;
387}
388
389static __init int armada_370_cpuidle_init(void)
390{
391 struct device_node *np;
392 phys_addr_t redirect_reg;
393
394 np = of_find_compatible_node(NULL, NULL, compat: "marvell,coherency-fabric");
395 if (!np)
396 return -ENODEV;
397
398 if (broken_idle(np))
399 goto end;
400
401 /*
402 * On Armada 370, there is "a slow exit process from the deep
403 * idle state due to heavy L1/L2 cache cleanup operations
404 * performed by the BootROM software". To avoid this, we
405 * replace the restart code of the bootrom by a a simple jump
406 * to the boot address. Then the code located at this boot
407 * address will take care of the initialization.
408 */
409 redirect_reg = pmsu_mp_phys_base + PMSU_BOOT_ADDR_REDIRECT_OFFSET(0);
410 mvebu_setup_boot_addr_wa(ARMADA_370_CRYPT0_ENG_TARGET,
411 ARMADA_370_CRYPT0_ENG_ATTR,
412 resume_addr_reg: redirect_reg);
413
414 mvebu_cpu_resume = armada_370_xp_cpu_resume;
415 mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
416 mvebu_v7_cpuidle_device.name = "cpuidle-armada-370";
417
418end:
419 of_node_put(node: np);
420 return 0;
421}
422
423static __init int armada_38x_cpuidle_init(void)
424{
425 struct device_node *np;
426 void __iomem *mpsoc_base;
427 u32 reg;
428
429 pr_warn("CPU idle is currently broken on Armada 38x: disabling\n");
430 return 0;
431
432 np = of_find_compatible_node(NULL, NULL,
433 compat: "marvell,armada-380-coherency-fabric");
434 if (!np)
435 return -ENODEV;
436
437 if (broken_idle(np))
438 goto end;
439
440 of_node_put(node: np);
441
442 np = of_find_compatible_node(NULL, NULL,
443 compat: "marvell,armada-380-mpcore-soc-ctrl");
444 if (!np)
445 return -ENODEV;
446 mpsoc_base = of_iomap(node: np, index: 0);
447 BUG_ON(!mpsoc_base);
448
449 /* Set up reset mask when powering down the cpus */
450 reg = readl(addr: mpsoc_base + MPCORE_RESET_CTL);
451 reg |= MPCORE_RESET_CTL_L2;
452 reg |= MPCORE_RESET_CTL_DEBUG;
453 writel(val: reg, addr: mpsoc_base + MPCORE_RESET_CTL);
454 iounmap(addr: mpsoc_base);
455
456 /* Set up delay */
457 reg = readl(addr: pmsu_mp_base + PMSU_POWERDOWN_DELAY);
458 reg &= ~PMSU_POWERDOWN_DELAY_MASK;
459 reg |= PMSU_DFLT_ARMADA38X_DELAY;
460 reg |= PMSU_POWERDOWN_DELAY_PMU;
461 writel(val: reg, addr: pmsu_mp_base + PMSU_POWERDOWN_DELAY);
462
463 mvebu_cpu_resume = armada_38x_cpu_resume;
464 mvebu_v7_cpuidle_device.dev.platform_data = armada_38x_cpu_suspend;
465 mvebu_v7_cpuidle_device.name = "cpuidle-armada-38x";
466
467end:
468 of_node_put(node: np);
469 return 0;
470}
471
472static __init int armada_xp_cpuidle_init(void)
473{
474 struct device_node *np;
475
476 np = of_find_compatible_node(NULL, NULL, compat: "marvell,coherency-fabric");
477 if (!np)
478 return -ENODEV;
479
480 if (broken_idle(np))
481 goto end;
482
483 mvebu_cpu_resume = armada_370_xp_cpu_resume;
484 mvebu_v7_cpuidle_device.dev.platform_data = armada_370_xp_cpu_suspend;
485 mvebu_v7_cpuidle_device.name = "cpuidle-armada-xp";
486
487end:
488 of_node_put(node: np);
489 return 0;
490}
491
492static int __init mvebu_v7_cpu_pm_init(void)
493{
494 struct device_node *np;
495 int ret;
496
497 np = of_find_matching_node(NULL, matches: of_pmsu_table);
498 if (!np)
499 return 0;
500 of_node_put(node: np);
501
502 /*
503 * Currently the CPU idle support for Armada 38x is broken, as
504 * the CPU hotplug uses some of the CPU idle functions it is
505 * broken too, so let's disable it
506 */
507 if (of_machine_is_compatible(compat: "marvell,armada380")) {
508 cpu_hotplug_disable();
509 pr_warn("CPU hotplug support is currently broken on Armada 38x: disabling\n");
510 }
511
512 if (of_machine_is_compatible(compat: "marvell,armadaxp"))
513 ret = armada_xp_cpuidle_init();
514 else if (of_machine_is_compatible(compat: "marvell,armada370"))
515 ret = armada_370_cpuidle_init();
516 else if (of_machine_is_compatible(compat: "marvell,armada380"))
517 ret = armada_38x_cpuidle_init();
518 else
519 return 0;
520
521 if (ret)
522 return ret;
523
524 mvebu_v7_pmsu_enable_l2_powerdown_onidle();
525 if (mvebu_v7_cpuidle_device.name)
526 platform_device_register(&mvebu_v7_cpuidle_device);
527 cpu_pm_register_notifier(nb: &mvebu_v7_cpu_pm_notifier);
528
529 return 0;
530}
531
532arch_initcall(mvebu_v7_cpu_pm_init);
533early_initcall(mvebu_v7_pmsu_init);
534
535static void mvebu_pmsu_dfs_request_local(void *data)
536{
537 u32 reg;
538 u32 cpu = smp_processor_id();
539 unsigned long flags;
540
541 local_irq_save(flags);
542
543 /* Prepare to enter idle */
544 reg = readl(addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
545 reg |= PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT |
546 PMSU_STATUS_AND_MASK_IRQ_MASK |
547 PMSU_STATUS_AND_MASK_FIQ_MASK;
548 writel(val: reg, addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
549
550 /* Request the DFS transition */
551 reg = readl(addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
552 reg |= PMSU_CONTROL_AND_CONFIG_DFS_REQ;
553 writel(val: reg, addr: pmsu_mp_base + PMSU_CONTROL_AND_CONFIG(cpu));
554
555 /* The fact of entering idle will trigger the DFS transition */
556 wfi();
557
558 /*
559 * We're back from idle, the DFS transition has completed,
560 * clear the idle wait indication.
561 */
562 reg = readl(addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
563 reg &= ~PMSU_STATUS_AND_MASK_CPU_IDLE_WAIT;
564 writel(val: reg, addr: pmsu_mp_base + PMSU_STATUS_AND_MASK(cpu));
565
566 local_irq_restore(flags);
567}
568
569int mvebu_pmsu_dfs_request(int cpu)
570{
571 unsigned long timeout;
572 int hwcpu = cpu_logical_map(cpu);
573 u32 reg;
574
575 /* Clear any previous DFS DONE event */
576 reg = readl(addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
577 reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE;
578 writel(val: reg, addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
579
580 /* Mask the DFS done interrupt, since we are going to poll */
581 reg = readl(addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
582 reg |= PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
583 writel(val: reg, addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
584
585 /* Trigger the DFS on the appropriate CPU */
586 smp_call_function_single(cpuid: cpu, func: mvebu_pmsu_dfs_request_local,
587 NULL, wait: false);
588
589 /* Poll until the DFS done event is generated */
590 timeout = jiffies + HZ;
591 while (time_before(jiffies, timeout)) {
592 reg = readl(addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
593 if (reg & PMSU_EVENT_STATUS_AND_MASK_DFS_DONE)
594 break;
595 udelay(10);
596 }
597
598 if (time_after(jiffies, timeout))
599 return -ETIME;
600
601 /* Restore the DFS mask to its original state */
602 reg = readl(addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
603 reg &= ~PMSU_EVENT_STATUS_AND_MASK_DFS_DONE_MASK;
604 writel(val: reg, addr: pmsu_mp_base + PMSU_EVENT_STATUS_AND_MASK(hwcpu));
605
606 return 0;
607}
608

source code of linux/arch/arm/mach-mvebu/pmsu.c