1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
3 // http://www.samsung.com
4 //
5 // Cloned from linux/arch/arm/mach-vexpress/platsmp.c
6 //
7 // Copyright (C) 2002 ARM Ltd.
8 // All Rights Reserved
9
10 #include <linux/init.h>
11 #include <linux/errno.h>
12 #include <linux/delay.h>
13 #include <linux/jiffies.h>
14 #include <linux/smp.h>
15 #include <linux/io.h>
16 #include <linux/of_address.h>
17 #include <linux/soc/samsung/exynos-regs-pmu.h>
18
19 #include <asm/cacheflush.h>
20 #include <asm/cp15.h>
21 #include <asm/smp_plat.h>
22 #include <asm/smp_scu.h>
23 #include <asm/firmware.h>
24
25 #include "common.h"
26
27 extern void exynos4_secondary_startup(void);
28
29 /* XXX exynos_pen_release is cargo culted code - DO NOT COPY XXX */
30 volatile int exynos_pen_release = -1;
31
32 #ifdef CONFIG_HOTPLUG_CPU
cpu_leave_lowpower(u32 core_id)33 static inline void cpu_leave_lowpower(u32 core_id)
34 {
35 unsigned int v;
36
37 asm volatile(
38 "mrc p15, 0, %0, c1, c0, 0\n"
39 " orr %0, %0, %1\n"
40 " mcr p15, 0, %0, c1, c0, 0\n"
41 " mrc p15, 0, %0, c1, c0, 1\n"
42 " orr %0, %0, %2\n"
43 " mcr p15, 0, %0, c1, c0, 1\n"
44 : "=&r" (v)
45 : "Ir" (CR_C), "Ir" (0x40)
46 : "cc");
47 }
48
platform_do_lowpower(unsigned int cpu,int * spurious)49 static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
50 {
51 u32 mpidr = cpu_logical_map(cpu);
52 u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
53
54 for (;;) {
55
56 /* Turn the CPU off on next WFI instruction. */
57 exynos_cpu_power_down(core_id);
58
59 wfi();
60
61 if (exynos_pen_release == core_id) {
62 /*
63 * OK, proper wakeup, we're done
64 */
65 break;
66 }
67
68 /*
69 * Getting here, means that we have come out of WFI without
70 * having been woken up - this shouldn't happen
71 *
72 * Just note it happening - when we're woken, we can report
73 * its occurrence.
74 */
75 (*spurious)++;
76 }
77 }
78 #endif /* CONFIG_HOTPLUG_CPU */
79
80 /**
81 * exynos_core_power_down : power down the specified cpu
82 * @cpu : the cpu to power down
83 *
84 * Power down the specified cpu. The sequence must be finished by a
85 * call to cpu_do_idle()
86 *
87 */
exynos_cpu_power_down(int cpu)88 void exynos_cpu_power_down(int cpu)
89 {
90 u32 core_conf;
91
92 if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
93 /*
94 * Bypass power down for CPU0 during suspend. Check for
95 * the SYS_PWR_REG value to decide if we are suspending
96 * the system.
97 */
98 int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);
99
100 if (!(val & S5P_CORE_LOCAL_PWR_EN))
101 return;
102 }
103
104 core_conf = pmu_raw_readl(EXYNOS_ARM_CORE_CONFIGURATION(cpu));
105 core_conf &= ~S5P_CORE_LOCAL_PWR_EN;
106 pmu_raw_writel(core_conf, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
107 }
108
109 /**
110 * exynos_cpu_power_up : power up the specified cpu
111 * @cpu : the cpu to power up
112 *
113 * Power up the specified cpu
114 */
exynos_cpu_power_up(int cpu)115 void exynos_cpu_power_up(int cpu)
116 {
117 u32 core_conf = S5P_CORE_LOCAL_PWR_EN;
118
119 if (soc_is_exynos3250())
120 core_conf |= S5P_CORE_AUTOWAKEUP_EN;
121
122 pmu_raw_writel(core_conf,
123 EXYNOS_ARM_CORE_CONFIGURATION(cpu));
124 }
125
126 /**
127 * exynos_cpu_power_state : returns the power state of the cpu
128 * @cpu : the cpu to retrieve the power state from
129 *
130 */
exynos_cpu_power_state(int cpu)131 int exynos_cpu_power_state(int cpu)
132 {
133 return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
134 S5P_CORE_LOCAL_PWR_EN);
135 }
136
137 /**
138 * exynos_cluster_power_down : power down the specified cluster
139 * @cluster : the cluster to power down
140 */
exynos_cluster_power_down(int cluster)141 void exynos_cluster_power_down(int cluster)
142 {
143 pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
144 }
145
146 /**
147 * exynos_cluster_power_up : power up the specified cluster
148 * @cluster : the cluster to power up
149 */
exynos_cluster_power_up(int cluster)150 void exynos_cluster_power_up(int cluster)
151 {
152 pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
153 EXYNOS_COMMON_CONFIGURATION(cluster));
154 }
155
156 /**
157 * exynos_cluster_power_state : returns the power state of the cluster
158 * @cluster : the cluster to retrieve the power state from
159 *
160 */
exynos_cluster_power_state(int cluster)161 int exynos_cluster_power_state(int cluster)
162 {
163 return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
164 S5P_CORE_LOCAL_PWR_EN);
165 }
166
167 /**
168 * exynos_scu_enable : enables SCU for Cortex-A9 based system
169 */
exynos_scu_enable(void)170 void exynos_scu_enable(void)
171 {
172 struct device_node *np;
173 static void __iomem *scu_base;
174
175 if (!scu_base) {
176 np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
177 if (np) {
178 scu_base = of_iomap(np, 0);
179 of_node_put(np);
180 } else {
181 scu_base = ioremap(scu_a9_get_base(), SZ_4K);
182 }
183 }
184 scu_enable(scu_base);
185 }
186
cpu_boot_reg_base(void)187 static void __iomem *cpu_boot_reg_base(void)
188 {
189 if (soc_is_exynos4210() && exynos_rev() == EXYNOS4210_REV_1_1)
190 return pmu_base_addr + S5P_INFORM5;
191 return sysram_base_addr;
192 }
193
cpu_boot_reg(int cpu)194 static inline void __iomem *cpu_boot_reg(int cpu)
195 {
196 void __iomem *boot_reg;
197
198 boot_reg = cpu_boot_reg_base();
199 if (!boot_reg)
200 return IOMEM_ERR_PTR(-ENODEV);
201 if (soc_is_exynos4412())
202 boot_reg += 4*cpu;
203 else if (soc_is_exynos5420() || soc_is_exynos5800())
204 boot_reg += 4;
205 return boot_reg;
206 }
207
208 /*
209 * Set wake up by local power mode and execute software reset for given core.
210 *
211 * Currently this is needed only when booting secondary CPU on Exynos3250.
212 */
exynos_core_restart(u32 core_id)213 void exynos_core_restart(u32 core_id)
214 {
215 unsigned int timeout = 16;
216 u32 val;
217
218 if (!of_machine_is_compatible("samsung,exynos3250"))
219 return;
220
221 while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
222 timeout--;
223 udelay(10);
224 }
225 if (timeout == 0) {
226 pr_err("cpu core %u restart failed\n", core_id);
227 return;
228 }
229 udelay(10);
230
231 val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
232 val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
233 pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
234
235 pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
236 }
237
238 /*
239 * XXX CARGO CULTED CODE - DO NOT COPY XXX
240 *
241 * Write exynos_pen_release in a way that is guaranteed to be visible to
242 * all observers, irrespective of whether they're taking part in coherency
243 * or not. This is necessary for the hotplug code to work reliably.
244 */
exynos_write_pen_release(int val)245 static void exynos_write_pen_release(int val)
246 {
247 exynos_pen_release = val;
248 smp_wmb();
249 sync_cache_w(&exynos_pen_release);
250 }
251
252 static DEFINE_SPINLOCK(boot_lock);
253
exynos_secondary_init(unsigned int cpu)254 static void exynos_secondary_init(unsigned int cpu)
255 {
256 /*
257 * let the primary processor know we're out of the
258 * pen, then head off into the C entry point
259 */
260 exynos_write_pen_release(-1);
261
262 /*
263 * Synchronise with the boot thread.
264 */
265 spin_lock(&boot_lock);
266 spin_unlock(&boot_lock);
267 }
268
exynos_set_boot_addr(u32 core_id,unsigned long boot_addr)269 int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr)
270 {
271 int ret;
272
273 /*
274 * Try to set boot address using firmware first
275 * and fall back to boot register if it fails.
276 */
277 ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
278 if (ret && ret != -ENOSYS)
279 goto fail;
280 if (ret == -ENOSYS) {
281 void __iomem *boot_reg = cpu_boot_reg(core_id);
282
283 if (IS_ERR(boot_reg)) {
284 ret = PTR_ERR(boot_reg);
285 goto fail;
286 }
287 writel_relaxed(boot_addr, boot_reg);
288 ret = 0;
289 }
290 fail:
291 return ret;
292 }
293
exynos_get_boot_addr(u32 core_id,unsigned long * boot_addr)294 int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
295 {
296 int ret;
297
298 /*
299 * Try to get boot address using firmware first
300 * and fall back to boot register if it fails.
301 */
302 ret = call_firmware_op(get_cpu_boot_addr, core_id, boot_addr);
303 if (ret && ret != -ENOSYS)
304 goto fail;
305 if (ret == -ENOSYS) {
306 void __iomem *boot_reg = cpu_boot_reg(core_id);
307
308 if (IS_ERR(boot_reg)) {
309 ret = PTR_ERR(boot_reg);
310 goto fail;
311 }
312 *boot_addr = readl_relaxed(boot_reg);
313 ret = 0;
314 }
315 fail:
316 return ret;
317 }
318
exynos_boot_secondary(unsigned int cpu,struct task_struct * idle)319 static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
320 {
321 unsigned long timeout;
322 u32 mpidr = cpu_logical_map(cpu);
323 u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
324 int ret = -ENOSYS;
325
326 /*
327 * Set synchronisation state between this boot processor
328 * and the secondary one
329 */
330 spin_lock(&boot_lock);
331
332 /*
333 * The secondary processor is waiting to be released from
334 * the holding pen - release it, then wait for it to flag
335 * that it has been released by resetting exynos_pen_release.
336 *
337 * Note that "exynos_pen_release" is the hardware CPU core ID, whereas
338 * "cpu" is Linux's internal ID.
339 */
340 exynos_write_pen_release(core_id);
341
342 if (!exynos_cpu_power_state(core_id)) {
343 exynos_cpu_power_up(core_id);
344 timeout = 10;
345
346 /* wait max 10 ms until cpu1 is on */
347 while (exynos_cpu_power_state(core_id)
348 != S5P_CORE_LOCAL_PWR_EN) {
349 if (timeout == 0)
350 break;
351 timeout--;
352 mdelay(1);
353 }
354
355 if (timeout == 0) {
356 printk(KERN_ERR "cpu1 power enable failed");
357 spin_unlock(&boot_lock);
358 return -ETIMEDOUT;
359 }
360 }
361
362 exynos_core_restart(core_id);
363
364 /*
365 * Send the secondary CPU a soft interrupt, thereby causing
366 * the boot monitor to read the system wide flags register,
367 * and branch to the address found there.
368 */
369
370 timeout = jiffies + (1 * HZ);
371 while (time_before(jiffies, timeout)) {
372 unsigned long boot_addr;
373
374 smp_rmb();
375
376 boot_addr = __pa_symbol(exynos4_secondary_startup);
377
378 ret = exynos_set_boot_addr(core_id, boot_addr);
379 if (ret)
380 goto fail;
381
382 call_firmware_op(cpu_boot, core_id);
383
384 if (soc_is_exynos3250())
385 dsb_sev();
386 else
387 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
388
389 if (exynos_pen_release == -1)
390 break;
391
392 udelay(10);
393 }
394
395 if (exynos_pen_release != -1)
396 ret = -ETIMEDOUT;
397
398 /*
399 * now the secondary core is starting up let it run its
400 * calibrations, then wait for it to finish
401 */
402 fail:
403 spin_unlock(&boot_lock);
404
405 return exynos_pen_release != -1 ? ret : 0;
406 }
407
exynos_smp_prepare_cpus(unsigned int max_cpus)408 static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
409 {
410 exynos_sysram_init();
411
412 exynos_set_delayed_reset_assertion(true);
413
414 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
415 exynos_scu_enable();
416 }
417
418 #ifdef CONFIG_HOTPLUG_CPU
419 /*
420 * platform-specific code to shutdown a CPU
421 *
422 * Called with IRQs disabled
423 */
exynos_cpu_die(unsigned int cpu)424 static void exynos_cpu_die(unsigned int cpu)
425 {
426 int spurious = 0;
427 u32 mpidr = cpu_logical_map(cpu);
428 u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
429
430 v7_exit_coherency_flush(louis);
431
432 platform_do_lowpower(cpu, &spurious);
433
434 /*
435 * bring this CPU back into the world of cache
436 * coherency, and then restore interrupts
437 */
438 cpu_leave_lowpower(core_id);
439
440 if (spurious)
441 pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
442 }
443 #endif /* CONFIG_HOTPLUG_CPU */
444
445 const struct smp_operations exynos_smp_ops __initconst = {
446 .smp_prepare_cpus = exynos_smp_prepare_cpus,
447 .smp_secondary_init = exynos_secondary_init,
448 .smp_boot_secondary = exynos_boot_secondary,
449 #ifdef CONFIG_HOTPLUG_CPU
450 .cpu_die = exynos_cpu_die,
451 #endif
452 };
453