1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2018 Chen-Yu Tsai
4 *
5 * Chen-Yu Tsai <wens@csie.org>
6 *
7 * arch/arm/mach-sunxi/mc_smp.c
8 *
9 * Based on Allwinner code, arch/arm/mach-exynos/mcpm-exynos.c, and
10 * arch/arm/mach-hisi/platmcpm.c
11 * Cluster cache enable trampoline code adapted from MCPM framework
12 */
13
14#include <linux/arm-cci.h>
15#include <linux/cpu_pm.h>
16#include <linux/delay.h>
17#include <linux/io.h>
18#include <linux/iopoll.h>
19#include <linux/irqchip/arm-gic.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22#include <linux/smp.h>
23
24#include <asm/cacheflush.h>
25#include <asm/cp15.h>
26#include <asm/cputype.h>
27#include <asm/idmap.h>
28#include <asm/smp_plat.h>
29#include <asm/suspend.h>
30
31#define SUNXI_CPUS_PER_CLUSTER		4
32#define SUNXI_NR_CLUSTERS		2
33
34#define POLL_USEC	100
35#define TIMEOUT_USEC	100000
36
37#define CPUCFG_CX_CTRL_REG0(c)		(0x10 * (c))
38#define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(n)	BIT(n)
39#define CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL	0xf
40#define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7	BIT(4)
41#define CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15	BIT(0)
42#define CPUCFG_CX_CTRL_REG1(c)		(0x10 * (c) + 0x4)
43#define CPUCFG_CX_CTRL_REG1_ACINACTM	BIT(0)
44#define CPUCFG_CX_STATUS(c)		(0x30 + 0x4 * (c))
45#define CPUCFG_CX_STATUS_STANDBYWFI(n)	BIT(16 + (n))
46#define CPUCFG_CX_STATUS_STANDBYWFIL2	BIT(0)
47#define CPUCFG_CX_RST_CTRL(c)		(0x80 + 0x4 * (c))
48#define CPUCFG_CX_RST_CTRL_DBG_SOC_RST	BIT(24)
49#define CPUCFG_CX_RST_CTRL_ETM_RST(n)	BIT(20 + (n))
50#define CPUCFG_CX_RST_CTRL_ETM_RST_ALL	(0xf << 20)
51#define CPUCFG_CX_RST_CTRL_DBG_RST(n)	BIT(16 + (n))
52#define CPUCFG_CX_RST_CTRL_DBG_RST_ALL	(0xf << 16)
53#define CPUCFG_CX_RST_CTRL_H_RST	BIT(12)
54#define CPUCFG_CX_RST_CTRL_L2_RST	BIT(8)
55#define CPUCFG_CX_RST_CTRL_CX_RST(n)	BIT(4 + (n))
56#define CPUCFG_CX_RST_CTRL_CORE_RST(n)	BIT(n)
57#define CPUCFG_CX_RST_CTRL_CORE_RST_ALL	(0xf << 0)
58
59#define PRCM_CPU_PO_RST_CTRL(c)		(0x4 + 0x4 * (c))
60#define PRCM_CPU_PO_RST_CTRL_CORE(n)	BIT(n)
61#define PRCM_CPU_PO_RST_CTRL_CORE_ALL	0xf
62#define PRCM_PWROFF_GATING_REG(c)	(0x100 + 0x4 * (c))
63/* The power off register for clusters are different from a80 and a83t */
64#define PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I	BIT(0)
65#define PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I	BIT(4)
66#define PRCM_PWROFF_GATING_REG_CORE(n)	BIT(n)
67#define PRCM_PWR_SWITCH_REG(c, cpu)	(0x140 + 0x10 * (c) + 0x4 * (cpu))
68#define PRCM_CPU_SOFT_ENTRY_REG		0x164
69
70/* R_CPUCFG registers, specific to sun8i-a83t */
71#define R_CPUCFG_CLUSTER_PO_RST_CTRL(c)	(0x30 + (c) * 0x4)
72#define R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(n)	BIT(n)
73#define R_CPUCFG_CPU_SOFT_ENTRY_REG		0x01a4
74
75#define CPU0_SUPPORT_HOTPLUG_MAGIC0	0xFA50392F
76#define CPU0_SUPPORT_HOTPLUG_MAGIC1	0x790DCA3A
77
78static void __iomem *cpucfg_base;
79static void __iomem *prcm_base;
80static void __iomem *sram_b_smp_base;
81static void __iomem *r_cpucfg_base;
82
83extern void sunxi_mc_smp_secondary_startup(void);
84extern void sunxi_mc_smp_resume(void);
85static bool is_a83t;
86
87static bool sunxi_core_is_cortex_a15(unsigned int core, unsigned int cluster)
88{
89	struct device_node *node;
90	int cpu = cluster * SUNXI_CPUS_PER_CLUSTER + core;
91	bool is_compatible;
92
93	node = of_cpu_device_node_get(cpu);
94
95	/* In case of_cpu_device_node_get fails */
96	if (!node)
97		node = of_get_cpu_node(cpu, NULL);
98
99	if (!node) {
100		/*
101		 * There's no point in returning an error, since we
102		 * would be mid way in a core or cluster power sequence.
103		 */
104		pr_err("%s: Couldn't get CPU cluster %u core %u device node\n",
105		       __func__, cluster, core);
106
107		return false;
108	}
109
110	is_compatible = of_device_is_compatible(node, "arm,cortex-a15");
111	of_node_put(node);
112	return is_compatible;
113}
114
115static int sunxi_cpu_power_switch_set(unsigned int cpu, unsigned int cluster,
116				      bool enable)
117{
118	u32 reg;
119
120	/* control sequence from Allwinner A80 user manual v1.2 PRCM section */
121	reg = readl(prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
122	if (enable) {
123		if (reg == 0x00) {
124			pr_debug("power clamp for cluster %u cpu %u already open\n",
125				 cluster, cpu);
126			return 0;
127		}
128
129		writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
130		udelay(10);
131		writel(0xfe, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
132		udelay(10);
133		writel(0xf8, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
134		udelay(10);
135		writel(0xf0, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
136		udelay(10);
137		writel(0x00, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
138		udelay(10);
139	} else {
140		writel(0xff, prcm_base + PRCM_PWR_SWITCH_REG(cluster, cpu));
141		udelay(10);
142	}
143
144	return 0;
145}
146
147static void sunxi_cpu0_hotplug_support_set(bool enable)
148{
149	if (enable) {
150		writel(CPU0_SUPPORT_HOTPLUG_MAGIC0, sram_b_smp_base);
151		writel(CPU0_SUPPORT_HOTPLUG_MAGIC1, sram_b_smp_base + 0x4);
152	} else {
153		writel(0x0, sram_b_smp_base);
154		writel(0x0, sram_b_smp_base + 0x4);
155	}
156}
157
158static int sunxi_cpu_powerup(unsigned int cpu, unsigned int cluster)
159{
160	u32 reg;
161
162	pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
163	if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
164		return -EINVAL;
165
166	/* Set hotplug support magic flags for cpu0 */
167	if (cluster == 0 && cpu == 0)
168		sunxi_cpu0_hotplug_support_set(true);
169
170	/* assert processor power-on reset */
171	reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
172	reg &= ~PRCM_CPU_PO_RST_CTRL_CORE(cpu);
173	writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
174
175	if (is_a83t) {
176		/* assert cpu power-on reset */
177		reg  = readl(r_cpucfg_base +
178			     R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
179		reg &= ~(R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(cpu));
180		writel(reg, r_cpucfg_base +
181		       R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
182		udelay(10);
183	}
184
185	/* Cortex-A7: hold L1 reset disable signal low */
186	if (!sunxi_core_is_cortex_a15(cpu, cluster)) {
187		reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
188		reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE(cpu);
189		writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
190	}
191
192	/* assert processor related resets */
193	reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
194	reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST(cpu);
195
196	/*
197	 * Allwinner code also asserts resets for NEON on A15. According
198	 * to ARM manuals, asserting power-on reset is sufficient.
199	 */
200	if (!sunxi_core_is_cortex_a15(cpu, cluster))
201		reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST(cpu);
202
203	writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
204
205	/* open power switch */
206	sunxi_cpu_power_switch_set(cpu, cluster, true);
207
208	/* Handle A83T bit swap */
209	if (is_a83t) {
210		if (cpu == 0)
211			cpu = 4;
212	}
213
214	/* clear processor power gate */
215	reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
216	reg &= ~PRCM_PWROFF_GATING_REG_CORE(cpu);
217	writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
218	udelay(20);
219
220	/* Handle A83T bit swap */
221	if (is_a83t) {
222		if (cpu == 4)
223			cpu = 0;
224	}
225
226	/* de-assert processor power-on reset */
227	reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
228	reg |= PRCM_CPU_PO_RST_CTRL_CORE(cpu);
229	writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
230
231	if (is_a83t) {
232		reg  = readl(r_cpucfg_base +
233			     R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
234		reg |= R_CPUCFG_CLUSTER_PO_RST_CTRL_CORE(cpu);
235		writel(reg, r_cpucfg_base +
236		       R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
237		udelay(10);
238	}
239
240	/* de-assert all processor resets */
241	reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
242	reg |= CPUCFG_CX_RST_CTRL_DBG_RST(cpu);
243	reg |= CPUCFG_CX_RST_CTRL_CORE_RST(cpu);
244	if (!sunxi_core_is_cortex_a15(cpu, cluster))
245		reg |= CPUCFG_CX_RST_CTRL_ETM_RST(cpu);
246	else
247		reg |= CPUCFG_CX_RST_CTRL_CX_RST(cpu); /* NEON */
248	writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
249
250	return 0;
251}
252
253static int sunxi_cluster_powerup(unsigned int cluster)
254{
255	u32 reg;
256
257	pr_debug("%s: cluster %u\n", __func__, cluster);
258	if (cluster >= SUNXI_NR_CLUSTERS)
259		return -EINVAL;
260
261	/* For A83T, assert cluster cores resets */
262	if (is_a83t) {
263		reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
264		reg &= ~CPUCFG_CX_RST_CTRL_CORE_RST_ALL;   /* Core Reset    */
265		writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
266		udelay(10);
267	}
268
269	/* assert ACINACTM */
270	reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
271	reg |= CPUCFG_CX_CTRL_REG1_ACINACTM;
272	writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
273
274	/* assert cluster processor power-on resets */
275	reg = readl(prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
276	reg &= ~PRCM_CPU_PO_RST_CTRL_CORE_ALL;
277	writel(reg, prcm_base + PRCM_CPU_PO_RST_CTRL(cluster));
278
279	/* assert cluster cores resets */
280	if (is_a83t) {
281		reg  = readl(r_cpucfg_base +
282			     R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
283		reg &= ~CPUCFG_CX_RST_CTRL_CORE_RST_ALL;
284		writel(reg, r_cpucfg_base +
285		       R_CPUCFG_CLUSTER_PO_RST_CTRL(cluster));
286		udelay(10);
287	}
288
289	/* assert cluster resets */
290	reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
291	reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
292	reg &= ~CPUCFG_CX_RST_CTRL_DBG_RST_ALL;
293	reg &= ~CPUCFG_CX_RST_CTRL_H_RST;
294	reg &= ~CPUCFG_CX_RST_CTRL_L2_RST;
295
296	/*
297	 * Allwinner code also asserts resets for NEON on A15. According
298	 * to ARM manuals, asserting power-on reset is sufficient.
299	 */
300	if (!sunxi_core_is_cortex_a15(0, cluster))
301		reg &= ~CPUCFG_CX_RST_CTRL_ETM_RST_ALL;
302
303	writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
304
305	/* hold L1/L2 reset disable signals low */
306	reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
307	if (sunxi_core_is_cortex_a15(0, cluster)) {
308		/* Cortex-A15: hold L2RSTDISABLE low */
309		reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A15;
310	} else {
311		/* Cortex-A7: hold L1RSTDISABLE and L2RSTDISABLE low */
312		reg &= ~CPUCFG_CX_CTRL_REG0_L1_RST_DISABLE_ALL;
313		reg &= ~CPUCFG_CX_CTRL_REG0_L2_RST_DISABLE_A7;
314	}
315	writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG0(cluster));
316
317	/* clear cluster power gate */
318	reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
319	if (is_a83t)
320		reg &= ~PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I;
321	else
322		reg &= ~PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I;
323	writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
324	udelay(20);
325
326	/* de-assert cluster resets */
327	reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
328	reg |= CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
329	reg |= CPUCFG_CX_RST_CTRL_H_RST;
330	reg |= CPUCFG_CX_RST_CTRL_L2_RST;
331	writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
332
333	/* de-assert ACINACTM */
334	reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
335	reg &= ~CPUCFG_CX_CTRL_REG1_ACINACTM;
336	writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
337
338	return 0;
339}
340
341/*
342 * This bit is shared between the initial nocache_trampoline call to
343 * enable CCI-400 and proper cluster cache disable before power down.
344 */
345static void sunxi_cluster_cache_disable_without_axi(void)
346{
347	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
348		/*
349		 * On the Cortex-A15 we need to disable
350		 * L2 prefetching before flushing the cache.
351		 */
352		asm volatile(
353		"mcr	p15, 1, %0, c15, c0, 3\n"
354		"isb\n"
355		"dsb"
356		: : "r" (0x400));
357	}
358
359	/* Flush all cache levels for this cluster. */
360	v7_exit_coherency_flush(all);
361
362	/*
363	 * Disable cluster-level coherency by masking
364	 * incoming snoops and DVM messages:
365	 */
366	cci_disable_port_by_cpu(read_cpuid_mpidr());
367}
368
369static int sunxi_mc_smp_cpu_table[SUNXI_NR_CLUSTERS][SUNXI_CPUS_PER_CLUSTER];
370int sunxi_mc_smp_first_comer;
371
372static DEFINE_SPINLOCK(boot_lock);
373
374static bool sunxi_mc_smp_cluster_is_down(unsigned int cluster)
375{
376	int i;
377
378	for (i = 0; i < SUNXI_CPUS_PER_CLUSTER; i++)
379		if (sunxi_mc_smp_cpu_table[cluster][i])
380			return false;
381	return true;
382}
383
384static void sunxi_mc_smp_secondary_init(unsigned int cpu)
385{
386	/* Clear hotplug support magic flags for cpu0 */
387	if (cpu == 0)
388		sunxi_cpu0_hotplug_support_set(false);
389}
390
391static int sunxi_mc_smp_boot_secondary(unsigned int l_cpu, struct task_struct *idle)
392{
393	unsigned int mpidr, cpu, cluster;
394
395	mpidr = cpu_logical_map(l_cpu);
396	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
397	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
398
399	if (!cpucfg_base)
400		return -ENODEV;
401	if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER)
402		return -EINVAL;
403
404	spin_lock_irq(&boot_lock);
405
406	if (sunxi_mc_smp_cpu_table[cluster][cpu])
407		goto out;
408
409	if (sunxi_mc_smp_cluster_is_down(cluster)) {
410		sunxi_mc_smp_first_comer = true;
411		sunxi_cluster_powerup(cluster);
412	} else {
413		sunxi_mc_smp_first_comer = false;
414	}
415
416	/* This is read by incoming CPUs with their cache and MMU disabled */
417	sync_cache_w(&sunxi_mc_smp_first_comer);
418	sunxi_cpu_powerup(cpu, cluster);
419
420out:
421	sunxi_mc_smp_cpu_table[cluster][cpu]++;
422	spin_unlock_irq(&boot_lock);
423
424	return 0;
425}
426
427#ifdef CONFIG_HOTPLUG_CPU
428static void sunxi_cluster_cache_disable(void)
429{
430	unsigned int cluster = MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 1);
431	u32 reg;
432
433	pr_debug("%s: cluster %u\n", __func__, cluster);
434
435	sunxi_cluster_cache_disable_without_axi();
436
437	/* last man standing, assert ACINACTM */
438	reg = readl(cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
439	reg |= CPUCFG_CX_CTRL_REG1_ACINACTM;
440	writel(reg, cpucfg_base + CPUCFG_CX_CTRL_REG1(cluster));
441}
442
443static void sunxi_mc_smp_cpu_die(unsigned int l_cpu)
444{
445	unsigned int mpidr, cpu, cluster;
446	bool last_man;
447
448	mpidr = cpu_logical_map(l_cpu);
449	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
450	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
451	pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
452
453	spin_lock(&boot_lock);
454	sunxi_mc_smp_cpu_table[cluster][cpu]--;
455	if (sunxi_mc_smp_cpu_table[cluster][cpu] == 1) {
456		/* A power_up request went ahead of us. */
457		pr_debug("%s: aborting due to a power up request\n",
458			 __func__);
459		spin_unlock(&boot_lock);
460		return;
461	} else if (sunxi_mc_smp_cpu_table[cluster][cpu] > 1) {
462		pr_err("Cluster %d CPU%d boots multiple times\n",
463		       cluster, cpu);
464		BUG();
465	}
466
467	last_man = sunxi_mc_smp_cluster_is_down(cluster);
468	spin_unlock(&boot_lock);
469
470	gic_cpu_if_down(0);
471	if (last_man)
472		sunxi_cluster_cache_disable();
473	else
474		v7_exit_coherency_flush(louis);
475
476	for (;;)
477		wfi();
478}
479
480static int sunxi_cpu_powerdown(unsigned int cpu, unsigned int cluster)
481{
482	u32 reg;
483	int gating_bit = cpu;
484
485	pr_debug("%s: cluster %u cpu %u\n", __func__, cluster, cpu);
486	if (cpu >= SUNXI_CPUS_PER_CLUSTER || cluster >= SUNXI_NR_CLUSTERS)
487		return -EINVAL;
488
489	if (is_a83t && cpu == 0)
490		gating_bit = 4;
491
492	/* gate processor power */
493	reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
494	reg |= PRCM_PWROFF_GATING_REG_CORE(gating_bit);
495	writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
496	udelay(20);
497
498	/* close power switch */
499	sunxi_cpu_power_switch_set(cpu, cluster, false);
500
501	return 0;
502}
503
504static int sunxi_cluster_powerdown(unsigned int cluster)
505{
506	u32 reg;
507
508	pr_debug("%s: cluster %u\n", __func__, cluster);
509	if (cluster >= SUNXI_NR_CLUSTERS)
510		return -EINVAL;
511
512	/* assert cluster resets or system will hang */
513	pr_debug("%s: assert cluster reset\n", __func__);
514	reg = readl(cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
515	reg &= ~CPUCFG_CX_RST_CTRL_DBG_SOC_RST;
516	reg &= ~CPUCFG_CX_RST_CTRL_H_RST;
517	reg &= ~CPUCFG_CX_RST_CTRL_L2_RST;
518	writel(reg, cpucfg_base + CPUCFG_CX_RST_CTRL(cluster));
519
520	/* gate cluster power */
521	pr_debug("%s: gate cluster power\n", __func__);
522	reg = readl(prcm_base + PRCM_PWROFF_GATING_REG(cluster));
523	if (is_a83t)
524		reg |= PRCM_PWROFF_GATING_REG_CLUSTER_SUN8I;
525	else
526		reg |= PRCM_PWROFF_GATING_REG_CLUSTER_SUN9I;
527	writel(reg, prcm_base + PRCM_PWROFF_GATING_REG(cluster));
528	udelay(20);
529
530	return 0;
531}
532
533static int sunxi_mc_smp_cpu_kill(unsigned int l_cpu)
534{
535	unsigned int mpidr, cpu, cluster;
536	unsigned int tries, count;
537	int ret = 0;
538	u32 reg;
539
540	mpidr = cpu_logical_map(l_cpu);
541	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
542	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
543
544	/* This should never happen */
545	if (WARN_ON(cluster >= SUNXI_NR_CLUSTERS ||
546		    cpu >= SUNXI_CPUS_PER_CLUSTER))
547		return 0;
548
549	/* wait for CPU core to die and enter WFI */
550	count = TIMEOUT_USEC / POLL_USEC;
551	spin_lock_irq(&boot_lock);
552	for (tries = 0; tries < count; tries++) {
553		spin_unlock_irq(&boot_lock);
554		usleep_range(POLL_USEC / 2, POLL_USEC);
555		spin_lock_irq(&boot_lock);
556
557		/*
558		 * If the user turns off a bunch of cores at the same
559		 * time, the kernel might call cpu_kill before some of
560		 * them are ready. This is because boot_lock serializes
561		 * both cpu_die and cpu_kill callbacks. Either one could
562		 * run first. We should wait for cpu_die to complete.
563		 */
564		if (sunxi_mc_smp_cpu_table[cluster][cpu])
565			continue;
566
567		reg = readl(cpucfg_base + CPUCFG_CX_STATUS(cluster));
568		if (reg & CPUCFG_CX_STATUS_STANDBYWFI(cpu))
569			break;
570	}
571
572	if (tries >= count) {
573		ret = ETIMEDOUT;
574		goto out;
575	}
576
577	/* power down CPU core */
578	sunxi_cpu_powerdown(cpu, cluster);
579
580	if (!sunxi_mc_smp_cluster_is_down(cluster))
581		goto out;
582
583	/* wait for cluster L2 WFI */
584	ret = readl_poll_timeout(cpucfg_base + CPUCFG_CX_STATUS(cluster), reg,
585				 reg & CPUCFG_CX_STATUS_STANDBYWFIL2,
586				 POLL_USEC, TIMEOUT_USEC);
587	if (ret) {
588		/*
589		 * Ignore timeout on the cluster. Leaving the cluster on
590		 * will not affect system execution, just use a bit more
591		 * power. But returning an error here will only confuse
592		 * the user as the CPU has already been shutdown.
593		 */
594		ret = 0;
595		goto out;
596	}
597
598	/* Power down cluster */
599	sunxi_cluster_powerdown(cluster);
600
601out:
602	spin_unlock_irq(&boot_lock);
603	pr_debug("%s: cluster %u cpu %u powerdown: %d\n",
604		 __func__, cluster, cpu, ret);
605	return !ret;
606}
607
608static bool sunxi_mc_smp_cpu_can_disable(unsigned int cpu)
609{
610	/* CPU0 hotplug not handled for sun8i-a83t */
611	if (is_a83t)
612		if (cpu == 0)
613			return false;
614	return true;
615}
616#endif
617
618static const struct smp_operations sunxi_mc_smp_smp_ops __initconst = {
619	.smp_secondary_init	= sunxi_mc_smp_secondary_init,
620	.smp_boot_secondary	= sunxi_mc_smp_boot_secondary,
621#ifdef CONFIG_HOTPLUG_CPU
622	.cpu_die		= sunxi_mc_smp_cpu_die,
623	.cpu_kill		= sunxi_mc_smp_cpu_kill,
624	.cpu_can_disable	= sunxi_mc_smp_cpu_can_disable,
625#endif
626};
627
628static bool __init sunxi_mc_smp_cpu_table_init(void)
629{
630	unsigned int mpidr, cpu, cluster;
631
632	mpidr = read_cpuid_mpidr();
633	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
634	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
635
636	if (cluster >= SUNXI_NR_CLUSTERS || cpu >= SUNXI_CPUS_PER_CLUSTER) {
637		pr_err("%s: boot CPU is out of bounds!\n", __func__);
638		return false;
639	}
640	sunxi_mc_smp_cpu_table[cluster][cpu] = 1;
641	return true;
642}
643
644/*
645 * Adapted from arch/arm/common/mc_smp_entry.c
646 *
647 * We need the trampoline code to enable CCI-400 on the first cluster
648 */
649typedef typeof(cpu_reset) phys_reset_t;
650
651static int __init nocache_trampoline(unsigned long __unused)
652{
653	phys_reset_t phys_reset;
654
655	setup_mm_for_reboot();
656	sunxi_cluster_cache_disable_without_axi();
657
658	phys_reset = (phys_reset_t)(unsigned long)__pa_symbol(cpu_reset);
659	phys_reset(__pa_symbol(sunxi_mc_smp_resume), false);
660	BUG();
661}
662
663static int __init sunxi_mc_smp_loopback(void)
664{
665	int ret;
666
667	/*
668	 * We're going to soft-restart the current CPU through the
669	 * low-level MCPM code by leveraging the suspend/resume
670	 * infrastructure. Let's play it safe by using cpu_pm_enter()
671	 * in case the CPU init code path resets the VFP or similar.
672	 */
673	sunxi_mc_smp_first_comer = true;
674	local_irq_disable();
675	local_fiq_disable();
676	ret = cpu_pm_enter();
677	if (!ret) {
678		ret = cpu_suspend(0, nocache_trampoline);
679		cpu_pm_exit();
680	}
681	local_fiq_enable();
682	local_irq_enable();
683	sunxi_mc_smp_first_comer = false;
684
685	return ret;
686}
687
688/*
689 * This holds any device nodes that we requested resources for,
690 * so that we may easily release resources in the error path.
691 */
692struct sunxi_mc_smp_nodes {
693	struct device_node *prcm_node;
694	struct device_node *cpucfg_node;
695	struct device_node *sram_node;
696	struct device_node *r_cpucfg_node;
697};
698
699/* This structure holds SoC-specific bits tied to an enable-method string. */
700struct sunxi_mc_smp_data {
701	const char *enable_method;
702	int (*get_smp_nodes)(struct sunxi_mc_smp_nodes *nodes);
703	bool is_a83t;
704};
705
706static void __init sunxi_mc_smp_put_nodes(struct sunxi_mc_smp_nodes *nodes)
707{
708	of_node_put(nodes->prcm_node);
709	of_node_put(nodes->cpucfg_node);
710	of_node_put(nodes->sram_node);
711	of_node_put(nodes->r_cpucfg_node);
712	memset(nodes, 0, sizeof(*nodes));
713}
714
715static int __init sun9i_a80_get_smp_nodes(struct sunxi_mc_smp_nodes *nodes)
716{
717	nodes->prcm_node = of_find_compatible_node(NULL, NULL,
718						   "allwinner,sun9i-a80-prcm");
719	if (!nodes->prcm_node) {
720		pr_err("%s: PRCM not available\n", __func__);
721		return -ENODEV;
722	}
723
724	nodes->cpucfg_node = of_find_compatible_node(NULL, NULL,
725						     "allwinner,sun9i-a80-cpucfg");
726	if (!nodes->cpucfg_node) {
727		pr_err("%s: CPUCFG not available\n", __func__);
728		return -ENODEV;
729	}
730
731	nodes->sram_node = of_find_compatible_node(NULL, NULL,
732						   "allwinner,sun9i-a80-smp-sram");
733	if (!nodes->sram_node) {
734		pr_err("%s: Secure SRAM not available\n", __func__);
735		return -ENODEV;
736	}
737
738	return 0;
739}
740
741static int __init sun8i_a83t_get_smp_nodes(struct sunxi_mc_smp_nodes *nodes)
742{
743	nodes->prcm_node = of_find_compatible_node(NULL, NULL,
744						   "allwinner,sun8i-a83t-r-ccu");
745	if (!nodes->prcm_node) {
746		pr_err("%s: PRCM not available\n", __func__);
747		return -ENODEV;
748	}
749
750	nodes->cpucfg_node = of_find_compatible_node(NULL, NULL,
751						     "allwinner,sun8i-a83t-cpucfg");
752	if (!nodes->cpucfg_node) {
753		pr_err("%s: CPUCFG not available\n", __func__);
754		return -ENODEV;
755	}
756
757	nodes->r_cpucfg_node = of_find_compatible_node(NULL, NULL,
758						       "allwinner,sun8i-a83t-r-cpucfg");
759	if (!nodes->r_cpucfg_node) {
760		pr_err("%s: RCPUCFG not available\n", __func__);
761		return -ENODEV;
762	}
763
764	return 0;
765}
766
767static const struct sunxi_mc_smp_data sunxi_mc_smp_data[] __initconst = {
768	{
769		.enable_method	= "allwinner,sun9i-a80-smp",
770		.get_smp_nodes	= sun9i_a80_get_smp_nodes,
771	},
772	{
773		.enable_method	= "allwinner,sun8i-a83t-smp",
774		.get_smp_nodes	= sun8i_a83t_get_smp_nodes,
775		.is_a83t	= true,
776	},
777};
778
779static int __init sunxi_mc_smp_init(void)
780{
781	struct sunxi_mc_smp_nodes nodes = { 0 };
782	struct device_node *node;
783	struct resource res;
784	void __iomem *addr;
785	int i, ret;
786
787	/*
788	 * Don't bother checking the "cpus" node, as an enable-method
789	 * property in that node is undocumented.
790	 */
791	node = of_cpu_device_node_get(0);
792	if (!node)
793		return -ENODEV;
794
795	/*
796	 * We can't actually use the enable-method magic in the kernel.
797	 * Our loopback / trampoline code uses the CPU suspend framework,
798	 * which requires the identity mapping be available. It would not
799	 * yet be available if we used the .init_cpus or .prepare_cpus
800	 * callbacks in smp_operations, which we would use if we were to
801	 * use CPU_METHOD_OF_DECLARE
802	 */
803	for (i = 0; i < ARRAY_SIZE(sunxi_mc_smp_data); i++) {
804		ret = of_property_match_string(node, "enable-method",
805					       sunxi_mc_smp_data[i].enable_method);
806		if (ret >= 0)
807			break;
808	}
809
810	of_node_put(node);
811	if (ret < 0)
812		return -ENODEV;
813
814	is_a83t = sunxi_mc_smp_data[i].is_a83t;
815
816	if (!sunxi_mc_smp_cpu_table_init())
817		return -EINVAL;
818
819	if (!cci_probed()) {
820		pr_err("%s: CCI-400 not available\n", __func__);
821		return -ENODEV;
822	}
823
824	/* Get needed device tree nodes */
825	ret = sunxi_mc_smp_data[i].get_smp_nodes(&nodes);
826	if (ret)
827		goto err_put_nodes;
828
829	/*
830	 * Unfortunately we can not request the I/O region for the PRCM.
831	 * It is shared with the PRCM clock.
832	 */
833	prcm_base = of_iomap(nodes.prcm_node, 0);
834	if (!prcm_base) {
835		pr_err("%s: failed to map PRCM registers\n", __func__);
836		ret = -ENOMEM;
837		goto err_put_nodes;
838	}
839
840	cpucfg_base = of_io_request_and_map(nodes.cpucfg_node, 0,
841					    "sunxi-mc-smp");
842	if (IS_ERR(cpucfg_base)) {
843		ret = PTR_ERR(cpucfg_base);
844		pr_err("%s: failed to map CPUCFG registers: %d\n",
845		       __func__, ret);
846		goto err_unmap_prcm;
847	}
848
849	if (is_a83t) {
850		r_cpucfg_base = of_io_request_and_map(nodes.r_cpucfg_node,
851						      0, "sunxi-mc-smp");
852		if (IS_ERR(r_cpucfg_base)) {
853			ret = PTR_ERR(r_cpucfg_base);
854			pr_err("%s: failed to map R-CPUCFG registers\n",
855			       __func__);
856			goto err_unmap_release_cpucfg;
857		}
858	} else {
859		sram_b_smp_base = of_io_request_and_map(nodes.sram_node, 0,
860							"sunxi-mc-smp");
861		if (IS_ERR(sram_b_smp_base)) {
862			ret = PTR_ERR(sram_b_smp_base);
863			pr_err("%s: failed to map secure SRAM\n", __func__);
864			goto err_unmap_release_cpucfg;
865		}
866	}
867
868	/* Configure CCI-400 for boot cluster */
869	ret = sunxi_mc_smp_loopback();
870	if (ret) {
871		pr_err("%s: failed to configure boot cluster: %d\n",
872		       __func__, ret);
873		goto err_unmap_release_sram_rcpucfg;
874	}
875
876	/* We don't need the device nodes anymore */
877	sunxi_mc_smp_put_nodes(&nodes);
878
879	/* Set the hardware entry point address */
880	if (is_a83t)
881		addr = r_cpucfg_base + R_CPUCFG_CPU_SOFT_ENTRY_REG;
882	else
883		addr = prcm_base + PRCM_CPU_SOFT_ENTRY_REG;
884	writel(__pa_symbol(sunxi_mc_smp_secondary_startup), addr);
885
886	/* Actually enable multi cluster SMP */
887	smp_set_ops(&sunxi_mc_smp_smp_ops);
888
889	pr_info("sunxi multi cluster SMP support installed\n");
890
891	return 0;
892
893err_unmap_release_sram_rcpucfg:
894	if (is_a83t) {
895		iounmap(r_cpucfg_base);
896		of_address_to_resource(nodes.r_cpucfg_node, 0, &res);
897	} else {
898		iounmap(sram_b_smp_base);
899		of_address_to_resource(nodes.sram_node, 0, &res);
900	}
901	release_mem_region(res.start, resource_size(&res));
902err_unmap_release_cpucfg:
903	iounmap(cpucfg_base);
904	of_address_to_resource(nodes.cpucfg_node, 0, &res);
905	release_mem_region(res.start, resource_size(&res));
906err_unmap_prcm:
907	iounmap(prcm_base);
908err_put_nodes:
909	sunxi_mc_smp_put_nodes(&nodes);
910	return ret;
911}
912
913early_initcall(sunxi_mc_smp_init);
914