xref: /openbmc/linux/arch/arm/mach-omap2/omap-smp.c (revision 981ab3f1)
1 /*
2  * OMAP4 SMP source file. It contains platform specific functions
3  * needed for the linux smp kernel.
4  *
5  * Copyright (C) 2009 Texas Instruments, Inc.
6  *
7  * Author:
8  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
9  *
10  * Platform file needed for the OMAP4 SMP. This file is based on arm
11  * realview smp platform.
12  * * Copyright (c) 2002 ARM Limited.
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License version 2 as
16  * published by the Free Software Foundation.
17  */
18 #include <linux/init.h>
19 #include <linux/device.h>
20 #include <linux/smp.h>
21 #include <linux/io.h>
22 #include <linux/irqchip/arm-gic.h>
23 
24 #include <asm/sections.h>
25 #include <asm/smp_scu.h>
26 #include <asm/virt.h>
27 
28 #include "omap-secure.h"
29 #include "omap-wakeupgen.h"
30 #include <asm/cputype.h>
31 
32 #include "soc.h"
33 #include "iomap.h"
34 #include "common.h"
35 #include "clockdomain.h"
36 #include "pm.h"
37 
38 #define CPU_MASK		0xff0ffff0
39 #define CPU_CORTEX_A9		0x410FC090
40 #define CPU_CORTEX_A15		0x410FC0F0
41 
42 #define OMAP5_CORE_COUNT	0x2
43 
44 #define AUX_CORE_BOOT0_GP_RELEASE	0x020
45 #define AUX_CORE_BOOT0_HS_RELEASE	0x200
46 
47 struct omap_smp_config {
48 	unsigned long cpu1_rstctrl_pa;
49 	void __iomem *cpu1_rstctrl_va;
50 	void __iomem *scu_base;
51 	void __iomem *wakeupgen_base;
52 	void *startup_addr;
53 };
54 
55 static struct omap_smp_config cfg;
56 
57 static const struct omap_smp_config omap443x_cfg __initconst = {
58 	.cpu1_rstctrl_pa = 0x4824380c,
59 	.startup_addr = omap4_secondary_startup,
60 };
61 
62 static const struct omap_smp_config omap446x_cfg __initconst = {
63 	.cpu1_rstctrl_pa = 0x4824380c,
64 	.startup_addr = omap4460_secondary_startup,
65 };
66 
67 static const struct omap_smp_config omap5_cfg __initconst = {
68 	.cpu1_rstctrl_pa = 0x48243810,
69 	.startup_addr = omap5_secondary_startup,
70 };
71 
72 static DEFINE_SPINLOCK(boot_lock);
73 
74 void __iomem *omap4_get_scu_base(void)
75 {
76 	return cfg.scu_base;
77 }
78 
79 #ifdef CONFIG_OMAP5_ERRATA_801819
80 void omap5_erratum_workaround_801819(void)
81 {
82 	u32 acr, revidr;
83 	u32 acr_mask;
84 
85 	/* REVIDR[3] indicates erratum fix available on silicon */
86 	asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr));
87 	if (revidr & (0x1 << 3))
88 		return;
89 
90 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
91 	/*
92 	 * BIT(27) - Disables streaming. All write-allocate lines allocate in
93 	 * the L1 or L2 cache.
94 	 * BIT(25) - Disables streaming. All write-allocate lines allocate in
95 	 * the L1 cache.
96 	 */
97 	acr_mask = (0x3 << 25) | (0x3 << 27);
98 	/* do we already have it done.. if yes, skip expensive smc */
99 	if ((acr & acr_mask) == acr_mask)
100 		return;
101 
102 	acr |= acr_mask;
103 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
104 
105 	pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n",
106 		 __func__, smp_processor_id());
107 }
108 #else
109 static inline void omap5_erratum_workaround_801819(void) { }
110 #endif
111 
112 static void omap4_secondary_init(unsigned int cpu)
113 {
114 	/*
115 	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
116 	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
117 	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
118 	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
119 	 * OMAP443X GP devices- SMP bit isn't accessible.
120 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
121 	 */
122 	if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
123 		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
124 							4, 0, 0, 0, 0, 0);
125 
126 	if (soc_is_omap54xx() || soc_is_dra7xx()) {
127 		/*
128 		 * Configure the CNTFRQ register for the secondary cpu's which
129 		 * indicates the frequency of the cpu local timers.
130 		 */
131 		set_cntfreq();
132 		/* Configure ACR to disable streaming WA for 801819 */
133 		omap5_erratum_workaround_801819();
134 	}
135 
136 	/*
137 	 * Synchronise with the boot thread.
138 	 */
139 	spin_lock(&boot_lock);
140 	spin_unlock(&boot_lock);
141 }
142 
143 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
144 {
145 	static struct clockdomain *cpu1_clkdm;
146 	static bool booted;
147 	static struct powerdomain *cpu1_pwrdm;
148 
149 	/*
150 	 * Set synchronisation state between this boot processor
151 	 * and the secondary one
152 	 */
153 	spin_lock(&boot_lock);
154 
155 	/*
156 	 * Update the AuxCoreBoot0 with boot state for secondary core.
157 	 * omap4_secondary_startup() routine will hold the secondary core till
158 	 * the AuxCoreBoot1 register is updated with cpu state
159 	 * A barrier is added to ensure that write buffer is drained
160 	 */
161 	if (omap_secure_apis_support())
162 		omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
163 					 0xfffffdff);
164 	else
165 		writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
166 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
167 
168 	if (!cpu1_clkdm && !cpu1_pwrdm) {
169 		cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
170 		cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
171 	}
172 
173 	/*
174 	 * The SGI(Software Generated Interrupts) are not wakeup capable
175 	 * from low power states. This is known limitation on OMAP4 and
176 	 * needs to be worked around by using software forced clockdomain
177 	 * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
178 	 * software force wakeup. The clockdomain is then put back to
179 	 * hardware supervised mode.
180 	 * More details can be found in OMAP4430 TRM - Version J
181 	 * Section :
182 	 *	4.3.4.2 Power States of CPU0 and CPU1
183 	 */
184 	if (booted && cpu1_pwrdm && cpu1_clkdm) {
185 		/*
186 		 * GIC distributor control register has changed between
187 		 * CortexA9 r1pX and r2pX. The Control Register secure
188 		 * banked version is now composed of 2 bits:
189 		 * bit 0 == Secure Enable
190 		 * bit 1 == Non-Secure Enable
191 		 * The Non-Secure banked register has not changed
192 		 * Because the ROM Code is based on the r1pX GIC, the CPU1
193 		 * GIC restoration will cause a problem to CPU0 Non-Secure SW.
194 		 * The workaround must be:
195 		 * 1) Before doing the CPU1 wakeup, CPU0 must disable
196 		 * the GIC distributor
197 		 * 2) CPU1 must re-enable the GIC distributor on
198 		 * it's wakeup path.
199 		 */
200 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
201 			local_irq_disable();
202 			gic_dist_disable();
203 		}
204 
205 		/*
206 		 * Ensure that CPU power state is set to ON to avoid CPU
207 		 * powerdomain transition on wfi
208 		 */
209 		clkdm_deny_idle_nolock(cpu1_clkdm);
210 		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
211 		clkdm_allow_idle_nolock(cpu1_clkdm);
212 
213 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
214 			while (gic_dist_disabled()) {
215 				udelay(1);
216 				cpu_relax();
217 			}
218 			gic_timer_retrigger();
219 			local_irq_enable();
220 		}
221 	} else {
222 		dsb_sev();
223 		booted = true;
224 	}
225 
226 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
227 
228 	/*
229 	 * Now the secondary core is starting up let it run its
230 	 * calibrations, then wait for it to finish
231 	 */
232 	spin_unlock(&boot_lock);
233 
234 	return 0;
235 }
236 
237 /*
238  * Initialise the CPU possible map early - this describes the CPUs
239  * which may be present or become present in the system.
240  */
241 static void __init omap4_smp_init_cpus(void)
242 {
243 	unsigned int i = 0, ncores = 1, cpu_id;
244 
245 	/* Use ARM cpuid check here, as SoC detection will not work so early */
246 	cpu_id = read_cpuid_id() & CPU_MASK;
247 	if (cpu_id == CPU_CORTEX_A9) {
248 		/*
249 		 * Currently we can't call ioremap here because
250 		 * SoC detection won't work until after init_early.
251 		 */
252 		cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
253 		BUG_ON(!cfg.scu_base);
254 		ncores = scu_get_core_count(cfg.scu_base);
255 	} else if (cpu_id == CPU_CORTEX_A15) {
256 		ncores = OMAP5_CORE_COUNT;
257 	}
258 
259 	/* sanity check */
260 	if (ncores > nr_cpu_ids) {
261 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
262 			ncores, nr_cpu_ids);
263 		ncores = nr_cpu_ids;
264 	}
265 
266 	for (i = 0; i < ncores; i++)
267 		set_cpu_possible(i, true);
268 }
269 
270 /*
271  * For now, just make sure the start-up address is not within the booting
272  * kernel space as that means we just overwrote whatever secondary_startup()
273  * code there was.
274  */
275 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
276 {
277 	if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
278 		return false;
279 
280 	return true;
281 }
282 
283 /*
284  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
285  * up trying to use old kernel startup address or suspend-resume will
286  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
287  * idle states.
288  */
289 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
290 {
291 	unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
292 	bool needs_reset = false;
293 	u32 released;
294 
295 	if (omap_secure_apis_support())
296 		released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
297 	else
298 		released = readl_relaxed(cfg.wakeupgen_base +
299 					 OMAP_AUX_CORE_BOOT_0) &
300 						AUX_CORE_BOOT0_GP_RELEASE;
301 	if (released) {
302 		pr_warn("smp: CPU1 not parked?\n");
303 
304 		return;
305 	}
306 
307 	cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
308 					OMAP_AUX_CORE_BOOT_1);
309 
310 	/* Did the configured secondary_startup() get overwritten? */
311 	if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
312 		needs_reset = true;
313 
314 	/*
315 	 * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
316 	 * deeper idle state in WFI and will wake to an invalid address.
317 	 */
318 	if ((soc_is_omap44xx() || soc_is_omap54xx())) {
319 		cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
320 		if (!omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
321 			needs_reset = true;
322 	} else {
323 		cpu1_ns_pa_addr = 0;
324 	}
325 
326 	if (!needs_reset || !c->cpu1_rstctrl_va)
327 		return;
328 
329 	pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
330 		cpu1_startup_pa, cpu1_ns_pa_addr);
331 
332 	writel_relaxed(1, c->cpu1_rstctrl_va);
333 	readl_relaxed(c->cpu1_rstctrl_va);
334 	writel_relaxed(0, c->cpu1_rstctrl_va);
335 }
336 
337 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
338 {
339 	const struct omap_smp_config *c = NULL;
340 
341 	if (soc_is_omap443x())
342 		c = &omap443x_cfg;
343 	else if (soc_is_omap446x())
344 		c = &omap446x_cfg;
345 	else if (soc_is_dra74x() || soc_is_omap54xx())
346 		c = &omap5_cfg;
347 
348 	if (!c) {
349 		pr_err("%s Unknown SMP SoC?\n", __func__);
350 		return;
351 	}
352 
353 	/* Must preserve cfg.scu_base set earlier */
354 	cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
355 	cfg.startup_addr = c->startup_addr;
356 	cfg.wakeupgen_base = omap_get_wakeupgen_base();
357 
358 	if (soc_is_dra74x() || soc_is_omap54xx()) {
359 		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
360 			cfg.startup_addr = omap5_secondary_hyp_startup;
361 		omap5_erratum_workaround_801819();
362 	}
363 
364 	cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
365 	if (!cfg.cpu1_rstctrl_va)
366 		return;
367 
368 	/*
369 	 * Initialise the SCU and wake up the secondary core using
370 	 * wakeup_secondary().
371 	 */
372 	if (cfg.scu_base)
373 		scu_enable(cfg.scu_base);
374 
375 	omap4_smp_maybe_reset_cpu1(&cfg);
376 
377 	/*
378 	 * Write the address of secondary startup routine into the
379 	 * AuxCoreBoot1 where ROM code will jump and start executing
380 	 * on secondary core once out of WFE
381 	 * A barrier is added to ensure that write buffer is drained
382 	 */
383 	if (omap_secure_apis_support())
384 		omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
385 	else
386 		writel_relaxed(__pa_symbol(cfg.startup_addr),
387 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
388 }
389 
390 const struct smp_operations omap4_smp_ops __initconst = {
391 	.smp_init_cpus		= omap4_smp_init_cpus,
392 	.smp_prepare_cpus	= omap4_smp_prepare_cpus,
393 	.smp_secondary_init	= omap4_secondary_init,
394 	.smp_boot_secondary	= omap4_boot_secondary,
395 #ifdef CONFIG_HOTPLUG_CPU
396 	.cpu_die		= omap4_cpu_die,
397 	.cpu_kill		= omap4_cpu_kill,
398 #endif
399 };
400