xref: /openbmc/linux/arch/arm/mach-omap2/omap-smp.c (revision 08193d1a)
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 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
113 /*
114  * Configure ACR and enable ACTLR[0] (Enable invalidates of BTB with
115  * ICIALLU) to activate the workaround for secondary Core.
116  * NOTE: it is assumed that the primary core's configuration is done
117  * by the boot loader (kernel will detect a misconfiguration and complain
118  * if this is not done).
119  *
120  * In General Purpose(GP) devices, ACR bit settings can only be done
121  * by ROM code in "secure world" using the smc call and there is no
122  * option to update the "firmware" on such devices. This also works for
123  * High security(HS) devices, as a backup option in case the
124  * "update" is not done in the "security firmware".
125  */
126 static void omap5_secondary_harden_predictor(void)
127 {
128 	u32 acr, acr_mask;
129 
130 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
131 
132 	/*
133 	 * ACTLR[0] (Enable invalidates of BTB with ICIALLU)
134 	 */
135 	acr_mask = BIT(0);
136 
137 	/* Do we already have it done.. if yes, skip expensive smc */
138 	if ((acr & acr_mask) == acr_mask)
139 		return;
140 
141 	acr |= acr_mask;
142 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
143 
144 	pr_debug("%s: ARM ACR setup for CVE_2017_5715 applied on CPU%d\n",
145 		 __func__, smp_processor_id());
146 }
147 #else
148 static inline void omap5_secondary_harden_predictor(void) { }
149 #endif
150 
151 static void omap4_secondary_init(unsigned int cpu)
152 {
153 	/*
154 	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
155 	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
156 	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
157 	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
158 	 * OMAP443X GP devices- SMP bit isn't accessible.
159 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
160 	 */
161 	if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
162 		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
163 							4, 0, 0, 0, 0, 0);
164 
165 	if (soc_is_omap54xx() || soc_is_dra7xx()) {
166 		/*
167 		 * Configure the CNTFRQ register for the secondary cpu's which
168 		 * indicates the frequency of the cpu local timers.
169 		 */
170 		set_cntfreq();
171 		/* Configure ACR to disable streaming WA for 801819 */
172 		omap5_erratum_workaround_801819();
173 		/* Enable ACR to allow for ICUALLU workaround */
174 		omap5_secondary_harden_predictor();
175 	}
176 
177 	/*
178 	 * Synchronise with the boot thread.
179 	 */
180 	spin_lock(&boot_lock);
181 	spin_unlock(&boot_lock);
182 }
183 
184 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
185 {
186 	static struct clockdomain *cpu1_clkdm;
187 	static bool booted;
188 	static struct powerdomain *cpu1_pwrdm;
189 
190 	/*
191 	 * Set synchronisation state between this boot processor
192 	 * and the secondary one
193 	 */
194 	spin_lock(&boot_lock);
195 
196 	/*
197 	 * Update the AuxCoreBoot0 with boot state for secondary core.
198 	 * omap4_secondary_startup() routine will hold the secondary core till
199 	 * the AuxCoreBoot1 register is updated with cpu state
200 	 * A barrier is added to ensure that write buffer is drained
201 	 */
202 	if (omap_secure_apis_support())
203 		omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
204 					 0xfffffdff);
205 	else
206 		writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
207 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
208 
209 	if (!cpu1_clkdm && !cpu1_pwrdm) {
210 		cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
211 		cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
212 	}
213 
214 	/*
215 	 * The SGI(Software Generated Interrupts) are not wakeup capable
216 	 * from low power states. This is known limitation on OMAP4 and
217 	 * needs to be worked around by using software forced clockdomain
218 	 * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
219 	 * software force wakeup. The clockdomain is then put back to
220 	 * hardware supervised mode.
221 	 * More details can be found in OMAP4430 TRM - Version J
222 	 * Section :
223 	 *	4.3.4.2 Power States of CPU0 and CPU1
224 	 */
225 	if (booted && cpu1_pwrdm && cpu1_clkdm) {
226 		/*
227 		 * GIC distributor control register has changed between
228 		 * CortexA9 r1pX and r2pX. The Control Register secure
229 		 * banked version is now composed of 2 bits:
230 		 * bit 0 == Secure Enable
231 		 * bit 1 == Non-Secure Enable
232 		 * The Non-Secure banked register has not changed
233 		 * Because the ROM Code is based on the r1pX GIC, the CPU1
234 		 * GIC restoration will cause a problem to CPU0 Non-Secure SW.
235 		 * The workaround must be:
236 		 * 1) Before doing the CPU1 wakeup, CPU0 must disable
237 		 * the GIC distributor
238 		 * 2) CPU1 must re-enable the GIC distributor on
239 		 * it's wakeup path.
240 		 */
241 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
242 			local_irq_disable();
243 			gic_dist_disable();
244 		}
245 
246 		/*
247 		 * Ensure that CPU power state is set to ON to avoid CPU
248 		 * powerdomain transition on wfi
249 		 */
250 		clkdm_deny_idle_nolock(cpu1_clkdm);
251 		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
252 		clkdm_allow_idle_nolock(cpu1_clkdm);
253 
254 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
255 			while (gic_dist_disabled()) {
256 				udelay(1);
257 				cpu_relax();
258 			}
259 			gic_timer_retrigger();
260 			local_irq_enable();
261 		}
262 	} else {
263 		dsb_sev();
264 		booted = true;
265 	}
266 
267 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
268 
269 	/*
270 	 * Now the secondary core is starting up let it run its
271 	 * calibrations, then wait for it to finish
272 	 */
273 	spin_unlock(&boot_lock);
274 
275 	return 0;
276 }
277 
278 /*
279  * Initialise the CPU possible map early - this describes the CPUs
280  * which may be present or become present in the system.
281  */
282 static void __init omap4_smp_init_cpus(void)
283 {
284 	unsigned int i = 0, ncores = 1, cpu_id;
285 
286 	/* Use ARM cpuid check here, as SoC detection will not work so early */
287 	cpu_id = read_cpuid_id() & CPU_MASK;
288 	if (cpu_id == CPU_CORTEX_A9) {
289 		/*
290 		 * Currently we can't call ioremap here because
291 		 * SoC detection won't work until after init_early.
292 		 */
293 		cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
294 		BUG_ON(!cfg.scu_base);
295 		ncores = scu_get_core_count(cfg.scu_base);
296 	} else if (cpu_id == CPU_CORTEX_A15) {
297 		ncores = OMAP5_CORE_COUNT;
298 	}
299 
300 	/* sanity check */
301 	if (ncores > nr_cpu_ids) {
302 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
303 			ncores, nr_cpu_ids);
304 		ncores = nr_cpu_ids;
305 	}
306 
307 	for (i = 0; i < ncores; i++)
308 		set_cpu_possible(i, true);
309 }
310 
311 /*
312  * For now, just make sure the start-up address is not within the booting
313  * kernel space as that means we just overwrote whatever secondary_startup()
314  * code there was.
315  */
316 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
317 {
318 	if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
319 		return false;
320 
321 	return true;
322 }
323 
324 /*
325  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
326  * up trying to use old kernel startup address or suspend-resume will
327  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
328  * idle states.
329  */
330 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
331 {
332 	unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
333 	bool needs_reset = false;
334 	u32 released;
335 
336 	if (omap_secure_apis_support())
337 		released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
338 	else
339 		released = readl_relaxed(cfg.wakeupgen_base +
340 					 OMAP_AUX_CORE_BOOT_0) &
341 						AUX_CORE_BOOT0_GP_RELEASE;
342 	if (released) {
343 		pr_warn("smp: CPU1 not parked?\n");
344 
345 		return;
346 	}
347 
348 	cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
349 					OMAP_AUX_CORE_BOOT_1);
350 
351 	/* Did the configured secondary_startup() get overwritten? */
352 	if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
353 		needs_reset = true;
354 
355 	/*
356 	 * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
357 	 * deeper idle state in WFI and will wake to an invalid address.
358 	 */
359 	if ((soc_is_omap44xx() || soc_is_omap54xx())) {
360 		cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
361 		if (!omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
362 			needs_reset = true;
363 	} else {
364 		cpu1_ns_pa_addr = 0;
365 	}
366 
367 	if (!needs_reset || !c->cpu1_rstctrl_va)
368 		return;
369 
370 	pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
371 		cpu1_startup_pa, cpu1_ns_pa_addr);
372 
373 	writel_relaxed(1, c->cpu1_rstctrl_va);
374 	readl_relaxed(c->cpu1_rstctrl_va);
375 	writel_relaxed(0, c->cpu1_rstctrl_va);
376 }
377 
378 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
379 {
380 	const struct omap_smp_config *c = NULL;
381 
382 	if (soc_is_omap443x())
383 		c = &omap443x_cfg;
384 	else if (soc_is_omap446x())
385 		c = &omap446x_cfg;
386 	else if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x())
387 		c = &omap5_cfg;
388 
389 	if (!c) {
390 		pr_err("%s Unknown SMP SoC?\n", __func__);
391 		return;
392 	}
393 
394 	/* Must preserve cfg.scu_base set earlier */
395 	cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
396 	cfg.startup_addr = c->startup_addr;
397 	cfg.wakeupgen_base = omap_get_wakeupgen_base();
398 
399 	if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x()) {
400 		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
401 			cfg.startup_addr = omap5_secondary_hyp_startup;
402 		omap5_erratum_workaround_801819();
403 	}
404 
405 	cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
406 	if (!cfg.cpu1_rstctrl_va)
407 		return;
408 
409 	/*
410 	 * Initialise the SCU and wake up the secondary core using
411 	 * wakeup_secondary().
412 	 */
413 	if (cfg.scu_base)
414 		scu_enable(cfg.scu_base);
415 
416 	omap4_smp_maybe_reset_cpu1(&cfg);
417 
418 	/*
419 	 * Write the address of secondary startup routine into the
420 	 * AuxCoreBoot1 where ROM code will jump and start executing
421 	 * on secondary core once out of WFE
422 	 * A barrier is added to ensure that write buffer is drained
423 	 */
424 	if (omap_secure_apis_support())
425 		omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
426 	else
427 		writel_relaxed(__pa_symbol(cfg.startup_addr),
428 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
429 }
430 
431 const struct smp_operations omap4_smp_ops __initconst = {
432 	.smp_init_cpus		= omap4_smp_init_cpus,
433 	.smp_prepare_cpus	= omap4_smp_prepare_cpus,
434 	.smp_secondary_init	= omap4_secondary_init,
435 	.smp_boot_secondary	= omap4_boot_secondary,
436 #ifdef CONFIG_HOTPLUG_CPU
437 	.cpu_die		= omap4_cpu_die,
438 	.cpu_kill		= omap4_cpu_kill,
439 #endif
440 };
441