xref: /linux/arch/arm/mach-omap2/omap-smp.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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 void __iomem *omap4_get_scu_base(void)
73 {
74 	return cfg.scu_base;
75 }
76 
77 #ifdef CONFIG_OMAP5_ERRATA_801819
78 void omap5_erratum_workaround_801819(void)
79 {
80 	u32 acr, revidr;
81 	u32 acr_mask;
82 
83 	/* REVIDR[3] indicates erratum fix available on silicon */
84 	asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr));
85 	if (revidr & (0x1 << 3))
86 		return;
87 
88 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
89 	/*
90 	 * BIT(27) - Disables streaming. All write-allocate lines allocate in
91 	 * the L1 or L2 cache.
92 	 * BIT(25) - Disables streaming. All write-allocate lines allocate in
93 	 * the L1 cache.
94 	 */
95 	acr_mask = (0x3 << 25) | (0x3 << 27);
96 	/* do we already have it done.. if yes, skip expensive smc */
97 	if ((acr & acr_mask) == acr_mask)
98 		return;
99 
100 	acr |= acr_mask;
101 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
102 
103 	pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n",
104 		 __func__, smp_processor_id());
105 }
106 #else
107 static inline void omap5_erratum_workaround_801819(void) { }
108 #endif
109 
110 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
111 /*
112  * Configure ACR and enable ACTLR[0] (Enable invalidates of BTB with
113  * ICIALLU) to activate the workaround for secondary Core.
114  * NOTE: it is assumed that the primary core's configuration is done
115  * by the boot loader (kernel will detect a misconfiguration and complain
116  * if this is not done).
117  *
118  * In General Purpose(GP) devices, ACR bit settings can only be done
119  * by ROM code in "secure world" using the smc call and there is no
120  * option to update the "firmware" on such devices. This also works for
121  * High security(HS) devices, as a backup option in case the
122  * "update" is not done in the "security firmware".
123  */
124 static void omap5_secondary_harden_predictor(void)
125 {
126 	u32 acr, acr_mask;
127 
128 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
129 
130 	/*
131 	 * ACTLR[0] (Enable invalidates of BTB with ICIALLU)
132 	 */
133 	acr_mask = BIT(0);
134 
135 	/* Do we already have it done.. if yes, skip expensive smc */
136 	if ((acr & acr_mask) == acr_mask)
137 		return;
138 
139 	acr |= acr_mask;
140 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
141 
142 	pr_debug("%s: ARM ACR setup for CVE_2017_5715 applied on CPU%d\n",
143 		 __func__, smp_processor_id());
144 }
145 #else
146 static inline void omap5_secondary_harden_predictor(void) { }
147 #endif
148 
149 static void omap4_secondary_init(unsigned int cpu)
150 {
151 	/*
152 	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
153 	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
154 	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
155 	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
156 	 * OMAP443X GP devices- SMP bit isn't accessible.
157 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
158 	 */
159 	if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
160 		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
161 							4, 0, 0, 0, 0, 0);
162 
163 	if (soc_is_omap54xx() || soc_is_dra7xx()) {
164 		/*
165 		 * Configure the CNTFRQ register for the secondary cpu's which
166 		 * indicates the frequency of the cpu local timers.
167 		 */
168 		set_cntfreq();
169 		/* Configure ACR to disable streaming WA for 801819 */
170 		omap5_erratum_workaround_801819();
171 		/* Enable ACR to allow for ICUALLU workaround */
172 		omap5_secondary_harden_predictor();
173 	}
174 }
175 
176 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
177 {
178 	static struct clockdomain *cpu1_clkdm;
179 	static bool booted;
180 	static struct powerdomain *cpu1_pwrdm;
181 
182 	/*
183 	 * Update the AuxCoreBoot0 with boot state for secondary core.
184 	 * omap4_secondary_startup() routine will hold the secondary core till
185 	 * the AuxCoreBoot1 register is updated with cpu state
186 	 * A barrier is added to ensure that write buffer is drained
187 	 */
188 	if (omap_secure_apis_support())
189 		omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
190 					 0xfffffdff);
191 	else
192 		writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
193 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
194 
195 	if (!cpu1_clkdm && !cpu1_pwrdm) {
196 		cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
197 		cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
198 	}
199 
200 	/*
201 	 * The SGI(Software Generated Interrupts) are not wakeup capable
202 	 * from low power states. This is known limitation on OMAP4 and
203 	 * needs to be worked around by using software forced clockdomain
204 	 * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
205 	 * software force wakeup. The clockdomain is then put back to
206 	 * hardware supervised mode.
207 	 * More details can be found in OMAP4430 TRM - Version J
208 	 * Section :
209 	 *	4.3.4.2 Power States of CPU0 and CPU1
210 	 */
211 	if (booted && cpu1_pwrdm && cpu1_clkdm) {
212 		/*
213 		 * GIC distributor control register has changed between
214 		 * CortexA9 r1pX and r2pX. The Control Register secure
215 		 * banked version is now composed of 2 bits:
216 		 * bit 0 == Secure Enable
217 		 * bit 1 == Non-Secure Enable
218 		 * The Non-Secure banked register has not changed
219 		 * Because the ROM Code is based on the r1pX GIC, the CPU1
220 		 * GIC restoration will cause a problem to CPU0 Non-Secure SW.
221 		 * The workaround must be:
222 		 * 1) Before doing the CPU1 wakeup, CPU0 must disable
223 		 * the GIC distributor
224 		 * 2) CPU1 must re-enable the GIC distributor on
225 		 * it's wakeup path.
226 		 */
227 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
228 			local_irq_disable();
229 			gic_dist_disable();
230 		}
231 
232 		/*
233 		 * Ensure that CPU power state is set to ON to avoid CPU
234 		 * powerdomain transition on wfi
235 		 */
236 		clkdm_deny_idle_nolock(cpu1_clkdm);
237 		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
238 		clkdm_allow_idle_nolock(cpu1_clkdm);
239 
240 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
241 			while (gic_dist_disabled()) {
242 				udelay(1);
243 				cpu_relax();
244 			}
245 			gic_timer_retrigger();
246 			local_irq_enable();
247 		}
248 	} else {
249 		dsb_sev();
250 		booted = true;
251 	}
252 
253 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
254 
255 	return 0;
256 }
257 
258 /*
259  * Initialise the CPU possible map early - this describes the CPUs
260  * which may be present or become present in the system.
261  */
262 static void __init omap4_smp_init_cpus(void)
263 {
264 	unsigned int i = 0, ncores = 1, cpu_id;
265 
266 	/* Use ARM cpuid check here, as SoC detection will not work so early */
267 	cpu_id = read_cpuid_id() & CPU_MASK;
268 	if (cpu_id == CPU_CORTEX_A9) {
269 		/*
270 		 * Currently we can't call ioremap here because
271 		 * SoC detection won't work until after init_early.
272 		 */
273 		cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
274 		BUG_ON(!cfg.scu_base);
275 		ncores = scu_get_core_count(cfg.scu_base);
276 	} else if (cpu_id == CPU_CORTEX_A15) {
277 		ncores = OMAP5_CORE_COUNT;
278 	}
279 
280 	/* sanity check */
281 	if (ncores > nr_cpu_ids) {
282 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
283 			ncores, nr_cpu_ids);
284 		ncores = nr_cpu_ids;
285 	}
286 
287 	for (i = 0; i < ncores; i++)
288 		set_cpu_possible(i, true);
289 }
290 
291 /*
292  * For now, just make sure the start-up address is not within the booting
293  * kernel space as that means we just overwrote whatever secondary_startup()
294  * code there was.
295  */
296 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
297 {
298 	if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
299 		return false;
300 
301 	return true;
302 }
303 
304 /*
305  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
306  * up trying to use old kernel startup address or suspend-resume will
307  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
308  * idle states.
309  */
310 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
311 {
312 	unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
313 	bool needs_reset = false;
314 	u32 released;
315 
316 	if (omap_secure_apis_support())
317 		released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
318 	else
319 		released = readl_relaxed(cfg.wakeupgen_base +
320 					 OMAP_AUX_CORE_BOOT_0) &
321 						AUX_CORE_BOOT0_GP_RELEASE;
322 	if (released) {
323 		pr_warn("smp: CPU1 not parked?\n");
324 
325 		return;
326 	}
327 
328 	cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
329 					OMAP_AUX_CORE_BOOT_1);
330 
331 	/* Did the configured secondary_startup() get overwritten? */
332 	if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
333 		needs_reset = true;
334 
335 	/*
336 	 * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
337 	 * deeper idle state in WFI and will wake to an invalid address.
338 	 */
339 	if ((soc_is_omap44xx() || soc_is_omap54xx())) {
340 		cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
341 		if (!omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
342 			needs_reset = true;
343 	} else {
344 		cpu1_ns_pa_addr = 0;
345 	}
346 
347 	if (!needs_reset || !c->cpu1_rstctrl_va)
348 		return;
349 
350 	pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
351 		cpu1_startup_pa, cpu1_ns_pa_addr);
352 
353 	writel_relaxed(1, c->cpu1_rstctrl_va);
354 	readl_relaxed(c->cpu1_rstctrl_va);
355 	writel_relaxed(0, c->cpu1_rstctrl_va);
356 }
357 
358 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
359 {
360 	const struct omap_smp_config *c = NULL;
361 
362 	if (soc_is_omap443x())
363 		c = &omap443x_cfg;
364 	else if (soc_is_omap446x())
365 		c = &omap446x_cfg;
366 	else if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x())
367 		c = &omap5_cfg;
368 
369 	if (!c) {
370 		pr_err("%s Unknown SMP SoC?\n", __func__);
371 		return;
372 	}
373 
374 	/* Must preserve cfg.scu_base set earlier */
375 	cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
376 	cfg.startup_addr = c->startup_addr;
377 	cfg.wakeupgen_base = omap_get_wakeupgen_base();
378 
379 	if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x()) {
380 		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
381 			cfg.startup_addr = omap5_secondary_hyp_startup;
382 		omap5_erratum_workaround_801819();
383 	}
384 
385 	cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
386 	if (!cfg.cpu1_rstctrl_va)
387 		return;
388 
389 	/*
390 	 * Initialise the SCU and wake up the secondary core using
391 	 * wakeup_secondary().
392 	 */
393 	if (cfg.scu_base)
394 		scu_enable(cfg.scu_base);
395 
396 	omap4_smp_maybe_reset_cpu1(&cfg);
397 
398 	/*
399 	 * Write the address of secondary startup routine into the
400 	 * AuxCoreBoot1 where ROM code will jump and start executing
401 	 * on secondary core once out of WFE
402 	 * A barrier is added to ensure that write buffer is drained
403 	 */
404 	if (omap_secure_apis_support())
405 		omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
406 	else
407 		writel_relaxed(__pa_symbol(cfg.startup_addr),
408 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
409 }
410 
411 const struct smp_operations omap4_smp_ops __initconst = {
412 	.smp_init_cpus		= omap4_smp_init_cpus,
413 	.smp_prepare_cpus	= omap4_smp_prepare_cpus,
414 	.smp_secondary_init	= omap4_secondary_init,
415 	.smp_boot_secondary	= omap4_boot_secondary,
416 #ifdef CONFIG_HOTPLUG_CPU
417 	.cpu_die		= omap4_cpu_die,
418 	.cpu_kill		= omap4_cpu_kill,
419 #endif
420 };
421