xref: /linux/arch/arm/mach-omap2/omap-smp.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP4 SMP source file. It contains platform specific functions
4  * needed for the linux smp kernel.
5  *
6  * Copyright (C) 2009 Texas Instruments, Inc.
7  *
8  * Author:
9  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
10  *
11  * Platform file needed for the OMAP4 SMP. This file is based on arm
12  * realview smp platform.
13  * * Copyright (c) 2002 ARM Limited.
14  */
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/smp.h>
18 #include <linux/io.h>
19 #include <linux/irqchip/arm-gic.h>
20 
21 #include <asm/sections.h>
22 #include <asm/smp_scu.h>
23 #include <asm/virt.h>
24 
25 #include "omap-secure.h"
26 #include "omap-wakeupgen.h"
27 #include <asm/cputype.h>
28 
29 #include "soc.h"
30 #include "iomap.h"
31 #include "common.h"
32 #include "clockdomain.h"
33 #include "pm.h"
34 
35 #define CPU_MASK		0xff0ffff0
36 #define CPU_CORTEX_A9		0x410FC090
37 #define CPU_CORTEX_A15		0x410FC0F0
38 
39 #define OMAP5_CORE_COUNT	0x2
40 
41 #define AUX_CORE_BOOT0_GP_RELEASE	0x020
42 #define AUX_CORE_BOOT0_HS_RELEASE	0x200
43 
44 struct omap_smp_config {
45 	unsigned long cpu1_rstctrl_pa;
46 	void __iomem *cpu1_rstctrl_va;
47 	void __iomem *scu_base;
48 	void __iomem *wakeupgen_base;
49 	void *startup_addr;
50 };
51 
52 static struct omap_smp_config cfg;
53 
54 static const struct omap_smp_config omap443x_cfg __initconst = {
55 	.cpu1_rstctrl_pa = 0x4824380c,
56 	.startup_addr = omap4_secondary_startup,
57 };
58 
59 static const struct omap_smp_config omap446x_cfg __initconst = {
60 	.cpu1_rstctrl_pa = 0x4824380c,
61 	.startup_addr = omap4460_secondary_startup,
62 };
63 
64 static const struct omap_smp_config omap5_cfg __initconst = {
65 	.cpu1_rstctrl_pa = 0x48243810,
66 	.startup_addr = omap5_secondary_startup,
67 };
68 
omap4_get_scu_base(void)69 void __iomem *omap4_get_scu_base(void)
70 {
71 	return cfg.scu_base;
72 }
73 
74 #ifdef CONFIG_OMAP5_ERRATA_801819
omap5_erratum_workaround_801819(void)75 static void omap5_erratum_workaround_801819(void)
76 {
77 	u32 acr, revidr;
78 	u32 acr_mask;
79 
80 	/* REVIDR[3] indicates erratum fix available on silicon */
81 	asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr));
82 	if (revidr & (0x1 << 3))
83 		return;
84 
85 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
86 	/*
87 	 * BIT(27) - Disables streaming. All write-allocate lines allocate in
88 	 * the L1 or L2 cache.
89 	 * BIT(25) - Disables streaming. All write-allocate lines allocate in
90 	 * the L1 cache.
91 	 */
92 	acr_mask = (0x3 << 25) | (0x3 << 27);
93 	/* do we already have it done.. if yes, skip expensive smc */
94 	if ((acr & acr_mask) == acr_mask)
95 		return;
96 
97 	acr |= acr_mask;
98 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
99 
100 	pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n",
101 		 __func__, smp_processor_id());
102 }
103 #else
omap5_erratum_workaround_801819(void)104 static inline void omap5_erratum_workaround_801819(void) { }
105 #endif
106 
107 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
108 /*
109  * Configure ACR and enable ACTLR[0] (Enable invalidates of BTB with
110  * ICIALLU) to activate the workaround for secondary Core.
111  * NOTE: it is assumed that the primary core's configuration is done
112  * by the boot loader (kernel will detect a misconfiguration and complain
113  * if this is not done).
114  *
115  * In General Purpose(GP) devices, ACR bit settings can only be done
116  * by ROM code in "secure world" using the smc call and there is no
117  * option to update the "firmware" on such devices. This also works for
118  * High security(HS) devices, as a backup option in case the
119  * "update" is not done in the "security firmware".
120  */
omap5_secondary_harden_predictor(void)121 static void omap5_secondary_harden_predictor(void)
122 {
123 	u32 acr, acr_mask;
124 
125 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
126 
127 	/*
128 	 * ACTLR[0] (Enable invalidates of BTB with ICIALLU)
129 	 */
130 	acr_mask = BIT(0);
131 
132 	/* Do we already have it done.. if yes, skip expensive smc */
133 	if ((acr & acr_mask) == acr_mask)
134 		return;
135 
136 	acr |= acr_mask;
137 	omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
138 
139 	pr_debug("%s: ARM ACR setup for CVE_2017_5715 applied on CPU%d\n",
140 		 __func__, smp_processor_id());
141 }
142 #else
omap5_secondary_harden_predictor(void)143 static inline void omap5_secondary_harden_predictor(void) { }
144 #endif
145 
omap4_secondary_init(unsigned int cpu)146 static void omap4_secondary_init(unsigned int cpu)
147 {
148 	/*
149 	 * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
150 	 * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
151 	 * init and for CPU1, a secure PPA API provided. CPU0 must be ON
152 	 * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
153 	 * OMAP443X GP devices- SMP bit isn't accessible.
154 	 * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
155 	 */
156 	if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
157 		omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
158 							4, 0, 0, 0, 0, 0);
159 
160 	if (soc_is_omap54xx() || soc_is_dra7xx()) {
161 		/*
162 		 * Configure the CNTFRQ register for the secondary cpu's which
163 		 * indicates the frequency of the cpu local timers.
164 		 */
165 		set_cntfreq();
166 		/* Configure ACR to disable streaming WA for 801819 */
167 		omap5_erratum_workaround_801819();
168 		/* Enable ACR to allow for ICUALLU workaround */
169 		omap5_secondary_harden_predictor();
170 	}
171 }
172 
omap4_boot_secondary(unsigned int cpu,struct task_struct * idle)173 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
174 {
175 	static struct clockdomain *cpu1_clkdm;
176 	static bool booted;
177 	static struct powerdomain *cpu1_pwrdm;
178 
179 	/*
180 	 * Update the AuxCoreBoot0 with boot state for secondary core.
181 	 * omap4_secondary_startup() routine will hold the secondary core till
182 	 * the AuxCoreBoot1 register is updated with cpu state
183 	 * A barrier is added to ensure that write buffer is drained
184 	 */
185 	if (omap_secure_apis_support())
186 		omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
187 					 0xfffffdff);
188 	else
189 		writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
190 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
191 
192 	if (!cpu1_clkdm && !cpu1_pwrdm) {
193 		cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
194 		cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
195 	}
196 
197 	/*
198 	 * The SGI(Software Generated Interrupts) are not wakeup capable
199 	 * from low power states. This is known limitation on OMAP4 and
200 	 * needs to be worked around by using software forced clockdomain
201 	 * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
202 	 * software force wakeup. The clockdomain is then put back to
203 	 * hardware supervised mode.
204 	 * More details can be found in OMAP4430 TRM - Version J
205 	 * Section :
206 	 *	4.3.4.2 Power States of CPU0 and CPU1
207 	 */
208 	if (booted && cpu1_pwrdm && cpu1_clkdm) {
209 		/*
210 		 * GIC distributor control register has changed between
211 		 * CortexA9 r1pX and r2pX. The Control Register secure
212 		 * banked version is now composed of 2 bits:
213 		 * bit 0 == Secure Enable
214 		 * bit 1 == Non-Secure Enable
215 		 * The Non-Secure banked register has not changed
216 		 * Because the ROM Code is based on the r1pX GIC, the CPU1
217 		 * GIC restoration will cause a problem to CPU0 Non-Secure SW.
218 		 * The workaround must be:
219 		 * 1) Before doing the CPU1 wakeup, CPU0 must disable
220 		 * the GIC distributor
221 		 * 2) CPU1 must re-enable the GIC distributor on
222 		 * it's wakeup path.
223 		 */
224 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
225 			local_irq_disable();
226 			gic_dist_disable();
227 		}
228 
229 		/*
230 		 * Ensure that CPU power state is set to ON to avoid CPU
231 		 * powerdomain transition on wfi
232 		 */
233 		clkdm_deny_idle_nolock(cpu1_clkdm);
234 		pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
235 		clkdm_allow_idle_nolock(cpu1_clkdm);
236 
237 		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
238 			while (gic_dist_disabled()) {
239 				udelay(1);
240 				cpu_relax();
241 			}
242 			gic_timer_retrigger();
243 			local_irq_enable();
244 		}
245 	} else {
246 		dsb_sev();
247 		booted = true;
248 	}
249 
250 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
251 
252 	return 0;
253 }
254 
255 /*
256  * Initialise the CPU possible map early - this describes the CPUs
257  * which may be present or become present in the system.
258  */
omap4_smp_init_cpus(void)259 static void __init omap4_smp_init_cpus(void)
260 {
261 	unsigned int i = 0, ncores = 1, cpu_id;
262 
263 	/* Use ARM cpuid check here, as SoC detection will not work so early */
264 	cpu_id = read_cpuid_id() & CPU_MASK;
265 	if (cpu_id == CPU_CORTEX_A9) {
266 		/*
267 		 * Currently we can't call ioremap here because
268 		 * SoC detection won't work until after init_early.
269 		 */
270 		cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
271 		BUG_ON(!cfg.scu_base);
272 		ncores = scu_get_core_count(cfg.scu_base);
273 	} else if (cpu_id == CPU_CORTEX_A15) {
274 		ncores = OMAP5_CORE_COUNT;
275 	}
276 
277 	/* sanity check */
278 	if (ncores > nr_cpu_ids) {
279 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
280 			ncores, nr_cpu_ids);
281 		ncores = nr_cpu_ids;
282 	}
283 
284 	for (i = 0; i < ncores; i++)
285 		set_cpu_possible(i, true);
286 }
287 
288 /*
289  * For now, just make sure the start-up address is not within the booting
290  * kernel space as that means we just overwrote whatever secondary_startup()
291  * code there was.
292  */
omap4_smp_cpu1_startup_valid(unsigned long addr)293 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
294 {
295 	if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
296 		return false;
297 
298 	return true;
299 }
300 
301 /*
302  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
303  * up trying to use old kernel startup address or suspend-resume will
304  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
305  * idle states.
306  */
omap4_smp_maybe_reset_cpu1(struct omap_smp_config * c)307 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
308 {
309 	unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
310 	bool needs_reset = false;
311 	u32 released;
312 
313 	if (omap_secure_apis_support())
314 		released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
315 	else
316 		released = readl_relaxed(cfg.wakeupgen_base +
317 					 OMAP_AUX_CORE_BOOT_0) &
318 						AUX_CORE_BOOT0_GP_RELEASE;
319 	if (released) {
320 		pr_warn("smp: CPU1 not parked?\n");
321 
322 		return;
323 	}
324 
325 	cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
326 					OMAP_AUX_CORE_BOOT_1);
327 
328 	/* Did the configured secondary_startup() get overwritten? */
329 	if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
330 		needs_reset = true;
331 
332 	/*
333 	 * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
334 	 * deeper idle state in WFI and will wake to an invalid address.
335 	 */
336 	if ((soc_is_omap44xx() || soc_is_omap54xx())) {
337 		cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
338 		if (!omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
339 			needs_reset = true;
340 	} else {
341 		cpu1_ns_pa_addr = 0;
342 	}
343 
344 	if (!needs_reset || !c->cpu1_rstctrl_va)
345 		return;
346 
347 	pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
348 		cpu1_startup_pa, cpu1_ns_pa_addr);
349 
350 	writel_relaxed(1, c->cpu1_rstctrl_va);
351 	readl_relaxed(c->cpu1_rstctrl_va);
352 	writel_relaxed(0, c->cpu1_rstctrl_va);
353 }
354 
omap4_smp_prepare_cpus(unsigned int max_cpus)355 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
356 {
357 	const struct omap_smp_config *c = NULL;
358 
359 	if (soc_is_omap443x())
360 		c = &omap443x_cfg;
361 	else if (soc_is_omap446x())
362 		c = &omap446x_cfg;
363 	else if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x())
364 		c = &omap5_cfg;
365 
366 	if (!c) {
367 		pr_err("%s Unknown SMP SoC?\n", __func__);
368 		return;
369 	}
370 
371 	/* Must preserve cfg.scu_base set earlier */
372 	cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
373 	cfg.startup_addr = c->startup_addr;
374 	cfg.wakeupgen_base = omap_get_wakeupgen_base();
375 
376 	if (soc_is_dra74x() || soc_is_omap54xx() || soc_is_dra76x()) {
377 		if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
378 			cfg.startup_addr = omap5_secondary_hyp_startup;
379 		omap5_erratum_workaround_801819();
380 	}
381 
382 	cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
383 	if (!cfg.cpu1_rstctrl_va)
384 		return;
385 
386 	/*
387 	 * Initialise the SCU and wake up the secondary core using
388 	 * wakeup_secondary().
389 	 */
390 	if (cfg.scu_base)
391 		scu_enable(cfg.scu_base);
392 
393 	omap4_smp_maybe_reset_cpu1(&cfg);
394 
395 	/*
396 	 * Write the address of secondary startup routine into the
397 	 * AuxCoreBoot1 where ROM code will jump and start executing
398 	 * on secondary core once out of WFE
399 	 * A barrier is added to ensure that write buffer is drained
400 	 */
401 	if (omap_secure_apis_support())
402 		omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
403 	else
404 		writel_relaxed(__pa_symbol(cfg.startup_addr),
405 			       cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
406 }
407 
408 const struct smp_operations omap4_smp_ops __initconst = {
409 	.smp_init_cpus		= omap4_smp_init_cpus,
410 	.smp_prepare_cpus	= omap4_smp_prepare_cpus,
411 	.smp_secondary_init	= omap4_secondary_init,
412 	.smp_boot_secondary	= omap4_boot_secondary,
413 #ifdef CONFIG_HOTPLUG_CPU
414 	.cpu_die		= omap4_cpu_die,
415 	.cpu_kill		= omap4_cpu_kill,
416 #endif
417 };
418