1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
3 // http://www.samsung.com
4 //
5 // Based on arch/arm/mach-vexpress/dcscb.c
6
7 #include <linux/arm-cci.h>
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include <linux/of_address.h>
11 #include <linux/syscore_ops.h>
12 #include <linux/soc/samsung/exynos-regs-pmu.h>
13
14 #include <asm/cputype.h>
15 #include <asm/cp15.h>
16 #include <asm/mcpm.h>
17 #include <asm/smp_plat.h>
18
19 #include "common.h"
20
21 #define EXYNOS5420_CPUS_PER_CLUSTER 4
22 #define EXYNOS5420_NR_CLUSTERS 2
23
24 #define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN BIT(9)
25 #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE BIT(29)
26 #define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30)
27
28 static void __iomem *ns_sram_base_addr __ro_after_init;
29 static bool secure_firmware __ro_after_init;
30
31 /*
32 * The common v7_exit_coherency_flush API could not be used because of the
33 * Erratum 799270 workaround. This macro is the same as the common one (in
34 * arch/arm/include/asm/cacheflush.h) except for the erratum handling.
35 */
36 #define exynos_v7_exit_coherency_flush(level) \
37 asm volatile( \
38 "mrc p15, 0, r0, c1, c0, 0 @ get SCTLR\n\t" \
39 "bic r0, r0, #"__stringify(CR_C)"\n\t" \
40 "mcr p15, 0, r0, c1, c0, 0 @ set SCTLR\n\t" \
41 "isb\n\t"\
42 "bl v7_flush_dcache_"__stringify(level)"\n\t" \
43 "mrc p15, 0, r0, c1, c0, 1 @ get ACTLR\n\t" \
44 "bic r0, r0, #(1 << 6) @ disable local coherency\n\t" \
45 /* Dummy Load of a device register to avoid Erratum 799270 */ \
46 "ldr r4, [%0]\n\t" \
47 "and r4, r4, #0\n\t" \
48 "orr r0, r0, r4\n\t" \
49 "mcr p15, 0, r0, c1, c0, 1 @ set ACTLR\n\t" \
50 "isb\n\t" \
51 "dsb\n\t" \
52 : \
53 : "Ir" (pmu_base_addr + S5P_INFORM0) \
54 : "r0", "r1", "r2", "r3", "r4", "r5", "r6", \
55 "r9", "r10", "ip", "lr", "memory")
56
57 static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
58 {
59 unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
60 bool state;
61
62 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
63 if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
64 cluster >= EXYNOS5420_NR_CLUSTERS)
65 return -EINVAL;
66
67 state = exynos_cpu_power_state(cpunr);
68 exynos_cpu_power_up(cpunr);
69 if (!state && secure_firmware) {
70 /*
71 * This assumes the cluster number of the big cores(Cortex A15)
72 * is 0 and the Little cores(Cortex A7) is 1.
73 * When the system was booted from the Little core,
74 * they should be reset during power up cpu.
75 */
76 if (cluster &&
77 cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
78 unsigned int timeout = 16;
79
80 /*
81 * Before we reset the Little cores, we should wait
82 * the SPARE2 register is set to 1 because the init
83 * codes of the iROM will set the register after
84 * initialization.
85 */
86 while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
87 timeout--;
88 udelay(10);
89 }
90
91 if (timeout == 0) {
92 pr_err("cpu %u cluster %u powerup failed\n",
93 cpu, cluster);
94 exynos_cpu_power_down(cpunr);
95 return -ETIMEDOUT;
96 }
97
98 pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
99 EXYNOS_SWRESET);
100 }
101 }
102
103 return 0;
104 }
105
106 static int exynos_cluster_powerup(unsigned int cluster)
107 {
108 pr_debug("%s: cluster %u\n", __func__, cluster);
109 if (cluster >= EXYNOS5420_NR_CLUSTERS)
110 return -EINVAL;
111
112 exynos_cluster_power_up(cluster);
113 return 0;
114 }
115
116 static void exynos_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
117 {
118 unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
119
120 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
121 BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
122 cluster >= EXYNOS5420_NR_CLUSTERS);
123 exynos_cpu_power_down(cpunr);
124 }
125
126 static void exynos_cluster_powerdown_prepare(unsigned int cluster)
127 {
128 pr_debug("%s: cluster %u\n", __func__, cluster);
129 BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
130 exynos_cluster_power_down(cluster);
131 }
132
133 static void exynos_cpu_cache_disable(void)
134 {
135 /* Disable and flush the local CPU cache. */
136 exynos_v7_exit_coherency_flush(louis);
137 }
138
139 static void exynos_cluster_cache_disable(void)
140 {
141 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
142 /*
143 * On the Cortex-A15 we need to disable
144 * L2 prefetching before flushing the cache.
145 */
146 asm volatile(
147 "mcr p15, 1, %0, c15, c0, 3\n\t"
148 "isb\n\t"
149 "dsb"
150 : : "r" (0x400));
151 }
152
153 /* Flush all cache levels for this cluster. */
154 exynos_v7_exit_coherency_flush(all);
155
156 /*
157 * Disable cluster-level coherency by masking
158 * incoming snoops and DVM messages:
159 */
160 cci_disable_port_by_cpu(read_cpuid_mpidr());
161 }
162
163 static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
164 {
165 unsigned int tries = 100;
166 unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
167
168 pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
169 BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
170 cluster >= EXYNOS5420_NR_CLUSTERS);
171
172 /* Wait for the core state to be OFF */
173 while (tries--) {
174 if ((exynos_cpu_power_state(cpunr) == 0))
175 return 0; /* success: the CPU is halted */
176
177 /* Otherwise, wait and retry: */
178 msleep(1);
179 }
180
181 return -ETIMEDOUT; /* timeout */
182 }
183
184 static void exynos_cpu_is_up(unsigned int cpu, unsigned int cluster)
185 {
186 /* especially when resuming: make sure power control is set */
187 exynos_cpu_powerup(cpu, cluster);
188 }
189
190 static const struct mcpm_platform_ops exynos_power_ops = {
191 .cpu_powerup = exynos_cpu_powerup,
192 .cluster_powerup = exynos_cluster_powerup,
193 .cpu_powerdown_prepare = exynos_cpu_powerdown_prepare,
194 .cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
195 .cpu_cache_disable = exynos_cpu_cache_disable,
196 .cluster_cache_disable = exynos_cluster_cache_disable,
197 .wait_for_powerdown = exynos_wait_for_powerdown,
198 .cpu_is_up = exynos_cpu_is_up,
199 };
200
201 /*
202 * Enable cluster-level coherency, in preparation for turning on the MMU.
203 */
204 static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
205 {
206 asm volatile ("\n"
207 "cmp r0, #1\n"
208 "bxne lr\n"
209 "b cci_enable_port_for_self");
210 }
211
212 static const struct of_device_id exynos_dt_mcpm_match[] = {
213 { .compatible = "samsung,exynos5420" },
214 { .compatible = "samsung,exynos5800" },
215 {},
216 };
217
218 static void exynos_mcpm_setup_entry_point(void)
219 {
220 /*
221 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
222 * as part of secondary_cpu_start(). Let's redirect it to the
223 * mcpm_entry_point(). This is done during both secondary boot-up as
224 * well as system resume.
225 */
226 __raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
227 __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
228 __raw_writel(__pa_symbol(mcpm_entry_point), ns_sram_base_addr + 8);
229 }
230
231 static struct syscore_ops exynos_mcpm_syscore_ops = {
232 .resume = exynos_mcpm_setup_entry_point,
233 };
234
235 static int __init exynos_mcpm_init(void)
236 {
237 struct device_node *node;
238 unsigned int value, i;
239 int ret;
240
241 node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
242 if (!node)
243 return -ENODEV;
244 of_node_put(node);
245
246 if (!cci_probed())
247 return -ENODEV;
248
249 node = of_find_compatible_node(NULL, NULL,
250 "samsung,exynos4210-sysram-ns");
251 if (!node)
252 return -ENODEV;
253
254 ns_sram_base_addr = of_iomap(node, 0);
255 of_node_put(node);
256 if (!ns_sram_base_addr) {
257 pr_err("failed to map non-secure iRAM base address\n");
258 return -ENOMEM;
259 }
260
261 secure_firmware = exynos_secure_firmware_available();
262
263 /*
264 * To increase the stability of KFC reset we need to program
265 * the PMU SPARE3 register
266 */
267 pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
268
269 ret = mcpm_platform_register(&exynos_power_ops);
270 if (!ret)
271 ret = mcpm_sync_init(exynos_pm_power_up_setup);
272 if (!ret)
273 ret = mcpm_loopback(exynos_cluster_cache_disable); /* turn on the CCI */
274 if (ret) {
275 iounmap(ns_sram_base_addr);
276 return ret;
277 }
278
279 mcpm_smp_set_ops();
280
281 pr_info("Exynos MCPM support installed\n");
282
283 /*
284 * On Exynos5420/5800 for the A15 and A7 clusters:
285 *
286 * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
287 * in a cluster are turned off before turning off the cluster L2.
288 *
289 * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
290 * off before waking it up.
291 *
292 * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
293 * turned on before the first man is powered up.
294 */
295 for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
296 value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
297 value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN |
298 EXYNOS5420_USE_ARM_CORE_DOWN_STATE |
299 EXYNOS5420_USE_L2_COMMON_UP_STATE;
300 pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
301 }
302
303 exynos_mcpm_setup_entry_point();
304
305 register_syscore_ops(&exynos_mcpm_syscore_ops);
306
307 return ret;
308 }
309
310 early_initcall(exynos_mcpm_init);
311
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