1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mach-tegra/platsmp.c
4 *
5 * Copyright (C) 2002 ARM Ltd.
6 * All Rights Reserved
7 *
8 * Copyright (C) 2009 Palm
9 * All Rights Reserved
10 */
11
12 #include <linux/clk/tegra.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/io.h>
18 #include <linux/jiffies.h>
19 #include <linux/smp.h>
20
21 #include <soc/tegra/flowctrl.h>
22 #include <soc/tegra/fuse.h>
23 #include <soc/tegra/pmc.h>
24
25 #include <asm/cacheflush.h>
26 #include <asm/mach-types.h>
27 #include <asm/smp_plat.h>
28 #include <asm/smp_scu.h>
29
30 #include "common.h"
31 #include "iomap.h"
32 #include "reset.h"
33
34 static cpumask_t tegra_cpu_init_mask;
35
36 static void tegra_secondary_init(unsigned int cpu)
37 {
38 cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
39 }
40
41
42 static int tegra20_boot_secondary(unsigned int cpu, struct task_struct *idle)
43 {
44 cpu = cpu_logical_map(cpu);
45
46 /*
47 * Force the CPU into reset. The CPU must remain in reset when
48 * the flow controller state is cleared (which will cause the
49 * flow controller to stop driving reset if the CPU has been
50 * power-gated via the flow controller). This will have no
51 * effect on first boot of the CPU since it should already be
52 * in reset.
53 */
54 tegra_put_cpu_in_reset(cpu);
55
56 /*
57 * Unhalt the CPU. If the flow controller was used to
58 * power-gate the CPU this will cause the flow controller to
59 * stop driving reset. The CPU will remain in reset because the
60 * clock and reset block is now driving reset.
61 */
62 flowctrl_write_cpu_halt(cpu, 0);
63
64 tegra_enable_cpu_clock(cpu);
65 flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
66 tegra_cpu_out_of_reset(cpu);
67 return 0;
68 }
69
70 static int tegra30_boot_secondary(unsigned int cpu, struct task_struct *idle)
71 {
72 int ret;
73 unsigned long timeout;
74
75 cpu = cpu_logical_map(cpu);
76 tegra_put_cpu_in_reset(cpu);
77 flowctrl_write_cpu_halt(cpu, 0);
78
79 /*
80 * The power up sequence of cold boot CPU and warm boot CPU
81 * was different.
82 *
83 * For warm boot CPU that was resumed from CPU hotplug, the
84 * power will be resumed automatically after un-halting the
85 * flow controller of the warm boot CPU. We need to wait for
86 * the confirmation that the CPU is powered then removing
87 * the IO clamps.
88 * For cold boot CPU, do not wait. After the cold boot CPU be
89 * booted, it will run to tegra_secondary_init() and set
90 * tegra_cpu_init_mask which influences what tegra30_boot_secondary()
91 * next time around.
92 */
93 if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
94 timeout = jiffies + msecs_to_jiffies(50);
95 do {
96 if (tegra_pmc_cpu_is_powered(cpu))
97 goto remove_clamps;
98 udelay(10);
99 } while (time_before(jiffies, timeout));
100 }
101
102 /*
103 * The power status of the cold boot CPU is power gated as
104 * default. To power up the cold boot CPU, the power should
105 * be un-gated by un-toggling the power gate register
106 * manually.
107 */
108 ret = tegra_pmc_cpu_power_on(cpu);
109 if (ret)
110 return ret;
111
112 remove_clamps:
113 /* CPU partition is powered. Enable the CPU clock. */
114 tegra_enable_cpu_clock(cpu);
115 udelay(10);
116
117 /* Remove I/O clamps. */
118 ret = tegra_pmc_cpu_remove_clamping(cpu);
119 if (ret)
120 return ret;
121
122 udelay(10);
123
124 flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
125 tegra_cpu_out_of_reset(cpu);
126 return 0;
127 }
128
129 static int tegra114_boot_secondary(unsigned int cpu, struct task_struct *idle)
130 {
131 int ret = 0;
132
133 cpu = cpu_logical_map(cpu);
134
135 if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
136 /*
137 * Warm boot flow
138 * The flow controller in charge of the power state and
139 * control for each CPU.
140 */
141 /* set SCLK as event trigger for flow controller */
142 flowctrl_write_cpu_csr(cpu, 1);
143 flowctrl_write_cpu_halt(cpu,
144 FLOW_CTRL_WAITEVENT | FLOW_CTRL_SCLK_RESUME);
145 } else {
146 /*
147 * Cold boot flow
148 * The CPU is powered up by toggling PMC directly. It will
149 * also initial power state in flow controller. After that,
150 * the CPU's power state is maintained by flow controller.
151 */
152 ret = tegra_pmc_cpu_power_on(cpu);
153 }
154
155 return ret;
156 }
157
158 static int tegra_boot_secondary(unsigned int cpu,
159 struct task_struct *idle)
160 {
161 if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && tegra_get_chip_id() == TEGRA20)
162 return tegra20_boot_secondary(cpu, idle);
163 if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) && tegra_get_chip_id() == TEGRA30)
164 return tegra30_boot_secondary(cpu, idle);
165 if (IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) && tegra_get_chip_id() == TEGRA114)
166 return tegra114_boot_secondary(cpu, idle);
167 if (IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC) && tegra_get_chip_id() == TEGRA124)
168 return tegra114_boot_secondary(cpu, idle);
169
170 return -EINVAL;
171 }
172
173 static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
174 {
175 /* Always mark the boot CPU (CPU0) as initialized. */
176 cpumask_set_cpu(0, &tegra_cpu_init_mask);
177
178 if (scu_a9_has_base())
179 scu_enable(IO_ADDRESS(scu_a9_get_base()));
180 }
181
182 const struct smp_operations tegra_smp_ops __initconst = {
183 .smp_prepare_cpus = tegra_smp_prepare_cpus,
184 .smp_secondary_init = tegra_secondary_init,
185 .smp_boot_secondary = tegra_boot_secondary,
186 #ifdef CONFIG_HOTPLUG_CPU
187 .cpu_kill = tegra_cpu_kill,
188 .cpu_die = tegra_cpu_die,
189 #endif
190 };
191
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