xref: /openbmc/linux/arch/arm/mach-tegra/platsmp.c (revision d5becc32)
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 
tegra_secondary_init(unsigned int cpu)36 static void tegra_secondary_init(unsigned int cpu)
37 {
38 	cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
39 }
40 
41 
tegra20_boot_secondary(unsigned int cpu,struct task_struct * idle)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 
tegra30_boot_secondary(unsigned int cpu,struct task_struct * idle)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 
tegra114_boot_secondary(unsigned int cpu,struct task_struct * idle)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 
tegra_boot_secondary(unsigned int cpu,struct task_struct * idle)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 
tegra_smp_prepare_cpus(unsigned int max_cpus)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