1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2007 MIPS Technologies, Inc.
5 * Chris Dearman (chris@mips.com)
6 */
7
8 #undef DEBUG
9
10 #include <linux/kernel.h>
11 #include <linux/sched/task_stack.h>
12 #include <linux/smp.h>
13 #include <linux/cpumask.h>
14 #include <linux/interrupt.h>
15 #include <linux/compiler.h>
16
17 #include <linux/atomic.h>
18 #include <asm/cacheflush.h>
19 #include <asm/cpu.h>
20 #include <asm/processor.h>
21 #include <asm/hardirq.h>
22 #include <asm/mmu_context.h>
23 #include <asm/smp.h>
24 #include <asm/time.h>
25 #include <asm/mipsregs.h>
26 #include <asm/mipsmtregs.h>
27 #include <asm/mips_mt.h>
28 #include <asm/amon.h>
29
cmp_init_secondary(void)30 static void cmp_init_secondary(void)
31 {
32 struct cpuinfo_mips *c __maybe_unused = ¤t_cpu_data;
33
34 /* Assume GIC is present */
35 change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 |
36 STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7);
37
38 /* Enable per-cpu interrupts: platform specific */
39
40 #ifdef CONFIG_MIPS_MT_SMP
41 if (cpu_has_mipsmt)
42 cpu_set_vpe_id(c, (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) &
43 TCBIND_CURVPE);
44 #endif
45 }
46
cmp_smp_finish(void)47 static void cmp_smp_finish(void)
48 {
49 pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
50
51 /* CDFIXME: remove this? */
52 write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));
53
54 #ifdef CONFIG_MIPS_MT_FPAFF
55 /* If we have an FPU, enroll ourselves in the FPU-full mask */
56 if (cpu_has_fpu)
57 cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask);
58 #endif /* CONFIG_MIPS_MT_FPAFF */
59
60 local_irq_enable();
61 }
62
63 /*
64 * Setup the PC, SP, and GP of a secondary processor and start it running
65 * smp_bootstrap is the place to resume from
66 * __KSTK_TOS(idle) is apparently the stack pointer
67 * (unsigned long)idle->thread_info the gp
68 */
cmp_boot_secondary(int cpu,struct task_struct * idle)69 static int cmp_boot_secondary(int cpu, struct task_struct *idle)
70 {
71 struct thread_info *gp = task_thread_info(idle);
72 unsigned long sp = __KSTK_TOS(idle);
73 unsigned long pc = (unsigned long)&smp_bootstrap;
74 unsigned long a0 = 0;
75
76 pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
77 __func__, cpu);
78
79 #if 0
80 /* Needed? */
81 flush_icache_range((unsigned long)gp,
82 (unsigned long)(gp + sizeof(struct thread_info)));
83 #endif
84
85 amon_cpu_start(cpu, pc, sp, (unsigned long)gp, a0);
86 return 0;
87 }
88
89 /*
90 * Common setup before any secondaries are started
91 */
cmp_smp_setup(void)92 void __init cmp_smp_setup(void)
93 {
94 int i;
95 int ncpu = 0;
96
97 pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
98
99 #ifdef CONFIG_MIPS_MT_FPAFF
100 /* If we have an FPU, enroll ourselves in the FPU-full mask */
101 if (cpu_has_fpu)
102 cpumask_set_cpu(0, &mt_fpu_cpumask);
103 #endif /* CONFIG_MIPS_MT_FPAFF */
104
105 for (i = 1; i < NR_CPUS; i++) {
106 if (amon_cpu_avail(i)) {
107 set_cpu_possible(i, true);
108 __cpu_number_map[i] = ++ncpu;
109 __cpu_logical_map[ncpu] = i;
110 }
111 }
112
113 if (cpu_has_mipsmt) {
114 unsigned int nvpe = 1;
115 #ifdef CONFIG_MIPS_MT_SMP
116 unsigned int mvpconf0 = read_c0_mvpconf0();
117
118 nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
119 #endif
120 smp_num_siblings = nvpe;
121 }
122 pr_info("Detected %i available secondary CPU(s)\n", ncpu);
123 }
124
cmp_prepare_cpus(unsigned int max_cpus)125 void __init cmp_prepare_cpus(unsigned int max_cpus)
126 {
127 pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
128 smp_processor_id(), __func__, max_cpus);
129
130 #ifdef CONFIG_MIPS_MT
131 /*
132 * FIXME: some of these options are per-system, some per-core and
133 * some per-cpu
134 */
135 mips_mt_set_cpuoptions();
136 #endif
137
138 }
139
140 const struct plat_smp_ops cmp_smp_ops = {
141 .send_ipi_single = mips_smp_send_ipi_single,
142 .send_ipi_mask = mips_smp_send_ipi_mask,
143 .init_secondary = cmp_init_secondary,
144 .smp_finish = cmp_smp_finish,
145 .boot_secondary = cmp_boot_secondary,
146 .smp_setup = cmp_smp_setup,
147 .prepare_cpus = cmp_prepare_cpus,
148 };
149