1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2004, 05, 06 MIPS Technologies, Inc.
5 * Elizabeth Clarke (beth@mips.com)
6 * Ralf Baechle (ralf@linux-mips.org)
7 * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
8 */
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/cpumask.h>
12 #include <linux/interrupt.h>
13 #include <linux/compiler.h>
14 #include <linux/sched/task_stack.h>
15 #include <linux/smp.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/time.h>
24 #include <asm/mipsregs.h>
25 #include <asm/mipsmtregs.h>
26 #include <asm/mips_mt.h>
27 #include <asm/mips-cps.h>
28
29 static void __init smvp_copy_vpe_config(void)
30 {
31 write_vpe_c0_status(
32 (read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
33
34 /* set config to be the same as vpe0, particularly kseg0 coherency alg */
35 write_vpe_c0_config( read_c0_config());
36
37 /* make sure there are no software interrupts pending */
38 write_vpe_c0_cause(0);
39
40 /* Propagate Config7 */
41 write_vpe_c0_config7(read_c0_config7());
42
43 write_vpe_c0_count(read_c0_count());
44 }
45
46 static unsigned int __init smvp_vpe_init(unsigned int tc, unsigned int mvpconf0,
47 unsigned int ncpu)
48 {
49 if (tc >= smp_max_threads ||
50 (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)))
51 return ncpu;
52
53 /* Deactivate all but VPE 0 */
54 if (tc != 0) {
55 unsigned long tmp = read_vpe_c0_vpeconf0();
56
57 tmp &= ~VPECONF0_VPA;
58
59 /* master VPE */
60 tmp |= VPECONF0_MVP;
61 write_vpe_c0_vpeconf0(tmp);
62
63 /* Record this as available CPU */
64 set_cpu_possible(tc, true);
65 set_cpu_present(tc, true);
66 __cpu_number_map[tc] = ++ncpu;
67 __cpu_logical_map[ncpu] = tc;
68 }
69
70 /* Disable multi-threading with TC's */
71 write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
72
73 if (tc != 0)
74 smvp_copy_vpe_config();
75
76 cpu_set_vpe_id(&cpu_data[ncpu], tc);
77
78 return ncpu;
79 }
80
81 static void __init smvp_tc_init(unsigned int tc, unsigned int mvpconf0)
82 {
83 unsigned long tmp;
84
85 if (!tc)
86 return;
87
88 /* bind a TC to each VPE, May as well put all excess TC's
89 on the last VPE */
90 if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
91 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
92 else {
93 write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
94
95 /* and set XTC */
96 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
97 }
98
99 tmp = read_tc_c0_tcstatus();
100
101 /* mark not allocated and not dynamically allocatable */
102 tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
103 tmp |= TCSTATUS_IXMT; /* interrupt exempt */
104 write_tc_c0_tcstatus(tmp);
105
106 write_tc_c0_tchalt(TCHALT_H);
107 }
108
109 static void vsmp_init_secondary(void)
110 {
111 /* This is Malta specific: IPI,performance and timer interrupts */
112 if (mips_gic_present())
113 change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 |
114 STATUSF_IP4 | STATUSF_IP5 |
115 STATUSF_IP6 | STATUSF_IP7);
116 else
117 change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
118 STATUSF_IP6 | STATUSF_IP7);
119 }
120
121 static void vsmp_smp_finish(void)
122 {
123 /* CDFIXME: remove this? */
124 write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
125
126 #ifdef CONFIG_MIPS_MT_FPAFF
127 /* If we have an FPU, enroll ourselves in the FPU-full mask */
128 if (cpu_has_fpu)
129 cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask);
130 #endif /* CONFIG_MIPS_MT_FPAFF */
131
132 local_irq_enable();
133 }
134
135 /*
136 * Setup the PC, SP, and GP of a secondary processor and start it
137 * running!
138 * smp_bootstrap is the place to resume from
139 * __KSTK_TOS(idle) is apparently the stack pointer
140 * (unsigned long)idle->thread_info the gp
141 * assumes a 1:1 mapping of TC => VPE
142 */
143 static int vsmp_boot_secondary(int cpu, struct task_struct *idle)
144 {
145 struct thread_info *gp = task_thread_info(idle);
146 dvpe();
147 set_c0_mvpcontrol(MVPCONTROL_VPC);
148
149 settc(cpu);
150
151 /* restart */
152 write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
153
154 /* enable the tc this vpe/cpu will be running */
155 write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
156
157 write_tc_c0_tchalt(0);
158
159 /* enable the VPE */
160 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
161
162 /* stack pointer */
163 write_tc_gpr_sp( __KSTK_TOS(idle));
164
165 /* global pointer */
166 write_tc_gpr_gp((unsigned long)gp);
167
168 flush_icache_range((unsigned long)gp,
169 (unsigned long)(gp + sizeof(struct thread_info)));
170
171 /* finally out of configuration and into chaos */
172 clear_c0_mvpcontrol(MVPCONTROL_VPC);
173
174 evpe(EVPE_ENABLE);
175
176 return 0;
177 }
178
179 /*
180 * Common setup before any secondaries are started
181 * Make sure all CPU's are in a sensible state before we boot any of the
182 * secondaries
183 */
184 static void __init vsmp_smp_setup(void)
185 {
186 unsigned int mvpconf0, ntc, tc, ncpu = 0;
187 unsigned int nvpe;
188
189 #ifdef CONFIG_MIPS_MT_FPAFF
190 /* If we have an FPU, enroll ourselves in the FPU-full mask */
191 if (cpu_has_fpu)
192 cpumask_set_cpu(0, &mt_fpu_cpumask);
193 #endif /* CONFIG_MIPS_MT_FPAFF */
194 if (!cpu_has_mipsmt)
195 return;
196
197 /* disable MT so we can configure */
198 dvpe();
199 dmt();
200
201 /* Put MVPE's into 'configuration state' */
202 set_c0_mvpcontrol(MVPCONTROL_VPC);
203
204 mvpconf0 = read_c0_mvpconf0();
205 ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
206
207 nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
208 smp_num_siblings = nvpe;
209
210 /* we'll always have more TC's than VPE's, so loop setting everything
211 to a sensible state */
212 for (tc = 0; tc <= ntc; tc++) {
213 settc(tc);
214
215 smvp_tc_init(tc, mvpconf0);
216 ncpu = smvp_vpe_init(tc, mvpconf0, ncpu);
217 }
218
219 /* Release config state */
220 clear_c0_mvpcontrol(MVPCONTROL_VPC);
221
222 /* We'll wait until starting the secondaries before starting MVPE */
223
224 printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
225 }
226
227 static void __init vsmp_prepare_cpus(unsigned int max_cpus)
228 {
229 mips_mt_set_cpuoptions();
230 }
231
232 const struct plat_smp_ops vsmp_smp_ops = {
233 .send_ipi_single = mips_smp_send_ipi_single,
234 .send_ipi_mask = mips_smp_send_ipi_mask,
235 .init_secondary = vsmp_init_secondary,
236 .smp_finish = vsmp_smp_finish,
237 .boot_secondary = vsmp_boot_secondary,
238 .smp_setup = vsmp_smp_setup,
239 .prepare_cpus = vsmp_prepare_cpus,
240 };
241
242
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