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
29static 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
46static 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
81static 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
109static 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
121static 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 */
143static 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 */
184static 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
227static void __init vsmp_prepare_cpus(unsigned int max_cpus)
228{
229	mips_mt_set_cpuoptions();
230}
231
232const 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