aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/kernel/smp-cmp.c
blob: f27beca4b26d22c67366b1be5d1f263637ad21c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
/*
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Copyright (C) 2007 MIPS Technologies, Inc.
 *    Chris Dearman (chris@mips.com)
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/compiler.h>

#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
#include <asm/smp.h>
#include <asm/time.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/mips_mt.h>

/*
 * Crude manipulation of the CPU masks to control which
 * which CPU's are brought online during initialisation
 *
 * Beware... this needs to be called after CPU discovery
 * but before CPU bringup
 */
static int __init allowcpus(char *str)
{
	cpumask_t cpu_allow_map;
	char buf[256];
	int len;

	cpus_clear(cpu_allow_map);
	if (cpulist_parse(str, &cpu_allow_map) == 0) {
		cpu_set(0, cpu_allow_map);
		cpus_and(cpu_possible_map, cpu_possible_map, cpu_allow_map);
		len = cpulist_scnprintf(buf, sizeof(buf)-1, &cpu_possible_map);
		buf[len] = '\0';
		pr_debug("Allowable CPUs: %s\n", buf);
		return 1;
	} else
		return 0;
}
__setup("allowcpus=", allowcpus);

static void ipi_call_function(unsigned int cpu)
{
	unsigned int action = 0;

	pr_debug("CPU%d: %s cpu %d status %08x\n",
		 smp_processor_id(), __func__, cpu, read_c0_status());

	switch (cpu) {
	case 0:
		action = GIC_IPI_EXT_INTR_CALLFNC_VPE0;
		break;
	case 1:
		action = GIC_IPI_EXT_INTR_CALLFNC_VPE1;
		break;
	case 2:
		action = GIC_IPI_EXT_INTR_CALLFNC_VPE2;
		break;
	case 3:
		action = GIC_IPI_EXT_INTR_CALLFNC_VPE3;
		break;
	}
	gic_send_ipi(action);
}


static void ipi_resched(unsigned int cpu)
{
	unsigned int action = 0;

	pr_debug("CPU%d: %s cpu %d status %08x\n",
		 smp_processor_id(), __func__, cpu, read_c0_status());

	switch (cpu) {
	case 0:
		action = GIC_IPI_EXT_INTR_RESCHED_VPE0;
		break;
	case 1:
		action = GIC_IPI_EXT_INTR_RESCHED_VPE1;
		break;
	case 2:
		action = GIC_IPI_EXT_INTR_RESCHED_VPE2;
		break;
	case 3:
		action = GIC_IPI_EXT_INTR_RESCHED_VPE3;
		break;
	}
	gic_send_ipi(action);
}

/*
 * FIXME: This isn't restricted to CMP
 * The SMVP kernel could use GIC interrupts if available
 */
void cmp_send_ipi_single(int cpu, unsigned int action)
{
	unsigned long flags;

	local_irq_save(flags);

	switch (action) {
	case SMP_CALL_FUNCTION:
		ipi_call_function(cpu);
		break;

	case SMP_RESCHEDULE_YOURSELF:
		ipi_resched(cpu);
		break;
	}

	local_irq_restore(flags);
}

static void cmp_send_ipi_mask(cpumask_t mask, unsigned int action)
{
	unsigned int i;

	for_each_cpu_mask(i, mask)
		cmp_send_ipi_single(i, action);
}

static void cmp_init_secondary(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;

	/* Assume GIC is present */
	change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP6 |
				 STATUSF_IP7);

	/* Enable per-cpu interrupts: platform specific */

	c->core = (read_c0_ebase() >> 1) & 0xff;
#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
	c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE;
#endif
#ifdef CONFIG_MIPS_MT_SMTC
	c->tc_id  = (read_c0_tcbind() >> TCBIND_CURTC_SHIFT) & TCBIND_CURTC;
#endif
}

static void cmp_smp_finish(void)
{
	pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);

	/* CDFIXME: remove this? */
	write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));

#ifdef CONFIG_MIPS_MT_FPAFF
	/* If we have an FPU, enroll ourselves in the FPU-full mask */
	if (cpu_has_fpu)
		cpu_set(smp_processor_id(), mt_fpu_cpumask);
#endif /* CONFIG_MIPS_MT_FPAFF */

	local_irq_enable();
}

static void cmp_cpus_done(void)
{
	pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
}

/*
 * Setup the PC, SP, and GP of a secondary processor and start it running
 * smp_bootstrap is the place to resume from
 * __KSTK_TOS(idle) is apparently the stack pointer
 * (unsigned long)idle->thread_info the gp
 */
static void cmp_boot_secondary(int cpu, struct task_struct *idle)
{
	struct thread_info *gp = task_thread_info(idle);
	unsigned long sp = __KSTK_TOS(idle);
	unsigned long pc = (unsigned long)&smp_bootstrap;
	unsigned long a0 = 0;

	pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
		__func__, cpu);

#if 0
	/* Needed? */
	flush_icache_range((unsigned long)gp,
			   (unsigned long)(gp + sizeof(struct thread_info)));
#endif

	amon_cpu_start(cpu, pc, sp, gp, a0);
}

/*
 * Common setup before any secondaries are started
 */
void __init cmp_smp_setup(void)
{
	int i;
	int ncpu = 0;

	pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);

#ifdef CONFIG_MIPS_MT_FPAFF
	/* If we have an FPU, enroll ourselves in the FPU-full mask */
	if (cpu_has_fpu)
		cpu_set(0, mt_fpu_cpumask);
#endif /* CONFIG_MIPS_MT_FPAFF */

	for (i = 1; i < NR_CPUS; i++) {
		if (amon_cpu_avail(i)) {
			cpu_set(i, cpu_possible_map);
			__cpu_number_map[i]	= ++ncpu;
			__cpu_logical_map[ncpu]	= i;
		}
	}

	if (cpu_has_mipsmt) {
		unsigned int nvpe, mvpconf0 = read_c0_mvpconf0();

		nvpe = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
		smp_num_siblings = nvpe;
	}
	pr_info("Detected %i available secondary CPU(s)\n", ncpu);
}

void __init cmp_prepare_cpus(unsigned int max_cpus)
{
	pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
		 smp_processor_id(), __func__, max_cpus);

	/*
	 * FIXME: some of these options are per-system, some per-core and
	 * some per-cpu
	 */
	mips_mt_set_cpuoptions();
}

struct plat_smp_ops cmp_smp_ops = {
	.send_ipi_single	= cmp_send_ipi_single,
	.send_ipi_mask		= cmp_send_ipi_mask,
	.init_secondary		= cmp_init_secondary,
	.smp_finish		= cmp_smp_finish,
	.cpus_done		= cmp_cpus_done,
	.boot_secondary		= cmp_boot_secondary,
	.smp_setup		= cmp_smp_setup,
	.prepare_cpus		= cmp_prepare_cpus,
};