summaryrefslogtreecommitdiff
path: root/arch/powerpc/sysdev/xics/icp-hv.c
blob: 21b9d1bf39ff608fde109901b8d624c726aaa1d7 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2011 IBM Corporation.
 */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/of.h>

#include <asm/smp.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xics.h>
#include <asm/io.h>
#include <asm/hvcall.h>

static inline unsigned int icp_hv_get_xirr(unsigned char cppr)
{
	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
	long rc;
	unsigned int ret = XICS_IRQ_SPURIOUS;

	rc = plpar_hcall(H_XIRR, retbuf, cppr);
	if (rc == H_SUCCESS) {
		ret = (unsigned int)retbuf[0];
	} else {
		pr_err("%s: bad return code xirr cppr=0x%x returned %ld\n",
			__func__, cppr, rc);
		WARN_ON_ONCE(1);
	}

	return ret;
}

static inline void icp_hv_set_cppr(u8 value)
{
	long rc = plpar_hcall_norets(H_CPPR, value);
	if (rc != H_SUCCESS) {
		pr_err("%s: bad return code cppr cppr=0x%x returned %ld\n",
			__func__, value, rc);
		WARN_ON_ONCE(1);
	}
}

static inline void icp_hv_set_xirr(unsigned int value)
{
	long rc = plpar_hcall_norets(H_EOI, value);
	if (rc != H_SUCCESS) {
		pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n",
			__func__, value, rc);
		WARN_ON_ONCE(1);
		icp_hv_set_cppr(value >> 24);
	}
}

static inline void icp_hv_set_qirr(int n_cpu , u8 value)
{
	int hw_cpu = get_hard_smp_processor_id(n_cpu);
	long rc;

	/* Make sure all previous accesses are ordered before IPI sending */
	mb();
	rc = plpar_hcall_norets(H_IPI, hw_cpu, value);
	if (rc != H_SUCCESS) {
		pr_err("%s: bad return code qirr cpu=%d hw_cpu=%d mfrr=0x%x "
			"returned %ld\n", __func__, n_cpu, hw_cpu, value, rc);
		WARN_ON_ONCE(1);
	}
}

static void icp_hv_eoi(struct irq_data *d)
{
	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);

	iosync();
	icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq);
}

static void icp_hv_teardown_cpu(void)
{
	int cpu = smp_processor_id();

	/* Clear any pending IPI */
	icp_hv_set_qirr(cpu, 0xff);
}

static void icp_hv_flush_ipi(void)
{
	/* We take the ipi irq but and never return so we
	 * need to EOI the IPI, but want to leave our priority 0
	 *
	 * should we check all the other interrupts too?
	 * should we be flagging idle loop instead?
	 * or creating some task to be scheduled?
	 */

	icp_hv_set_xirr((0x00 << 24) | XICS_IPI);
}

static unsigned int icp_hv_get_irq(void)
{
	unsigned int xirr = icp_hv_get_xirr(xics_cppr_top());
	unsigned int vec = xirr & 0x00ffffff;
	unsigned int irq;

	if (vec == XICS_IRQ_SPURIOUS)
		return 0;

	irq = irq_find_mapping(xics_host, vec);
	if (likely(irq)) {
		xics_push_cppr(vec);
		return irq;
	}

	/* We don't have a linux mapping, so have rtas mask it. */
	xics_mask_unknown_vec(vec);

	/* We might learn about it later, so EOI it */
	icp_hv_set_xirr(xirr);

	return 0;
}

static void icp_hv_set_cpu_priority(unsigned char cppr)
{
	xics_set_base_cppr(cppr);
	icp_hv_set_cppr(cppr);
	iosync();
}

#ifdef CONFIG_SMP

static void icp_hv_cause_ipi(int cpu)
{
	icp_hv_set_qirr(cpu, IPI_PRIORITY);
}

static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id)
{
	int cpu = smp_processor_id();

	icp_hv_set_qirr(cpu, 0xff);

	return smp_ipi_demux();
}

#endif /* CONFIG_SMP */

static const struct icp_ops icp_hv_ops = {
	.get_irq	= icp_hv_get_irq,
	.eoi		= icp_hv_eoi,
	.set_priority	= icp_hv_set_cpu_priority,
	.teardown_cpu	= icp_hv_teardown_cpu,
	.flush_ipi	= icp_hv_flush_ipi,
#ifdef CONFIG_SMP
	.ipi_action	= icp_hv_ipi_action,
	.cause_ipi	= icp_hv_cause_ipi,
#endif
};

int icp_hv_init(void)
{
	struct device_node *np;

	np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp");
	if (!np)
		np = of_find_node_by_type(NULL,
				    "PowerPC-External-Interrupt-Presentation");
	if (!np)
		return -ENODEV;

	icp_ops = &icp_hv_ops;

	of_node_put(np);
	return 0;
}