summaryrefslogtreecommitdiffstats
path: root/kernel/arch/powerpc/sysdev/ehv_pic.c
blob: bffcc7a486a11c9821ded7f18178c336aa58b9b7 (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
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*
 *  Driver for ePAPR Embedded Hypervisor PIC
 *
 *  Copyright 2008-2011 Freescale Semiconductor, Inc.
 *
 *  Author: Ashish Kalra <ashish.kalra@freescale.com>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_address.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/ehv_pic.h>
#include <asm/fsl_hcalls.h>

static struct ehv_pic *global_ehv_pic;
static DEFINE_SPINLOCK(ehv_pic_lock);

static u32 hwirq_intspec[NR_EHV_PIC_INTS];
static u32 __iomem *mpic_percpu_base_vaddr;

#define IRQ_TYPE_MPIC_DIRECT 4
#define MPIC_EOI  0x00B0

/*
 * Linux descriptor level callbacks
 */

void ehv_pic_unmask_irq(struct irq_data *d)
{
	unsigned int src = virq_to_hw(d->irq);

	ev_int_set_mask(src, 0);
}

void ehv_pic_mask_irq(struct irq_data *d)
{
	unsigned int src = virq_to_hw(d->irq);

	ev_int_set_mask(src, 1);
}

void ehv_pic_end_irq(struct irq_data *d)
{
	unsigned int src = virq_to_hw(d->irq);

	ev_int_eoi(src);
}

void ehv_pic_direct_end_irq(struct irq_data *d)
{
	out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
}

int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
			 bool force)
{
	unsigned int src = virq_to_hw(d->irq);
	unsigned int config, prio, cpu_dest;
	int cpuid = irq_choose_cpu(dest);
	unsigned long flags;

	spin_lock_irqsave(&ehv_pic_lock, flags);
	ev_int_get_config(src, &config, &prio, &cpu_dest);
	ev_int_set_config(src, config, prio, cpuid);
	spin_unlock_irqrestore(&ehv_pic_lock, flags);

	return IRQ_SET_MASK_OK;
}

static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
{
	/* Now convert sense value */

	switch (type & IRQ_TYPE_SENSE_MASK) {
	case IRQ_TYPE_EDGE_RISING:
		return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
		       EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);

	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_EDGE_BOTH:
		return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
		       EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);

	case IRQ_TYPE_LEVEL_HIGH:
		return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
		       EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);

	case IRQ_TYPE_LEVEL_LOW:
	default:
		return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
		       EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
	}
}

int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
{
	unsigned int src = virq_to_hw(d->irq);
	unsigned int vecpri, vold, vnew, prio, cpu_dest;
	unsigned long flags;

	if (flow_type == IRQ_TYPE_NONE)
		flow_type = IRQ_TYPE_LEVEL_LOW;

	irqd_set_trigger_type(d, flow_type);

	vecpri = ehv_pic_type_to_vecpri(flow_type);

	spin_lock_irqsave(&ehv_pic_lock, flags);
	ev_int_get_config(src, &vold, &prio, &cpu_dest);
	vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
			EHV_PIC_INFO(VECPRI_SENSE_MASK));
	vnew |= vecpri;

	/*
	 * TODO : Add specific interface call for platform to set
	 * individual interrupt priorities.
	 * platform currently using static/default priority for all ints
	 */

	prio = 8;

	ev_int_set_config(src, vecpri, prio, cpu_dest);

	spin_unlock_irqrestore(&ehv_pic_lock, flags);
	return IRQ_SET_MASK_OK_NOCOPY;
}

static struct irq_chip ehv_pic_irq_chip = {
	.irq_mask	= ehv_pic_mask_irq,
	.irq_unmask	= ehv_pic_unmask_irq,
	.irq_eoi	= ehv_pic_end_irq,
	.irq_set_type	= ehv_pic_set_irq_type,
};

static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
	.irq_mask	= ehv_pic_mask_irq,
	.irq_unmask	= ehv_pic_unmask_irq,
	.irq_eoi	= ehv_pic_direct_end_irq,
	.irq_set_type	= ehv_pic_set_irq_type,
};

/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
unsigned int ehv_pic_get_irq(void)
{
	int irq;

	BUG_ON(global_ehv_pic == NULL);

	if (global_ehv_pic->coreint_flag)
		irq = mfspr(SPRN_EPR); /* if core int mode */
	else
		ev_int_iack(0, &irq); /* legacy mode */

	if (irq == 0xFFFF)    /* 0xFFFF --> no irq is pending */
		return NO_IRQ;

	/*
	 * this will also setup revmap[] in the slow path for the first
	 * time, next calls will always use fast path by indexing revmap
	 */
	return irq_linear_revmap(global_ehv_pic->irqhost, irq);
}

static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node,
			      enum irq_domain_bus_token bus_token)
{
	/* Exact match, unless ehv_pic node is NULL */
	struct device_node *of_node = irq_domain_get_of_node(h);
	return of_node == NULL || of_node == node;
}

static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
			 irq_hw_number_t hw)
{
	struct ehv_pic *ehv_pic = h->host_data;
	struct irq_chip *chip;

	/* Default chip */
	chip = &ehv_pic->hc_irq;

	if (mpic_percpu_base_vaddr)
		if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
			chip = &ehv_pic_direct_eoi_irq_chip;

	irq_set_chip_data(virq, chip);
	/*
	 * using handle_fasteoi_irq as our irq handler, this will
	 * only call the eoi callback and suitable for the MPIC
	 * controller which set ISR/IPR automatically and clear the
	 * highest priority active interrupt in ISR/IPR when we do
	 * a specific eoi
	 */
	irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);

	/* Set default irq type */
	irq_set_irq_type(virq, IRQ_TYPE_NONE);

	return 0;
}

static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
			   const u32 *intspec, unsigned int intsize,
			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)

{
	/*
	 * interrupt sense values coming from the guest device tree
	 * interrupt specifiers can have four possible sense and
	 * level encoding information and they need to
	 * be translated between firmware type & linux type.
	 */

	static unsigned char map_of_senses_to_linux_irqtype[4] = {
		IRQ_TYPE_EDGE_FALLING,
		IRQ_TYPE_EDGE_RISING,
		IRQ_TYPE_LEVEL_LOW,
		IRQ_TYPE_LEVEL_HIGH,
	};

	*out_hwirq = intspec[0];
	if (intsize > 1) {
		hwirq_intspec[intspec[0]] = intspec[1];
		*out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
							~IRQ_TYPE_MPIC_DIRECT];
	} else {
		*out_flags = IRQ_TYPE_NONE;
	}

	return 0;
}

static const struct irq_domain_ops ehv_pic_host_ops = {
	.match = ehv_pic_host_match,
	.map = ehv_pic_host_map,
	.xlate = ehv_pic_host_xlate,
};

void __init ehv_pic_init(void)
{
	struct device_node *np, *np2;
	struct ehv_pic *ehv_pic;
	int coreint_flag = 1;

	np = of_find_compatible_node(NULL, NULL, "epapr,hv-pic");
	if (!np) {
		pr_err("ehv_pic_init: could not find epapr,hv-pic node\n");
		return;
	}

	if (!of_find_property(np, "has-external-proxy", NULL))
		coreint_flag = 0;

	ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
	if (!ehv_pic) {
		of_node_put(np);
		return;
	}

	ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
						 &ehv_pic_host_ops, ehv_pic);
	if (!ehv_pic->irqhost) {
		of_node_put(np);
		kfree(ehv_pic);
		return;
	}

	np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
	if (np2) {
		mpic_percpu_base_vaddr = of_iomap(np2, 0);
		if (!mpic_percpu_base_vaddr)
			pr_err("ehv_pic_init: of_iomap failed\n");

		of_node_put(np2);
	}

	ehv_pic->hc_irq = ehv_pic_irq_chip;
	ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
	ehv_pic->coreint_flag = coreint_flag;

	global_ehv_pic = ehv_pic;
	irq_set_default_host(global_ehv_pic->irqhost);
}