summaryrefslogtreecommitdiff
path: root/arch/powerpc/sysdev/xics/icp-native.c
blob: 2fc4cf1b75575f9916e26fcf330cfce4959f39a5 (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
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
/*
 * Copyright 2011 IBM Corporation.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

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

#include <asm/prom.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xics.h>
#include <asm/kvm_ppc.h>
#include <asm/dbell.h>

struct icp_ipl {
	union {
		u32 word;
		u8 bytes[4];
	} xirr_poll;
	union {
		u32 word;
		u8 bytes[4];
	} xirr;
	u32 dummy;
	union {
		u32 word;
		u8 bytes[4];
	} qirr;
	u32 link_a;
	u32 link_b;
	u32 link_c;
};

static struct icp_ipl __iomem *icp_native_regs[NR_CPUS];

static inline unsigned int icp_native_get_xirr(void)
{
	int cpu = smp_processor_id();
	unsigned int xirr;

	/* Handled an interrupt latched by KVM */
	xirr = kvmppc_get_xics_latch();
	if (xirr)
		return xirr;

	return in_be32(&icp_native_regs[cpu]->xirr.word);
}

static inline void icp_native_set_xirr(unsigned int value)
{
	int cpu = smp_processor_id();

	out_be32(&icp_native_regs[cpu]->xirr.word, value);
}

static inline void icp_native_set_cppr(u8 value)
{
	int cpu = smp_processor_id();

	out_8(&icp_native_regs[cpu]->xirr.bytes[0], value);
}

static inline void icp_native_set_qirr(int n_cpu, u8 value)
{
	out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value);
}

static void icp_native_set_cpu_priority(unsigned char cppr)
{
	xics_set_base_cppr(cppr);
	icp_native_set_cppr(cppr);
	iosync();
}

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

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

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

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

static void icp_native_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_native_set_xirr((0x00 << 24) | XICS_IPI);
}

static unsigned int icp_native_get_irq(void)
{
	unsigned int xirr = icp_native_get_xirr();
	unsigned int vec = xirr & 0x00ffffff;
	unsigned int irq;

	if (vec == XICS_IRQ_SPURIOUS)
		return NO_IRQ;

	irq = irq_find_mapping(xics_host, vec);
	if (likely(irq != NO_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_native_set_xirr(xirr);

	return NO_IRQ;
}

#ifdef CONFIG_SMP

static void icp_native_cause_ipi(int cpu, unsigned long data)
{
	kvmppc_set_host_ipi(cpu, 1);
#ifdef CONFIG_PPC_DOORBELL
	if (cpu_has_feature(CPU_FTR_DBELL) &&
	    (cpumask_test_cpu(cpu, cpu_sibling_mask(smp_processor_id()))))
		doorbell_cause_ipi(cpu, data);
	else
#endif
		icp_native_set_qirr(cpu, IPI_PRIORITY);
}

/*
 * Called when an interrupt is received on an off-line CPU to
 * clear the interrupt, so that the CPU can go back to nap mode.
 */
void icp_native_flush_interrupt(void)
{
	unsigned int xirr = icp_native_get_xirr();
	unsigned int vec = xirr & 0x00ffffff;

	if (vec == XICS_IRQ_SPURIOUS)
		return;
	if (vec == XICS_IPI) {
		/* Clear pending IPI */
		int cpu = smp_processor_id();
		kvmppc_set_host_ipi(cpu, 0);
		icp_native_set_qirr(cpu, 0xff);
	} else {
		pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n",
		       vec);
		xics_mask_unknown_vec(vec);
	}
	/* EOI the interrupt */
	icp_native_set_xirr(xirr);
}

void xics_wake_cpu(int cpu)
{
	icp_native_set_qirr(cpu, IPI_PRIORITY);
}
EXPORT_SYMBOL_GPL(xics_wake_cpu);

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

	kvmppc_set_host_ipi(cpu, 0);
	icp_native_set_qirr(cpu, 0xff);

	return smp_ipi_demux();
}

#endif /* CONFIG_SMP */

static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
					 unsigned long size)
{
	char *rname;
	int i, cpu = -1;

	/* This may look gross but it's good enough for now, we don't quite
	 * have a hard -> linux processor id matching.
	 */
	for_each_possible_cpu(i) {
		if (!cpu_present(i))
			continue;
		if (hw_id == get_hard_smp_processor_id(i)) {
			cpu = i;
			break;
		}
	}

	/* Fail, skip that CPU. Don't print, it's normal, some XICS come up
	 * with way more entries in there than you have CPUs
	 */
	if (cpu == -1)
		return 0;

	rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation",
			  cpu, hw_id);

	if (!request_mem_region(addr, size, rname)) {
		pr_warning("icp_native: Could not reserve ICP MMIO"
			   " for CPU %d, interrupt server #0x%x\n",
			   cpu, hw_id);
		return -EBUSY;
	}

	icp_native_regs[cpu] = ioremap(addr, size);
	kvmppc_set_xics_phys(cpu, addr);
	if (!icp_native_regs[cpu]) {
		pr_warning("icp_native: Failed ioremap for CPU %d, "
			   "interrupt server #0x%x, addr %#lx\n",
			   cpu, hw_id, addr);
		release_mem_region(addr, size);
		return -ENOMEM;
	}
	return 0;
}

static int __init icp_native_init_one_node(struct device_node *np,
					   unsigned int *indx)
{
	unsigned int ilen;
	const __be32 *ireg;
	int i;
	int reg_tuple_size;
	int num_servers = 0;

	/* This code does the theorically broken assumption that the interrupt
	 * server numbers are the same as the hard CPU numbers.
	 * This happens to be the case so far but we are playing with fire...
	 * should be fixed one of these days. -BenH.
	 */
	ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen);

	/* Do that ever happen ? we'll know soon enough... but even good'old
	 * f80 does have that property ..
	 */
	WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32)));

	if (ireg) {
		*indx = of_read_number(ireg, 1);
		if (ilen >= 2*sizeof(u32))
			num_servers = of_read_number(ireg + 1, 1);
	}

	ireg = of_get_property(np, "reg", &ilen);
	if (!ireg) {
		pr_err("icp_native: Can't find interrupt reg property");
		return -1;
	}

	reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4;
	if (((ilen % reg_tuple_size) != 0)
	    || (num_servers && (num_servers != (ilen / reg_tuple_size)))) {
		pr_err("icp_native: ICP reg len (%d) != num servers (%d)",
		       ilen / reg_tuple_size, num_servers);
		return -1;
	}

	for (i = 0; i < (ilen / reg_tuple_size); i++) {
		struct resource r;
		int err;

		err = of_address_to_resource(np, i, &r);
		if (err) {
			pr_err("icp_native: Could not translate ICP MMIO"
			       " for interrupt server 0x%x (%d)\n", *indx, err);
			return -1;
		}

		if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r)))
			return -1;

		(*indx)++;
	}
	return 0;
}

static const struct icp_ops icp_native_ops = {
	.get_irq	= icp_native_get_irq,
	.eoi		= icp_native_eoi,
	.set_priority	= icp_native_set_cpu_priority,
	.teardown_cpu	= icp_native_teardown_cpu,
	.flush_ipi	= icp_native_flush_ipi,
#ifdef CONFIG_SMP
	.ipi_action	= icp_native_ipi_action,
	.cause_ipi	= icp_native_cause_ipi,
#endif
};

int __init icp_native_init(void)
{
	struct device_node *np;
	u32 indx = 0;
	int found = 0;

	for_each_compatible_node(np, NULL, "ibm,ppc-xicp")
		if (icp_native_init_one_node(np, &indx) == 0)
			found = 1;
	if (!found) {
		for_each_node_by_type(np,
			"PowerPC-External-Interrupt-Presentation") {
				if (icp_native_init_one_node(np, &indx) == 0)
					found = 1;
		}
	}

	if (found == 0)
		return -ENODEV;

	icp_ops = &icp_native_ops;

	return 0;
}