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1/*
2 * Driver for ePAPR Embedded Hypervisor PIC
3 *
4 * Copyright 2008-2011 Freescale Semiconductor, Inc.
5 *
6 * Author: Ashish Kalra <[email protected]>
7 *
8 * This file is licensed under the terms of the GNU General Public License
9 * version 2. This program is licensed "as is" without any warranty of any
10 * kind, whether express or implied.
11 */
12
13#include <linux/types.h>
14#include <linux/kernel.h>
15#include <linux/init.h>
16#include <linux/irq.h>
17#include <linux/irqdomain.h>
18#include <linux/smp.h>
19#include <linux/interrupt.h>
20#include <linux/slab.h>
21#include <linux/spinlock.h>
22#include <linux/of.h>
23#include <linux/of_address.h>
24
25#include <asm/io.h>
26#include <asm/irq.h>
27#include <asm/smp.h>
28#include <asm/machdep.h>
29#include <asm/ehv_pic.h>
30#include <asm/fsl_hcalls.h>
31
32static struct ehv_pic *global_ehv_pic;
33static DEFINE_SPINLOCK(ehv_pic_lock);
34
35static u32 hwirq_intspec[NR_EHV_PIC_INTS];
36static u32 __iomem *mpic_percpu_base_vaddr;
37
38#define IRQ_TYPE_MPIC_DIRECT 4
39#define MPIC_EOI 0x00B0
40
41/*
42 * Linux descriptor level callbacks
43 */
44
45static void ehv_pic_unmask_irq(struct irq_data *d)
46{
47 unsigned int src = virq_to_hw(d->irq);
48
49 ev_int_set_mask(src, 0);
50}
51
52static void ehv_pic_mask_irq(struct irq_data *d)
53{
54 unsigned int src = virq_to_hw(d->irq);
55
56 ev_int_set_mask(src, 1);
57}
58
59static void ehv_pic_end_irq(struct irq_data *d)
60{
61 unsigned int src = virq_to_hw(d->irq);
62
63 ev_int_eoi(src);
64}
65
66static void ehv_pic_direct_end_irq(struct irq_data *d)
67{
68 out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
69}
70
71static int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
72 bool force)
73{
74 unsigned int src = virq_to_hw(d->irq);
75 unsigned int config, prio, cpu_dest;
76 int cpuid = irq_choose_cpu(dest);
77 unsigned long flags;
78
79 spin_lock_irqsave(&ehv_pic_lock, flags);
80 ev_int_get_config(src, &config, &prio, &cpu_dest);
81 ev_int_set_config(src, config, prio, cpuid);
82 spin_unlock_irqrestore(&ehv_pic_lock, flags);
83
84 return IRQ_SET_MASK_OK;
85}
86
87static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
88{
89 /* Now convert sense value */
90
91 switch (type & IRQ_TYPE_SENSE_MASK) {
92 case IRQ_TYPE_EDGE_RISING:
93 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
94 EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
95
96 case IRQ_TYPE_EDGE_FALLING:
97 case IRQ_TYPE_EDGE_BOTH:
98 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
99 EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
100
101 case IRQ_TYPE_LEVEL_HIGH:
102 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
103 EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
104
105 case IRQ_TYPE_LEVEL_LOW:
106 default:
107 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
108 EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
109 }
110}
111
112static int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
113{
114 unsigned int src = virq_to_hw(d->irq);
115 unsigned int vecpri, vold, vnew, prio, cpu_dest;
116 unsigned long flags;
117
118 if (flow_type == IRQ_TYPE_NONE)
119 flow_type = IRQ_TYPE_LEVEL_LOW;
120
121 irqd_set_trigger_type(d, flow_type);
122
123 vecpri = ehv_pic_type_to_vecpri(flow_type);
124
125 spin_lock_irqsave(&ehv_pic_lock, flags);
126 ev_int_get_config(src, &vold, &prio, &cpu_dest);
127 vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
128 EHV_PIC_INFO(VECPRI_SENSE_MASK));
129 vnew |= vecpri;
130
131 /*
132 * TODO : Add specific interface call for platform to set
133 * individual interrupt priorities.
134 * platform currently using static/default priority for all ints
135 */
136
137 prio = 8;
138
139 ev_int_set_config(src, vecpri, prio, cpu_dest);
140
141 spin_unlock_irqrestore(&ehv_pic_lock, flags);
142 return IRQ_SET_MASK_OK_NOCOPY;
143}
144
145static struct irq_chip ehv_pic_irq_chip = {
146 .irq_mask = ehv_pic_mask_irq,
147 .irq_unmask = ehv_pic_unmask_irq,
148 .irq_eoi = ehv_pic_end_irq,
149 .irq_set_type = ehv_pic_set_irq_type,
150};
151
152static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
153 .irq_mask = ehv_pic_mask_irq,
154 .irq_unmask = ehv_pic_unmask_irq,
155 .irq_eoi = ehv_pic_direct_end_irq,
156 .irq_set_type = ehv_pic_set_irq_type,
157};
158
159/* Return an interrupt vector or 0 if no interrupt is pending. */
160unsigned int ehv_pic_get_irq(void)
161{
162 int irq;
163
164 BUG_ON(global_ehv_pic == NULL);
165
166 if (global_ehv_pic->coreint_flag)
167 irq = mfspr(SPRN_EPR); /* if core int mode */
168 else
169 ev_int_iack(0, &irq); /* legacy mode */
170
171 if (irq == 0xFFFF) /* 0xFFFF --> no irq is pending */
172 return 0;
173
174 /*
175 * this will also setup revmap[] in the slow path for the first
176 * time, next calls will always use fast path by indexing revmap
177 */
178 return irq_find_mapping(global_ehv_pic->irqhost, irq);
179}
180
181static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node,
182 enum irq_domain_bus_token bus_token)
183{
184 /* Exact match, unless ehv_pic node is NULL */
185 struct device_node *of_node = irq_domain_get_of_node(h);
186 return of_node == NULL || of_node == node;
187}
188
189static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
190 irq_hw_number_t hw)
191{
192 struct ehv_pic *ehv_pic = h->host_data;
193 struct irq_chip *chip;
194
195 /* Default chip */
196 chip = &ehv_pic->hc_irq;
197
198 if (mpic_percpu_base_vaddr)
199 if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
200 chip = &ehv_pic_direct_eoi_irq_chip;
201
202 irq_set_chip_data(virq, chip);
203 /*
204 * using handle_fasteoi_irq as our irq handler, this will
205 * only call the eoi callback and suitable for the MPIC
206 * controller which set ISR/IPR automatically and clear the
207 * highest priority active interrupt in ISR/IPR when we do
208 * a specific eoi
209 */
210 irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
211
212 /* Set default irq type */
213 irq_set_irq_type(virq, IRQ_TYPE_NONE);
214
215 return 0;
216}
217
218static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
219 const u32 *intspec, unsigned int intsize,
220 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
221
222{
223 /*
224 * interrupt sense values coming from the guest device tree
225 * interrupt specifiers can have four possible sense and
226 * level encoding information and they need to
227 * be translated between firmware type & linux type.
228 */
229
230 static unsigned char map_of_senses_to_linux_irqtype[4] = {
231 IRQ_TYPE_EDGE_FALLING,
232 IRQ_TYPE_EDGE_RISING,
233 IRQ_TYPE_LEVEL_LOW,
234 IRQ_TYPE_LEVEL_HIGH,
235 };
236
237 *out_hwirq = intspec[0];
238 if (intsize > 1) {
239 hwirq_intspec[intspec[0]] = intspec[1];
240 *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
241 ~IRQ_TYPE_MPIC_DIRECT];
242 } else {
243 *out_flags = IRQ_TYPE_NONE;
244 }
245
246 return 0;
247}
248
249static const struct irq_domain_ops ehv_pic_host_ops = {
250 .match = ehv_pic_host_match,
251 .map = ehv_pic_host_map,
252 .xlate = ehv_pic_host_xlate,
253};
254
255void __init ehv_pic_init(void)
256{
257 struct device_node *np, *np2;
258 struct ehv_pic *ehv_pic;
259
260 np = of_find_compatible_node(NULL, NULL, "epapr,hv-pic");
261 if (!np) {
262 pr_err("ehv_pic_init: could not find epapr,hv-pic node\n");
263 return;
264 }
265
266 ehv_pic = kzalloc_obj(struct ehv_pic);
267 if (!ehv_pic) {
268 of_node_put(np);
269 return;
270 }
271
272 ehv_pic->irqhost = irq_domain_create_linear(of_fwnode_handle(np),
273 NR_EHV_PIC_INTS,
274 &ehv_pic_host_ops, ehv_pic);
275 if (!ehv_pic->irqhost) {
276 of_node_put(np);
277 kfree(ehv_pic);
278 return;
279 }
280
281 np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
282 if (np2) {
283 mpic_percpu_base_vaddr = of_iomap(np2, 0);
284 if (!mpic_percpu_base_vaddr)
285 pr_err("ehv_pic_init: of_iomap failed\n");
286
287 of_node_put(np2);
288 }
289
290 ehv_pic->hc_irq = ehv_pic_irq_chip;
291 ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
292 ehv_pic->coreint_flag = of_property_read_bool(np, "has-external-proxy");
293
294 global_ehv_pic = ehv_pic;
295 irq_set_default_domain(global_ehv_pic->irqhost);
296}