1 /*
2 * Driver for ePAPR Embedded Hypervisor PIC
3 *
4 * Copyright 2008-2011 Freescale Semiconductor, Inc.
5 *
6 * Author: Ashish Kalra <ashish.kalra@freescale.com>
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/smp.h>
18 #include <linux/interrupt.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23
24 #include <asm/io.h>
25 #include <asm/irq.h>
26 #include <asm/smp.h>
27 #include <asm/machdep.h>
28 #include <asm/ehv_pic.h>
29 #include <asm/fsl_hcalls.h>
30
31 static struct ehv_pic *global_ehv_pic;
32 static DEFINE_SPINLOCK(ehv_pic_lock);
33
34 static u32 hwirq_intspec[NR_EHV_PIC_INTS];
35 static u32 __iomem *mpic_percpu_base_vaddr;
36
37 #define IRQ_TYPE_MPIC_DIRECT 4
38 #define MPIC_EOI 0x00B0
39
40 /*
41 * Linux descriptor level callbacks
42 */
43
ehv_pic_unmask_irq(struct irq_data * d)44 void ehv_pic_unmask_irq(struct irq_data *d)
45 {
46 unsigned int src = virq_to_hw(d->irq);
47
48 ev_int_set_mask(src, 0);
49 }
50
ehv_pic_mask_irq(struct irq_data * d)51 void ehv_pic_mask_irq(struct irq_data *d)
52 {
53 unsigned int src = virq_to_hw(d->irq);
54
55 ev_int_set_mask(src, 1);
56 }
57
ehv_pic_end_irq(struct irq_data * d)58 void ehv_pic_end_irq(struct irq_data *d)
59 {
60 unsigned int src = virq_to_hw(d->irq);
61
62 ev_int_eoi(src);
63 }
64
ehv_pic_direct_end_irq(struct irq_data * d)65 void ehv_pic_direct_end_irq(struct irq_data *d)
66 {
67 out_be32(mpic_percpu_base_vaddr + MPIC_EOI / 4, 0);
68 }
69
ehv_pic_set_affinity(struct irq_data * d,const struct cpumask * dest,bool force)70 int ehv_pic_set_affinity(struct irq_data *d, const struct cpumask *dest,
71 bool force)
72 {
73 unsigned int src = virq_to_hw(d->irq);
74 unsigned int config, prio, cpu_dest;
75 int cpuid = irq_choose_cpu(dest);
76 unsigned long flags;
77
78 spin_lock_irqsave(&ehv_pic_lock, flags);
79 ev_int_get_config(src, &config, &prio, &cpu_dest);
80 ev_int_set_config(src, config, prio, cpuid);
81 spin_unlock_irqrestore(&ehv_pic_lock, flags);
82
83 return IRQ_SET_MASK_OK;
84 }
85
ehv_pic_type_to_vecpri(unsigned int type)86 static unsigned int ehv_pic_type_to_vecpri(unsigned int type)
87 {
88 /* Now convert sense value */
89
90 switch (type & IRQ_TYPE_SENSE_MASK) {
91 case IRQ_TYPE_EDGE_RISING:
92 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
93 EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
94
95 case IRQ_TYPE_EDGE_FALLING:
96 case IRQ_TYPE_EDGE_BOTH:
97 return EHV_PIC_INFO(VECPRI_SENSE_EDGE) |
98 EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
99
100 case IRQ_TYPE_LEVEL_HIGH:
101 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
102 EHV_PIC_INFO(VECPRI_POLARITY_POSITIVE);
103
104 case IRQ_TYPE_LEVEL_LOW:
105 default:
106 return EHV_PIC_INFO(VECPRI_SENSE_LEVEL) |
107 EHV_PIC_INFO(VECPRI_POLARITY_NEGATIVE);
108 }
109 }
110
ehv_pic_set_irq_type(struct irq_data * d,unsigned int flow_type)111 int ehv_pic_set_irq_type(struct irq_data *d, unsigned int flow_type)
112 {
113 unsigned int src = virq_to_hw(d->irq);
114 unsigned int vecpri, vold, vnew, prio, cpu_dest;
115 unsigned long flags;
116
117 if (flow_type == IRQ_TYPE_NONE)
118 flow_type = IRQ_TYPE_LEVEL_LOW;
119
120 irqd_set_trigger_type(d, flow_type);
121
122 vecpri = ehv_pic_type_to_vecpri(flow_type);
123
124 spin_lock_irqsave(&ehv_pic_lock, flags);
125 ev_int_get_config(src, &vold, &prio, &cpu_dest);
126 vnew = vold & ~(EHV_PIC_INFO(VECPRI_POLARITY_MASK) |
127 EHV_PIC_INFO(VECPRI_SENSE_MASK));
128 vnew |= vecpri;
129
130 /*
131 * TODO : Add specific interface call for platform to set
132 * individual interrupt priorities.
133 * platform currently using static/default priority for all ints
134 */
135
136 prio = 8;
137
138 ev_int_set_config(src, vecpri, prio, cpu_dest);
139
140 spin_unlock_irqrestore(&ehv_pic_lock, flags);
141 return IRQ_SET_MASK_OK_NOCOPY;
142 }
143
144 static struct irq_chip ehv_pic_irq_chip = {
145 .irq_mask = ehv_pic_mask_irq,
146 .irq_unmask = ehv_pic_unmask_irq,
147 .irq_eoi = ehv_pic_end_irq,
148 .irq_set_type = ehv_pic_set_irq_type,
149 };
150
151 static struct irq_chip ehv_pic_direct_eoi_irq_chip = {
152 .irq_mask = ehv_pic_mask_irq,
153 .irq_unmask = ehv_pic_unmask_irq,
154 .irq_eoi = ehv_pic_direct_end_irq,
155 .irq_set_type = ehv_pic_set_irq_type,
156 };
157
158 /* Return an interrupt vector or 0 if no interrupt is pending. */
ehv_pic_get_irq(void)159 unsigned int ehv_pic_get_irq(void)
160 {
161 int irq;
162
163 BUG_ON(global_ehv_pic == NULL);
164
165 if (global_ehv_pic->coreint_flag)
166 irq = mfspr(SPRN_EPR); /* if core int mode */
167 else
168 ev_int_iack(0, &irq); /* legacy mode */
169
170 if (irq == 0xFFFF) /* 0xFFFF --> no irq is pending */
171 return 0;
172
173 /*
174 * this will also setup revmap[] in the slow path for the first
175 * time, next calls will always use fast path by indexing revmap
176 */
177 return irq_linear_revmap(global_ehv_pic->irqhost, irq);
178 }
179
ehv_pic_host_match(struct irq_domain * h,struct device_node * node,enum irq_domain_bus_token bus_token)180 static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node,
181 enum irq_domain_bus_token bus_token)
182 {
183 /* Exact match, unless ehv_pic node is NULL */
184 struct device_node *of_node = irq_domain_get_of_node(h);
185 return of_node == NULL || of_node == node;
186 }
187
ehv_pic_host_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)188 static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
189 irq_hw_number_t hw)
190 {
191 struct ehv_pic *ehv_pic = h->host_data;
192 struct irq_chip *chip;
193
194 /* Default chip */
195 chip = &ehv_pic->hc_irq;
196
197 if (mpic_percpu_base_vaddr)
198 if (hwirq_intspec[hw] & IRQ_TYPE_MPIC_DIRECT)
199 chip = &ehv_pic_direct_eoi_irq_chip;
200
201 irq_set_chip_data(virq, chip);
202 /*
203 * using handle_fasteoi_irq as our irq handler, this will
204 * only call the eoi callback and suitable for the MPIC
205 * controller which set ISR/IPR automatically and clear the
206 * highest priority active interrupt in ISR/IPR when we do
207 * a specific eoi
208 */
209 irq_set_chip_and_handler(virq, chip, handle_fasteoi_irq);
210
211 /* Set default irq type */
212 irq_set_irq_type(virq, IRQ_TYPE_NONE);
213
214 return 0;
215 }
216
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)217 static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
218 const u32 *intspec, unsigned int intsize,
219 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
220
221 {
222 /*
223 * interrupt sense values coming from the guest device tree
224 * interrupt specifiers can have four possible sense and
225 * level encoding information and they need to
226 * be translated between firmware type & linux type.
227 */
228
229 static unsigned char map_of_senses_to_linux_irqtype[4] = {
230 IRQ_TYPE_EDGE_FALLING,
231 IRQ_TYPE_EDGE_RISING,
232 IRQ_TYPE_LEVEL_LOW,
233 IRQ_TYPE_LEVEL_HIGH,
234 };
235
236 *out_hwirq = intspec[0];
237 if (intsize > 1) {
238 hwirq_intspec[intspec[0]] = intspec[1];
239 *out_flags = map_of_senses_to_linux_irqtype[intspec[1] &
240 ~IRQ_TYPE_MPIC_DIRECT];
241 } else {
242 *out_flags = IRQ_TYPE_NONE;
243 }
244
245 return 0;
246 }
247
248 static const struct irq_domain_ops ehv_pic_host_ops = {
249 .match = ehv_pic_host_match,
250 .map = ehv_pic_host_map,
251 .xlate = ehv_pic_host_xlate,
252 };
253
ehv_pic_init(void)254 void __init ehv_pic_init(void)
255 {
256 struct device_node *np, *np2;
257 struct ehv_pic *ehv_pic;
258 int coreint_flag = 1;
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 if (!of_find_property(np, "has-external-proxy", NULL))
267 coreint_flag = 0;
268
269 ehv_pic = kzalloc(sizeof(struct ehv_pic), GFP_KERNEL);
270 if (!ehv_pic) {
271 of_node_put(np);
272 return;
273 }
274
275 ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
276 &ehv_pic_host_ops, ehv_pic);
277 if (!ehv_pic->irqhost) {
278 of_node_put(np);
279 kfree(ehv_pic);
280 return;
281 }
282
283 np2 = of_find_compatible_node(NULL, NULL, "fsl,hv-mpic-per-cpu");
284 if (np2) {
285 mpic_percpu_base_vaddr = of_iomap(np2, 0);
286 if (!mpic_percpu_base_vaddr)
287 pr_err("ehv_pic_init: of_iomap failed\n");
288
289 of_node_put(np2);
290 }
291
292 ehv_pic->hc_irq = ehv_pic_irq_chip;
293 ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
294 ehv_pic->coreint_flag = coreint_flag;
295
296 global_ehv_pic = ehv_pic;
297 irq_set_default_host(global_ehv_pic->irqhost);
298 }
299