1 /*
2 * Celleb/Beat Interrupt controller
3 *
4 * (C) Copyright 2006-2007 TOSHIBA CORPORATION
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/irq.h>
24 #include <linux/percpu.h>
25 #include <linux/types.h>
26
27 #include <asm/machdep.h>
28
29 #include "beat_interrupt.h"
30 #include "beat_wrapper.h"
31
32 #define MAX_IRQS NR_IRQS
33 static DEFINE_RAW_SPINLOCK(beatic_irq_mask_lock);
34 static uint64_t beatic_irq_mask_enable[(MAX_IRQS+255)/64];
35 static uint64_t beatic_irq_mask_ack[(MAX_IRQS+255)/64];
36
37 static struct irq_domain *beatic_host;
38
39 /*
40 * In this implementation, "virq" == "IRQ plug number",
41 * "(irq_hw_number_t)hwirq" == "IRQ outlet number".
42 */
43
44 /* assumption: locked */
beatic_update_irq_mask(unsigned int irq_plug)45 static inline void beatic_update_irq_mask(unsigned int irq_plug)
46 {
47 int off;
48 unsigned long masks[4];
49
50 off = (irq_plug / 256) * 4;
51 masks[0] = beatic_irq_mask_enable[off + 0]
52 & beatic_irq_mask_ack[off + 0];
53 masks[1] = beatic_irq_mask_enable[off + 1]
54 & beatic_irq_mask_ack[off + 1];
55 masks[2] = beatic_irq_mask_enable[off + 2]
56 & beatic_irq_mask_ack[off + 2];
57 masks[3] = beatic_irq_mask_enable[off + 3]
58 & beatic_irq_mask_ack[off + 3];
59 if (beat_set_interrupt_mask(irq_plug&~255UL,
60 masks[0], masks[1], masks[2], masks[3]) != 0)
61 panic("Failed to set mask IRQ!");
62 }
63
beatic_mask_irq(struct irq_data * d)64 static void beatic_mask_irq(struct irq_data *d)
65 {
66 unsigned long flags;
67
68 raw_spin_lock_irqsave(&beatic_irq_mask_lock, flags);
69 beatic_irq_mask_enable[d->irq/64] &= ~(1UL << (63 - (d->irq%64)));
70 beatic_update_irq_mask(d->irq);
71 raw_spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
72 }
73
beatic_unmask_irq(struct irq_data * d)74 static void beatic_unmask_irq(struct irq_data *d)
75 {
76 unsigned long flags;
77
78 raw_spin_lock_irqsave(&beatic_irq_mask_lock, flags);
79 beatic_irq_mask_enable[d->irq/64] |= 1UL << (63 - (d->irq%64));
80 beatic_update_irq_mask(d->irq);
81 raw_spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
82 }
83
beatic_ack_irq(struct irq_data * d)84 static void beatic_ack_irq(struct irq_data *d)
85 {
86 unsigned long flags;
87
88 raw_spin_lock_irqsave(&beatic_irq_mask_lock, flags);
89 beatic_irq_mask_ack[d->irq/64] &= ~(1UL << (63 - (d->irq%64)));
90 beatic_update_irq_mask(d->irq);
91 raw_spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
92 }
93
beatic_end_irq(struct irq_data * d)94 static void beatic_end_irq(struct irq_data *d)
95 {
96 s64 err;
97 unsigned long flags;
98
99 err = beat_downcount_of_interrupt(d->irq);
100 if (err != 0) {
101 if ((err & 0xFFFFFFFF) != 0xFFFFFFF5) /* -11: wrong state */
102 panic("Failed to downcount IRQ! Error = %16llx", err);
103
104 printk(KERN_ERR "IRQ over-downcounted, plug %d\n", d->irq);
105 }
106 raw_spin_lock_irqsave(&beatic_irq_mask_lock, flags);
107 beatic_irq_mask_ack[d->irq/64] |= 1UL << (63 - (d->irq%64));
108 beatic_update_irq_mask(d->irq);
109 raw_spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
110 }
111
112 static struct irq_chip beatic_pic = {
113 .name = "CELL-BEAT",
114 .irq_unmask = beatic_unmask_irq,
115 .irq_mask = beatic_mask_irq,
116 .irq_eoi = beatic_end_irq,
117 };
118
119 /*
120 * Dispose binding hardware IRQ number (hw) and Virtuql IRQ number (virq),
121 * update flags.
122 *
123 * Note that the number (virq) is already assigned at upper layer.
124 */
beatic_pic_host_unmap(struct irq_domain * h,unsigned int virq)125 static void beatic_pic_host_unmap(struct irq_domain *h, unsigned int virq)
126 {
127 beat_destruct_irq_plug(virq);
128 }
129
130 /*
131 * Create or update binding hardware IRQ number (hw) and Virtuql
132 * IRQ number (virq). This is called only once for a given mapping.
133 *
134 * Note that the number (virq) is already assigned at upper layer.
135 */
beatic_pic_host_map(struct irq_domain * h,unsigned int virq,irq_hw_number_t hw)136 static int beatic_pic_host_map(struct irq_domain *h, unsigned int virq,
137 irq_hw_number_t hw)
138 {
139 int64_t err;
140
141 err = beat_construct_and_connect_irq_plug(virq, hw);
142 if (err < 0)
143 return -EIO;
144
145 irq_set_status_flags(virq, IRQ_LEVEL);
146 irq_set_chip_and_handler(virq, &beatic_pic, handle_fasteoi_irq);
147 return 0;
148 }
149
150 /*
151 * Translate device-tree interrupt spec to irq_hw_number_t style (ulong),
152 * to pass away to irq_create_mapping().
153 *
154 * Called from irq_create_of_mapping() only.
155 * Note: We have only 1 entry to translate.
156 */
beatic_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)157 static int beatic_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
158 const u32 *intspec, unsigned int intsize,
159 irq_hw_number_t *out_hwirq,
160 unsigned int *out_flags)
161 {
162 const u64 *intspec2 = (const u64 *)intspec;
163
164 *out_hwirq = *intspec2;
165 *out_flags |= IRQ_TYPE_LEVEL_LOW;
166 return 0;
167 }
168
beatic_pic_host_match(struct irq_domain * h,struct device_node * np)169 static int beatic_pic_host_match(struct irq_domain *h, struct device_node *np)
170 {
171 /* Match all */
172 return 1;
173 }
174
175 static const struct irq_domain_ops beatic_pic_host_ops = {
176 .map = beatic_pic_host_map,
177 .unmap = beatic_pic_host_unmap,
178 .xlate = beatic_pic_host_xlate,
179 .match = beatic_pic_host_match,
180 };
181
182 /*
183 * Get an IRQ number
184 * Note: returns VIRQ
185 */
beatic_get_irq_plug(void)186 static inline unsigned int beatic_get_irq_plug(void)
187 {
188 int i;
189 uint64_t pending[4], ub;
190
191 for (i = 0; i < MAX_IRQS; i += 256) {
192 beat_detect_pending_interrupts(i, pending);
193 __asm__ ("cntlzd %0,%1":"=r"(ub):
194 "r"(pending[0] & beatic_irq_mask_enable[i/64+0]
195 & beatic_irq_mask_ack[i/64+0]));
196 if (ub != 64)
197 return i + ub + 0;
198 __asm__ ("cntlzd %0,%1":"=r"(ub):
199 "r"(pending[1] & beatic_irq_mask_enable[i/64+1]
200 & beatic_irq_mask_ack[i/64+1]));
201 if (ub != 64)
202 return i + ub + 64;
203 __asm__ ("cntlzd %0,%1":"=r"(ub):
204 "r"(pending[2] & beatic_irq_mask_enable[i/64+2]
205 & beatic_irq_mask_ack[i/64+2]));
206 if (ub != 64)
207 return i + ub + 128;
208 __asm__ ("cntlzd %0,%1":"=r"(ub):
209 "r"(pending[3] & beatic_irq_mask_enable[i/64+3]
210 & beatic_irq_mask_ack[i/64+3]));
211 if (ub != 64)
212 return i + ub + 192;
213 }
214
215 return NO_IRQ;
216 }
beatic_get_irq(void)217 unsigned int beatic_get_irq(void)
218 {
219 unsigned int ret;
220
221 ret = beatic_get_irq_plug();
222 if (ret != NO_IRQ)
223 beatic_ack_irq(irq_get_irq_data(ret));
224 return ret;
225 }
226
227 /*
228 */
beatic_init_IRQ(void)229 void __init beatic_init_IRQ(void)
230 {
231 int i;
232
233 memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));
234 memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));
235 for (i = 0; i < MAX_IRQS; i += 256)
236 beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);
237
238 /* Set out get_irq function */
239 ppc_md.get_irq = beatic_get_irq;
240
241 /* Allocate an irq host */
242 beatic_host = irq_domain_add_nomap(NULL, 0, &beatic_pic_host_ops, NULL);
243 BUG_ON(beatic_host == NULL);
244 irq_set_default_host(beatic_host);
245 }
246
beatic_deinit_IRQ(void)247 void beatic_deinit_IRQ(void)
248 {
249 int i;
250
251 for (i = 1; i < nr_irqs; i++)
252 beat_destruct_irq_plug(i);
253 }
254