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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_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_host *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(unsigned int irq_plug)64 static void beatic_mask_irq(unsigned int irq_plug)
65 {
66 	unsigned long flags;
67 
68 	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
69 	beatic_irq_mask_enable[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
70 	beatic_update_irq_mask(irq_plug);
71 	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
72 }
73 
beatic_unmask_irq(unsigned int irq_plug)74 static void beatic_unmask_irq(unsigned int irq_plug)
75 {
76 	unsigned long flags;
77 
78 	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
79 	beatic_irq_mask_enable[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
80 	beatic_update_irq_mask(irq_plug);
81 	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
82 }
83 
beatic_ack_irq(unsigned int irq_plug)84 static void beatic_ack_irq(unsigned int irq_plug)
85 {
86 	unsigned long flags;
87 
88 	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
89 	beatic_irq_mask_ack[irq_plug/64] &= ~(1UL << (63 - (irq_plug%64)));
90 	beatic_update_irq_mask(irq_plug);
91 	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
92 }
93 
beatic_end_irq(unsigned int irq_plug)94 static void beatic_end_irq(unsigned int irq_plug)
95 {
96 	s64 err;
97 	unsigned long flags;
98 
99 	err = beat_downcount_of_interrupt(irq_plug);
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", irq_plug);
105 	}
106 	spin_lock_irqsave(&beatic_irq_mask_lock, flags);
107 	beatic_irq_mask_ack[irq_plug/64] |= 1UL << (63 - (irq_plug%64));
108 	beatic_update_irq_mask(irq_plug);
109 	spin_unlock_irqrestore(&beatic_irq_mask_lock, flags);
110 }
111 
112 static struct irq_chip beatic_pic = {
113 	.typename = " CELL-BEAT ",
114 	.unmask = beatic_unmask_irq,
115 	.mask = beatic_mask_irq,
116 	.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_host * h,unsigned int virq)125 static void beatic_pic_host_unmap(struct irq_host *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_host * h,unsigned int virq,irq_hw_number_t hw)136 static int beatic_pic_host_map(struct irq_host *h, unsigned int virq,
137 			       irq_hw_number_t hw)
138 {
139 	struct irq_desc *desc = get_irq_desc(virq);
140 	int64_t	err;
141 
142 	err = beat_construct_and_connect_irq_plug(virq, hw);
143 	if (err < 0)
144 		return -EIO;
145 
146 	desc->status |= IRQ_LEVEL;
147 	set_irq_chip_and_handler(virq, &beatic_pic, handle_fasteoi_irq);
148 	return 0;
149 }
150 
151 /*
152  * Update binding hardware IRQ number (hw) and Virtuql
153  * IRQ number (virq). This is called only once for a given mapping.
154  */
beatic_pic_host_remap(struct irq_host * h,unsigned int virq,irq_hw_number_t hw)155 static void beatic_pic_host_remap(struct irq_host *h, unsigned int virq,
156 			       irq_hw_number_t hw)
157 {
158 	beat_construct_and_connect_irq_plug(virq, hw);
159 }
160 
161 /*
162  * Translate device-tree interrupt spec to irq_hw_number_t style (ulong),
163  * to pass away to irq_create_mapping().
164  *
165  * Called from irq_create_of_mapping() only.
166  * Note: We have only 1 entry to translate.
167  */
beatic_pic_host_xlate(struct irq_host * h,struct device_node * ct,u32 * intspec,unsigned int intsize,irq_hw_number_t * out_hwirq,unsigned int * out_flags)168 static int beatic_pic_host_xlate(struct irq_host *h, struct device_node *ct,
169 				 u32 *intspec, unsigned int intsize,
170 				 irq_hw_number_t *out_hwirq,
171 				 unsigned int *out_flags)
172 {
173 	u64 *intspec2 = (u64 *)intspec;
174 
175 	*out_hwirq = *intspec2;
176 	*out_flags |= IRQ_TYPE_LEVEL_LOW;
177 	return 0;
178 }
179 
beatic_pic_host_match(struct irq_host * h,struct device_node * np)180 static int beatic_pic_host_match(struct irq_host *h, struct device_node *np)
181 {
182 	/* Match all */
183 	return 1;
184 }
185 
186 static struct irq_host_ops beatic_pic_host_ops = {
187 	.map = beatic_pic_host_map,
188 	.remap = beatic_pic_host_remap,
189 	.unmap = beatic_pic_host_unmap,
190 	.xlate = beatic_pic_host_xlate,
191 	.match = beatic_pic_host_match,
192 };
193 
194 /*
195  * Get an IRQ number
196  * Note: returns VIRQ
197  */
beatic_get_irq_plug(void)198 static inline unsigned int beatic_get_irq_plug(void)
199 {
200 	int i;
201 	uint64_t	pending[4], ub;
202 
203 	for (i = 0; i < MAX_IRQS; i += 256) {
204 		beat_detect_pending_interrupts(i, pending);
205 		__asm__ ("cntlzd %0,%1":"=r"(ub):
206 			"r"(pending[0] & beatic_irq_mask_enable[i/64+0]
207 				       & beatic_irq_mask_ack[i/64+0]));
208 		if (ub != 64)
209 			return i + ub + 0;
210 		__asm__ ("cntlzd %0,%1":"=r"(ub):
211 			"r"(pending[1] & beatic_irq_mask_enable[i/64+1]
212 				       & beatic_irq_mask_ack[i/64+1]));
213 		if (ub != 64)
214 			return i + ub + 64;
215 		__asm__ ("cntlzd %0,%1":"=r"(ub):
216 			"r"(pending[2] & beatic_irq_mask_enable[i/64+2]
217 				       & beatic_irq_mask_ack[i/64+2]));
218 		if (ub != 64)
219 			return i + ub + 128;
220 		__asm__ ("cntlzd %0,%1":"=r"(ub):
221 			"r"(pending[3] & beatic_irq_mask_enable[i/64+3]
222 				       & beatic_irq_mask_ack[i/64+3]));
223 		if (ub != 64)
224 			return i + ub + 192;
225 	}
226 
227 	return NO_IRQ;
228 }
beatic_get_irq(void)229 unsigned int beatic_get_irq(void)
230 {
231 	unsigned int ret;
232 
233 	ret = beatic_get_irq_plug();
234 	if (ret != NO_IRQ)
235 		beatic_ack_irq(ret);
236 	return ret;
237 }
238 
239 /*
240  */
beatic_init_IRQ(void)241 void __init beatic_init_IRQ(void)
242 {
243 	int	i;
244 
245 	memset(beatic_irq_mask_enable, 0, sizeof(beatic_irq_mask_enable));
246 	memset(beatic_irq_mask_ack, 255, sizeof(beatic_irq_mask_ack));
247 	for (i = 0; i < MAX_IRQS; i += 256)
248 		beat_set_interrupt_mask(i, 0L, 0L, 0L, 0L);
249 
250 	/* Set out get_irq function */
251 	ppc_md.get_irq = beatic_get_irq;
252 
253 	/* Allocate an irq host */
254 	beatic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
255 				     &beatic_pic_host_ops,
256 					 0);
257 	BUG_ON(beatic_host == NULL);
258 	irq_set_default_host(beatic_host);
259 }
260 
261 #ifdef CONFIG_SMP
262 
263 /* Nullified to compile with SMP mode */
beatic_setup_cpu(int cpu)264 void beatic_setup_cpu(int cpu)
265 {
266 }
267 
beatic_cause_IPI(int cpu,int mesg)268 void beatic_cause_IPI(int cpu, int mesg)
269 {
270 }
271 
beatic_request_IPIs(void)272 void beatic_request_IPIs(void)
273 {
274 }
275 #endif /* CONFIG_SMP */
276 
beatic_deinit_IRQ(void)277 void beatic_deinit_IRQ(void)
278 {
279 	int	i;
280 
281 	for (i = 1; i < NR_IRQS; i++)
282 		beat_destruct_irq_plug(i);
283 }
284