1 #undef DEBUG
2 
3 #include <linux/bitmap.h>
4 #include <linux/init.h>
5 #include <linux/smp.h>
6 #include <linux/irq.h>
7 
8 #include <asm/io.h>
9 #include <asm/gic.h>
10 #include <asm/gcmpregs.h>
11 #include <linux/hardirq.h>
12 #include <asm-generic/bitops/find.h>
13 
14 
15 static unsigned long _gic_base;
16 static unsigned int _irqbase;
17 static unsigned int gic_irq_flags[GIC_NUM_INTRS];
18 #define GIC_IRQ_FLAG_EDGE      0x0001
19 
20 struct gic_pcpu_mask pcpu_masks[NR_CPUS];
21 static struct gic_pending_regs pending_regs[NR_CPUS];
22 static struct gic_intrmask_regs intrmask_regs[NR_CPUS];
23 
gic_send_ipi(unsigned int intr)24 void gic_send_ipi(unsigned int intr)
25 {
26 	pr_debug("CPU%d: %s status %08x\n", smp_processor_id(), __func__,
27 		 read_c0_status());
28 	GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), 0x80000000 | intr);
29 }
30 
31 /* This is Malta specific and needs to be exported */
vpe_local_setup(unsigned int numvpes)32 static void __init vpe_local_setup(unsigned int numvpes)
33 {
34 	int i;
35 	unsigned long timer_interrupt = 5, perf_interrupt = 5;
36 	unsigned int vpe_ctl;
37 
38 	/*
39 	 * Setup the default performance counter timer interrupts
40 	 * for all VPEs
41 	 */
42 	for (i = 0; i < numvpes; i++) {
43 		GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_OTHER_ADDR), i);
44 
45 		/* Are Interrupts locally routable? */
46 		GICREAD(GIC_REG(VPE_OTHER, GIC_VPE_CTL), vpe_ctl);
47 		if (vpe_ctl & GIC_VPE_CTL_TIMER_RTBL_MSK)
48 			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_TIMER_MAP),
49 				 GIC_MAP_TO_PIN_MSK | timer_interrupt);
50 
51 		if (vpe_ctl & GIC_VPE_CTL_PERFCNT_RTBL_MSK)
52 			GICWRITE(GIC_REG(VPE_OTHER, GIC_VPE_PERFCTR_MAP),
53 				 GIC_MAP_TO_PIN_MSK | perf_interrupt);
54 	}
55 }
56 
gic_get_int(void)57 unsigned int gic_get_int(void)
58 {
59 	unsigned int i;
60 	unsigned long *pending, *intrmask, *pcpu_mask;
61 	unsigned long *pending_abs, *intrmask_abs;
62 
63 	/* Get per-cpu bitmaps */
64 	pending = pending_regs[smp_processor_id()].pending;
65 	intrmask = intrmask_regs[smp_processor_id()].intrmask;
66 	pcpu_mask = pcpu_masks[smp_processor_id()].pcpu_mask;
67 
68 	pending_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
69 							 GIC_SH_PEND_31_0_OFS);
70 	intrmask_abs = (unsigned long *) GIC_REG_ABS_ADDR(SHARED,
71 							  GIC_SH_MASK_31_0_OFS);
72 
73 	for (i = 0; i < BITS_TO_LONGS(GIC_NUM_INTRS); i++) {
74 		GICREAD(*pending_abs, pending[i]);
75 		GICREAD(*intrmask_abs, intrmask[i]);
76 		pending_abs++;
77 		intrmask_abs++;
78 	}
79 
80 	bitmap_and(pending, pending, intrmask, GIC_NUM_INTRS);
81 	bitmap_and(pending, pending, pcpu_mask, GIC_NUM_INTRS);
82 
83 	i = find_first_bit(pending, GIC_NUM_INTRS);
84 
85 	pr_debug("CPU%d: %s pend=%d\n", smp_processor_id(), __func__, i);
86 
87 	return i;
88 }
89 
gic_irq_ack(struct irq_data * d)90 static void gic_irq_ack(struct irq_data *d)
91 {
92 	unsigned int irq = d->irq - _irqbase;
93 
94 	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
95 	GIC_CLR_INTR_MASK(irq);
96 
97 	if (gic_irq_flags[irq] & GIC_IRQ_FLAG_EDGE)
98 		GICWRITE(GIC_REG(SHARED, GIC_SH_WEDGE), irq);
99 }
100 
gic_mask_irq(struct irq_data * d)101 static void gic_mask_irq(struct irq_data *d)
102 {
103 	unsigned int irq = d->irq - _irqbase;
104 	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
105 	GIC_CLR_INTR_MASK(irq);
106 }
107 
gic_unmask_irq(struct irq_data * d)108 static void gic_unmask_irq(struct irq_data *d)
109 {
110 	unsigned int irq = d->irq - _irqbase;
111 	pr_debug("CPU%d: %s: irq%d\n", smp_processor_id(), __func__, irq);
112 	GIC_SET_INTR_MASK(irq);
113 }
114 
115 #ifdef CONFIG_SMP
116 
117 static DEFINE_SPINLOCK(gic_lock);
118 
gic_set_affinity(struct irq_data * d,const struct cpumask * cpumask,bool force)119 static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
120 			    bool force)
121 {
122 	unsigned int irq = d->irq - _irqbase;
123 	cpumask_t	tmp = CPU_MASK_NONE;
124 	unsigned long	flags;
125 	int		i;
126 
127 	pr_debug("%s(%d) called\n", __func__, irq);
128 	cpumask_and(&tmp, cpumask, cpu_online_mask);
129 	if (cpus_empty(tmp))
130 		return -1;
131 
132 	/* Assumption : cpumask refers to a single CPU */
133 	spin_lock_irqsave(&gic_lock, flags);
134 	for (;;) {
135 		/* Re-route this IRQ */
136 		GIC_SH_MAP_TO_VPE_SMASK(irq, first_cpu(tmp));
137 
138 		/* Update the pcpu_masks */
139 		for (i = 0; i < NR_CPUS; i++)
140 			clear_bit(irq, pcpu_masks[i].pcpu_mask);
141 		set_bit(irq, pcpu_masks[first_cpu(tmp)].pcpu_mask);
142 
143 	}
144 	cpumask_copy(d->affinity, cpumask);
145 	spin_unlock_irqrestore(&gic_lock, flags);
146 
147 	return IRQ_SET_MASK_OK_NOCOPY;
148 }
149 #endif
150 
151 static struct irq_chip gic_irq_controller = {
152 	.name			=	"MIPS GIC",
153 	.irq_ack		=	gic_irq_ack,
154 	.irq_mask		=	gic_mask_irq,
155 	.irq_mask_ack		=	gic_mask_irq,
156 	.irq_unmask		=	gic_unmask_irq,
157 	.irq_eoi		=	gic_unmask_irq,
158 #ifdef CONFIG_SMP
159 	.irq_set_affinity	=	gic_set_affinity,
160 #endif
161 };
162 
gic_setup_intr(unsigned int intr,unsigned int cpu,unsigned int pin,unsigned int polarity,unsigned int trigtype,unsigned int flags)163 static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,
164 	unsigned int pin, unsigned int polarity, unsigned int trigtype,
165 	unsigned int flags)
166 {
167 	/* Setup Intr to Pin mapping */
168 	if (pin & GIC_MAP_TO_NMI_MSK) {
169 		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
170 		/* FIXME: hack to route NMI to all cpu's */
171 		for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
172 			GICWRITE(GIC_REG_ADDR(SHARED,
173 					  GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
174 				 0xffffffff);
175 		}
176 	} else {
177 		GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)),
178 			 GIC_MAP_TO_PIN_MSK | pin);
179 		/* Setup Intr to CPU mapping */
180 		GIC_SH_MAP_TO_VPE_SMASK(intr, cpu);
181 	}
182 
183 	/* Setup Intr Polarity */
184 	GIC_SET_POLARITY(intr, polarity);
185 
186 	/* Setup Intr Trigger Type */
187 	GIC_SET_TRIGGER(intr, trigtype);
188 
189 	/* Init Intr Masks */
190 	GIC_CLR_INTR_MASK(intr);
191 	/* Initialise per-cpu Interrupt software masks */
192 	if (flags & GIC_FLAG_IPI)
193 		set_bit(intr, pcpu_masks[cpu].pcpu_mask);
194 	if (flags & GIC_FLAG_TRANSPARENT)
195 		GIC_SET_INTR_MASK(intr);
196 	if (trigtype == GIC_TRIG_EDGE)
197 		gic_irq_flags[intr] |= GIC_IRQ_FLAG_EDGE;
198 }
199 
gic_basic_init(int numintrs,int numvpes,struct gic_intr_map * intrmap,int mapsize)200 static void __init gic_basic_init(int numintrs, int numvpes,
201 			struct gic_intr_map *intrmap, int mapsize)
202 {
203 	unsigned int i, cpu;
204 
205 	/* Setup defaults */
206 	for (i = 0; i < numintrs; i++) {
207 		GIC_SET_POLARITY(i, GIC_POL_POS);
208 		GIC_SET_TRIGGER(i, GIC_TRIG_LEVEL);
209 		GIC_CLR_INTR_MASK(i);
210 		if (i < GIC_NUM_INTRS)
211 			gic_irq_flags[i] = 0;
212 	}
213 
214 	/* Setup specifics */
215 	for (i = 0; i < mapsize; i++) {
216 		cpu = intrmap[i].cpunum;
217 		if (cpu == GIC_UNUSED)
218 			continue;
219 		if (cpu == 0 && i != 0 && intrmap[i].flags == 0)
220 			continue;
221 		gic_setup_intr(i,
222 			intrmap[i].cpunum,
223 			intrmap[i].pin,
224 			intrmap[i].polarity,
225 			intrmap[i].trigtype,
226 			intrmap[i].flags);
227 	}
228 
229 	vpe_local_setup(numvpes);
230 
231 	for (i = _irqbase; i < (_irqbase + numintrs); i++)
232 		irq_set_chip(i, &gic_irq_controller);
233 }
234 
gic_init(unsigned long gic_base_addr,unsigned long gic_addrspace_size,struct gic_intr_map * intr_map,unsigned int intr_map_size,unsigned int irqbase)235 void __init gic_init(unsigned long gic_base_addr,
236 		     unsigned long gic_addrspace_size,
237 		     struct gic_intr_map *intr_map, unsigned int intr_map_size,
238 		     unsigned int irqbase)
239 {
240 	unsigned int gicconfig;
241 	int numvpes, numintrs;
242 
243 	_gic_base = (unsigned long) ioremap_nocache(gic_base_addr,
244 						    gic_addrspace_size);
245 	_irqbase = irqbase;
246 
247 	GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), gicconfig);
248 	numintrs = (gicconfig & GIC_SH_CONFIG_NUMINTRS_MSK) >>
249 		   GIC_SH_CONFIG_NUMINTRS_SHF;
250 	numintrs = ((numintrs + 1) * 8);
251 
252 	numvpes = (gicconfig & GIC_SH_CONFIG_NUMVPES_MSK) >>
253 		  GIC_SH_CONFIG_NUMVPES_SHF;
254 
255 	pr_debug("%s called\n", __func__);
256 
257 	gic_basic_init(numintrs, numvpes, intr_map, intr_map_size);
258 }
259