Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
[linux-2.6.git] / arch / powerpc / sysdev / xics / icp-native.c
1 /*
2  * Copyright 2011 IBM Corporation.
3  *
4  *  This program is free software; you can redistribute it and/or
5  *  modify it under the terms of the GNU General Public License
6  *  as published by the Free Software Foundation; either version
7  *  2 of the License, or (at your option) any later version.
8  *
9  */
10
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/irq.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/cpu.h>
18 #include <linux/of.h>
19 #include <linux/spinlock.h>
20 #include <linux/module.h>
21
22 #include <asm/prom.h>
23 #include <asm/io.h>
24 #include <asm/smp.h>
25 #include <asm/irq.h>
26 #include <asm/errno.h>
27 #include <asm/xics.h>
28 #include <asm/kvm_ppc.h>
29
30 struct icp_ipl {
31         union {
32                 u32 word;
33                 u8 bytes[4];
34         } xirr_poll;
35         union {
36                 u32 word;
37                 u8 bytes[4];
38         } xirr;
39         u32 dummy;
40         union {
41                 u32 word;
42                 u8 bytes[4];
43         } qirr;
44         u32 link_a;
45         u32 link_b;
46         u32 link_c;
47 };
48
49 static struct icp_ipl __iomem *icp_native_regs[NR_CPUS];
50
51 static inline unsigned int icp_native_get_xirr(void)
52 {
53         int cpu = smp_processor_id();
54
55         return in_be32(&icp_native_regs[cpu]->xirr.word);
56 }
57
58 static inline void icp_native_set_xirr(unsigned int value)
59 {
60         int cpu = smp_processor_id();
61
62         out_be32(&icp_native_regs[cpu]->xirr.word, value);
63 }
64
65 static inline void icp_native_set_cppr(u8 value)
66 {
67         int cpu = smp_processor_id();
68
69         out_8(&icp_native_regs[cpu]->xirr.bytes[0], value);
70 }
71
72 static inline void icp_native_set_qirr(int n_cpu, u8 value)
73 {
74         out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value);
75 }
76
77 static void icp_native_set_cpu_priority(unsigned char cppr)
78 {
79         xics_set_base_cppr(cppr);
80         icp_native_set_cppr(cppr);
81         iosync();
82 }
83
84 static void icp_native_eoi(struct irq_data *d)
85 {
86         unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
87
88         iosync();
89         icp_native_set_xirr((xics_pop_cppr() << 24) | hw_irq);
90 }
91
92 static void icp_native_teardown_cpu(void)
93 {
94         int cpu = smp_processor_id();
95
96         /* Clear any pending IPI */
97         icp_native_set_qirr(cpu, 0xff);
98 }
99
100 static void icp_native_flush_ipi(void)
101 {
102         /* We take the ipi irq but and never return so we
103          * need to EOI the IPI, but want to leave our priority 0
104          *
105          * should we check all the other interrupts too?
106          * should we be flagging idle loop instead?
107          * or creating some task to be scheduled?
108          */
109
110         icp_native_set_xirr((0x00 << 24) | XICS_IPI);
111 }
112
113 static unsigned int icp_native_get_irq(void)
114 {
115         unsigned int xirr = icp_native_get_xirr();
116         unsigned int vec = xirr & 0x00ffffff;
117         unsigned int irq;
118
119         if (vec == XICS_IRQ_SPURIOUS)
120                 return NO_IRQ;
121
122         irq = irq_radix_revmap_lookup(xics_host, vec);
123         if (likely(irq != NO_IRQ)) {
124                 xics_push_cppr(vec);
125                 return irq;
126         }
127
128         /* We don't have a linux mapping, so have rtas mask it. */
129         xics_mask_unknown_vec(vec);
130
131         /* We might learn about it later, so EOI it */
132         icp_native_set_xirr(xirr);
133
134         return NO_IRQ;
135 }
136
137 #ifdef CONFIG_SMP
138
139 static void icp_native_cause_ipi(int cpu, unsigned long data)
140 {
141         icp_native_set_qirr(cpu, IPI_PRIORITY);
142 }
143
144 void xics_wake_cpu(int cpu)
145 {
146         icp_native_set_qirr(cpu, IPI_PRIORITY);
147 }
148 EXPORT_SYMBOL_GPL(xics_wake_cpu);
149
150 static irqreturn_t icp_native_ipi_action(int irq, void *dev_id)
151 {
152         int cpu = smp_processor_id();
153
154         icp_native_set_qirr(cpu, 0xff);
155
156         return smp_ipi_demux();
157 }
158
159 #endif /* CONFIG_SMP */
160
161 static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr,
162                                          unsigned long size)
163 {
164         char *rname;
165         int i, cpu = -1;
166
167         /* This may look gross but it's good enough for now, we don't quite
168          * have a hard -> linux processor id matching.
169          */
170         for_each_possible_cpu(i) {
171                 if (!cpu_present(i))
172                         continue;
173                 if (hw_id == get_hard_smp_processor_id(i)) {
174                         cpu = i;
175                         break;
176                 }
177         }
178
179         /* Fail, skip that CPU. Don't print, it's normal, some XICS come up
180          * with way more entries in there than you have CPUs
181          */
182         if (cpu == -1)
183                 return 0;
184
185         rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation",
186                           cpu, hw_id);
187
188         if (!request_mem_region(addr, size, rname)) {
189                 pr_warning("icp_native: Could not reserve ICP MMIO"
190                            " for CPU %d, interrupt server #0x%x\n",
191                            cpu, hw_id);
192                 return -EBUSY;
193         }
194
195         icp_native_regs[cpu] = ioremap(addr, size);
196         kvmppc_set_xics_phys(cpu, addr);
197         if (!icp_native_regs[cpu]) {
198                 pr_warning("icp_native: Failed ioremap for CPU %d, "
199                            "interrupt server #0x%x, addr %#lx\n",
200                            cpu, hw_id, addr);
201                 release_mem_region(addr, size);
202                 return -ENOMEM;
203         }
204         return 0;
205 }
206
207 static int __init icp_native_init_one_node(struct device_node *np,
208                                            unsigned int *indx)
209 {
210         unsigned int ilen;
211         const u32 *ireg;
212         int i;
213         int reg_tuple_size;
214         int num_servers = 0;
215
216         /* This code does the theorically broken assumption that the interrupt
217          * server numbers are the same as the hard CPU numbers.
218          * This happens to be the case so far but we are playing with fire...
219          * should be fixed one of these days. -BenH.
220          */
221         ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen);
222
223         /* Do that ever happen ? we'll know soon enough... but even good'old
224          * f80 does have that property ..
225          */
226         WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32)));
227
228         if (ireg) {
229                 *indx = of_read_number(ireg, 1);
230                 if (ilen >= 2*sizeof(u32))
231                         num_servers = of_read_number(ireg + 1, 1);
232         }
233
234         ireg = of_get_property(np, "reg", &ilen);
235         if (!ireg) {
236                 pr_err("icp_native: Can't find interrupt reg property");
237                 return -1;
238         }
239
240         reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4;
241         if (((ilen % reg_tuple_size) != 0)
242             || (num_servers && (num_servers != (ilen / reg_tuple_size)))) {
243                 pr_err("icp_native: ICP reg len (%d) != num servers (%d)",
244                        ilen / reg_tuple_size, num_servers);
245                 return -1;
246         }
247
248         for (i = 0; i < (ilen / reg_tuple_size); i++) {
249                 struct resource r;
250                 int err;
251
252                 err = of_address_to_resource(np, i, &r);
253                 if (err) {
254                         pr_err("icp_native: Could not translate ICP MMIO"
255                                " for interrupt server 0x%x (%d)\n", *indx, err);
256                         return -1;
257                 }
258
259                 if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r)))
260                         return -1;
261
262                 (*indx)++;
263         }
264         return 0;
265 }
266
267 static const struct icp_ops icp_native_ops = {
268         .get_irq        = icp_native_get_irq,
269         .eoi            = icp_native_eoi,
270         .set_priority   = icp_native_set_cpu_priority,
271         .teardown_cpu   = icp_native_teardown_cpu,
272         .flush_ipi      = icp_native_flush_ipi,
273 #ifdef CONFIG_SMP
274         .ipi_action     = icp_native_ipi_action,
275         .cause_ipi      = icp_native_cause_ipi,
276 #endif
277 };
278
279 int icp_native_init(void)
280 {
281         struct device_node *np;
282         u32 indx = 0;
283         int found = 0;
284
285         for_each_compatible_node(np, NULL, "ibm,ppc-xicp")
286                 if (icp_native_init_one_node(np, &indx) == 0)
287                         found = 1;
288         if (!found) {
289                 for_each_node_by_type(np,
290                         "PowerPC-External-Interrupt-Presentation") {
291                                 if (icp_native_init_one_node(np, &indx) == 0)
292                                         found = 1;
293                 }
294         }
295
296         if (found == 0)
297                 return -ENODEV;
298
299         icp_ops = &icp_native_ops;
300
301         return 0;
302 }