xref: /linux/arch/alpha/kernel/irq_alpha.c (revision f4cdf7ca9a1fdcca413157df19753f388a5a224e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Alpha specific irq code.
4  */
5 
6 #include <linux/init.h>
7 #include <linux/sched.h>
8 #include <linux/irq.h>
9 #include <linux/kernel_stat.h>
10 #include <linux/module.h>
11 
12 #include <asm/machvec.h>
13 #include <asm/dma.h>
14 #include <asm/perf_event.h>
15 #include <asm/mce.h>
16 
17 #include "proto.h"
18 #include "irq_impl.h"
19 
20 /* Hack minimum IPL during interrupt processing for broken hardware.  */
21 #ifdef CONFIG_ALPHA_BROKEN_IRQ_MASK
22 int __min_ipl;
23 EXPORT_SYMBOL(__min_ipl);
24 #endif
25 
26 /*
27  * Performance counter hook.  A module can override this to
28  * do something useful.
29  */
30 static void
31 dummy_perf(unsigned long vector, struct pt_regs *regs)
32 {
33 	irq_err_count++;
34 	printk(KERN_CRIT "Performance counter interrupt!\n");
35 }
36 
37 void (*perf_irq)(unsigned long, struct pt_regs *) = dummy_perf;
38 EXPORT_SYMBOL(perf_irq);
39 
40 /*
41  * The main interrupt entry point.
42  */
43 
44 asmlinkage void
45 do_entInt(unsigned long type, unsigned long vector,
46 	  unsigned long la_ptr, struct pt_regs *regs)
47 {
48 	struct pt_regs *old_regs;
49 
50 	/*
51 	 * Disable interrupts during IRQ handling.
52 	 * Note that there is no matching local_irq_enable() due to
53 	 * severe problems with RTI at IPL0 and some MILO PALcode
54 	 * (namely LX164).
55 	 *
56 	 * PALcode has already raised PS.IPL to the level of the interrupt
57 	 * being delivered.  For an IPL 7 entry - a machine check or a system
58 	 * event - that is IPL_MAX, which is what arch_irqs_disabled() tests
59 	 * for, so local_irq_disable() would decide interrupts were already
60 	 * off and skip trace_hardirqs_off().  lockdep would then spend the
61 	 * whole handler believing interrupts are enabled.  Drive the
62 	 * annotation from lockdep's own state rather than the hardware IPL.
63 	 */
64 	raw_local_irq_disable();
65 	if (lockdep_hardirqs_enabled())
66 		trace_hardirqs_off();
67 
68 	old_regs = set_irq_regs(regs);
69 
70 	switch (type) {
71 	case 0:
72 #ifdef CONFIG_SMP
73 		irq_enter();
74 		handle_ipi(regs);
75 		irq_exit();
76 		break;
77 #else
78 		irq_err_count++;
79 		pr_crit("Interprocessor interrupt? You must be kidding!\n");
80 		break;
81 #endif
82 	case 1:
83 		/* handle_irq() already does irq_enter()/irq_exit() */
84 		handle_irq(RTC_IRQ);
85 		break;
86 	case 2:
87 		irq_enter();
88 		alpha_mv.machine_check(vector, la_ptr);
89 		irq_exit();
90 		break;
91 	case 3:
92 		irq_enter();
93 		alpha_mv.device_interrupt(vector);
94 		irq_exit();
95 		break;
96 	case 4:
97 		irq_enter();
98 		perf_irq(la_ptr, regs);
99 		irq_exit();
100 		break;
101 	default:
102 		pr_crit("Hardware intr %lu %lx? Huh?\n", type, vector);
103 		pr_crit("PC = %016lx PS=%04lx\n", regs->pc, regs->ps);
104 		break;
105 	}
106 
107 	set_irq_regs(old_regs);
108 
109 	/*
110 	 * Intentionally no local_irq_enable(): Alpha historically avoids
111 	 * enabling at IPL0 here due to PAL/RTI issues (LX164/MILO note).
112 	 */
113 }
114 
115 void notrace lockdep_on_restore(unsigned long ps,
116 				unsigned long ip)
117 {
118 #ifdef CONFIG_PROVE_LOCKING
119 	/* Restoring IPL==7 means interrupts remain disabled. */
120 	if ((ps & 7) == 7)
121 		return;
122 
123 	/*
124 	 * If hardware IRQs are already enabled here, then emitting a
125 	 * hardirqs-on transition is redundant.
126 	 */
127 	if (!irqs_disabled())
128 		return;
129 
130 	/*
131 	 * Only emit the transition if lockdep currently believes
132 	 * hardirqs are off.
133 	 */
134 	if (lockdep_hardirqs_enabled())
135 		return;
136 
137 	lockdep_hardirqs_on_prepare();
138 	lockdep_hardirqs_on(ip);
139 #endif
140 }
141 
142 void __init
143 common_init_isa_dma(void)
144 {
145 	outb(0, DMA1_RESET_REG);
146 	outb(0, DMA2_RESET_REG);
147 	outb(0, DMA1_CLR_MASK_REG);
148 	outb(0, DMA2_CLR_MASK_REG);
149 }
150 
151 void __init
152 init_IRQ(void)
153 {
154 	/* Just in case the platform init_irq() causes interrupts/mchecks
155 	   (as is the case with RAWHIDE, at least).  */
156 	wrent(entInt, 0);
157 
158 	alpha_mv.init_irq();
159 }
160 
161 /*
162  * machine error checks
163  */
164 #define MCHK_K_TPERR           0x0080
165 #define MCHK_K_TCPERR          0x0082
166 #define MCHK_K_HERR            0x0084
167 #define MCHK_K_ECC_C           0x0086
168 #define MCHK_K_ECC_NC          0x0088
169 #define MCHK_K_OS_BUGCHECK     0x008A
170 #define MCHK_K_PAL_BUGCHECK    0x0090
171 
172 #ifndef CONFIG_SMP
173 struct mcheck_info __mcheck_info;
174 #endif
175 
176 void
177 process_mcheck_info(unsigned long vector, unsigned long la_ptr,
178 		    const char *machine, int expected)
179 {
180 	struct el_common *mchk_header;
181 	const char *reason;
182 
183 	/*
184 	 * See if the machine check is due to a badaddr() and if so,
185 	 * ignore it.
186 	 */
187 
188 #ifdef CONFIG_VERBOSE_MCHECK
189 	if (alpha_verbose_mcheck > 1) {
190 		printk(KERN_CRIT "%s machine check %s\n", machine,
191 		       expected ? "expected." : "NOT expected!!!");
192 	}
193 #endif
194 
195 	if (expected) {
196 		int cpu = smp_processor_id();
197 		mcheck_expected(cpu) = 0;
198 		mcheck_taken(cpu) = 1;
199 		return;
200 	}
201 
202 	mchk_header = (struct el_common *)la_ptr;
203 
204 	printk(KERN_CRIT "%s machine check: vector=0x%lx pc=0x%lx code=0x%x\n",
205 	       machine, vector, get_irq_regs()->pc, mchk_header->code);
206 
207 	switch (mchk_header->code) {
208 	/* Machine check reasons.  Defined according to PALcode sources.  */
209 	case 0x80: reason = "tag parity error"; break;
210 	case 0x82: reason = "tag control parity error"; break;
211 	case 0x84: reason = "generic hard error"; break;
212 	case 0x86: reason = "correctable ECC error"; break;
213 	case 0x88: reason = "uncorrectable ECC error"; break;
214 	case 0x8A: reason = "OS-specific PAL bugcheck"; break;
215 	case 0x90: reason = "callsys in kernel mode"; break;
216 	case 0x96: reason = "i-cache read retryable error"; break;
217 	case 0x98: reason = "processor detected hard error"; break;
218 
219 	/* System specific (these are for Alcor, at least): */
220 	case 0x202: reason = "system detected hard error"; break;
221 	case 0x203: reason = "system detected uncorrectable ECC error"; break;
222 	case 0x204: reason = "SIO SERR occurred on PCI bus"; break;
223 	case 0x205: reason = "parity error detected by core logic"; break;
224 	case 0x206: reason = "SIO IOCHK occurred on ISA bus"; break;
225 	case 0x207: reason = "non-existent memory error"; break;
226 	case 0x208: reason = "MCHK_K_DCSR"; break;
227 	case 0x209: reason = "PCI SERR detected"; break;
228 	case 0x20b: reason = "PCI data parity error detected"; break;
229 	case 0x20d: reason = "PCI address parity error detected"; break;
230 	case 0x20f: reason = "PCI master abort error"; break;
231 	case 0x211: reason = "PCI target abort error"; break;
232 	case 0x213: reason = "scatter/gather PTE invalid error"; break;
233 	case 0x215: reason = "flash ROM write error"; break;
234 	case 0x217: reason = "IOA timeout detected"; break;
235 	case 0x219: reason = "IOCHK#, EISA add-in board parity or other catastrophic error"; break;
236 	case 0x21b: reason = "EISA fail-safe timer timeout"; break;
237 	case 0x21d: reason = "EISA bus time-out"; break;
238 	case 0x21f: reason = "EISA software generated NMI"; break;
239 	case 0x221: reason = "unexpected ev5 IRQ[3] interrupt"; break;
240 	default: reason = "unknown"; break;
241 	}
242 
243 	printk(KERN_CRIT "machine check type: %s%s\n",
244 	       reason, mchk_header->retry ? " (retryable)" : "");
245 
246 	dik_show_regs(get_irq_regs(), NULL);
247 
248 #ifdef CONFIG_VERBOSE_MCHECK
249 	if (alpha_verbose_mcheck > 1) {
250 		/* Dump the logout area to give all info.  */
251 		unsigned long *ptr = (unsigned long *)la_ptr;
252 		long i;
253 		for (i = 0; i < mchk_header->size / sizeof(long); i += 2) {
254 			printk(KERN_CRIT "   +%8lx %016lx %016lx\n",
255 			       i*sizeof(long), ptr[i], ptr[i+1]);
256 		}
257 	}
258 #endif /* CONFIG_VERBOSE_MCHECK */
259 }
260 
261 /*
262  * The special RTC interrupt type.  The interrupt itself was
263  * processed by PALcode, and comes in via entInt vector 1.
264  */
265 void __init
266 init_rtc_irq(irq_handler_t handler)
267 {
268 	irq_set_chip_and_handler_name(RTC_IRQ, &dummy_irq_chip,
269 				      handle_percpu_irq, "RTC");
270 	if (!handler)
271 		handler = rtc_timer_interrupt;
272 	if (request_irq(RTC_IRQ, handler, 0, "timer", NULL))
273 		pr_err("Failed to register timer interrupt\n");
274 }
275