xref: /openbmc/linux/arch/alpha/kernel/core_t2.c (revision 56a0eccd)
1 /*
2  *	linux/arch/alpha/kernel/core_t2.c
3  *
4  * Written by Jay A Estabrook (jestabro@amt.tay1.dec.com).
5  * December 1996.
6  *
7  * based on CIA code by David A Rusling (david.rusling@reo.mts.dec.com)
8  *
9  * Code common to all T2 core logic chips.
10  */
11 
12 #define __EXTERN_INLINE
13 #include <asm/io.h>
14 #include <asm/core_t2.h>
15 #undef __EXTERN_INLINE
16 
17 #include <linux/types.h>
18 #include <linux/pci.h>
19 #include <linux/sched.h>
20 #include <linux/init.h>
21 
22 #include <asm/ptrace.h>
23 #include <asm/delay.h>
24 #include <asm/mce.h>
25 
26 #include "proto.h"
27 #include "pci_impl.h"
28 
29 /* For dumping initial DMA window settings. */
30 #define DEBUG_PRINT_INITIAL_SETTINGS 0
31 
32 /* For dumping final DMA window settings. */
33 #define DEBUG_PRINT_FINAL_SETTINGS 0
34 
35 /*
36  * By default, we direct-map starting at 2GB, in order to allow the
37  * maximum size direct-map window (2GB) to match the maximum amount of
38  * memory (2GB) that can be present on SABLEs. But that limits the
39  * floppy to DMA only via the scatter/gather window set up for 8MB
40  * ISA DMA, since the maximum ISA DMA address is 2GB-1.
41  *
42  * For now, this seems a reasonable trade-off: even though most SABLEs
43  * have less than 1GB of memory, floppy usage/performance will not
44  * really be affected by forcing it to go via scatter/gather...
45  */
46 #define T2_DIRECTMAP_2G 1
47 
48 #if T2_DIRECTMAP_2G
49 # define T2_DIRECTMAP_START	0x80000000UL
50 # define T2_DIRECTMAP_LENGTH	0x80000000UL
51 #else
52 # define T2_DIRECTMAP_START	0x40000000UL
53 # define T2_DIRECTMAP_LENGTH	0x40000000UL
54 #endif
55 
56 /* The ISA scatter/gather window settings. */
57 #define T2_ISA_SG_START		0x00800000UL
58 #define T2_ISA_SG_LENGTH	0x00800000UL
59 
60 /*
61  * NOTE: Herein lie back-to-back mb instructions.  They are magic.
62  * One plausible explanation is that the i/o controller does not properly
63  * handle the system transaction.  Another involves timing.  Ho hum.
64  */
65 
66 /*
67  * BIOS32-style PCI interface:
68  */
69 
70 #define DEBUG_CONFIG 0
71 
72 #if DEBUG_CONFIG
73 # define DBG(args)	printk args
74 #else
75 # define DBG(args)
76 #endif
77 
78 static volatile unsigned int t2_mcheck_any_expected;
79 static volatile unsigned int t2_mcheck_last_taken;
80 
81 /* Place to save the DMA Window registers as set up by SRM
82    for restoration during shutdown. */
83 static struct
84 {
85 	struct {
86 		unsigned long wbase;
87 		unsigned long wmask;
88 		unsigned long tbase;
89 	} window[2];
90 	unsigned long hae_1;
91   	unsigned long hae_2;
92 	unsigned long hae_3;
93 	unsigned long hae_4;
94 	unsigned long hbase;
95 } t2_saved_config __attribute((common));
96 
97 /*
98  * Given a bus, device, and function number, compute resulting
99  * configuration space address and setup the T2_HAXR2 register
100  * accordingly.  It is therefore not safe to have concurrent
101  * invocations to configuration space access routines, but there
102  * really shouldn't be any need for this.
103  *
104  * Type 0:
105  *
106  *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
107  *  3 2|1 0 9 8|7 6 5 4|3 2 1 0|9 8 7 6|5 4 3 2|1 0 9 8|7 6 5 4|3 2 1 0
108  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
109  * | | |D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|0|
110  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
111  *
112  *	31:11	Device select bit.
113  * 	10:8	Function number
114  * 	 7:2	Register number
115  *
116  * Type 1:
117  *
118  *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
119  *  3 2|1 0 9 8|7 6 5 4|3 2 1 0|9 8 7 6|5 4 3 2|1 0 9 8|7 6 5 4|3 2 1 0
120  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121  * | | | | | | | | | | |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|1|
122  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123  *
124  *	31:24	reserved
125  *	23:16	bus number (8 bits = 128 possible buses)
126  *	15:11	Device number (5 bits)
127  *	10:8	function number
128  *	 7:2	register number
129  *
130  * Notes:
131  *	The function number selects which function of a multi-function device
132  *	(e.g., SCSI and Ethernet).
133  *
134  *	The register selects a DWORD (32 bit) register offset.  Hence it
135  *	doesn't get shifted by 2 bits as we want to "drop" the bottom two
136  *	bits.
137  */
138 
139 static int
140 mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
141 	     unsigned long *pci_addr, unsigned char *type1)
142 {
143 	unsigned long addr;
144 	u8 bus = pbus->number;
145 
146 	DBG(("mk_conf_addr(bus=%d, dfn=0x%x, where=0x%x,"
147 	     " addr=0x%lx, type1=0x%x)\n",
148 	     bus, device_fn, where, pci_addr, type1));
149 
150 	if (bus == 0) {
151 		int device = device_fn >> 3;
152 
153 		/* Type 0 configuration cycle.  */
154 
155 		if (device > 8) {
156 			DBG(("mk_conf_addr: device (%d)>20, returning -1\n",
157 			     device));
158 			return -1;
159 		}
160 
161 		*type1 = 0;
162 		addr = (0x0800L << device) | ((device_fn & 7) << 8) | (where);
163 	} else {
164 		/* Type 1 configuration cycle.  */
165 		*type1 = 1;
166 		addr = (bus << 16) | (device_fn << 8) | (where);
167 	}
168 	*pci_addr = addr;
169 	DBG(("mk_conf_addr: returning pci_addr 0x%lx\n", addr));
170 	return 0;
171 }
172 
173 /*
174  * NOTE: both conf_read() and conf_write() may set HAE_3 when needing
175  *       to do type1 access. This is protected by the use of spinlock IRQ
176  *       primitives in the wrapper functions pci_{read,write}_config_*()
177  *       defined in drivers/pci/pci.c.
178  */
179 static unsigned int
180 conf_read(unsigned long addr, unsigned char type1)
181 {
182 	unsigned int value, cpu, taken;
183 	unsigned long t2_cfg = 0;
184 
185 	cpu = smp_processor_id();
186 
187 	DBG(("conf_read(addr=0x%lx, type1=%d)\n", addr, type1));
188 
189 	/* If Type1 access, must set T2 CFG.  */
190 	if (type1) {
191 		t2_cfg = *(vulp)T2_HAE_3 & ~0xc0000000UL;
192 		*(vulp)T2_HAE_3 = 0x40000000UL | t2_cfg;
193 		mb();
194 	}
195 	mb();
196 	draina();
197 
198 	mcheck_expected(cpu) = 1;
199 	mcheck_taken(cpu) = 0;
200 	t2_mcheck_any_expected |= (1 << cpu);
201 	mb();
202 
203 	/* Access configuration space. */
204 	value = *(vuip)addr;
205 	mb();
206 	mb();  /* magic */
207 
208 	/* Wait for possible mcheck. Also, this lets other CPUs clear
209 	   their mchecks as well, as they can reliably tell when
210 	   another CPU is in the midst of handling a real mcheck via
211 	   the "taken" function. */
212 	udelay(100);
213 
214 	if ((taken = mcheck_taken(cpu))) {
215 		mcheck_taken(cpu) = 0;
216 		t2_mcheck_last_taken |= (1 << cpu);
217 		value = 0xffffffffU;
218 		mb();
219 	}
220 	mcheck_expected(cpu) = 0;
221 	t2_mcheck_any_expected = 0;
222 	mb();
223 
224 	/* If Type1 access, must reset T2 CFG so normal IO space ops work.  */
225 	if (type1) {
226 		*(vulp)T2_HAE_3 = t2_cfg;
227 		mb();
228 	}
229 
230 	return value;
231 }
232 
233 static void
234 conf_write(unsigned long addr, unsigned int value, unsigned char type1)
235 {
236 	unsigned int cpu, taken;
237 	unsigned long t2_cfg = 0;
238 
239 	cpu = smp_processor_id();
240 
241 	/* If Type1 access, must set T2 CFG.  */
242 	if (type1) {
243 		t2_cfg = *(vulp)T2_HAE_3 & ~0xc0000000UL;
244 		*(vulp)T2_HAE_3 = t2_cfg | 0x40000000UL;
245 		mb();
246 	}
247 	mb();
248 	draina();
249 
250 	mcheck_expected(cpu) = 1;
251 	mcheck_taken(cpu) = 0;
252 	t2_mcheck_any_expected |= (1 << cpu);
253 	mb();
254 
255 	/* Access configuration space.  */
256 	*(vuip)addr = value;
257 	mb();
258 	mb();  /* magic */
259 
260 	/* Wait for possible mcheck. Also, this lets other CPUs clear
261 	   their mchecks as well, as they can reliably tell when
262 	   this CPU is in the midst of handling a real mcheck via
263 	   the "taken" function. */
264 	udelay(100);
265 
266 	if ((taken = mcheck_taken(cpu))) {
267 		mcheck_taken(cpu) = 0;
268 		t2_mcheck_last_taken |= (1 << cpu);
269 		mb();
270 	}
271 	mcheck_expected(cpu) = 0;
272 	t2_mcheck_any_expected = 0;
273 	mb();
274 
275 	/* If Type1 access, must reset T2 CFG so normal IO space ops work.  */
276 	if (type1) {
277 		*(vulp)T2_HAE_3 = t2_cfg;
278 		mb();
279 	}
280 }
281 
282 static int
283 t2_read_config(struct pci_bus *bus, unsigned int devfn, int where,
284 	       int size, u32 *value)
285 {
286 	unsigned long addr, pci_addr;
287 	unsigned char type1;
288 	int shift;
289 	long mask;
290 
291 	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
292 		return PCIBIOS_DEVICE_NOT_FOUND;
293 
294 	mask = (size - 1) * 8;
295 	shift = (where & 3) * 8;
296 	addr = (pci_addr << 5) + mask + T2_CONF;
297 	*value = conf_read(addr, type1) >> (shift);
298 	return PCIBIOS_SUCCESSFUL;
299 }
300 
301 static int
302 t2_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size,
303 		u32 value)
304 {
305 	unsigned long addr, pci_addr;
306 	unsigned char type1;
307 	long mask;
308 
309 	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
310 		return PCIBIOS_DEVICE_NOT_FOUND;
311 
312 	mask = (size - 1) * 8;
313 	addr = (pci_addr << 5) + mask + T2_CONF;
314 	conf_write(addr, value << ((where & 3) * 8), type1);
315 	return PCIBIOS_SUCCESSFUL;
316 }
317 
318 struct pci_ops t2_pci_ops =
319 {
320 	.read =		t2_read_config,
321 	.write =	t2_write_config,
322 };
323 
324 static void __init
325 t2_direct_map_window1(unsigned long base, unsigned long length)
326 {
327 	unsigned long temp;
328 
329 	__direct_map_base = base;
330 	__direct_map_size = length;
331 
332 	temp = (base & 0xfff00000UL) | ((base + length - 1) >> 20);
333 	*(vulp)T2_WBASE1 = temp | 0x80000UL; /* OR in ENABLE bit */
334 	temp = (length - 1) & 0xfff00000UL;
335 	*(vulp)T2_WMASK1 = temp;
336 	*(vulp)T2_TBASE1 = 0;
337 
338 #if DEBUG_PRINT_FINAL_SETTINGS
339 	printk("%s: setting WBASE1=0x%lx WMASK1=0x%lx TBASE1=0x%lx\n",
340 	       __func__, *(vulp)T2_WBASE1, *(vulp)T2_WMASK1, *(vulp)T2_TBASE1);
341 #endif
342 }
343 
344 static void __init
345 t2_sg_map_window2(struct pci_controller *hose,
346 		  unsigned long base,
347 		  unsigned long length)
348 {
349 	unsigned long temp;
350 
351 	/* Note we can only do 1 SG window, as the other is for direct, so
352 	   do an ISA SG area, especially for the floppy. */
353 	hose->sg_isa = iommu_arena_new(hose, base, length, 0);
354 	hose->sg_pci = NULL;
355 
356 	temp = (base & 0xfff00000UL) | ((base + length - 1) >> 20);
357 	*(vulp)T2_WBASE2 = temp | 0xc0000UL; /* OR in ENABLE/SG bits */
358 	temp = (length - 1) & 0xfff00000UL;
359 	*(vulp)T2_WMASK2 = temp;
360 	*(vulp)T2_TBASE2 = virt_to_phys(hose->sg_isa->ptes) >> 1;
361 	mb();
362 
363 	t2_pci_tbi(hose, 0, -1); /* flush TLB all */
364 
365 #if DEBUG_PRINT_FINAL_SETTINGS
366 	printk("%s: setting WBASE2=0x%lx WMASK2=0x%lx TBASE2=0x%lx\n",
367 	       __func__, *(vulp)T2_WBASE2, *(vulp)T2_WMASK2, *(vulp)T2_TBASE2);
368 #endif
369 }
370 
371 static void __init
372 t2_save_configuration(void)
373 {
374 #if DEBUG_PRINT_INITIAL_SETTINGS
375 	printk("%s: HAE_1 was 0x%lx\n", __func__, srm_hae); /* HW is 0 */
376 	printk("%s: HAE_2 was 0x%lx\n", __func__, *(vulp)T2_HAE_2);
377 	printk("%s: HAE_3 was 0x%lx\n", __func__, *(vulp)T2_HAE_3);
378 	printk("%s: HAE_4 was 0x%lx\n", __func__, *(vulp)T2_HAE_4);
379 	printk("%s: HBASE was 0x%lx\n", __func__, *(vulp)T2_HBASE);
380 
381 	printk("%s: WBASE1=0x%lx WMASK1=0x%lx TBASE1=0x%lx\n", __func__,
382 	       *(vulp)T2_WBASE1, *(vulp)T2_WMASK1, *(vulp)T2_TBASE1);
383 	printk("%s: WBASE2=0x%lx WMASK2=0x%lx TBASE2=0x%lx\n", __func__,
384 	       *(vulp)T2_WBASE2, *(vulp)T2_WMASK2, *(vulp)T2_TBASE2);
385 #endif
386 
387 	/*
388 	 * Save the DMA Window registers.
389 	 */
390 	t2_saved_config.window[0].wbase = *(vulp)T2_WBASE1;
391 	t2_saved_config.window[0].wmask = *(vulp)T2_WMASK1;
392 	t2_saved_config.window[0].tbase = *(vulp)T2_TBASE1;
393 	t2_saved_config.window[1].wbase = *(vulp)T2_WBASE2;
394 	t2_saved_config.window[1].wmask = *(vulp)T2_WMASK2;
395 	t2_saved_config.window[1].tbase = *(vulp)T2_TBASE2;
396 
397 	t2_saved_config.hae_1 = srm_hae; /* HW is already set to 0 */
398 	t2_saved_config.hae_2 = *(vulp)T2_HAE_2;
399 	t2_saved_config.hae_3 = *(vulp)T2_HAE_3;
400 	t2_saved_config.hae_4 = *(vulp)T2_HAE_4;
401 	t2_saved_config.hbase = *(vulp)T2_HBASE;
402 }
403 
404 void __init
405 t2_init_arch(void)
406 {
407 	struct pci_controller *hose;
408 	struct resource *hae_mem;
409 	unsigned long temp;
410 	unsigned int i;
411 
412 	for (i = 0; i < NR_CPUS; i++) {
413 		mcheck_expected(i) = 0;
414 		mcheck_taken(i) = 0;
415 	}
416 	t2_mcheck_any_expected = 0;
417 	t2_mcheck_last_taken = 0;
418 
419 	/* Enable scatter/gather TLB use.  */
420 	temp = *(vulp)T2_IOCSR;
421 	if (!(temp & (0x1UL << 26))) {
422 		printk("t2_init_arch: enabling SG TLB, IOCSR was 0x%lx\n",
423 		       temp);
424 		*(vulp)T2_IOCSR = temp | (0x1UL << 26);
425 		mb();
426 		*(vulp)T2_IOCSR; /* read it back to make sure */
427 	}
428 
429 	t2_save_configuration();
430 
431 	/*
432 	 * Create our single hose.
433 	 */
434 	pci_isa_hose = hose = alloc_pci_controller();
435 	hose->io_space = &ioport_resource;
436 	hae_mem = alloc_resource();
437 	hae_mem->start = 0;
438 	hae_mem->end = T2_MEM_R1_MASK;
439 	hae_mem->name = pci_hae0_name;
440 	if (request_resource(&iomem_resource, hae_mem) < 0)
441 		printk(KERN_ERR "Failed to request HAE_MEM\n");
442 	hose->mem_space = hae_mem;
443 	hose->index = 0;
444 
445 	hose->sparse_mem_base = T2_SPARSE_MEM - IDENT_ADDR;
446 	hose->dense_mem_base = T2_DENSE_MEM - IDENT_ADDR;
447 	hose->sparse_io_base = T2_IO - IDENT_ADDR;
448 	hose->dense_io_base = 0;
449 
450 	/*
451 	 * Set up the PCI->physical memory translation windows.
452 	 *
453 	 * Window 1 is direct mapped.
454 	 * Window 2 is scatter/gather (for ISA).
455 	 */
456 
457 	t2_direct_map_window1(T2_DIRECTMAP_START, T2_DIRECTMAP_LENGTH);
458 
459 	/* Always make an ISA DMA window. */
460 	t2_sg_map_window2(hose, T2_ISA_SG_START, T2_ISA_SG_LENGTH);
461 
462 	*(vulp)T2_HBASE = 0x0; /* Disable HOLES. */
463 
464 	/* Zero HAE.  */
465 	*(vulp)T2_HAE_1 = 0; mb(); /* Sparse MEM HAE */
466 	*(vulp)T2_HAE_2 = 0; mb(); /* Sparse I/O HAE */
467 	*(vulp)T2_HAE_3 = 0; mb(); /* Config Space HAE */
468 
469 	/*
470 	 * We also now zero out HAE_4, the dense memory HAE, so that
471 	 * we need not account for its "offset" when accessing dense
472 	 * memory resources which we allocated in our normal way. This
473 	 * HAE would need to stay untouched were we to keep the SRM
474 	 * resource settings.
475 	 *
476 	 * Thus we can now run standard X servers on SABLE/LYNX. :-)
477 	 */
478 	*(vulp)T2_HAE_4 = 0; mb();
479 }
480 
481 void
482 t2_kill_arch(int mode)
483 {
484 	/*
485 	 * Restore the DMA Window registers.
486 	 */
487 	*(vulp)T2_WBASE1 = t2_saved_config.window[0].wbase;
488 	*(vulp)T2_WMASK1 = t2_saved_config.window[0].wmask;
489 	*(vulp)T2_TBASE1 = t2_saved_config.window[0].tbase;
490 	*(vulp)T2_WBASE2 = t2_saved_config.window[1].wbase;
491 	*(vulp)T2_WMASK2 = t2_saved_config.window[1].wmask;
492 	*(vulp)T2_TBASE2 = t2_saved_config.window[1].tbase;
493 	mb();
494 
495 	*(vulp)T2_HAE_1 = srm_hae;
496 	*(vulp)T2_HAE_2 = t2_saved_config.hae_2;
497 	*(vulp)T2_HAE_3 = t2_saved_config.hae_3;
498 	*(vulp)T2_HAE_4 = t2_saved_config.hae_4;
499 	*(vulp)T2_HBASE = t2_saved_config.hbase;
500 	mb();
501 	*(vulp)T2_HBASE; /* READ it back to ensure WRITE occurred. */
502 }
503 
504 void
505 t2_pci_tbi(struct pci_controller *hose, dma_addr_t start, dma_addr_t end)
506 {
507 	unsigned long t2_iocsr;
508 
509 	t2_iocsr = *(vulp)T2_IOCSR;
510 
511 	/* set the TLB Clear bit */
512 	*(vulp)T2_IOCSR = t2_iocsr | (0x1UL << 28);
513 	mb();
514 	*(vulp)T2_IOCSR; /* read it back to make sure */
515 
516 	/* clear the TLB Clear bit */
517 	*(vulp)T2_IOCSR = t2_iocsr & ~(0x1UL << 28);
518 	mb();
519 	*(vulp)T2_IOCSR; /* read it back to make sure */
520 }
521 
522 #define SIC_SEIC (1UL << 33)    /* System Event Clear */
523 
524 static void
525 t2_clear_errors(int cpu)
526 {
527 	struct sable_cpu_csr *cpu_regs;
528 
529 	cpu_regs = (struct sable_cpu_csr *)T2_CPUn_BASE(cpu);
530 
531 	cpu_regs->sic &= ~SIC_SEIC;
532 
533 	/* Clear CPU errors.  */
534 	cpu_regs->bcce |= cpu_regs->bcce;
535 	cpu_regs->cbe  |= cpu_regs->cbe;
536 	cpu_regs->bcue |= cpu_regs->bcue;
537 	cpu_regs->dter |= cpu_regs->dter;
538 
539 	*(vulp)T2_CERR1 |= *(vulp)T2_CERR1;
540 	*(vulp)T2_PERR1 |= *(vulp)T2_PERR1;
541 
542 	mb();
543 	mb();  /* magic */
544 }
545 
546 /*
547  * SABLE seems to have a "broadcast" style machine check, in that all
548  * CPUs receive it. And, the issuing CPU, in the case of PCI Config
549  * space read/write faults, will also receive a second mcheck, upon
550  * lowering IPL during completion processing in pci_read_config_byte()
551  * et al.
552  *
553  * Hence all the taken/expected/any_expected/last_taken stuff...
554  */
555 void
556 t2_machine_check(unsigned long vector, unsigned long la_ptr)
557 {
558 	int cpu = smp_processor_id();
559 #ifdef CONFIG_VERBOSE_MCHECK
560 	struct el_common *mchk_header = (struct el_common *)la_ptr;
561 #endif
562 
563 	/* Clear the error before any reporting.  */
564 	mb();
565 	mb();  /* magic */
566 	draina();
567 	t2_clear_errors(cpu);
568 
569 	/* This should not actually be done until the logout frame is
570 	   examined, but, since we don't do that, go on and do this... */
571 	wrmces(0x7);
572 	mb();
573 
574 	/* Now, do testing for the anomalous conditions. */
575 	if (!mcheck_expected(cpu) && t2_mcheck_any_expected) {
576 		/*
577 		 * FUNKY: Received mcheck on a CPU and not
578 		 * expecting it, but another CPU is expecting one.
579 		 *
580 		 * Just dismiss it for now on this CPU...
581 		 */
582 #ifdef CONFIG_VERBOSE_MCHECK
583 		if (alpha_verbose_mcheck > 1) {
584 			printk("t2_machine_check(cpu%d): any_expected 0x%x -"
585 			       " (assumed) spurious -"
586 			       " code 0x%x\n", cpu, t2_mcheck_any_expected,
587 			       (unsigned int)mchk_header->code);
588 		}
589 #endif
590 		return;
591 	}
592 
593 	if (!mcheck_expected(cpu) && !t2_mcheck_any_expected) {
594 		if (t2_mcheck_last_taken & (1 << cpu)) {
595 #ifdef CONFIG_VERBOSE_MCHECK
596 		    if (alpha_verbose_mcheck > 1) {
597 			printk("t2_machine_check(cpu%d): last_taken 0x%x - "
598 			       "unexpected mcheck - code 0x%x\n",
599 			       cpu, t2_mcheck_last_taken,
600 			       (unsigned int)mchk_header->code);
601 		    }
602 #endif
603 		    t2_mcheck_last_taken = 0;
604 		    mb();
605 		    return;
606 		} else {
607 			t2_mcheck_last_taken = 0;
608 			mb();
609 		}
610 	}
611 
612 #ifdef CONFIG_VERBOSE_MCHECK
613 	if (alpha_verbose_mcheck > 1) {
614 		printk("%s t2_mcheck(cpu%d): last_taken 0x%x - "
615 		       "any_expected 0x%x - code 0x%x\n",
616 		       (mcheck_expected(cpu) ? "EX" : "UN"), cpu,
617 		       t2_mcheck_last_taken, t2_mcheck_any_expected,
618 		       (unsigned int)mchk_header->code);
619 	}
620 #endif
621 
622 	process_mcheck_info(vector, la_ptr, "T2", mcheck_expected(cpu));
623 }
624