xref: /openbmc/linux/arch/alpha/kernel/core_t2.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/core_t2.c
4  *
5  * Written by Jay A Estabrook (jestabro@amt.tay1.dec.com).
6  * December 1996.
7  *
8  * based on CIA code by David A Rusling (david.rusling@reo.mts.dec.com)
9  *
10  * Code common to all T2 core logic chips.
11  */
12 
13 #define __EXTERN_INLINE
14 #include <asm/io.h>
15 #include <asm/core_t2.h>
16 #undef __EXTERN_INLINE
17 
18 #include <linux/types.h>
19 #include <linux/pci.h>
20 #include <linux/sched.h>
21 #include <linux/init.h>
22 
23 #include <asm/ptrace.h>
24 #include <asm/delay.h>
25 #include <asm/mce.h>
26 
27 #include "proto.h"
28 #include "pci_impl.h"
29 
30 /* For dumping initial DMA window settings. */
31 #define DEBUG_PRINT_INITIAL_SETTINGS 0
32 
33 /* For dumping final DMA window settings. */
34 #define DEBUG_PRINT_FINAL_SETTINGS 0
35 
36 /*
37  * By default, we direct-map starting at 2GB, in order to allow the
38  * maximum size direct-map window (2GB) to match the maximum amount of
39  * memory (2GB) that can be present on SABLEs. But that limits the
40  * floppy to DMA only via the scatter/gather window set up for 8MB
41  * ISA DMA, since the maximum ISA DMA address is 2GB-1.
42  *
43  * For now, this seems a reasonable trade-off: even though most SABLEs
44  * have less than 1GB of memory, floppy usage/performance will not
45  * really be affected by forcing it to go via scatter/gather...
46  */
47 #define T2_DIRECTMAP_2G 1
48 
49 #if T2_DIRECTMAP_2G
50 # define T2_DIRECTMAP_START	0x80000000UL
51 # define T2_DIRECTMAP_LENGTH	0x80000000UL
52 #else
53 # define T2_DIRECTMAP_START	0x40000000UL
54 # define T2_DIRECTMAP_LENGTH	0x40000000UL
55 #endif
56 
57 /* The ISA scatter/gather window settings. */
58 #define T2_ISA_SG_START		0x00800000UL
59 #define T2_ISA_SG_LENGTH	0x00800000UL
60 
61 /*
62  * NOTE: Herein lie back-to-back mb instructions.  They are magic.
63  * One plausible explanation is that the i/o controller does not properly
64  * handle the system transaction.  Another involves timing.  Ho hum.
65  */
66 
67 /*
68  * BIOS32-style PCI interface:
69  */
70 
71 #define DEBUG_CONFIG 0
72 
73 #if DEBUG_CONFIG
74 # define DBG(args)	printk args
75 #else
76 # define DBG(args)
77 #endif
78 
79 static volatile unsigned int t2_mcheck_any_expected;
80 static volatile unsigned int t2_mcheck_last_taken;
81 
82 /* Place to save the DMA Window registers as set up by SRM
83    for restoration during shutdown. */
84 static struct
85 {
86 	struct {
87 		unsigned long wbase;
88 		unsigned long wmask;
89 		unsigned long tbase;
90 	} window[2];
91 	unsigned long hae_1;
92   	unsigned long hae_2;
93 	unsigned long hae_3;
94 	unsigned long hae_4;
95 	unsigned long hbase;
96 } t2_saved_config __attribute((common));
97 
98 /*
99  * Given a bus, device, and function number, compute resulting
100  * configuration space address and setup the T2_HAXR2 register
101  * accordingly.  It is therefore not safe to have concurrent
102  * invocations to configuration space access routines, but there
103  * really shouldn't be any need for this.
104  *
105  * Type 0:
106  *
107  *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
108  *  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
109  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110  * | | |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|
111  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112  *
113  *	31:11	Device select bit.
114  * 	10:8	Function number
115  * 	 7:2	Register number
116  *
117  * Type 1:
118  *
119  *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
120  *  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
121  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
122  * | | | | | | | | | | |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|1|
123  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124  *
125  *	31:24	reserved
126  *	23:16	bus number (8 bits = 128 possible buses)
127  *	15:11	Device number (5 bits)
128  *	10:8	function number
129  *	 7:2	register number
130  *
131  * Notes:
132  *	The function number selects which function of a multi-function device
133  *	(e.g., SCSI and Ethernet).
134  *
135  *	The register selects a DWORD (32 bit) register offset.  Hence it
136  *	doesn't get shifted by 2 bits as we want to "drop" the bottom two
137  *	bits.
138  */
139 
140 static int
141 mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
142 	     unsigned long *pci_addr, unsigned char *type1)
143 {
144 	unsigned long addr;
145 	u8 bus = pbus->number;
146 
147 	DBG(("mk_conf_addr(bus=%d, dfn=0x%x, where=0x%x,"
148 	     " addr=0x%lx, type1=0x%x)\n",
149 	     bus, device_fn, where, pci_addr, type1));
150 
151 	if (bus == 0) {
152 		int device = device_fn >> 3;
153 
154 		/* Type 0 configuration cycle.  */
155 
156 		if (device > 8) {
157 			DBG(("mk_conf_addr: device (%d)>20, returning -1\n",
158 			     device));
159 			return -1;
160 		}
161 
162 		*type1 = 0;
163 		addr = (0x0800L << device) | ((device_fn & 7) << 8) | (where);
164 	} else {
165 		/* Type 1 configuration cycle.  */
166 		*type1 = 1;
167 		addr = (bus << 16) | (device_fn << 8) | (where);
168 	}
169 	*pci_addr = addr;
170 	DBG(("mk_conf_addr: returning pci_addr 0x%lx\n", addr));
171 	return 0;
172 }
173 
174 /*
175  * NOTE: both conf_read() and conf_write() may set HAE_3 when needing
176  *       to do type1 access. This is protected by the use of spinlock IRQ
177  *       primitives in the wrapper functions pci_{read,write}_config_*()
178  *       defined in drivers/pci/pci.c.
179  */
180 static unsigned int
181 conf_read(unsigned long addr, unsigned char type1)
182 {
183 	unsigned int value, cpu, taken;
184 	unsigned long t2_cfg = 0;
185 
186 	cpu = smp_processor_id();
187 
188 	DBG(("conf_read(addr=0x%lx, type1=%d)\n", addr, type1));
189 
190 	/* If Type1 access, must set T2 CFG.  */
191 	if (type1) {
192 		t2_cfg = *(vulp)T2_HAE_3 & ~0xc0000000UL;
193 		*(vulp)T2_HAE_3 = 0x40000000UL | t2_cfg;
194 		mb();
195 	}
196 	mb();
197 	draina();
198 
199 	mcheck_expected(cpu) = 1;
200 	mcheck_taken(cpu) = 0;
201 	t2_mcheck_any_expected |= (1 << cpu);
202 	mb();
203 
204 	/* Access configuration space. */
205 	value = *(vuip)addr;
206 	mb();
207 	mb();  /* magic */
208 
209 	/* Wait for possible mcheck. Also, this lets other CPUs clear
210 	   their mchecks as well, as they can reliably tell when
211 	   another CPU is in the midst of handling a real mcheck via
212 	   the "taken" function. */
213 	udelay(100);
214 
215 	if ((taken = mcheck_taken(cpu))) {
216 		mcheck_taken(cpu) = 0;
217 		t2_mcheck_last_taken |= (1 << cpu);
218 		value = 0xffffffffU;
219 		mb();
220 	}
221 	mcheck_expected(cpu) = 0;
222 	t2_mcheck_any_expected = 0;
223 	mb();
224 
225 	/* If Type1 access, must reset T2 CFG so normal IO space ops work.  */
226 	if (type1) {
227 		*(vulp)T2_HAE_3 = t2_cfg;
228 		mb();
229 	}
230 
231 	return value;
232 }
233 
234 static void
235 conf_write(unsigned long addr, unsigned int value, unsigned char type1)
236 {
237 	unsigned int cpu, taken;
238 	unsigned long t2_cfg = 0;
239 
240 	cpu = smp_processor_id();
241 
242 	/* If Type1 access, must set T2 CFG.  */
243 	if (type1) {
244 		t2_cfg = *(vulp)T2_HAE_3 & ~0xc0000000UL;
245 		*(vulp)T2_HAE_3 = t2_cfg | 0x40000000UL;
246 		mb();
247 	}
248 	mb();
249 	draina();
250 
251 	mcheck_expected(cpu) = 1;
252 	mcheck_taken(cpu) = 0;
253 	t2_mcheck_any_expected |= (1 << cpu);
254 	mb();
255 
256 	/* Access configuration space.  */
257 	*(vuip)addr = value;
258 	mb();
259 	mb();  /* magic */
260 
261 	/* Wait for possible mcheck. Also, this lets other CPUs clear
262 	   their mchecks as well, as they can reliably tell when
263 	   this CPU is in the midst of handling a real mcheck via
264 	   the "taken" function. */
265 	udelay(100);
266 
267 	if ((taken = mcheck_taken(cpu))) {
268 		mcheck_taken(cpu) = 0;
269 		t2_mcheck_last_taken |= (1 << cpu);
270 		mb();
271 	}
272 	mcheck_expected(cpu) = 0;
273 	t2_mcheck_any_expected = 0;
274 	mb();
275 
276 	/* If Type1 access, must reset T2 CFG so normal IO space ops work.  */
277 	if (type1) {
278 		*(vulp)T2_HAE_3 = t2_cfg;
279 		mb();
280 	}
281 }
282 
283 static int
284 t2_read_config(struct pci_bus *bus, unsigned int devfn, int where,
285 	       int size, u32 *value)
286 {
287 	unsigned long addr, pci_addr;
288 	unsigned char type1;
289 	int shift;
290 	long mask;
291 
292 	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
293 		return PCIBIOS_DEVICE_NOT_FOUND;
294 
295 	mask = (size - 1) * 8;
296 	shift = (where & 3) * 8;
297 	addr = (pci_addr << 5) + mask + T2_CONF;
298 	*value = conf_read(addr, type1) >> (shift);
299 	return PCIBIOS_SUCCESSFUL;
300 }
301 
302 static int
303 t2_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size,
304 		u32 value)
305 {
306 	unsigned long addr, pci_addr;
307 	unsigned char type1;
308 	long mask;
309 
310 	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
311 		return PCIBIOS_DEVICE_NOT_FOUND;
312 
313 	mask = (size - 1) * 8;
314 	addr = (pci_addr << 5) + mask + T2_CONF;
315 	conf_write(addr, value << ((where & 3) * 8), type1);
316 	return PCIBIOS_SUCCESSFUL;
317 }
318 
319 struct pci_ops t2_pci_ops =
320 {
321 	.read =		t2_read_config,
322 	.write =	t2_write_config,
323 };
324 
325 static void __init
326 t2_direct_map_window1(unsigned long base, unsigned long length)
327 {
328 	unsigned long temp;
329 
330 	__direct_map_base = base;
331 	__direct_map_size = length;
332 
333 	temp = (base & 0xfff00000UL) | ((base + length - 1) >> 20);
334 	*(vulp)T2_WBASE1 = temp | 0x80000UL; /* OR in ENABLE bit */
335 	temp = (length - 1) & 0xfff00000UL;
336 	*(vulp)T2_WMASK1 = temp;
337 	*(vulp)T2_TBASE1 = 0;
338 
339 #if DEBUG_PRINT_FINAL_SETTINGS
340 	printk("%s: setting WBASE1=0x%lx WMASK1=0x%lx TBASE1=0x%lx\n",
341 	       __func__, *(vulp)T2_WBASE1, *(vulp)T2_WMASK1, *(vulp)T2_TBASE1);
342 #endif
343 }
344 
345 static void __init
346 t2_sg_map_window2(struct pci_controller *hose,
347 		  unsigned long base,
348 		  unsigned long length)
349 {
350 	unsigned long temp;
351 
352 	/* Note we can only do 1 SG window, as the other is for direct, so
353 	   do an ISA SG area, especially for the floppy. */
354 	hose->sg_isa = iommu_arena_new(hose, base, length, SMP_CACHE_BYTES);
355 	hose->sg_pci = NULL;
356 
357 	temp = (base & 0xfff00000UL) | ((base + length - 1) >> 20);
358 	*(vulp)T2_WBASE2 = temp | 0xc0000UL; /* OR in ENABLE/SG bits */
359 	temp = (length - 1) & 0xfff00000UL;
360 	*(vulp)T2_WMASK2 = temp;
361 	*(vulp)T2_TBASE2 = virt_to_phys(hose->sg_isa->ptes) >> 1;
362 	mb();
363 
364 	t2_pci_tbi(hose, 0, -1); /* flush TLB all */
365 
366 #if DEBUG_PRINT_FINAL_SETTINGS
367 	printk("%s: setting WBASE2=0x%lx WMASK2=0x%lx TBASE2=0x%lx\n",
368 	       __func__, *(vulp)T2_WBASE2, *(vulp)T2_WMASK2, *(vulp)T2_TBASE2);
369 #endif
370 }
371 
372 static void __init
373 t2_save_configuration(void)
374 {
375 #if DEBUG_PRINT_INITIAL_SETTINGS
376 	printk("%s: HAE_1 was 0x%lx\n", __func__, srm_hae); /* HW is 0 */
377 	printk("%s: HAE_2 was 0x%lx\n", __func__, *(vulp)T2_HAE_2);
378 	printk("%s: HAE_3 was 0x%lx\n", __func__, *(vulp)T2_HAE_3);
379 	printk("%s: HAE_4 was 0x%lx\n", __func__, *(vulp)T2_HAE_4);
380 	printk("%s: HBASE was 0x%lx\n", __func__, *(vulp)T2_HBASE);
381 
382 	printk("%s: WBASE1=0x%lx WMASK1=0x%lx TBASE1=0x%lx\n", __func__,
383 	       *(vulp)T2_WBASE1, *(vulp)T2_WMASK1, *(vulp)T2_TBASE1);
384 	printk("%s: WBASE2=0x%lx WMASK2=0x%lx TBASE2=0x%lx\n", __func__,
385 	       *(vulp)T2_WBASE2, *(vulp)T2_WMASK2, *(vulp)T2_TBASE2);
386 #endif
387 
388 	/*
389 	 * Save the DMA Window registers.
390 	 */
391 	t2_saved_config.window[0].wbase = *(vulp)T2_WBASE1;
392 	t2_saved_config.window[0].wmask = *(vulp)T2_WMASK1;
393 	t2_saved_config.window[0].tbase = *(vulp)T2_TBASE1;
394 	t2_saved_config.window[1].wbase = *(vulp)T2_WBASE2;
395 	t2_saved_config.window[1].wmask = *(vulp)T2_WMASK2;
396 	t2_saved_config.window[1].tbase = *(vulp)T2_TBASE2;
397 
398 	t2_saved_config.hae_1 = srm_hae; /* HW is already set to 0 */
399 	t2_saved_config.hae_2 = *(vulp)T2_HAE_2;
400 	t2_saved_config.hae_3 = *(vulp)T2_HAE_3;
401 	t2_saved_config.hae_4 = *(vulp)T2_HAE_4;
402 	t2_saved_config.hbase = *(vulp)T2_HBASE;
403 }
404 
405 void __init
406 t2_init_arch(void)
407 {
408 	struct pci_controller *hose;
409 	struct resource *hae_mem;
410 	unsigned long temp;
411 	unsigned int i;
412 
413 	for (i = 0; i < NR_CPUS; i++) {
414 		mcheck_expected(i) = 0;
415 		mcheck_taken(i) = 0;
416 	}
417 	t2_mcheck_any_expected = 0;
418 	t2_mcheck_last_taken = 0;
419 
420 	/* Enable scatter/gather TLB use.  */
421 	temp = *(vulp)T2_IOCSR;
422 	if (!(temp & (0x1UL << 26))) {
423 		printk("t2_init_arch: enabling SG TLB, IOCSR was 0x%lx\n",
424 		       temp);
425 		*(vulp)T2_IOCSR = temp | (0x1UL << 26);
426 		mb();
427 		*(vulp)T2_IOCSR; /* read it back to make sure */
428 	}
429 
430 	t2_save_configuration();
431 
432 	/*
433 	 * Create our single hose.
434 	 */
435 	pci_isa_hose = hose = alloc_pci_controller();
436 	hose->io_space = &ioport_resource;
437 	hae_mem = alloc_resource();
438 	hae_mem->start = 0;
439 	hae_mem->end = T2_MEM_R1_MASK;
440 	hae_mem->name = pci_hae0_name;
441 	if (request_resource(&iomem_resource, hae_mem) < 0)
442 		printk(KERN_ERR "Failed to request HAE_MEM\n");
443 	hose->mem_space = hae_mem;
444 	hose->index = 0;
445 
446 	hose->sparse_mem_base = T2_SPARSE_MEM - IDENT_ADDR;
447 	hose->dense_mem_base = T2_DENSE_MEM - IDENT_ADDR;
448 	hose->sparse_io_base = T2_IO - IDENT_ADDR;
449 	hose->dense_io_base = 0;
450 
451 	/*
452 	 * Set up the PCI->physical memory translation windows.
453 	 *
454 	 * Window 1 is direct mapped.
455 	 * Window 2 is scatter/gather (for ISA).
456 	 */
457 
458 	t2_direct_map_window1(T2_DIRECTMAP_START, T2_DIRECTMAP_LENGTH);
459 
460 	/* Always make an ISA DMA window. */
461 	t2_sg_map_window2(hose, T2_ISA_SG_START, T2_ISA_SG_LENGTH);
462 
463 	*(vulp)T2_HBASE = 0x0; /* Disable HOLES. */
464 
465 	/* Zero HAE.  */
466 	*(vulp)T2_HAE_1 = 0; mb(); /* Sparse MEM HAE */
467 	*(vulp)T2_HAE_2 = 0; mb(); /* Sparse I/O HAE */
468 	*(vulp)T2_HAE_3 = 0; mb(); /* Config Space HAE */
469 
470 	/*
471 	 * We also now zero out HAE_4, the dense memory HAE, so that
472 	 * we need not account for its "offset" when accessing dense
473 	 * memory resources which we allocated in our normal way. This
474 	 * HAE would need to stay untouched were we to keep the SRM
475 	 * resource settings.
476 	 *
477 	 * Thus we can now run standard X servers on SABLE/LYNX. :-)
478 	 */
479 	*(vulp)T2_HAE_4 = 0; mb();
480 }
481 
482 void
483 t2_kill_arch(int mode)
484 {
485 	/*
486 	 * Restore the DMA Window registers.
487 	 */
488 	*(vulp)T2_WBASE1 = t2_saved_config.window[0].wbase;
489 	*(vulp)T2_WMASK1 = t2_saved_config.window[0].wmask;
490 	*(vulp)T2_TBASE1 = t2_saved_config.window[0].tbase;
491 	*(vulp)T2_WBASE2 = t2_saved_config.window[1].wbase;
492 	*(vulp)T2_WMASK2 = t2_saved_config.window[1].wmask;
493 	*(vulp)T2_TBASE2 = t2_saved_config.window[1].tbase;
494 	mb();
495 
496 	*(vulp)T2_HAE_1 = srm_hae;
497 	*(vulp)T2_HAE_2 = t2_saved_config.hae_2;
498 	*(vulp)T2_HAE_3 = t2_saved_config.hae_3;
499 	*(vulp)T2_HAE_4 = t2_saved_config.hae_4;
500 	*(vulp)T2_HBASE = t2_saved_config.hbase;
501 	mb();
502 	*(vulp)T2_HBASE; /* READ it back to ensure WRITE occurred. */
503 }
504 
505 void
506 t2_pci_tbi(struct pci_controller *hose, dma_addr_t start, dma_addr_t end)
507 {
508 	unsigned long t2_iocsr;
509 
510 	t2_iocsr = *(vulp)T2_IOCSR;
511 
512 	/* set the TLB Clear bit */
513 	*(vulp)T2_IOCSR = t2_iocsr | (0x1UL << 28);
514 	mb();
515 	*(vulp)T2_IOCSR; /* read it back to make sure */
516 
517 	/* clear the TLB Clear bit */
518 	*(vulp)T2_IOCSR = t2_iocsr & ~(0x1UL << 28);
519 	mb();
520 	*(vulp)T2_IOCSR; /* read it back to make sure */
521 }
522 
523 #define SIC_SEIC (1UL << 33)    /* System Event Clear */
524 
525 static void
526 t2_clear_errors(int cpu)
527 {
528 	struct sable_cpu_csr *cpu_regs;
529 
530 	cpu_regs = (struct sable_cpu_csr *)T2_CPUn_BASE(cpu);
531 
532 	cpu_regs->sic &= ~SIC_SEIC;
533 
534 	/* Clear CPU errors.  */
535 	cpu_regs->bcce |= cpu_regs->bcce;
536 	cpu_regs->cbe  |= cpu_regs->cbe;
537 	cpu_regs->bcue |= cpu_regs->bcue;
538 	cpu_regs->dter |= cpu_regs->dter;
539 
540 	*(vulp)T2_CERR1 |= *(vulp)T2_CERR1;
541 	*(vulp)T2_PERR1 |= *(vulp)T2_PERR1;
542 
543 	mb();
544 	mb();  /* magic */
545 }
546 
547 /*
548  * SABLE seems to have a "broadcast" style machine check, in that all
549  * CPUs receive it. And, the issuing CPU, in the case of PCI Config
550  * space read/write faults, will also receive a second mcheck, upon
551  * lowering IPL during completion processing in pci_read_config_byte()
552  * et al.
553  *
554  * Hence all the taken/expected/any_expected/last_taken stuff...
555  */
556 void
557 t2_machine_check(unsigned long vector, unsigned long la_ptr)
558 {
559 	int cpu = smp_processor_id();
560 #ifdef CONFIG_VERBOSE_MCHECK
561 	struct el_common *mchk_header = (struct el_common *)la_ptr;
562 #endif
563 
564 	/* Clear the error before any reporting.  */
565 	mb();
566 	mb();  /* magic */
567 	draina();
568 	t2_clear_errors(cpu);
569 
570 	/* This should not actually be done until the logout frame is
571 	   examined, but, since we don't do that, go on and do this... */
572 	wrmces(0x7);
573 	mb();
574 
575 	/* Now, do testing for the anomalous conditions. */
576 	if (!mcheck_expected(cpu) && t2_mcheck_any_expected) {
577 		/*
578 		 * FUNKY: Received mcheck on a CPU and not
579 		 * expecting it, but another CPU is expecting one.
580 		 *
581 		 * Just dismiss it for now on this CPU...
582 		 */
583 #ifdef CONFIG_VERBOSE_MCHECK
584 		if (alpha_verbose_mcheck > 1) {
585 			printk("t2_machine_check(cpu%d): any_expected 0x%x -"
586 			       " (assumed) spurious -"
587 			       " code 0x%x\n", cpu, t2_mcheck_any_expected,
588 			       (unsigned int)mchk_header->code);
589 		}
590 #endif
591 		return;
592 	}
593 
594 	if (!mcheck_expected(cpu) && !t2_mcheck_any_expected) {
595 		if (t2_mcheck_last_taken & (1 << cpu)) {
596 #ifdef CONFIG_VERBOSE_MCHECK
597 		    if (alpha_verbose_mcheck > 1) {
598 			printk("t2_machine_check(cpu%d): last_taken 0x%x - "
599 			       "unexpected mcheck - code 0x%x\n",
600 			       cpu, t2_mcheck_last_taken,
601 			       (unsigned int)mchk_header->code);
602 		    }
603 #endif
604 		    t2_mcheck_last_taken = 0;
605 		    mb();
606 		    return;
607 		} else {
608 			t2_mcheck_last_taken = 0;
609 			mb();
610 		}
611 	}
612 
613 #ifdef CONFIG_VERBOSE_MCHECK
614 	if (alpha_verbose_mcheck > 1) {
615 		printk("%s t2_mcheck(cpu%d): last_taken 0x%x - "
616 		       "any_expected 0x%x - code 0x%x\n",
617 		       (mcheck_expected(cpu) ? "EX" : "UN"), cpu,
618 		       t2_mcheck_last_taken, t2_mcheck_any_expected,
619 		       (unsigned int)mchk_header->code);
620 	}
621 #endif
622 
623 	process_mcheck_info(vector, la_ptr, "T2", mcheck_expected(cpu));
624 }
625