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
79static volatile unsigned int t2_mcheck_any_expected;
80static 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. */
84static 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
140static int
141mk_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 */
180static unsigned int
181conf_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
234static void
235conf_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
283static int
284t2_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(pbus: bus, device_fn: devfn, where, pci_addr: &pci_addr, type1: &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
302static int
303t2_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(pbus: bus, device_fn: devfn, where, pci_addr: &pci_addr, type1: &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: value << ((where & 3) * 8), type1);
316 return PCIBIOS_SUCCESSFUL;
317}
318
319struct pci_ops t2_pci_ops =
320{
321 .read = t2_read_config,
322 .write = t2_write_config,
323};
324
325static void __init
326t2_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
345static void __init
346t2_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
372static void __init
373t2_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
405void __init
406t2_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(root: &iomem_resource, new: 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
482void
483t2_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
505void
506t2_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
525static void
526t2_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 */
556void
557t2_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(mces: 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

source code of linux/arch/alpha/kernel/core_t2.c