1// SPDX-License-Identifier: GPL-2.0
2/*
3 *	linux/arch/alpha/kernel/core_apecs.c
4 *
5 * Rewritten for Apecs from the lca.c from:
6 *
7 * Written by David Mosberger (davidm@cs.arizona.edu) with some code
8 * taken from Dave Rusling's (david.rusling@reo.mts.dec.com) 32-bit
9 * bios code.
10 *
11 * Code common to all APECS core logic chips.
12 */
13
14#define __EXTERN_INLINE inline
15#include <asm/io.h>
16#include <asm/core_apecs.h>
17#undef __EXTERN_INLINE
18
19#include <linux/types.h>
20#include <linux/pci.h>
21#include <linux/init.h>
22
23#include <asm/ptrace.h>
24#include <asm/smp.h>
25#include <asm/mce.h>
26
27#include "proto.h"
28#include "pci_impl.h"
29
30/*
31 * NOTE: Herein lie back-to-back mb instructions.  They are magic.
32 * One plausible explanation is that the i/o controller does not properly
33 * handle the system transaction.  Another involves timing.  Ho hum.
34 */
35
36/*
37 * BIOS32-style PCI interface:
38 */
39
40#define DEBUG_CONFIG 0
41
42#if DEBUG_CONFIG
43# define DBGC(args)	printk args
44#else
45# define DBGC(args)
46#endif
47
48#define vuip	volatile unsigned int  *
49
50/*
51 * Given a bus, device, and function number, compute resulting
52 * configuration space address and setup the APECS_HAXR2 register
53 * accordingly.  It is therefore not safe to have concurrent
54 * invocations to configuration space access routines, but there
55 * really shouldn't be any need for this.
56 *
57 * Type 0:
58 *
59 *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
60 *  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
61 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62 * | | | | | | | | | | | | | | | | | | | | | | | |F|F|F|R|R|R|R|R|R|0|0|
63 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
64 *
65 *	31:11	Device select bit.
66 * 	10:8	Function number
67 * 	 7:2	Register number
68 *
69 * Type 1:
70 *
71 *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1
72 *  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
73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
74 * | | | | | | | | | | |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|1|
75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
76 *
77 *	31:24	reserved
78 *	23:16	bus number (8 bits = 128 possible buses)
79 *	15:11	Device number (5 bits)
80 *	10:8	function number
81 *	 7:2	register number
82 *
83 * Notes:
84 *	The function number selects which function of a multi-function device
85 *	(e.g., SCSI and Ethernet).
86 *
87 *	The register selects a DWORD (32 bit) register offset.  Hence it
88 *	doesn't get shifted by 2 bits as we want to "drop" the bottom two
89 *	bits.
90 */
91
92static int
93mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
94	     unsigned long *pci_addr, unsigned char *type1)
95{
96	unsigned long addr;
97	u8 bus = pbus->number;
98
99	DBGC(("mk_conf_addr(bus=%d ,device_fn=0x%x, where=0x%x,"
100	      " pci_addr=0x%p, type1=0x%p)\n",
101	      bus, device_fn, where, pci_addr, type1));
102
103	if (bus == 0) {
104		int device = device_fn >> 3;
105
106		/* type 0 configuration cycle: */
107
108		if (device > 20) {
109			DBGC(("mk_conf_addr: device (%d) > 20, returning -1\n",
110			      device));
111			return -1;
112		}
113
114		*type1 = 0;
115		addr = (device_fn << 8) | (where);
116	} else {
117		/* type 1 configuration cycle: */
118		*type1 = 1;
119		addr = (bus << 16) | (device_fn << 8) | (where);
120	}
121	*pci_addr = addr;
122	DBGC(("mk_conf_addr: returning pci_addr 0x%lx\n", addr));
123	return 0;
124}
125
126static unsigned int
127conf_read(unsigned long addr, unsigned char type1)
128{
129	unsigned long flags;
130	unsigned int stat0, value;
131	unsigned int haxr2 = 0;
132
133	local_irq_save(flags);	/* avoid getting hit by machine check */
134
135	DBGC(("conf_read(addr=0x%lx, type1=%d)\n", addr, type1));
136
137	/* Reset status register to avoid losing errors.  */
138	stat0 = *(vuip)APECS_IOC_DCSR;
139	*(vuip)APECS_IOC_DCSR = stat0;
140	mb();
141	DBGC(("conf_read: APECS DCSR was 0x%x\n", stat0));
142
143	/* If Type1 access, must set HAE #2. */
144	if (type1) {
145		haxr2 = *(vuip)APECS_IOC_HAXR2;
146		mb();
147		*(vuip)APECS_IOC_HAXR2 = haxr2 | 1;
148		DBGC(("conf_read: TYPE1 access\n"));
149	}
150
151	draina();
152	mcheck_expected(0) = 1;
153	mcheck_taken(0) = 0;
154	mb();
155
156	/* Access configuration space.  */
157
158	/* Some SRMs step on these registers during a machine check.  */
159	asm volatile("ldl %0,%1; mb; mb" : "=r"(value) : "m"(*(vuip)addr)
160		     : "$9", "$10", "$11", "$12", "$13", "$14", "memory");
161
162	if (mcheck_taken(0)) {
163		mcheck_taken(0) = 0;
164		value = 0xffffffffU;
165		mb();
166	}
167	mcheck_expected(0) = 0;
168	mb();
169
170#if 1
171	/*
172	 * david.rusling@reo.mts.dec.com.  This code is needed for the
173	 * EB64+ as it does not generate a machine check (why I don't
174	 * know).  When we build kernels for one particular platform
175	 * then we can make this conditional on the type.
176	 */
177	draina();
178
179	/* Now look for any errors.  */
180	stat0 = *(vuip)APECS_IOC_DCSR;
181	DBGC(("conf_read: APECS DCSR after read 0x%x\n", stat0));
182
183	/* Is any error bit set? */
184	if (stat0 & 0xffe0U) {
185		/* If not NDEV, print status.  */
186		if (!(stat0 & 0x0800)) {
187			printk("apecs.c:conf_read: got stat0=%x\n", stat0);
188		}
189
190		/* Reset error status.  */
191		*(vuip)APECS_IOC_DCSR = stat0;
192		mb();
193		wrmces(0x7);			/* reset machine check */
194		value = 0xffffffff;
195	}
196#endif
197
198	/* If Type1 access, must reset HAE #2 so normal IO space ops work.  */
199	if (type1) {
200		*(vuip)APECS_IOC_HAXR2 = haxr2 & ~1;
201		mb();
202	}
203	local_irq_restore(flags);
204
205	return value;
206}
207
208static void
209conf_write(unsigned long addr, unsigned int value, unsigned char type1)
210{
211	unsigned long flags;
212	unsigned int stat0;
213	unsigned int haxr2 = 0;
214
215	local_irq_save(flags);	/* avoid getting hit by machine check */
216
217	/* Reset status register to avoid losing errors.  */
218	stat0 = *(vuip)APECS_IOC_DCSR;
219	*(vuip)APECS_IOC_DCSR = stat0;
220	mb();
221
222	/* If Type1 access, must set HAE #2. */
223	if (type1) {
224		haxr2 = *(vuip)APECS_IOC_HAXR2;
225		mb();
226		*(vuip)APECS_IOC_HAXR2 = haxr2 | 1;
227	}
228
229	draina();
230	mcheck_expected(0) = 1;
231	mb();
232
233	/* Access configuration space.  */
234	*(vuip)addr = value;
235	mb();
236	mb();  /* magic */
237	mcheck_expected(0) = 0;
238	mb();
239
240#if 1
241	/*
242	 * david.rusling@reo.mts.dec.com.  This code is needed for the
243	 * EB64+ as it does not generate a machine check (why I don't
244	 * know).  When we build kernels for one particular platform
245	 * then we can make this conditional on the type.
246	 */
247	draina();
248
249	/* Now look for any errors.  */
250	stat0 = *(vuip)APECS_IOC_DCSR;
251
252	/* Is any error bit set? */
253	if (stat0 & 0xffe0U) {
254		/* If not NDEV, print status.  */
255		if (!(stat0 & 0x0800)) {
256			printk("apecs.c:conf_write: got stat0=%x\n", stat0);
257		}
258
259		/* Reset error status.  */
260		*(vuip)APECS_IOC_DCSR = stat0;
261		mb();
262		wrmces(0x7);			/* reset machine check */
263	}
264#endif
265
266	/* If Type1 access, must reset HAE #2 so normal IO space ops work.  */
267	if (type1) {
268		*(vuip)APECS_IOC_HAXR2 = haxr2 & ~1;
269		mb();
270	}
271	local_irq_restore(flags);
272}
273
274static int
275apecs_read_config(struct pci_bus *bus, unsigned int devfn, int where,
276		  int size, u32 *value)
277{
278	unsigned long addr, pci_addr;
279	unsigned char type1;
280	long mask;
281	int shift;
282
283	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
284		return PCIBIOS_DEVICE_NOT_FOUND;
285
286	mask = (size - 1) * 8;
287	shift = (where & 3) * 8;
288	addr = (pci_addr << 5) + mask + APECS_CONF;
289	*value = conf_read(addr, type1) >> (shift);
290	return PCIBIOS_SUCCESSFUL;
291}
292
293static int
294apecs_write_config(struct pci_bus *bus, unsigned int devfn, int where,
295		   int size, u32 value)
296{
297	unsigned long addr, pci_addr;
298	unsigned char type1;
299	long mask;
300
301	if (mk_conf_addr(bus, devfn, where, &pci_addr, &type1))
302		return PCIBIOS_DEVICE_NOT_FOUND;
303
304	mask = (size - 1) * 8;
305	addr = (pci_addr << 5) + mask + APECS_CONF;
306	conf_write(addr, value << ((where & 3) * 8), type1);
307	return PCIBIOS_SUCCESSFUL;
308}
309
310struct pci_ops apecs_pci_ops =
311{
312	.read =		apecs_read_config,
313	.write =	apecs_write_config,
314};
315
316void
317apecs_pci_tbi(struct pci_controller *hose, dma_addr_t start, dma_addr_t end)
318{
319	wmb();
320	*(vip)APECS_IOC_TBIA = 0;
321	mb();
322}
323
324void __init
325apecs_init_arch(void)
326{
327	struct pci_controller *hose;
328
329	/*
330	 * Create our single hose.
331	 */
332
333	pci_isa_hose = hose = alloc_pci_controller();
334	hose->io_space = &ioport_resource;
335	hose->mem_space = &iomem_resource;
336	hose->index = 0;
337
338	hose->sparse_mem_base = APECS_SPARSE_MEM - IDENT_ADDR;
339	hose->dense_mem_base = APECS_DENSE_MEM - IDENT_ADDR;
340	hose->sparse_io_base = APECS_IO - IDENT_ADDR;
341	hose->dense_io_base = 0;
342
343	/*
344	 * Set up the PCI to main memory translation windows.
345	 *
346	 * Window 1 is direct access 1GB at 1GB
347	 * Window 2 is scatter-gather 8MB at 8MB (for isa)
348	 */
349	hose->sg_isa = iommu_arena_new(hose, 0x00800000, 0x00800000,
350				       SMP_CACHE_BYTES);
351	hose->sg_pci = NULL;
352	__direct_map_base = 0x40000000;
353	__direct_map_size = 0x40000000;
354
355	*(vuip)APECS_IOC_PB1R = __direct_map_base | 0x00080000;
356	*(vuip)APECS_IOC_PM1R = (__direct_map_size - 1) & 0xfff00000U;
357	*(vuip)APECS_IOC_TB1R = 0;
358
359	*(vuip)APECS_IOC_PB2R = hose->sg_isa->dma_base | 0x000c0000;
360	*(vuip)APECS_IOC_PM2R = (hose->sg_isa->size - 1) & 0xfff00000;
361	*(vuip)APECS_IOC_TB2R = virt_to_phys(hose->sg_isa->ptes) >> 1;
362
363	apecs_pci_tbi(hose, 0, -1);
364
365	/*
366	 * Finally, clear the HAXR2 register, which gets used
367	 * for PCI Config Space accesses. That is the way
368	 * we want to use it, and we do not want to depend on
369	 * what ARC or SRM might have left behind...
370	 */
371	*(vuip)APECS_IOC_HAXR2 = 0;
372	mb();
373}
374
375void
376apecs_pci_clr_err(void)
377{
378	unsigned int jd;
379
380	jd = *(vuip)APECS_IOC_DCSR;
381	if (jd & 0xffe0L) {
382		*(vuip)APECS_IOC_SEAR;
383		*(vuip)APECS_IOC_DCSR = jd | 0xffe1L;
384		mb();
385		*(vuip)APECS_IOC_DCSR;
386	}
387	*(vuip)APECS_IOC_TBIA = (unsigned int)APECS_IOC_TBIA;
388	mb();
389	*(vuip)APECS_IOC_TBIA;
390}
391
392void
393apecs_machine_check(unsigned long vector, unsigned long la_ptr)
394{
395	struct el_common *mchk_header;
396	struct el_apecs_procdata *mchk_procdata;
397	struct el_apecs_sysdata_mcheck *mchk_sysdata;
398
399	mchk_header = (struct el_common *)la_ptr;
400
401	mchk_procdata = (struct el_apecs_procdata *)
402		(la_ptr + mchk_header->proc_offset
403		 - sizeof(mchk_procdata->paltemp));
404
405	mchk_sysdata = (struct el_apecs_sysdata_mcheck *)
406		(la_ptr + mchk_header->sys_offset);
407
408
409	/* Clear the error before any reporting.  */
410	mb();
411	mb(); /* magic */
412	draina();
413	apecs_pci_clr_err();
414	wrmces(0x7);		/* reset machine check pending flag */
415	mb();
416
417	process_mcheck_info(vector, la_ptr, "APECS",
418			    (mcheck_expected(0)
419			     && (mchk_sysdata->epic_dcsr & 0x0c00UL)));
420}
421