xref: /openbmc/linux/arch/alpha/kernel/sys_alcor.c (revision fd589a8f)
1 /*
2  *	linux/arch/alpha/kernel/sys_alcor.c
3  *
4  *	Copyright (C) 1995 David A Rusling
5  *	Copyright (C) 1996 Jay A Estabrook
6  *	Copyright (C) 1998, 1999 Richard Henderson
7  *
8  * Code supporting the ALCOR and XLT (XL-300/366/433).
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/mm.h>
14 #include <linux/sched.h>
15 #include <linux/pci.h>
16 #include <linux/init.h>
17 #include <linux/reboot.h>
18 #include <linux/bitops.h>
19 
20 #include <asm/ptrace.h>
21 #include <asm/system.h>
22 #include <asm/io.h>
23 #include <asm/dma.h>
24 #include <asm/mmu_context.h>
25 #include <asm/irq.h>
26 #include <asm/pgtable.h>
27 #include <asm/core_cia.h>
28 #include <asm/tlbflush.h>
29 
30 #include "proto.h"
31 #include "irq_impl.h"
32 #include "pci_impl.h"
33 #include "machvec_impl.h"
34 
35 
36 /* Note mask bit is true for ENABLED irqs.  */
37 static unsigned long cached_irq_mask;
38 
39 static inline void
40 alcor_update_irq_hw(unsigned long mask)
41 {
42 	*(vuip)GRU_INT_MASK = mask;
43 	mb();
44 }
45 
46 static inline void
47 alcor_enable_irq(unsigned int irq)
48 {
49 	alcor_update_irq_hw(cached_irq_mask |= 1UL << (irq - 16));
50 }
51 
52 static void
53 alcor_disable_irq(unsigned int irq)
54 {
55 	alcor_update_irq_hw(cached_irq_mask &= ~(1UL << (irq - 16)));
56 }
57 
58 static void
59 alcor_mask_and_ack_irq(unsigned int irq)
60 {
61 	alcor_disable_irq(irq);
62 
63 	/* On ALCOR/XLT, need to dismiss interrupt via GRU. */
64 	*(vuip)GRU_INT_CLEAR = 1 << (irq - 16); mb();
65 	*(vuip)GRU_INT_CLEAR = 0; mb();
66 }
67 
68 static unsigned int
69 alcor_startup_irq(unsigned int irq)
70 {
71 	alcor_enable_irq(irq);
72 	return 0;
73 }
74 
75 static void
76 alcor_isa_mask_and_ack_irq(unsigned int irq)
77 {
78 	i8259a_mask_and_ack_irq(irq);
79 
80 	/* On ALCOR/XLT, need to dismiss interrupt via GRU. */
81 	*(vuip)GRU_INT_CLEAR = 0x80000000; mb();
82 	*(vuip)GRU_INT_CLEAR = 0; mb();
83 }
84 
85 static void
86 alcor_end_irq(unsigned int irq)
87 {
88 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
89 		alcor_enable_irq(irq);
90 }
91 
92 static struct irq_chip alcor_irq_type = {
93 	.typename	= "ALCOR",
94 	.startup	= alcor_startup_irq,
95 	.shutdown	= alcor_disable_irq,
96 	.enable		= alcor_enable_irq,
97 	.disable	= alcor_disable_irq,
98 	.ack		= alcor_mask_and_ack_irq,
99 	.end		= alcor_end_irq,
100 };
101 
102 static void
103 alcor_device_interrupt(unsigned long vector)
104 {
105 	unsigned long pld;
106 	unsigned int i;
107 
108 	/* Read the interrupt summary register of the GRU */
109 	pld = (*(vuip)GRU_INT_REQ) & GRU_INT_REQ_BITS;
110 
111 	/*
112 	 * Now for every possible bit set, work through them and call
113 	 * the appropriate interrupt handler.
114 	 */
115 	while (pld) {
116 		i = ffz(~pld);
117 		pld &= pld - 1; /* clear least bit set */
118 		if (i == 31) {
119 			isa_device_interrupt(vector);
120 		} else {
121 			handle_irq(16 + i);
122 		}
123 	}
124 }
125 
126 static void __init
127 alcor_init_irq(void)
128 {
129 	long i;
130 
131 	if (alpha_using_srm)
132 		alpha_mv.device_interrupt = srm_device_interrupt;
133 
134 	*(vuip)GRU_INT_MASK  = 0; mb();			/* all disabled */
135 	*(vuip)GRU_INT_EDGE  = 0; mb();			/* all are level */
136 	*(vuip)GRU_INT_HILO  = 0x80000000U; mb();	/* ISA only HI */
137 	*(vuip)GRU_INT_CLEAR = 0; mb();			/* all clear */
138 
139 	for (i = 16; i < 48; ++i) {
140 		/* On Alcor, at least, lines 20..30 are not connected
141 		   and can generate spurious interrupts if we turn them
142 		   on while IRQ probing.  */
143 		if (i >= 16+20 && i <= 16+30)
144 			continue;
145 		irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
146 		irq_desc[i].chip = &alcor_irq_type;
147 	}
148 	i8259a_irq_type.ack = alcor_isa_mask_and_ack_irq;
149 
150 	init_i8259a_irqs();
151 	common_init_isa_dma();
152 
153 	setup_irq(16+31, &isa_cascade_irqaction);
154 }
155 
156 
157 /*
158  * PCI Fixup configuration.
159  *
160  * Summary @ GRU_INT_REQ:
161  * Bit      Meaning
162  * 0        Interrupt Line A from slot 2
163  * 1        Interrupt Line B from slot 2
164  * 2        Interrupt Line C from slot 2
165  * 3        Interrupt Line D from slot 2
166  * 4        Interrupt Line A from slot 1
167  * 5        Interrupt line B from slot 1
168  * 6        Interrupt Line C from slot 1
169  * 7        Interrupt Line D from slot 1
170  * 8        Interrupt Line A from slot 0
171  * 9        Interrupt Line B from slot 0
172  *10        Interrupt Line C from slot 0
173  *11        Interrupt Line D from slot 0
174  *12        Interrupt Line A from slot 4
175  *13        Interrupt Line B from slot 4
176  *14        Interrupt Line C from slot 4
177  *15        Interrupt Line D from slot 4
178  *16        Interrupt Line D from slot 3
179  *17        Interrupt Line D from slot 3
180  *18        Interrupt Line D from slot 3
181  *19        Interrupt Line D from slot 3
182  *20-30     Reserved
183  *31        EISA interrupt
184  *
185  * The device to slot mapping looks like:
186  *
187  * Slot     Device
188  *  6       built-in TULIP (XLT only)
189  *  7       PCI on board slot 0
190  *  8       PCI on board slot 3
191  *  9       PCI on board slot 4
192  * 10       PCEB (PCI-EISA bridge)
193  * 11       PCI on board slot 2
194  * 12       PCI on board slot 1
195  *
196  *
197  * This two layered interrupt approach means that we allocate IRQ 16 and
198  * above for PCI interrupts.  The IRQ relates to which bit the interrupt
199  * comes in on.  This makes interrupt processing much easier.
200  */
201 
202 static int __init
203 alcor_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
204 {
205 	static char irq_tab[7][5] __initdata = {
206 		/*INT    INTA   INTB   INTC   INTD */
207 		/* note: IDSEL 17 is XLT only */
208 		{16+13, 16+13, 16+13, 16+13, 16+13},	/* IdSel 17,  TULIP  */
209 		{ 16+8,  16+8,  16+9, 16+10, 16+11},	/* IdSel 18,  slot 0 */
210 		{16+16, 16+16, 16+17, 16+18, 16+19},	/* IdSel 19,  slot 3 */
211 		{16+12, 16+12, 16+13, 16+14, 16+15},	/* IdSel 20,  slot 4 */
212 		{   -1,    -1,    -1,    -1,    -1},	/* IdSel 21,  PCEB   */
213 		{ 16+0,  16+0,  16+1,  16+2,  16+3},	/* IdSel 22,  slot 2 */
214 		{ 16+4,  16+4,  16+5,  16+6,  16+7},	/* IdSel 23,  slot 1 */
215 	};
216 	const long min_idsel = 6, max_idsel = 12, irqs_per_slot = 5;
217 	return COMMON_TABLE_LOOKUP;
218 }
219 
220 static void
221 alcor_kill_arch(int mode)
222 {
223 	cia_kill_arch(mode);
224 
225 #ifndef ALPHA_RESTORE_SRM_SETUP
226 	switch(mode) {
227 	case LINUX_REBOOT_CMD_RESTART:
228 		/* Who said DEC engineer's have no sense of humor? ;-)  */
229 		if (alpha_using_srm) {
230 			*(vuip) GRU_RESET = 0x0000dead;
231 			mb();
232 		}
233 		break;
234 	case LINUX_REBOOT_CMD_HALT:
235 		break;
236 	case LINUX_REBOOT_CMD_POWER_OFF:
237 		break;
238 	}
239 
240 	halt();
241 #endif
242 }
243 
244 static void __init
245 alcor_init_pci(void)
246 {
247 	struct pci_dev *dev;
248 
249 	cia_init_pci();
250 
251 	/*
252 	 * Now we can look to see if we are really running on an XLT-type
253 	 * motherboard, by looking for a 21040 TULIP in slot 6, which is
254 	 * built into XLT and BRET/MAVERICK, but not available on ALCOR.
255 	 */
256 	dev = pci_get_device(PCI_VENDOR_ID_DEC,
257 			      PCI_DEVICE_ID_DEC_TULIP,
258 			      NULL);
259 	if (dev && dev->devfn == PCI_DEVFN(6,0)) {
260 		alpha_mv.sys.cia.gru_int_req_bits = XLT_GRU_INT_REQ_BITS;
261 		printk(KERN_INFO "%s: Detected AS500 or XLT motherboard.\n",
262 		       __func__);
263 	}
264 	pci_dev_put(dev);
265 }
266 
267 
268 /*
269  * The System Vectors
270  */
271 
272 struct alpha_machine_vector alcor_mv __initmv = {
273 	.vector_name		= "Alcor",
274 	DO_EV5_MMU,
275 	DO_DEFAULT_RTC,
276 	DO_CIA_IO,
277 	.machine_check		= cia_machine_check,
278 	.max_isa_dma_address	= ALPHA_ALCOR_MAX_ISA_DMA_ADDRESS,
279 	.min_io_address		= EISA_DEFAULT_IO_BASE,
280 	.min_mem_address	= CIA_DEFAULT_MEM_BASE,
281 
282 	.nr_irqs		= 48,
283 	.device_interrupt	= alcor_device_interrupt,
284 
285 	.init_arch		= cia_init_arch,
286 	.init_irq		= alcor_init_irq,
287 	.init_rtc		= common_init_rtc,
288 	.init_pci		= alcor_init_pci,
289 	.kill_arch		= alcor_kill_arch,
290 	.pci_map_irq		= alcor_map_irq,
291 	.pci_swizzle		= common_swizzle,
292 
293 	.sys = { .cia = {
294 		.gru_int_req_bits = ALCOR_GRU_INT_REQ_BITS
295 	}}
296 };
297 ALIAS_MV(alcor)
298 
299 struct alpha_machine_vector xlt_mv __initmv = {
300 	.vector_name		= "XLT",
301 	DO_EV5_MMU,
302 	DO_DEFAULT_RTC,
303 	DO_CIA_IO,
304 	.machine_check		= cia_machine_check,
305 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
306 	.min_io_address		= EISA_DEFAULT_IO_BASE,
307 	.min_mem_address	= CIA_DEFAULT_MEM_BASE,
308 
309 	.nr_irqs		= 48,
310 	.device_interrupt	= alcor_device_interrupt,
311 
312 	.init_arch		= cia_init_arch,
313 	.init_irq		= alcor_init_irq,
314 	.init_rtc		= common_init_rtc,
315 	.init_pci		= alcor_init_pci,
316 	.kill_arch		= alcor_kill_arch,
317 	.pci_map_irq		= alcor_map_irq,
318 	.pci_swizzle		= common_swizzle,
319 
320 	.sys = { .cia = {
321 		.gru_int_req_bits = XLT_GRU_INT_REQ_BITS
322 	}}
323 };
324 
325 /* No alpha_mv alias for XLT, since we compile it in unconditionally
326    with ALCOR; setup_arch knows how to cope.  */
327