xref: /openbmc/linux/arch/alpha/kernel/sys_alcor.c (revision 87c2ce3b)
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/config.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/mm.h>
15 #include <linux/sched.h>
16 #include <linux/pci.h>
17 #include <linux/init.h>
18 #include <linux/reboot.h>
19 #include <linux/bitops.h>
20 
21 #include <asm/ptrace.h>
22 #include <asm/system.h>
23 #include <asm/io.h>
24 #include <asm/dma.h>
25 #include <asm/mmu_context.h>
26 #include <asm/irq.h>
27 #include <asm/pgtable.h>
28 #include <asm/core_cia.h>
29 #include <asm/tlbflush.h>
30 
31 #include "proto.h"
32 #include "irq_impl.h"
33 #include "pci_impl.h"
34 #include "machvec_impl.h"
35 
36 
37 /* Note mask bit is true for ENABLED irqs.  */
38 static unsigned long cached_irq_mask;
39 
40 static inline void
41 alcor_update_irq_hw(unsigned long mask)
42 {
43 	*(vuip)GRU_INT_MASK = mask;
44 	mb();
45 }
46 
47 static inline void
48 alcor_enable_irq(unsigned int irq)
49 {
50 	alcor_update_irq_hw(cached_irq_mask |= 1UL << (irq - 16));
51 }
52 
53 static void
54 alcor_disable_irq(unsigned int irq)
55 {
56 	alcor_update_irq_hw(cached_irq_mask &= ~(1UL << (irq - 16)));
57 }
58 
59 static void
60 alcor_mask_and_ack_irq(unsigned int irq)
61 {
62 	alcor_disable_irq(irq);
63 
64 	/* On ALCOR/XLT, need to dismiss interrupt via GRU. */
65 	*(vuip)GRU_INT_CLEAR = 1 << (irq - 16); mb();
66 	*(vuip)GRU_INT_CLEAR = 0; mb();
67 }
68 
69 static unsigned int
70 alcor_startup_irq(unsigned int irq)
71 {
72 	alcor_enable_irq(irq);
73 	return 0;
74 }
75 
76 static void
77 alcor_isa_mask_and_ack_irq(unsigned int irq)
78 {
79 	i8259a_mask_and_ack_irq(irq);
80 
81 	/* On ALCOR/XLT, need to dismiss interrupt via GRU. */
82 	*(vuip)GRU_INT_CLEAR = 0x80000000; mb();
83 	*(vuip)GRU_INT_CLEAR = 0; mb();
84 }
85 
86 static void
87 alcor_end_irq(unsigned int irq)
88 {
89 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
90 		alcor_enable_irq(irq);
91 }
92 
93 static struct hw_interrupt_type alcor_irq_type = {
94 	.typename	= "ALCOR",
95 	.startup	= alcor_startup_irq,
96 	.shutdown	= alcor_disable_irq,
97 	.enable		= alcor_enable_irq,
98 	.disable	= alcor_disable_irq,
99 	.ack		= alcor_mask_and_ack_irq,
100 	.end		= alcor_end_irq,
101 };
102 
103 static void
104 alcor_device_interrupt(unsigned long vector, struct pt_regs *regs)
105 {
106 	unsigned long pld;
107 	unsigned int i;
108 
109 	/* Read the interrupt summary register of the GRU */
110 	pld = (*(vuip)GRU_INT_REQ) & GRU_INT_REQ_BITS;
111 
112 	/*
113 	 * Now for every possible bit set, work through them and call
114 	 * the appropriate interrupt handler.
115 	 */
116 	while (pld) {
117 		i = ffz(~pld);
118 		pld &= pld - 1; /* clear least bit set */
119 		if (i == 31) {
120 			isa_device_interrupt(vector, regs);
121 		} else {
122 			handle_irq(16 + i, regs);
123 		}
124 	}
125 }
126 
127 static void __init
128 alcor_init_irq(void)
129 {
130 	long i;
131 
132 	if (alpha_using_srm)
133 		alpha_mv.device_interrupt = srm_device_interrupt;
134 
135 	*(vuip)GRU_INT_MASK  = 0; mb();			/* all disabled */
136 	*(vuip)GRU_INT_EDGE  = 0; mb();			/* all are level */
137 	*(vuip)GRU_INT_HILO  = 0x80000000U; mb();	/* ISA only HI */
138 	*(vuip)GRU_INT_CLEAR = 0; mb();			/* all clear */
139 
140 	for (i = 16; i < 48; ++i) {
141 		/* On Alcor, at least, lines 20..30 are not connected
142 		   and can generate spurrious interrupts if we turn them
143 		   on while IRQ probing.  */
144 		if (i >= 16+20 && i <= 16+30)
145 			continue;
146 		irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
147 		irq_desc[i].handler = &alcor_irq_type;
148 	}
149 	i8259a_irq_type.ack = alcor_isa_mask_and_ack_irq;
150 
151 	init_i8259a_irqs();
152 	common_init_isa_dma();
153 
154 	setup_irq(16+31, &isa_cascade_irqaction);
155 }
156 
157 
158 /*
159  * PCI Fixup configuration.
160  *
161  * Summary @ GRU_INT_REQ:
162  * Bit      Meaning
163  * 0        Interrupt Line A from slot 2
164  * 1        Interrupt Line B from slot 2
165  * 2        Interrupt Line C from slot 2
166  * 3        Interrupt Line D from slot 2
167  * 4        Interrupt Line A from slot 1
168  * 5        Interrupt line B from slot 1
169  * 6        Interrupt Line C from slot 1
170  * 7        Interrupt Line D from slot 1
171  * 8        Interrupt Line A from slot 0
172  * 9        Interrupt Line B from slot 0
173  *10        Interrupt Line C from slot 0
174  *11        Interrupt Line D from slot 0
175  *12        Interrupt Line A from slot 4
176  *13        Interrupt Line B from slot 4
177  *14        Interrupt Line C from slot 4
178  *15        Interrupt Line D from slot 4
179  *16        Interrupt Line D from slot 3
180  *17        Interrupt Line D from slot 3
181  *18        Interrupt Line D from slot 3
182  *19        Interrupt Line D from slot 3
183  *20-30     Reserved
184  *31        EISA interrupt
185  *
186  * The device to slot mapping looks like:
187  *
188  * Slot     Device
189  *  6       built-in TULIP (XLT only)
190  *  7       PCI on board slot 0
191  *  8       PCI on board slot 3
192  *  9       PCI on board slot 4
193  * 10       PCEB (PCI-EISA bridge)
194  * 11       PCI on board slot 2
195  * 12       PCI on board slot 1
196  *
197  *
198  * This two layered interrupt approach means that we allocate IRQ 16 and
199  * above for PCI interrupts.  The IRQ relates to which bit the interrupt
200  * comes in on.  This makes interrupt processing much easier.
201  */
202 
203 static int __init
204 alcor_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
205 {
206 	static char irq_tab[7][5] __initdata = {
207 		/*INT    INTA   INTB   INTC   INTD */
208 		/* note: IDSEL 17 is XLT only */
209 		{16+13, 16+13, 16+13, 16+13, 16+13},	/* IdSel 17,  TULIP  */
210 		{ 16+8,  16+8,  16+9, 16+10, 16+11},	/* IdSel 18,  slot 0 */
211 		{16+16, 16+16, 16+17, 16+18, 16+19},	/* IdSel 19,  slot 3 */
212 		{16+12, 16+12, 16+13, 16+14, 16+15},	/* IdSel 20,  slot 4 */
213 		{   -1,    -1,    -1,    -1,    -1},	/* IdSel 21,  PCEB   */
214 		{ 16+0,  16+0,  16+1,  16+2,  16+3},	/* IdSel 22,  slot 2 */
215 		{ 16+4,  16+4,  16+5,  16+6,  16+7},	/* IdSel 23,  slot 1 */
216 	};
217 	const long min_idsel = 6, max_idsel = 12, irqs_per_slot = 5;
218 	return COMMON_TABLE_LOOKUP;
219 }
220 
221 static void
222 alcor_kill_arch(int mode)
223 {
224 	cia_kill_arch(mode);
225 
226 #ifndef ALPHA_RESTORE_SRM_SETUP
227 	switch(mode) {
228 	case LINUX_REBOOT_CMD_RESTART:
229 		/* Who said DEC engineer's have no sense of humor? ;-)  */
230 		if (alpha_using_srm) {
231 			*(vuip) GRU_RESET = 0x0000dead;
232 			mb();
233 		}
234 		break;
235 	case LINUX_REBOOT_CMD_HALT:
236 		break;
237 	case LINUX_REBOOT_CMD_POWER_OFF:
238 		break;
239 	}
240 
241 	halt();
242 #endif
243 }
244 
245 static void __init
246 alcor_init_pci(void)
247 {
248 	struct pci_dev *dev;
249 
250 	cia_init_pci();
251 
252 	/*
253 	 * Now we can look to see if we are really running on an XLT-type
254 	 * motherboard, by looking for a 21040 TULIP in slot 6, which is
255 	 * built into XLT and BRET/MAVERICK, but not available on ALCOR.
256 	 */
257 	dev = pci_get_device(PCI_VENDOR_ID_DEC,
258 			      PCI_DEVICE_ID_DEC_TULIP,
259 			      NULL);
260 	if (dev && dev->devfn == PCI_DEVFN(6,0)) {
261 		alpha_mv.sys.cia.gru_int_req_bits = XLT_GRU_INT_REQ_BITS;
262 		printk(KERN_INFO "%s: Detected AS500 or XLT motherboard.\n",
263 		       __FUNCTION__);
264 	}
265 	pci_dev_put(dev);
266 }
267 
268 
269 /*
270  * The System Vectors
271  */
272 
273 struct alpha_machine_vector alcor_mv __initmv = {
274 	.vector_name		= "Alcor",
275 	DO_EV5_MMU,
276 	DO_DEFAULT_RTC,
277 	DO_CIA_IO,
278 	.machine_check		= cia_machine_check,
279 	.max_isa_dma_address	= ALPHA_ALCOR_MAX_ISA_DMA_ADDRESS,
280 	.min_io_address		= EISA_DEFAULT_IO_BASE,
281 	.min_mem_address	= CIA_DEFAULT_MEM_BASE,
282 
283 	.nr_irqs		= 48,
284 	.device_interrupt	= alcor_device_interrupt,
285 
286 	.init_arch		= cia_init_arch,
287 	.init_irq		= alcor_init_irq,
288 	.init_rtc		= common_init_rtc,
289 	.init_pci		= alcor_init_pci,
290 	.kill_arch		= alcor_kill_arch,
291 	.pci_map_irq		= alcor_map_irq,
292 	.pci_swizzle		= common_swizzle,
293 
294 	.sys = { .cia = {
295 		.gru_int_req_bits = ALCOR_GRU_INT_REQ_BITS
296 	}}
297 };
298 ALIAS_MV(alcor)
299 
300 struct alpha_machine_vector xlt_mv __initmv = {
301 	.vector_name		= "XLT",
302 	DO_EV5_MMU,
303 	DO_DEFAULT_RTC,
304 	DO_CIA_IO,
305 	.machine_check		= cia_machine_check,
306 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
307 	.min_io_address		= EISA_DEFAULT_IO_BASE,
308 	.min_mem_address	= CIA_DEFAULT_MEM_BASE,
309 
310 	.nr_irqs		= 48,
311 	.device_interrupt	= alcor_device_interrupt,
312 
313 	.init_arch		= cia_init_arch,
314 	.init_irq		= alcor_init_irq,
315 	.init_rtc		= common_init_rtc,
316 	.init_pci		= alcor_init_pci,
317 	.kill_arch		= alcor_kill_arch,
318 	.pci_map_irq		= alcor_map_irq,
319 	.pci_swizzle		= common_swizzle,
320 
321 	.sys = { .cia = {
322 		.gru_int_req_bits = XLT_GRU_INT_REQ_BITS
323 	}}
324 };
325 
326 /* No alpha_mv alias for XLT, since we compile it in unconditionally
327    with ALCOR; setup_arch knows how to cope.  */
328