xref: /openbmc/linux/arch/alpha/kernel/sys_eb64p.c (revision f3539c12)
1 /*
2  *	linux/arch/alpha/kernel/sys_eb64p.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 EB64+ and EB66.
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/bitops.h>
18 
19 #include <asm/ptrace.h>
20 #include <asm/dma.h>
21 #include <asm/irq.h>
22 #include <asm/mmu_context.h>
23 #include <asm/io.h>
24 #include <asm/pgtable.h>
25 #include <asm/core_apecs.h>
26 #include <asm/core_lca.h>
27 #include <asm/hwrpb.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 DISABLED irqs.  */
37 static unsigned int cached_irq_mask = -1;
38 
39 static inline void
40 eb64p_update_irq_hw(unsigned int irq, unsigned long mask)
41 {
42 	outb(mask >> (irq >= 24 ? 24 : 16), (irq >= 24 ? 0x27 : 0x26));
43 }
44 
45 static inline void
46 eb64p_enable_irq(struct irq_data *d)
47 {
48 	eb64p_update_irq_hw(d->irq, cached_irq_mask &= ~(1 << d->irq));
49 }
50 
51 static void
52 eb64p_disable_irq(struct irq_data *d)
53 {
54 	eb64p_update_irq_hw(d->irq, cached_irq_mask |= 1 << d->irq);
55 }
56 
57 static struct irq_chip eb64p_irq_type = {
58 	.name		= "EB64P",
59 	.irq_unmask	= eb64p_enable_irq,
60 	.irq_mask	= eb64p_disable_irq,
61 	.irq_mask_ack	= eb64p_disable_irq,
62 };
63 
64 static void
65 eb64p_device_interrupt(unsigned long vector)
66 {
67 	unsigned long pld;
68 	unsigned int i;
69 
70 	/* Read the interrupt summary registers */
71 	pld = inb(0x26) | (inb(0x27) << 8);
72 
73 	/*
74 	 * Now, for every possible bit set, work through
75 	 * them and call the appropriate interrupt handler.
76 	 */
77 	while (pld) {
78 		i = ffz(~pld);
79 		pld &= pld - 1;	/* clear least bit set */
80 
81 		if (i == 5) {
82 			isa_device_interrupt(vector);
83 		} else {
84 			handle_irq(16 + i);
85 		}
86 	}
87 }
88 
89 static void __init
90 eb64p_init_irq(void)
91 {
92 	long i;
93 
94 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_CABRIOLET)
95 	/*
96 	 * CABRIO SRM may not set variation correctly, so here we test
97 	 * the high word of the interrupt summary register for the RAZ
98 	 * bits, and hope that a true EB64+ would read all ones...
99 	 */
100 	if (inw(0x806) != 0xffff) {
101 		extern struct alpha_machine_vector cabriolet_mv;
102 
103 		printk("Detected Cabriolet: correcting HWRPB.\n");
104 
105 		hwrpb->sys_variation |= 2L << 10;
106 		hwrpb_update_checksum(hwrpb);
107 
108 		alpha_mv = cabriolet_mv;
109 		alpha_mv.init_irq();
110 		return;
111 	}
112 #endif /* GENERIC */
113 
114 	outb(0xff, 0x26);
115 	outb(0xff, 0x27);
116 
117 	init_i8259a_irqs();
118 
119 	for (i = 16; i < 32; ++i) {
120 		irq_set_chip_and_handler(i, &eb64p_irq_type, handle_level_irq);
121 		irq_set_status_flags(i, IRQ_LEVEL);
122 	}
123 
124 	common_init_isa_dma();
125 	setup_irq(16+5, &isa_cascade_irqaction);
126 }
127 
128 /*
129  * PCI Fixup configuration.
130  *
131  * There are two 8 bit external summary registers as follows:
132  *
133  * Summary @ 0x26:
134  * Bit      Meaning
135  * 0        Interrupt Line A from slot 0
136  * 1        Interrupt Line A from slot 1
137  * 2        Interrupt Line B from slot 0
138  * 3        Interrupt Line B from slot 1
139  * 4        Interrupt Line C from slot 0
140  * 5        Interrupt line from the two ISA PICs
141  * 6        Tulip
142  * 7        NCR SCSI
143  *
144  * Summary @ 0x27
145  * Bit      Meaning
146  * 0        Interrupt Line C from slot 1
147  * 1        Interrupt Line D from slot 0
148  * 2        Interrupt Line D from slot 1
149  * 3        RAZ
150  * 4        RAZ
151  * 5        RAZ
152  * 6        RAZ
153  * 7        RAZ
154  *
155  * The device to slot mapping looks like:
156  *
157  * Slot     Device
158  *  5       NCR SCSI controller
159  *  6       PCI on board slot 0
160  *  7       PCI on board slot 1
161  *  8       Intel SIO PCI-ISA bridge chip
162  *  9       Tulip - DECchip 21040 Ethernet controller
163  *
164  *
165  * This two layered interrupt approach means that we allocate IRQ 16 and
166  * above for PCI interrupts.  The IRQ relates to which bit the interrupt
167  * comes in on.  This makes interrupt processing much easier.
168  */
169 
170 static int __init
171 eb64p_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
172 {
173 	static char irq_tab[5][5] __initdata = {
174 		/*INT  INTA  INTB  INTC   INTD */
175 		{16+7, 16+7, 16+7, 16+7,  16+7},  /* IdSel 5,  slot ?, ?? */
176 		{16+0, 16+0, 16+2, 16+4,  16+9},  /* IdSel 6,  slot ?, ?? */
177 		{16+1, 16+1, 16+3, 16+8, 16+10},  /* IdSel 7,  slot ?, ?? */
178 		{  -1,   -1,   -1,   -1,    -1},  /* IdSel 8,  SIO */
179 		{16+6, 16+6, 16+6, 16+6,  16+6},  /* IdSel 9,  TULIP */
180 	};
181 	const long min_idsel = 5, max_idsel = 9, irqs_per_slot = 5;
182 	return COMMON_TABLE_LOOKUP;
183 }
184 
185 
186 /*
187  * The System Vector
188  */
189 
190 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_EB64P)
191 struct alpha_machine_vector eb64p_mv __initmv = {
192 	.vector_name		= "EB64+",
193 	DO_EV4_MMU,
194 	DO_DEFAULT_RTC,
195 	DO_APECS_IO,
196 	.machine_check		= apecs_machine_check,
197 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
198 	.min_io_address		= DEFAULT_IO_BASE,
199 	.min_mem_address	= APECS_AND_LCA_DEFAULT_MEM_BASE,
200 
201 	.nr_irqs		= 32,
202 	.device_interrupt	= eb64p_device_interrupt,
203 
204 	.init_arch		= apecs_init_arch,
205 	.init_irq		= eb64p_init_irq,
206 	.init_rtc		= common_init_rtc,
207 	.init_pci		= common_init_pci,
208 	.kill_arch		= NULL,
209 	.pci_map_irq		= eb64p_map_irq,
210 	.pci_swizzle		= common_swizzle,
211 };
212 ALIAS_MV(eb64p)
213 #endif
214 
215 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_EB66)
216 struct alpha_machine_vector eb66_mv __initmv = {
217 	.vector_name		= "EB66",
218 	DO_EV4_MMU,
219 	DO_DEFAULT_RTC,
220 	DO_LCA_IO,
221 	.machine_check		= lca_machine_check,
222 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
223 	.min_io_address		= DEFAULT_IO_BASE,
224 	.min_mem_address	= APECS_AND_LCA_DEFAULT_MEM_BASE,
225 
226 	.nr_irqs		= 32,
227 	.device_interrupt	= eb64p_device_interrupt,
228 
229 	.init_arch		= lca_init_arch,
230 	.init_irq		= eb64p_init_irq,
231 	.init_rtc		= common_init_rtc,
232 	.init_pci		= common_init_pci,
233 	.pci_map_irq		= eb64p_map_irq,
234 	.pci_swizzle		= common_swizzle,
235 };
236 ALIAS_MV(eb66)
237 #endif
238