xref: /openbmc/linux/arch/alpha/kernel/sys_rx164.c (revision 1d05334d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/sys_rx164.c
4  *
5  *	Copyright (C) 1995 David A Rusling
6  *	Copyright (C) 1996 Jay A Estabrook
7  *	Copyright (C) 1998, 1999 Richard Henderson
8  *
9  * Code supporting the RX164 (PCA56+POLARIS).
10  */
11 
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/bitops.h>
19 
20 #include <asm/ptrace.h>
21 #include <asm/dma.h>
22 #include <asm/irq.h>
23 #include <asm/mmu_context.h>
24 #include <asm/io.h>
25 #include <asm/pgtable.h>
26 #include <asm/core_polaris.h>
27 #include <asm/tlbflush.h>
28 
29 #include "proto.h"
30 #include "irq_impl.h"
31 #include "pci_impl.h"
32 #include "machvec_impl.h"
33 
34 
35 /* Note mask bit is true for ENABLED irqs.  */
36 static unsigned long cached_irq_mask;
37 
38 static inline void
39 rx164_update_irq_hw(unsigned long mask)
40 {
41 	volatile unsigned int *irq_mask;
42 
43 	irq_mask = (void *)(POLARIS_DENSE_CONFIG_BASE + 0x74);
44 	*irq_mask = mask;
45 	mb();
46 	*irq_mask;
47 }
48 
49 static inline void
50 rx164_enable_irq(struct irq_data *d)
51 {
52 	rx164_update_irq_hw(cached_irq_mask |= 1UL << (d->irq - 16));
53 }
54 
55 static void
56 rx164_disable_irq(struct irq_data *d)
57 {
58 	rx164_update_irq_hw(cached_irq_mask &= ~(1UL << (d->irq - 16)));
59 }
60 
61 static struct irq_chip rx164_irq_type = {
62 	.name		= "RX164",
63 	.irq_unmask	= rx164_enable_irq,
64 	.irq_mask	= rx164_disable_irq,
65 	.irq_mask_ack	= rx164_disable_irq,
66 };
67 
68 static void
69 rx164_device_interrupt(unsigned long vector)
70 {
71 	unsigned long pld;
72 	volatile unsigned int *dirr;
73 	long i;
74 
75 	/* Read the interrupt summary register.  On Polaris, this is
76 	   the DIRR register in PCI config space (offset 0x84).  */
77 	dirr = (void *)(POLARIS_DENSE_CONFIG_BASE + 0x84);
78 	pld = *dirr;
79 
80 	/*
81 	 * Now for every possible bit set, work through them and call
82 	 * the appropriate interrupt handler.
83 	 */
84 	while (pld) {
85 		i = ffz(~pld);
86 		pld &= pld - 1; /* clear least bit set */
87 		if (i == 20) {
88 			isa_no_iack_sc_device_interrupt(vector);
89 		} else {
90 			handle_irq(16+i);
91 		}
92 	}
93 }
94 
95 static void __init
96 rx164_init_irq(void)
97 {
98 	long i;
99 
100 	rx164_update_irq_hw(0);
101 	for (i = 16; i < 40; ++i) {
102 		irq_set_chip_and_handler(i, &rx164_irq_type, handle_level_irq);
103 		irq_set_status_flags(i, IRQ_LEVEL);
104 	}
105 
106 	init_i8259a_irqs();
107 	common_init_isa_dma();
108 
109 	if (request_irq(16 + 20, no_action, 0, "isa-cascade", NULL))
110 		pr_err("Failed to register isa-cascade interrupt\n");
111 }
112 
113 
114 /*
115  * The RX164 changed its interrupt routing between pass1 and pass2...
116  *
117  * PASS1:
118  *
119  *      Slot    IDSEL   INTA    INTB    INTC    INTD
120  *      0       6       5       10      15      20
121  *      1       7       4       9       14      19
122  *      2       5       3       8       13      18
123  *      3       9       2       7       12      17
124  *      4       10      1       6       11      16
125  *
126  * PASS2:
127  *      Slot    IDSEL   INTA    INTB    INTC    INTD
128  *      0       5       1       7       12      17
129  *      1       6       2       8       13      18
130  *      2       8       3       9       14      19
131  *      3       9       4       10      15      20
132  *      4       10      5       11      16      6
133  *
134  */
135 
136 /*
137  * IdSel
138  *   5  32 bit PCI option slot 0
139  *   6  64 bit PCI option slot 1
140  *   7  PCI-ISA bridge
141  *   7  64 bit PCI option slot 2
142  *   9  32 bit PCI option slot 3
143  *  10  PCI-PCI bridge
144  *
145  */
146 
147 static int
148 rx164_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
149 {
150 #if 0
151 	static char irq_tab_pass1[6][5] __initdata = {
152 	  /*INT   INTA  INTB  INTC   INTD */
153 	  { 16+3, 16+3, 16+8, 16+13, 16+18},      /* IdSel 5,  slot 2 */
154 	  { 16+5, 16+5, 16+10, 16+15, 16+20},     /* IdSel 6,  slot 0 */
155 	  { 16+4, 16+4, 16+9, 16+14, 16+19},      /* IdSel 7,  slot 1 */
156 	  { -1,     -1,    -1,    -1,   -1},      /* IdSel 8, PCI/ISA bridge */
157 	  { 16+2, 16+2, 16+7, 16+12, 16+17},      /* IdSel 9,  slot 3 */
158 	  { 16+1, 16+1, 16+6, 16+11, 16+16},      /* IdSel 10, slot 4 */
159 	};
160 #else
161 	static char irq_tab[6][5] = {
162 	  /*INT   INTA  INTB  INTC   INTD */
163 	  { 16+0, 16+0, 16+6, 16+11, 16+16},      /* IdSel 5,  slot 0 */
164 	  { 16+1, 16+1, 16+7, 16+12, 16+17},      /* IdSel 6,  slot 1 */
165 	  { -1,     -1,    -1,    -1,   -1},      /* IdSel 7, PCI/ISA bridge */
166 	  { 16+2, 16+2, 16+8, 16+13, 16+18},      /* IdSel 8,  slot 2 */
167 	  { 16+3, 16+3, 16+9, 16+14, 16+19},      /* IdSel 9,  slot 3 */
168 	  { 16+4, 16+4, 16+10, 16+15, 16+5},      /* IdSel 10, PCI-PCI */
169 	};
170 #endif
171 	const long min_idsel = 5, max_idsel = 10, irqs_per_slot = 5;
172 
173 	/* JRP - Need to figure out how to distinguish pass1 from pass2,
174 	   and use the correct table.  */
175 	return COMMON_TABLE_LOOKUP;
176 }
177 
178 
179 /*
180  * The System Vector
181  */
182 
183 struct alpha_machine_vector rx164_mv __initmv = {
184 	.vector_name		= "RX164",
185 	DO_EV5_MMU,
186 	DO_DEFAULT_RTC,
187 	DO_POLARIS_IO,
188 	.machine_check		= polaris_machine_check,
189 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
190 	.min_io_address		= DEFAULT_IO_BASE,
191 	.min_mem_address	= DEFAULT_MEM_BASE,
192 
193 	.nr_irqs		= 40,
194 	.device_interrupt	= rx164_device_interrupt,
195 
196 	.init_arch		= polaris_init_arch,
197 	.init_irq		= rx164_init_irq,
198 	.init_rtc		= common_init_rtc,
199 	.init_pci		= common_init_pci,
200 	.kill_arch		= NULL,
201 	.pci_map_irq		= rx164_map_irq,
202 	.pci_swizzle		= common_swizzle,
203 };
204 ALIAS_MV(rx164)
205