xref: /openbmc/linux/arch/alpha/kernel/sys_rawhide.c (revision c67e8ec0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/sys_rawhide.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 RAWHIDE.
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 
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_mcpcia.h>
26 #include <asm/tlbflush.h>
27 
28 #include "proto.h"
29 #include "irq_impl.h"
30 #include "pci_impl.h"
31 #include "machvec_impl.h"
32 
33 
34 /*
35  * HACK ALERT! only the boot cpu is used for interrupts.
36  */
37 
38 
39 /* Note mask bit is true for ENABLED irqs.  */
40 
41 static unsigned int hose_irq_masks[4] = {
42 	0xff0000, 0xfe0000, 0xff0000, 0xff0000
43 };
44 static unsigned int cached_irq_masks[4];
45 DEFINE_SPINLOCK(rawhide_irq_lock);
46 
47 static inline void
48 rawhide_update_irq_hw(int hose, int mask)
49 {
50 	*(vuip)MCPCIA_INT_MASK0(MCPCIA_HOSE2MID(hose)) = mask;
51 	mb();
52 	*(vuip)MCPCIA_INT_MASK0(MCPCIA_HOSE2MID(hose));
53 }
54 
55 #define hose_exists(h) \
56   (((h) < MCPCIA_MAX_HOSES) && (cached_irq_masks[(h)] != 0))
57 
58 static inline void
59 rawhide_enable_irq(struct irq_data *d)
60 {
61 	unsigned int mask, hose;
62 	unsigned int irq = d->irq;
63 
64 	irq -= 16;
65 	hose = irq / 24;
66 	if (!hose_exists(hose)) /* if hose non-existent, exit */
67 		return;
68 
69 	irq -= hose * 24;
70 	mask = 1 << irq;
71 
72 	spin_lock(&rawhide_irq_lock);
73 	mask |= cached_irq_masks[hose];
74 	cached_irq_masks[hose] = mask;
75 	rawhide_update_irq_hw(hose, mask);
76 	spin_unlock(&rawhide_irq_lock);
77 }
78 
79 static void
80 rawhide_disable_irq(struct irq_data *d)
81 {
82 	unsigned int mask, hose;
83 	unsigned int irq = d->irq;
84 
85 	irq -= 16;
86 	hose = irq / 24;
87 	if (!hose_exists(hose)) /* if hose non-existent, exit */
88 		return;
89 
90 	irq -= hose * 24;
91 	mask = ~(1 << irq) | hose_irq_masks[hose];
92 
93 	spin_lock(&rawhide_irq_lock);
94 	mask &= cached_irq_masks[hose];
95 	cached_irq_masks[hose] = mask;
96 	rawhide_update_irq_hw(hose, mask);
97 	spin_unlock(&rawhide_irq_lock);
98 }
99 
100 static void
101 rawhide_mask_and_ack_irq(struct irq_data *d)
102 {
103 	unsigned int mask, mask1, hose;
104 	unsigned int irq = d->irq;
105 
106 	irq -= 16;
107 	hose = irq / 24;
108 	if (!hose_exists(hose)) /* if hose non-existent, exit */
109 		return;
110 
111 	irq -= hose * 24;
112 	mask1 = 1 << irq;
113 	mask = ~mask1 | hose_irq_masks[hose];
114 
115 	spin_lock(&rawhide_irq_lock);
116 
117 	mask &= cached_irq_masks[hose];
118 	cached_irq_masks[hose] = mask;
119 	rawhide_update_irq_hw(hose, mask);
120 
121 	/* Clear the interrupt.  */
122 	*(vuip)MCPCIA_INT_REQ(MCPCIA_HOSE2MID(hose)) = mask1;
123 
124 	spin_unlock(&rawhide_irq_lock);
125 }
126 
127 static struct irq_chip rawhide_irq_type = {
128 	.name		= "RAWHIDE",
129 	.irq_unmask	= rawhide_enable_irq,
130 	.irq_mask	= rawhide_disable_irq,
131 	.irq_mask_ack	= rawhide_mask_and_ack_irq,
132 };
133 
134 static void
135 rawhide_srm_device_interrupt(unsigned long vector)
136 {
137 	int irq;
138 
139 	irq = (vector - 0x800) >> 4;
140 
141         /*
142          * The RAWHIDE SRM console reports PCI interrupts with a vector
143 	 * 0x80 *higher* than one might expect, as PCI IRQ 0 (ie bit 0)
144 	 * shows up as IRQ 24, etc, etc. We adjust it down by 8 to have
145 	 * it line up with the actual bit numbers from the REQ registers,
146 	 * which is how we manage the interrupts/mask. Sigh...
147 	 *
148 	 * Also, PCI #1 interrupts are offset some more... :-(
149          */
150 
151 	if (irq == 52) {
152 		/* SCSI on PCI1 is special.  */
153 		irq = 72;
154 	}
155 
156 	/* Adjust by which hose it is from.  */
157 	irq -= ((irq + 16) >> 2) & 0x38;
158 
159 	handle_irq(irq);
160 }
161 
162 static void __init
163 rawhide_init_irq(void)
164 {
165 	struct pci_controller *hose;
166 	long i;
167 
168 	mcpcia_init_hoses();
169 
170 	/* Clear them all; only hoses that exist will be non-zero. */
171 	for (i = 0; i < MCPCIA_MAX_HOSES; i++) cached_irq_masks[i] = 0;
172 
173 	for (hose = hose_head; hose; hose = hose->next) {
174 		unsigned int h = hose->index;
175 		unsigned int mask = hose_irq_masks[h];
176 
177 		cached_irq_masks[h] = mask;
178 		*(vuip)MCPCIA_INT_MASK0(MCPCIA_HOSE2MID(h)) = mask;
179 		*(vuip)MCPCIA_INT_MASK1(MCPCIA_HOSE2MID(h)) = 0;
180 	}
181 
182 	for (i = 16; i < 128; ++i) {
183 		irq_set_chip_and_handler(i, &rawhide_irq_type,
184 					 handle_level_irq);
185 		irq_set_status_flags(i, IRQ_LEVEL);
186 	}
187 
188 	init_i8259a_irqs();
189 	common_init_isa_dma();
190 }
191 
192 /*
193  * PCI Fixup configuration.
194  *
195  * Summary @ MCPCIA_PCI0_INT_REQ:
196  * Bit      Meaning
197  * 0        Interrupt Line A from slot 2 PCI0
198  * 1        Interrupt Line B from slot 2 PCI0
199  * 2        Interrupt Line C from slot 2 PCI0
200  * 3        Interrupt Line D from slot 2 PCI0
201  * 4        Interrupt Line A from slot 3 PCI0
202  * 5        Interrupt Line B from slot 3 PCI0
203  * 6        Interrupt Line C from slot 3 PCI0
204  * 7        Interrupt Line D from slot 3 PCI0
205  * 8        Interrupt Line A from slot 4 PCI0
206  * 9        Interrupt Line B from slot 4 PCI0
207  * 10       Interrupt Line C from slot 4 PCI0
208  * 11       Interrupt Line D from slot 4 PCI0
209  * 12       Interrupt Line A from slot 5 PCI0
210  * 13       Interrupt Line B from slot 5 PCI0
211  * 14       Interrupt Line C from slot 5 PCI0
212  * 15       Interrupt Line D from slot 5 PCI0
213  * 16       EISA interrupt (PCI 0) or SCSI interrupt (PCI 1)
214  * 17-23    NA
215  *
216  * IdSel
217  *   1	 EISA bridge (PCI bus 0 only)
218  *   2 	 PCI option slot 2
219  *   3	 PCI option slot 3
220  *   4   PCI option slot 4
221  *   5   PCI option slot 5
222  *
223  */
224 
225 static int
226 rawhide_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
227 {
228 	static char irq_tab[5][5] = {
229 		/*INT    INTA   INTB   INTC   INTD */
230 		{ 16+16, 16+16, 16+16, 16+16, 16+16}, /* IdSel 1 SCSI PCI 1 */
231 		{ 16+ 0, 16+ 0, 16+ 1, 16+ 2, 16+ 3}, /* IdSel 2 slot 2 */
232 		{ 16+ 4, 16+ 4, 16+ 5, 16+ 6, 16+ 7}, /* IdSel 3 slot 3 */
233 		{ 16+ 8, 16+ 8, 16+ 9, 16+10, 16+11}, /* IdSel 4 slot 4 */
234 		{ 16+12, 16+12, 16+13, 16+14, 16+15}  /* IdSel 5 slot 5 */
235 	};
236 	const long min_idsel = 1, max_idsel = 5, irqs_per_slot = 5;
237 
238 	struct pci_controller *hose = dev->sysdata;
239 	int irq = COMMON_TABLE_LOOKUP;
240 	if (irq >= 0)
241 		irq += 24 * hose->index;
242 	return irq;
243 }
244 
245 
246 /*
247  * The System Vector
248  */
249 
250 struct alpha_machine_vector rawhide_mv __initmv = {
251 	.vector_name		= "Rawhide",
252 	DO_EV5_MMU,
253 	DO_DEFAULT_RTC,
254 	DO_MCPCIA_IO,
255 	.machine_check		= mcpcia_machine_check,
256 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
257 	.min_io_address		= DEFAULT_IO_BASE,
258 	.min_mem_address	= MCPCIA_DEFAULT_MEM_BASE,
259 	.pci_dac_offset		= MCPCIA_DAC_OFFSET,
260 
261 	.nr_irqs		= 128,
262 	.device_interrupt	= rawhide_srm_device_interrupt,
263 
264 	.init_arch		= mcpcia_init_arch,
265 	.init_irq		= rawhide_init_irq,
266 	.init_rtc		= common_init_rtc,
267 	.init_pci		= common_init_pci,
268 	.kill_arch		= NULL,
269 	.pci_map_irq		= rawhide_map_irq,
270 	.pci_swizzle		= common_swizzle,
271 };
272 ALIAS_MV(rawhide)
273