1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * sc-ip22.c: Indy cache management functions.
4 *
5 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
6 * derived from r4xx0.c by David S. Miller (davem@davemloft.net).
7 */
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12
13 #include <asm/bcache.h>
14 #include <asm/page.h>
15 #include <asm/bootinfo.h>
16 #include <asm/sgi/ip22.h>
17 #include <asm/sgi/mc.h>
18
19 /* Secondary cache size in bytes, if present. */
20 static unsigned long scache_size;
21
22 #undef DEBUG_CACHE
23
24 #define SC_SIZE 0x00080000
25 #define SC_LINE 32
26 #define CI_MASK (SC_SIZE - SC_LINE)
27 #define SC_INDEX(n) ((n) & CI_MASK)
28
29 static inline void indy_sc_wipe(unsigned long first, unsigned long last)
30 {
31 unsigned long tmp;
32
33 __asm__ __volatile__(
34 " .set push # indy_sc_wipe \n"
35 " .set noreorder \n"
36 " .set mips3 \n"
37 " .set noat \n"
38 " mfc0 %2, $12 \n"
39 " li $1, 0x80 # Go 64 bit \n"
40 " mtc0 $1, $12 \n"
41 " \n"
42 " # \n"
43 " # Open code a dli $1, 0x9000000080000000 \n"
44 " # \n"
45 " # Required because binutils 2.25 will happily accept \n"
46 " # 64 bit instructions in .set mips3 mode but puke on \n"
47 " # 64 bit constants when generating 32 bit ELF \n"
48 " # \n"
49 " lui $1,0x9000 \n"
50 " dsll $1,$1,0x10 \n"
51 " ori $1,$1,0x8000 \n"
52 " dsll $1,$1,0x10 \n"
53 " \n"
54 " or %0, $1 # first line to flush \n"
55 " or %1, $1 # last line to flush \n"
56 " .set at \n"
57 " \n"
58 "1: sw $0, 0(%0) \n"
59 " bne %0, %1, 1b \n"
60 " daddu %0, 32 \n"
61 " \n"
62 " mtc0 %2, $12 # Back to 32 bit \n"
63 " nop # pipeline hazard \n"
64 " nop \n"
65 " nop \n"
66 " nop \n"
67 " .set pop \n"
68 : "=r" (first), "=r" (last), "=&r" (tmp)
69 : "" (first), "1" (last));
70 }
71
72 static void indy_sc_wback_invalidate(unsigned long addr, unsigned long size)
73 {
74 unsigned long first_line, last_line;
75 unsigned long flags;
76
77 #ifdef DEBUG_CACHE
78 printk("indy_sc_wback_invalidate[%08lx,%08lx]", addr, size);
79 #endif
80
81 /* Catch bad driver code */
82 BUG_ON(size == 0);
83
84 /* Which lines to flush? */
85 first_line = SC_INDEX(addr);
86 last_line = SC_INDEX(addr + size - 1);
87
88 local_irq_save(flags);
89 if (first_line <= last_line) {
90 indy_sc_wipe(first_line, last_line);
91 goto out;
92 }
93
94 indy_sc_wipe(first_line, SC_SIZE - SC_LINE);
95 indy_sc_wipe(0, last_line);
96 out:
97 local_irq_restore(flags);
98 }
99
100 static void indy_sc_enable(void)
101 {
102 unsigned long addr, tmp1, tmp2;
103
104 /* This is really cool... */
105 #ifdef DEBUG_CACHE
106 printk("Enabling R4600 SCACHE\n");
107 #endif
108 __asm__ __volatile__(
109 ".set\tpush\n\t"
110 ".set\tnoreorder\n\t"
111 ".set\tmips3\n\t"
112 "mfc0\t%2, $12\n\t"
113 "nop; nop; nop; nop;\n\t"
114 "li\t%1, 0x80\n\t"
115 "mtc0\t%1, $12\n\t"
116 "nop; nop; nop; nop;\n\t"
117 "li\t%0, 0x1\n\t"
118 "dsll\t%0, 31\n\t"
119 "lui\t%1, 0x9000\n\t"
120 "dsll32\t%1, 0\n\t"
121 "or\t%0, %1, %0\n\t"
122 "sb\t$0, 0(%0)\n\t"
123 "mtc0\t$0, $12\n\t"
124 "nop; nop; nop; nop;\n\t"
125 "mtc0\t%2, $12\n\t"
126 "nop; nop; nop; nop;\n\t"
127 ".set\tpop"
128 : "=r" (tmp1), "=r" (tmp2), "=r" (addr));
129 }
130
131 static void indy_sc_disable(void)
132 {
133 unsigned long tmp1, tmp2, tmp3;
134
135 #ifdef DEBUG_CACHE
136 printk("Disabling R4600 SCACHE\n");
137 #endif
138 __asm__ __volatile__(
139 ".set\tpush\n\t"
140 ".set\tnoreorder\n\t"
141 ".set\tmips3\n\t"
142 "li\t%0, 0x1\n\t"
143 "dsll\t%0, 31\n\t"
144 "lui\t%1, 0x9000\n\t"
145 "dsll32\t%1, 0\n\t"
146 "or\t%0, %1, %0\n\t"
147 "mfc0\t%2, $12\n\t"
148 "nop; nop; nop; nop\n\t"
149 "li\t%1, 0x80\n\t"
150 "mtc0\t%1, $12\n\t"
151 "nop; nop; nop; nop\n\t"
152 "sh\t$0, 0(%0)\n\t"
153 "mtc0\t$0, $12\n\t"
154 "nop; nop; nop; nop\n\t"
155 "mtc0\t%2, $12\n\t"
156 "nop; nop; nop; nop\n\t"
157 ".set\tpop"
158 : "=r" (tmp1), "=r" (tmp2), "=r" (tmp3));
159 }
160
161 static inline int __init indy_sc_probe(void)
162 {
163 unsigned int size = ip22_eeprom_read(&sgimc->eeprom, 17);
164 if (size == 0)
165 return 0;
166
167 size <<= PAGE_SHIFT;
168 printk(KERN_INFO "R4600/R5000 SCACHE size %dK, linesize 32 bytes.\n",
169 size >> 10);
170 scache_size = size;
171
172 return 1;
173 }
174
175 /* XXX Check with wje if the Indy caches can differentiate between
176 writeback + invalidate and just invalidate. */
177 static struct bcache_ops indy_sc_ops = {
178 .bc_enable = indy_sc_enable,
179 .bc_disable = indy_sc_disable,
180 .bc_wback_inv = indy_sc_wback_invalidate,
181 .bc_inv = indy_sc_wback_invalidate
182 };
183
184 void indy_sc_init(void)
185 {
186 if (indy_sc_probe()) {
187 indy_sc_enable();
188 bcops = &indy_sc_ops;
189 }
190 }
191
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