1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/m68k/mm/memory.c
4 *
5 * Copyright (C) 1995 Hamish Macdonald
6 */
7
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/pagemap.h>
15 #include <linux/gfp.h>
16
17 #include <asm/setup.h>
18 #include <asm/segment.h>
19 #include <asm/page.h>
20 #include <asm/traps.h>
21 #include <asm/machdep.h>
22
23
24 /* invalidate page in both caches */
clear040(unsigned long paddr)25 static inline void clear040(unsigned long paddr)
26 {
27 asm volatile (
28 "nop\n\t"
29 ".chip 68040\n\t"
30 "cinvp %%bc,(%0)\n\t"
31 ".chip 68k"
32 : : "a" (paddr));
33 }
34
35 /* invalidate page in i-cache */
cleari040(unsigned long paddr)36 static inline void cleari040(unsigned long paddr)
37 {
38 asm volatile (
39 "nop\n\t"
40 ".chip 68040\n\t"
41 "cinvp %%ic,(%0)\n\t"
42 ".chip 68k"
43 : : "a" (paddr));
44 }
45
46 /* push page in both caches */
47 /* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */
push040(unsigned long paddr)48 static inline void push040(unsigned long paddr)
49 {
50 asm volatile (
51 "nop\n\t"
52 ".chip 68040\n\t"
53 "cpushp %%bc,(%0)\n\t"
54 ".chip 68k"
55 : : "a" (paddr));
56 }
57
58 /* push and invalidate page in both caches, must disable ints
59 * to avoid invalidating valid data */
pushcl040(unsigned long paddr)60 static inline void pushcl040(unsigned long paddr)
61 {
62 unsigned long flags;
63
64 local_irq_save(flags);
65 push040(paddr);
66 if (CPU_IS_060)
67 clear040(paddr);
68 local_irq_restore(flags);
69 }
70
71 /*
72 * 040: Hit every page containing an address in the range paddr..paddr+len-1.
73 * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s).
74 * Hit every page until there is a page or less to go. Hit the next page,
75 * and the one after that if the range hits it.
76 */
77 /* ++roman: A little bit more care is required here: The CINVP instruction
78 * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning
79 * and the end of the region must be treated differently if they are not
80 * exactly at the beginning or end of a page boundary. Else, maybe too much
81 * data becomes invalidated and thus lost forever. CPUSHP does what we need:
82 * it invalidates the page after pushing dirty data to memory. (Thanks to Jes
83 * for discovering the problem!)
84 */
85 /* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set
86 * the DPI bit in the CACR; would it cause problems with temporarily changing
87 * this?). So we have to push first and then additionally to invalidate.
88 */
89
90
91 /*
92 * cache_clear() semantics: Clear any cache entries for the area in question,
93 * without writing back dirty entries first. This is useful if the data will
94 * be overwritten anyway, e.g. by DMA to memory. The range is defined by a
95 * _physical_ address.
96 */
97
cache_clear(unsigned long paddr,int len)98 void cache_clear (unsigned long paddr, int len)
99 {
100 if (CPU_IS_COLDFIRE) {
101 clear_cf_bcache(0, DCACHE_MAX_ADDR);
102 } else if (CPU_IS_040_OR_060) {
103 int tmp;
104
105 /*
106 * We need special treatment for the first page, in case it
107 * is not page-aligned. Page align the addresses to work
108 * around bug I17 in the 68060.
109 */
110 if ((tmp = -paddr & (PAGE_SIZE - 1))) {
111 pushcl040(paddr & PAGE_MASK);
112 if ((len -= tmp) <= 0)
113 return;
114 paddr += tmp;
115 }
116 tmp = PAGE_SIZE;
117 paddr &= PAGE_MASK;
118 while ((len -= tmp) >= 0) {
119 clear040(paddr);
120 paddr += tmp;
121 }
122 if ((len += tmp))
123 /* a page boundary gets crossed at the end */
124 pushcl040(paddr);
125 }
126 else /* 68030 or 68020 */
127 asm volatile ("movec %/cacr,%/d0\n\t"
128 "oriw %0,%/d0\n\t"
129 "movec %/d0,%/cacr"
130 : : "i" (FLUSH_I_AND_D)
131 : "d0");
132 #ifdef CONFIG_M68K_L2_CACHE
133 if(mach_l2_flush)
134 mach_l2_flush(0);
135 #endif
136 }
137 EXPORT_SYMBOL(cache_clear);
138
139
140 /*
141 * cache_push() semantics: Write back any dirty cache data in the given area,
142 * and invalidate the range in the instruction cache. It needs not (but may)
143 * invalidate those entries also in the data cache. The range is defined by a
144 * _physical_ address.
145 */
146
cache_push(unsigned long paddr,int len)147 void cache_push (unsigned long paddr, int len)
148 {
149 if (CPU_IS_COLDFIRE) {
150 flush_cf_bcache(0, DCACHE_MAX_ADDR);
151 } else if (CPU_IS_040_OR_060) {
152 int tmp = PAGE_SIZE;
153
154 /*
155 * on 68040 or 68060, push cache lines for pages in the range;
156 * on the '040 this also invalidates the pushed lines, but not on
157 * the '060!
158 */
159 len += paddr & (PAGE_SIZE - 1);
160
161 /*
162 * Work around bug I17 in the 68060 affecting some instruction
163 * lines not being invalidated properly.
164 */
165 paddr &= PAGE_MASK;
166
167 do {
168 push040(paddr);
169 paddr += tmp;
170 } while ((len -= tmp) > 0);
171 }
172 /*
173 * 68030/68020 have no writeback cache. On the other hand,
174 * cache_push is actually a superset of cache_clear (the lines
175 * get written back and invalidated), so we should make sure
176 * to perform the corresponding actions. After all, this is getting
177 * called in places where we've just loaded code, or whatever, so
178 * flushing the icache is appropriate; flushing the dcache shouldn't
179 * be required.
180 */
181 else /* 68030 or 68020 */
182 asm volatile ("movec %/cacr,%/d0\n\t"
183 "oriw %0,%/d0\n\t"
184 "movec %/d0,%/cacr"
185 : : "i" (FLUSH_I)
186 : "d0");
187 #ifdef CONFIG_M68K_L2_CACHE
188 if(mach_l2_flush)
189 mach_l2_flush(1);
190 #endif
191 }
192 EXPORT_SYMBOL(cache_push);
193
194
