1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
4 * derived from r4xx0.c by David S. Miller (davem@davemloft.net).
5 */
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/mm.h>
10
11 #include <asm/mipsregs.h>
12 #include <asm/bcache.h>
13 #include <asm/cacheops.h>
14 #include <asm/page.h>
15 #include <asm/mmu_context.h>
16 #include <asm/r4kcache.h>
17
18 /* Secondary cache size in bytes, if present. */
19 static unsigned long scache_size;
20
21 #define SC_LINE 32
22 #define SC_PAGE (128*SC_LINE)
23
24 static inline void blast_r5000_scache(void)
25 {
26 unsigned long start = INDEX_BASE;
27 unsigned long end = start + scache_size;
28
29 while(start < end) {
30 cache_op(R5K_Page_Invalidate_S, start);
31 start += SC_PAGE;
32 }
33 }
34
35 static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size)
36 {
37 unsigned long end, a;
38
39 /* Catch bad driver code */
40 BUG_ON(size == 0);
41
42 if (size >= scache_size) {
43 blast_r5000_scache();
44 return;
45 }
46
47 /* On the R5000 secondary cache we cannot
48 * invalidate less than a page at a time.
49 * The secondary cache is physically indexed, write-through.
50 */
51 a = addr & ~(SC_PAGE - 1);
52 end = (addr + size - 1) & ~(SC_PAGE - 1);
53 while (a <= end) {
54 cache_op(R5K_Page_Invalidate_S, a);
55 a += SC_PAGE;
56 }
57 }
58
59 static void r5k_sc_enable(void)
60 {
61 unsigned long flags;
62
63 local_irq_save(flags);
64 set_c0_config(R5K_CONF_SE);
65 blast_r5000_scache();
66 local_irq_restore(flags);
67 }
68
69 static void r5k_sc_disable(void)
70 {
71 unsigned long flags;
72
73 local_irq_save(flags);
74 blast_r5000_scache();
75 clear_c0_config(R5K_CONF_SE);
76 local_irq_restore(flags);
77 }
78
79 static inline int __init r5k_sc_probe(void)
80 {
81 unsigned long config = read_c0_config();
82
83 if (config & CONF_SC)
84 return 0;
85
86 scache_size = (512 * 1024) << ((config & R5K_CONF_SS) >> 20);
87
88 printk("R5000 SCACHE size %ldkB, linesize 32 bytes.\n",
89 scache_size >> 10);
90
91 return 1;
92 }
93
94 static struct bcache_ops r5k_sc_ops = {
95 .bc_enable = r5k_sc_enable,
96 .bc_disable = r5k_sc_disable,
97 .bc_wback_inv = r5k_dma_cache_inv_sc,
98 .bc_inv = r5k_dma_cache_inv_sc
99 };
100
101 void r5k_sc_init(void)
102 {
103 if (r5k_sc_probe()) {
104 r5k_sc_enable();
105 bcops = &r5k_sc_ops;
106 }
107 }
108
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