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.  */
19static unsigned long scache_size;
20
21#define SC_LINE 32
22#define SC_PAGE (128*SC_LINE)
23
24static 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
35static 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
59static 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
69static 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
79static 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
94static 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
101void r5k_sc_init(void)
102{
103	if (r5k_sc_probe()) {
104		r5k_sc_enable();
105		bcops = &r5k_sc_ops;
106	}
107}
108