aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/mm/sc-mips.c
blob: df96da7e939b540f9b1b9c73dae3f73162845d8e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/*
 * Copyright (C) 2006 Chris Dearman (chris@mips.com),
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>

#include <asm/mipsregs.h>
#include <asm/bcache.h>
#include <asm/cacheops.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
#include <asm/r4kcache.h>

/*
 * MIPS32/MIPS64 L2 cache handling
 */

/*
 * Writeback and invalidate the secondary cache before DMA.
 */
static void mips_sc_wback_inv(unsigned long addr, unsigned long size)
{
	blast_scache_range(addr, addr + size);
}

/*
 * Invalidate the secondary cache before DMA.
 */
static void mips_sc_inv(unsigned long addr, unsigned long size)
{
	unsigned long lsize = cpu_scache_line_size();
	unsigned long almask = ~(lsize - 1);

	cache_op(Hit_Writeback_Inv_SD, addr & almask);
	cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask);
	blast_inv_scache_range(addr, addr + size);
}

static void mips_sc_enable(void)
{
	/* L2 cache is permanently enabled */
}

static void mips_sc_disable(void)
{
	/* L2 cache is permanently enabled */
}

static struct bcache_ops mips_sc_ops = {
	.bc_enable = mips_sc_enable,
	.bc_disable = mips_sc_disable,
	.bc_wback_inv = mips_sc_wback_inv,
	.bc_inv = mips_sc_inv
};

/*
 * Check if the L2 cache controller is activated on a particular platform.
 * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS
 * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the
 * cache being disabled.  However there is no guarantee for this to be
 * true on all platforms.  In an act of stupidity the spec defined bits
 * 12..15 as implementation defined so below function will eventually have
 * to be replaced by a platform specific probe.
 */
static inline int mips_sc_is_activated(struct cpuinfo_mips *c)
{
	unsigned int config2 = read_c0_config2();
	unsigned int tmp;

	/* Check the bypass bit (L2B) */
	switch (c->cputype) {
	case CPU_34K:
	case CPU_74K:
	case CPU_1004K:
	case CPU_BMIPS5000:
		if (config2 & (1 << 12))
			return 0;
	}

	tmp = (config2 >> 4) & 0x0f;
	if (0 < tmp && tmp <= 7)
		c->scache.linesz = 2 << tmp;
	else
		return 0;
	return 1;
}

static inline int __init mips_sc_probe(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;
	unsigned int config1, config2;
	unsigned int tmp;

	/* Mark as not present until probe completed */
	c->scache.flags |= MIPS_CACHE_NOT_PRESENT;

	/* Ignore anything but MIPSxx processors */
	if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 |
			      MIPS_CPU_ISA_M64R1 | MIPS_CPU_ISA_M64R2)))
		return 0;

	/* Does this MIPS32/MIPS64 CPU have a config2 register? */
	config1 = read_c0_config1();
	if (!(config1 & MIPS_CONF_M))
		return 0;

	config2 = read_c0_config2();

	if (!mips_sc_is_activated(c))
		return 0;

	tmp = (config2 >> 8) & 0x0f;
	if (0 <= tmp && tmp <= 7)
		c->scache.sets = 64 << tmp;
	else
		return 0;

	tmp = (config2 >> 0) & 0x0f;
	if (0 <= tmp && tmp <= 7)
		c->scache.ways = tmp + 1;
	else
		return 0;

	c->scache.waysize = c->scache.sets * c->scache.linesz;
	c->scache.waybit = __ffs(c->scache.waysize);

	c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;

	return 1;
}

int __cpuinit mips_sc_init(void)
{
	int found = mips_sc_probe();
	if (found) {
		mips_sc_enable();
		bcops = &mips_sc_ops;
	}
	return found;
}