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9318c51a CD |
1 | /* |
2 | * Copyright (C) 2006 Chris Dearman (chris@mips.com), | |
3 | */ | |
4 | #include <linux/init.h> | |
5 | #include <linux/kernel.h> | |
6 | #include <linux/sched.h> | |
7 | #include <linux/mm.h> | |
8 | ||
9 | #include <asm/mipsregs.h> | |
10 | #include <asm/bcache.h> | |
11 | #include <asm/cacheops.h> | |
12 | #include <asm/page.h> | |
13 | #include <asm/pgtable.h> | |
9318c51a CD |
14 | #include <asm/mmu_context.h> |
15 | #include <asm/r4kcache.h> | |
16 | ||
17 | /* | |
18 | * MIPS32/MIPS64 L2 cache handling | |
19 | */ | |
20 | ||
21 | /* | |
22 | * Writeback and invalidate the secondary cache before DMA. | |
23 | */ | |
24 | static void mips_sc_wback_inv(unsigned long addr, unsigned long size) | |
25 | { | |
a2c2bc4b | 26 | blast_scache_range(addr, addr + size); |
9318c51a CD |
27 | } |
28 | ||
29 | /* | |
30 | * Invalidate the secondary cache before DMA. | |
31 | */ | |
32 | static void mips_sc_inv(unsigned long addr, unsigned long size) | |
33 | { | |
96983ffe KC |
34 | unsigned long lsize = cpu_scache_line_size(); |
35 | unsigned long almask = ~(lsize - 1); | |
36 | ||
37 | cache_op(Hit_Writeback_Inv_SD, addr & almask); | |
38 | cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask); | |
a2c2bc4b | 39 | blast_inv_scache_range(addr, addr + size); |
9318c51a CD |
40 | } |
41 | ||
42 | static void mips_sc_enable(void) | |
43 | { | |
44 | /* L2 cache is permanently enabled */ | |
45 | } | |
46 | ||
47 | static void mips_sc_disable(void) | |
48 | { | |
49 | /* L2 cache is permanently enabled */ | |
50 | } | |
51 | ||
52 | static struct bcache_ops mips_sc_ops = { | |
53 | .bc_enable = mips_sc_enable, | |
54 | .bc_disable = mips_sc_disable, | |
55 | .bc_wback_inv = mips_sc_wback_inv, | |
56 | .bc_inv = mips_sc_inv | |
57 | }; | |
58 | ||
ea31a6b2 KC |
59 | /* |
60 | * Check if the L2 cache controller is activated on a particular platform. | |
61 | * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS | |
62 | * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the | |
63 | * cache being disabled. However there is no guarantee for this to be | |
64 | * true on all platforms. In an act of stupidity the spec defined bits | |
65 | * 12..15 as implementation defined so below function will eventually have | |
66 | * to be replaced by a platform specific probe. | |
67 | */ | |
68 | static inline int mips_sc_is_activated(struct cpuinfo_mips *c) | |
69 | { | |
081d835f KC |
70 | unsigned int config2 = read_c0_config2(); |
71 | unsigned int tmp; | |
72 | ||
ea31a6b2 KC |
73 | /* Check the bypass bit (L2B) */ |
74 | switch (c->cputype) { | |
75 | case CPU_34K: | |
76 | case CPU_74K: | |
77 | case CPU_1004K: | |
78 | case CPU_BMIPS5000: | |
79 | if (config2 & (1 << 12)) | |
80 | return 0; | |
81 | } | |
82 | ||
83 | tmp = (config2 >> 4) & 0x0f; | |
84 | if (0 < tmp && tmp <= 7) | |
85 | c->scache.linesz = 2 << tmp; | |
86 | else | |
87 | return 0; | |
081d835f | 88 | return 1; |
ea31a6b2 KC |
89 | } |
90 | ||
9318c51a CD |
91 | static inline int __init mips_sc_probe(void) |
92 | { | |
93 | struct cpuinfo_mips *c = ¤t_cpu_data; | |
94 | unsigned int config1, config2; | |
95 | unsigned int tmp; | |
96 | ||
97 | /* Mark as not present until probe completed */ | |
98 | c->scache.flags |= MIPS_CACHE_NOT_PRESENT; | |
99 | ||
100 | /* Ignore anything but MIPSxx processors */ | |
101 | if (c->isa_level != MIPS_CPU_ISA_M32R1 && | |
102 | c->isa_level != MIPS_CPU_ISA_M32R2 && | |
103 | c->isa_level != MIPS_CPU_ISA_M64R1 && | |
104 | c->isa_level != MIPS_CPU_ISA_M64R2) | |
105 | return 0; | |
106 | ||
107 | /* Does this MIPS32/MIPS64 CPU have a config2 register? */ | |
108 | config1 = read_c0_config1(); | |
109 | if (!(config1 & MIPS_CONF_M)) | |
110 | return 0; | |
111 | ||
112 | config2 = read_c0_config2(); | |
ea31a6b2 KC |
113 | |
114 | if (!mips_sc_is_activated(c)) | |
9318c51a CD |
115 | return 0; |
116 | ||
117 | tmp = (config2 >> 8) & 0x0f; | |
118 | if (0 <= tmp && tmp <= 7) | |
119 | c->scache.sets = 64 << tmp; | |
120 | else | |
121 | return 0; | |
122 | ||
123 | tmp = (config2 >> 0) & 0x0f; | |
124 | if (0 <= tmp && tmp <= 7) | |
125 | c->scache.ways = tmp + 1; | |
126 | else | |
127 | return 0; | |
128 | ||
129 | c->scache.waysize = c->scache.sets * c->scache.linesz; | |
a2c2bc4b | 130 | c->scache.waybit = __ffs(c->scache.waysize); |
9318c51a CD |
131 | |
132 | c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; | |
133 | ||
134 | return 1; | |
135 | } | |
136 | ||
234fcd14 | 137 | int __cpuinit mips_sc_init(void) |
9318c51a | 138 | { |
49a89efb | 139 | int found = mips_sc_probe(); |
9318c51a CD |
140 | if (found) { |
141 | mips_sc_enable(); | |
142 | bcops = &mips_sc_ops; | |
143 | } | |
144 | return found; | |
145 | } |