Commit | Line | Data |
---|---|---|
99ef7c2a JH |
1 | #include <linux/init.h> |
2 | #include <linux/kernel.h> | |
3 | #include <linux/delay.h> | |
4 | ||
5 | #include <asm/l2cache.h> | |
6 | #include <asm/metag_isa.h> | |
7 | ||
8 | /* If non-0, then initialise the L2 cache */ | |
9 | static int l2cache_init = 1; | |
10 | /* If non-0, then initialise the L2 cache prefetch */ | |
11 | static int l2cache_init_pf = 1; | |
12 | ||
13 | int l2c_pfenable; | |
14 | ||
15 | static volatile u32 l2c_testdata[16] __initdata __aligned(64); | |
16 | ||
17 | static int __init parse_l2cache(char *p) | |
18 | { | |
19 | char *cp = p; | |
20 | ||
21 | if (get_option(&cp, &l2cache_init) != 1) { | |
22 | pr_err("Bad l2cache parameter (%s)\n", p); | |
23 | return 1; | |
24 | } | |
25 | return 0; | |
26 | } | |
27 | early_param("l2cache", parse_l2cache); | |
28 | ||
29 | static int __init parse_l2cache_pf(char *p) | |
30 | { | |
31 | char *cp = p; | |
32 | ||
33 | if (get_option(&cp, &l2cache_init_pf) != 1) { | |
34 | pr_err("Bad l2cache_pf parameter (%s)\n", p); | |
35 | return 1; | |
36 | } | |
37 | return 0; | |
38 | } | |
39 | early_param("l2cache_pf", parse_l2cache_pf); | |
40 | ||
41 | static int __init meta_l2c_setup(void) | |
42 | { | |
43 | /* | |
44 | * If the L2 cache isn't even present, don't do anything, but say so in | |
45 | * the log. | |
46 | */ | |
47 | if (!meta_l2c_is_present()) { | |
48 | pr_info("L2 Cache: Not present\n"); | |
49 | return 0; | |
50 | } | |
51 | ||
52 | /* | |
53 | * Check whether the line size is recognised. | |
54 | */ | |
55 | if (!meta_l2c_linesize()) { | |
56 | pr_warn_once("L2 Cache: unknown line size id (config=0x%08x)\n", | |
57 | meta_l2c_config()); | |
58 | } | |
59 | ||
60 | /* | |
61 | * Initialise state. | |
62 | */ | |
63 | l2c_pfenable = _meta_l2c_pf_is_enabled(); | |
64 | ||
65 | /* | |
66 | * Enable the L2 cache and print to log whether it was already enabled | |
67 | * by the bootloader. | |
68 | */ | |
69 | if (l2cache_init) { | |
70 | pr_info("L2 Cache: Enabling... "); | |
71 | if (meta_l2c_enable()) | |
72 | pr_cont("already enabled\n"); | |
73 | else | |
74 | pr_cont("done\n"); | |
75 | } else { | |
76 | pr_info("L2 Cache: Not enabling\n"); | |
77 | } | |
78 | ||
79 | /* | |
80 | * Enable L2 cache prefetch. | |
81 | */ | |
82 | if (l2cache_init_pf) { | |
83 | pr_info("L2 Cache: Enabling prefetch... "); | |
84 | if (meta_l2c_pf_enable(1)) | |
85 | pr_cont("already enabled\n"); | |
86 | else | |
87 | pr_cont("done\n"); | |
88 | } else { | |
89 | pr_info("L2 Cache: Not enabling prefetch\n"); | |
90 | } | |
91 | ||
92 | return 0; | |
93 | } | |
94 | core_initcall(meta_l2c_setup); | |
95 | ||
96 | int meta_l2c_disable(void) | |
97 | { | |
98 | unsigned long flags; | |
99 | int en; | |
100 | ||
101 | if (!meta_l2c_is_present()) | |
102 | return 1; | |
103 | ||
104 | /* | |
105 | * Prevent other threads writing during the writeback, otherwise the | |
106 | * writes will get "lost" when the L2 is disabled. | |
107 | */ | |
108 | __global_lock2(flags); | |
109 | en = meta_l2c_is_enabled(); | |
110 | if (likely(en)) { | |
111 | _meta_l2c_pf_enable(0); | |
112 | wr_fence(); | |
113 | _meta_l2c_purge(); | |
114 | _meta_l2c_enable(0); | |
115 | } | |
116 | __global_unlock2(flags); | |
117 | ||
118 | return !en; | |
119 | } | |
120 | ||
121 | int meta_l2c_enable(void) | |
122 | { | |
123 | unsigned long flags; | |
124 | int en; | |
125 | ||
126 | if (!meta_l2c_is_present()) | |
127 | return 0; | |
128 | ||
129 | /* | |
130 | * Init (clearing the L2) can happen while the L2 is disabled, so other | |
131 | * threads are safe to continue executing, however we must not init the | |
132 | * cache if it's already enabled (dirty lines would be discarded), so | |
133 | * this operation should still be atomic with other threads. | |
134 | */ | |
135 | __global_lock1(flags); | |
136 | en = meta_l2c_is_enabled(); | |
137 | if (likely(!en)) { | |
138 | _meta_l2c_init(); | |
139 | _meta_l2c_enable(1); | |
140 | _meta_l2c_pf_enable(l2c_pfenable); | |
141 | } | |
142 | __global_unlock1(flags); | |
143 | ||
144 | return en; | |
145 | } | |
146 | ||
147 | int meta_l2c_pf_enable(int pfenable) | |
148 | { | |
149 | unsigned long flags; | |
150 | int en = l2c_pfenable; | |
151 | ||
152 | if (!meta_l2c_is_present()) | |
153 | return 0; | |
154 | ||
155 | /* | |
156 | * We read modify write the enable register, so this operation must be | |
157 | * atomic with other threads. | |
158 | */ | |
159 | __global_lock1(flags); | |
160 | en = l2c_pfenable; | |
161 | l2c_pfenable = pfenable; | |
162 | if (meta_l2c_is_enabled()) | |
163 | _meta_l2c_pf_enable(pfenable); | |
164 | __global_unlock1(flags); | |
165 | ||
166 | return en; | |
167 | } | |
168 | ||
169 | int meta_l2c_flush(void) | |
170 | { | |
171 | unsigned long flags; | |
172 | int en; | |
173 | ||
174 | /* | |
175 | * Prevent other threads writing during the writeback. This also | |
176 | * involves read modify writes. | |
177 | */ | |
178 | __global_lock2(flags); | |
179 | en = meta_l2c_is_enabled(); | |
180 | if (likely(en)) { | |
181 | _meta_l2c_pf_enable(0); | |
182 | wr_fence(); | |
183 | _meta_l2c_purge(); | |
184 | _meta_l2c_enable(0); | |
185 | _meta_l2c_init(); | |
186 | _meta_l2c_enable(1); | |
187 | _meta_l2c_pf_enable(l2c_pfenable); | |
188 | } | |
189 | __global_unlock2(flags); | |
190 | ||
191 | return !en; | |
192 | } |