projects / deliverable / linux.git / blame
| 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 | } |