arch/arm/mm/cache-tauros2.c

   1 /*
   2  * arch/arm/mm/cache-tauros2.c - Tauros2 L2 cache controller support
   3  *
   4  * Copyright (C) 2008 Marvell Semiconductor
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2.  This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  *
  10  * References:
  11  * - PJ1 CPU Core Datasheet,
  12  *   Document ID MV-S104837-01, Rev 0.7, January 24 2008.
  13  * - PJ4 CPU Core Datasheet,
  14  *   Document ID MV-S105190-00, Rev 0.7, March 14 2008.
  15  */
  16
  17 #include <linux/init.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <asm/cacheflush.h>
  21 #include <asm/cp15.h>
  22 #include <asm/cputype.h>
  23 #include <asm/hardware/cache-tauros2.h>
  24
  25 /* CP15 PJ4 Control configuration register */
  26 #define CCR_L2C_PREFETCH_DISABLE        BIT(24)
  27 #define CCR_L2C_ECC_ENABLE              BIT(23)
  28 #define CCR_L2C_WAY7_4_DISABLE          BIT(21)
  29 #define CCR_L2C_BURST8_ENABLE           BIT(20)
  30
  31 /*
  32  * When Tauros2 is used on a CPU that supports the v7 hierarchical
  33  * cache operations, the cache handling code in proc-v7.S takes care
  34  * of everything, including handling DMA coherency.
  35  *
  36  * So, we only need to register outer cache operations here if we're
  37  * being used on a pre-v7 CPU, and we only need to build support for
  38  * outer cache operations into the kernel image if the kernel has been
  39  * configured to support a pre-v7 CPU.
  40  */
  41 #ifdef CONFIG_CPU_32v5
  42 /*
  43  * Low-level cache maintenance operations.
  44  */
  45 static inline void tauros2_clean_pa(unsigned long addr)
  46 {
  47         __asm__("mcr p15, 1, %0, c7, c11, 3" : : "r" (addr));
  48 }
  49
  50 static inline void tauros2_clean_inv_pa(unsigned long addr)
  51 {
  52         __asm__("mcr p15, 1, %0, c7, c15, 3" : : "r" (addr));
  53 }
  54
  55 static inline void tauros2_inv_pa(unsigned long addr)
  56 {
  57         __asm__("mcr p15, 1, %0, c7, c7, 3" : : "r" (addr));
  58 }
  59
  60
  61 /*
  62  * Linux primitives.
  63  *
  64  * Note that the end addresses passed to Linux primitives are
  65  * noninclusive.
  66  */
  67 #define CACHE_LINE_SIZE         32
  68
  69 static void tauros2_inv_range(unsigned long start, unsigned long end)
  70 {
  71         /*
  72          * Clean and invalidate partial first cache line.
  73          */
  74         if (start & (CACHE_LINE_SIZE - 1)) {
  75                 tauros2_clean_inv_pa(start & ~(CACHE_LINE_SIZE - 1));
  76                 start = (start | (CACHE_LINE_SIZE - 1)) + 1;
  77         }
  78
  79         /*
  80          * Clean and invalidate partial last cache line.
  81          */
  82         if (end & (CACHE_LINE_SIZE - 1)) {
  83                 tauros2_clean_inv_pa(end & ~(CACHE_LINE_SIZE - 1));
  84                 end &= ~(CACHE_LINE_SIZE - 1);
  85         }
  86
  87         /*
  88          * Invalidate all full cache lines between 'start' and 'end'.
  89          */
  90         while (start < end) {
  91                 tauros2_inv_pa(start);
  92                 start += CACHE_LINE_SIZE;
  93         }
  94
  95         dsb();
  96 }
  97
  98 static void tauros2_clean_range(unsigned long start, unsigned long end)
  99 {
 100         start &= ~(CACHE_LINE_SIZE - 1);
 101         while (start < end) {
 102                 tauros2_clean_pa(start);
 103                 start += CACHE_LINE_SIZE;
 104         }
 105
 106         dsb();
 107 }
 108
 109 static void tauros2_flush_range(unsigned long start, unsigned long end)
 110 {
 111         start &= ~(CACHE_LINE_SIZE - 1);
 112         while (start < end) {
 113                 tauros2_clean_inv_pa(start);
 114                 start += CACHE_LINE_SIZE;
 115         }
 116
 117         dsb();
 118 }
 119
 120 static void tauros2_disable(void)
 121 {
 122         __asm__ __volatile__ (
 123         "mcr    p15, 1, %0, c7, c11, 0 @L2 Cache Clean All\n\t"
 124         "mrc    p15, 0, %0, c1, c0, 0\n\t"
 125         "bic    %0, %0, #(1 << 26)\n\t"
 126         "mcr    p15, 0, %0, c1, c0, 0  @Disable L2 Cache\n\t"
 127         : : "r" (0x0));
 128 }
 129
 130 static void tauros2_resume(void)
 131 {
 132         __asm__ __volatile__ (
 133         "mcr    p15, 1, %0, c7, c7, 0 @L2 Cache Invalidate All\n\t"
 134         "mrc    p15, 0, %0, c1, c0, 0\n\t"
 135         "orr    %0, %0, #(1 << 26)\n\t"
 136         "mcr    p15, 0, %0, c1, c0, 0 @Enable L2 Cache\n\t"
 137         : : "r" (0x0));
 138 }
 139 #endif
 140
 141 static inline u32 __init read_extra_features(void)
 142 {
 143         u32 u;
 144
 145         __asm__("mrc p15, 1, %0, c15, c1, 0" : "=r" (u));
 146
 147         return u;
 148 }
 149
 150 static inline void __init write_extra_features(u32 u)
 151 {
 152         __asm__("mcr p15, 1, %0, c15, c1, 0" : : "r" (u));
 153 }
 154
 155 static inline int __init cpuid_scheme(void)
 156 {
 157         return !!((processor_id & 0x000f0000) == 0x000f0000);
 158 }
 159
 160 static inline u32 __init read_mmfr3(void)
 161 {
 162         u32 mmfr3;
 163
 164         __asm__("mrc p15, 0, %0, c0, c1, 7\n" : "=r" (mmfr3));
 165
 166         return mmfr3;
 167 }
 168
 169 static inline u32 __init read_actlr(void)
 170 {
 171         u32 actlr;
 172
 173         __asm__("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
 174
 175         return actlr;
 176 }
 177
 178 static inline void __init write_actlr(u32 actlr)
 179 {
 180         __asm__("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr));
 181 }
 182
 183 static void enable_extra_feature(unsigned int features)
 184 {
 185         u32 u;
 186
 187         u = read_extra_features();
 188
 189         if (features & CACHE_TAUROS2_PREFETCH_ON)
 190                 u &= ~CCR_L2C_PREFETCH_DISABLE;
 191         else
 192                 u |= CCR_L2C_PREFETCH_DISABLE;
 193         pr_info("Tauros2: %s L2 prefetch.\n",
 194                         (features & CACHE_TAUROS2_PREFETCH_ON)
 195                         ? "Enabling" : "Disabling");
 196
 197         if (features & CACHE_TAUROS2_LINEFILL_BURST8)
 198                 u |= CCR_L2C_BURST8_ENABLE;
 199         else
 200                 u &= ~CCR_L2C_BURST8_ENABLE;
 201         pr_info("Tauros2: %s burst8 line fill.\n",
 202                         (features & CACHE_TAUROS2_LINEFILL_BURST8)
 203                         ? "Enabling" : "Disabling");
 204
 205         write_extra_features(u);
 206 }
 207
 208 static void __init tauros2_internal_init(unsigned int features)
 209 {
 210         char *mode = NULL;
 211
 212         enable_extra_feature(features);
 213
 214 #ifdef CONFIG_CPU_32v5
 215         if ((processor_id & 0xff0f0000) == 0x56050000) {
 216                 u32 feat;
 217
 218                 /*
 219                  * v5 CPUs with Tauros2 have the L2 cache enable bit
 220                  * located in the CPU Extra Features register.
 221                  */
 222                 feat = read_extra_features();
 223                 if (!(feat & 0x00400000)) {
 224                         pr_info("Tauros2: Enabling L2 cache.\n");
 225                         write_extra_features(feat | 0x00400000);
 226                 }
 227
 228                 mode = "ARMv5";
 229                 outer_cache.inv_range = tauros2_inv_range;
 230                 outer_cache.clean_range = tauros2_clean_range;
 231                 outer_cache.flush_range = tauros2_flush_range;
 232                 outer_cache.disable = tauros2_disable;
 233                 outer_cache.resume = tauros2_resume;
 234         }
 235 #endif
 236
 237 #ifdef CONFIG_CPU_32v7
 238         /*
 239          * Check whether this CPU has support for the v7 hierarchical
 240          * cache ops.  (PJ4 is in its v7 personality mode if the MMFR3
 241          * register indicates support for the v7 hierarchical cache
 242          * ops.)
 243          *
 244          * (Although strictly speaking there may exist CPUs that
 245          * implement the v7 cache ops but are only ARMv6 CPUs (due to
 246          * not complying with all of the other ARMv7 requirements),
 247          * there are no real-life examples of Tauros2 being used on
 248          * such CPUs as of yet.)
 249          */
 250         if (cpuid_scheme() && (read_mmfr3() & 0xf) == 1) {
 251                 u32 actlr;
 252
 253                 /*
 254                  * When Tauros2 is used in an ARMv7 system, the L2
 255                  * enable bit is located in the Auxiliary System Control
 256                  * Register (which is the only register allowed by the
 257                  * ARMv7 spec to contain fine-grained cache control bits).
 258                  */
 259                 actlr = read_actlr();
 260                 if (!(actlr & 0x00000002)) {
 261                         pr_info("Tauros2: Enabling L2 cache.\n");
 262                         write_actlr(actlr | 0x00000002);
 263                 }
 264
 265                 mode = "ARMv7";
 266         }
 267 #endif
 268
 269         if (mode == NULL) {
 270                 pr_crit("Tauros2: Unable to detect CPU mode.\n");
 271                 return;
 272         }
 273
 274         pr_info("Tauros2: L2 cache support initialised "
 275                          "in %s mode.\n", mode);
 276 }
 277
 278 #ifdef CONFIG_OF
 279 static const struct of_device_id tauros2_ids[] __initconst = {
 280         { .compatible = "marvell,tauros2-cache"},
 281         {}
 282 };
 283 #endif
 284
 285 void __init tauros2_init(unsigned int features)
 286 {
 287 #ifdef CONFIG_OF
 288         struct device_node *node;
 289         int ret;
 290         unsigned int f;
 291
 292         node = of_find_matching_node(NULL, tauros2_ids);
 293         if (!node) {
 294                 pr_info("Not found marvell,tauros2-cache, disable it\n");
 295         } else {
 296                 ret = of_property_read_u32(node, "marvell,tauros2-cache-features", &f);
 297                 if (ret) {
 298                         pr_info("Not found marvell,tauros-cache-features property, "
 299                                 "disable extra features\n");
 300                         features = 0;
 301                 } else
 302                         features = f;
 303         }
 304 #endif
 305         tauros2_internal_init(features);
 306 }