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
  26 /*
  27  * When Tauros2 is used on a CPU that supports the v7 hierarchical
  28  * cache operations, the cache handling code in proc-v7.S takes care
  29  * of everything, including handling DMA coherency.
  30  *
  31  * So, we only need to register outer cache operations here if we're
  32  * being used on a pre-v7 CPU, and we only need to build support for
  33  * outer cache operations into the kernel image if the kernel has been
  34  * configured to support a pre-v7 CPU.
  35  */
  36 #if __LINUX_ARM_ARCH__ < 7
  37 /*
  38  * Low-level cache maintenance operations.
  39  */
  40 static inline void tauros2_clean_pa(unsigned long addr)
  41 {
  42         __asm__("mcr p15, 1, %0, c7, c11, 3" : : "r" (addr));
  43 }
  44
  45 static inline void tauros2_clean_inv_pa(unsigned long addr)
  46 {
  47         __asm__("mcr p15, 1, %0, c7, c15, 3" : : "r" (addr));
  48 }
  49
  50 static inline void tauros2_inv_pa(unsigned long addr)
  51 {
  52         __asm__("mcr p15, 1, %0, c7, c7, 3" : : "r" (addr));
  53 }
  54
  55
  56 /*
  57  * Linux primitives.
  58  *
  59  * Note that the end addresses passed to Linux primitives are
  60  * noninclusive.
  61  */
  62 #define CACHE_LINE_SIZE         32
  63
  64 static void tauros2_inv_range(unsigned long start, unsigned long end)
  65 {
  66         /*
  67          * Clean and invalidate partial first cache line.
  68          */
  69         if (start & (CACHE_LINE_SIZE - 1)) {
  70                 tauros2_clean_inv_pa(start & ~(CACHE_LINE_SIZE - 1));
  71                 start = (start | (CACHE_LINE_SIZE - 1)) + 1;
  72         }
  73
  74         /*
  75          * Clean and invalidate partial last cache line.
  76          */
  77         if (end & (CACHE_LINE_SIZE - 1)) {
  78                 tauros2_clean_inv_pa(end & ~(CACHE_LINE_SIZE - 1));
  79                 end &= ~(CACHE_LINE_SIZE - 1);
  80         }
  81
  82         /*
  83          * Invalidate all full cache lines between 'start' and 'end'.
  84          */
  85         while (start < end) {
  86                 tauros2_inv_pa(start);
  87                 start += CACHE_LINE_SIZE;
  88         }
  89
  90         dsb();
  91 }
  92
  93 static void tauros2_clean_range(unsigned long start, unsigned long end)
  94 {
  95         start &= ~(CACHE_LINE_SIZE - 1);
  96         while (start < end) {
  97                 tauros2_clean_pa(start);
  98                 start += CACHE_LINE_SIZE;
  99         }
 100
 101         dsb();
 102 }
 103
 104 static void tauros2_flush_range(unsigned long start, unsigned long end)
 105 {
 106         start &= ~(CACHE_LINE_SIZE - 1);
 107         while (start < end) {
 108                 tauros2_clean_inv_pa(start);
 109                 start += CACHE_LINE_SIZE;
 110         }
 111
 112         dsb();
 113 }
 114
 115 static void tauros2_disable(void)
 116 {
 117         __asm__ __volatile__ (
 118         "mcr    p15, 1, %0, c7, c11, 0 @L2 Cache Clean All\n\t"
 119         "mrc    p15, 0, %0, c1, c0, 0\n\t"
 120         "bic    %0, %0, #(1 << 26)\n\t"
 121         "mcr    p15, 0, %0, c1, c0, 0  @Disable L2 Cache\n\t"
 122         : : "r" (0x0));
 123 }
 124
 125 static void tauros2_resume(void)
 126 {
 127         __asm__ __volatile__ (
 128         "mcr    p15, 1, %0, c7, c7, 0 @L2 Cache Invalidate All\n\t"
 129         "mrc    p15, 0, %0, c1, c0, 0\n\t"
 130         "orr    %0, %0, #(1 << 26)\n\t"
 131         "mcr    p15, 0, %0, c1, c0, 0 @Enable L2 Cache\n\t"
 132         : : "r" (0x0));
 133 }
 134 #endif
 135
 136 static inline u32 __init read_extra_features(void)
 137 {
 138         u32 u;
 139
 140         __asm__("mrc p15, 1, %0, c15, c1, 0" : "=r" (u));
 141
 142         return u;
 143 }
 144
 145 static inline void __init write_extra_features(u32 u)
 146 {
 147         __asm__("mcr p15, 1, %0, c15, c1, 0" : : "r" (u));
 148 }
 149
 150 static inline int __init cpuid_scheme(void)
 151 {
 152         return !!((processor_id & 0x000f0000) == 0x000f0000);
 153 }
 154
 155 static inline u32 __init read_mmfr3(void)
 156 {
 157         u32 mmfr3;
 158
 159         __asm__("mrc p15, 0, %0, c0, c1, 7\n" : "=r" (mmfr3));
 160
 161         return mmfr3;
 162 }
 163
 164 static inline u32 __init read_actlr(void)
 165 {
 166         u32 actlr;
 167
 168         __asm__("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
 169
 170         return actlr;
 171 }
 172
 173 static inline void __init write_actlr(u32 actlr)
 174 {
 175         __asm__("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr));
 176 }
 177
 178 static void enable_extra_feature(unsigned int features)
 179 {
 180         u32 u;
 181
 182         u = read_extra_features();
 183
 184         if (features & CACHE_TAUROS2_PREFETCH_ON)
 185                 u &= ~0x01000000;
 186         else
 187                 u |= 0x01000000;
 188         printk(KERN_INFO "Tauros2: %s L2 prefetch.\n",
 189                         (features & CACHE_TAUROS2_PREFETCH_ON)
 190                         ? "Enabling" : "Disabling");
 191
 192         if (features & CACHE_TAUROS2_LINEFILL_BURST8)
 193                 u |= 0x00100000;
 194         else
 195                 u &= ~0x00100000;
 196         printk(KERN_INFO "Tauros2: %s line fill burt8.\n",
 197                         (features & CACHE_TAUROS2_LINEFILL_BURST8)
 198                         ? "Enabling" : "Disabling");
 199
 200         write_extra_features(u);
 201 }
 202
 203 static void __init tauros2_internal_init(unsigned int features)
 204 {
 205         char *mode = NULL;
 206
 207         enable_extra_feature(features);
 208
 209 #ifdef CONFIG_CPU_32v5
 210         if ((processor_id & 0xff0f0000) == 0x56050000) {
 211                 u32 feat;
 212
 213                 /*
 214                  * v5 CPUs with Tauros2 have the L2 cache enable bit
 215                  * located in the CPU Extra Features register.
 216                  */
 217                 feat = read_extra_features();
 218                 if (!(feat & 0x00400000)) {
 219                         printk(KERN_INFO "Tauros2: Enabling L2 cache.\n");
 220                         write_extra_features(feat | 0x00400000);
 221                 }
 222
 223                 mode = "ARMv5";
 224                 outer_cache.inv_range = tauros2_inv_range;
 225                 outer_cache.clean_range = tauros2_clean_range;
 226                 outer_cache.flush_range = tauros2_flush_range;
 227                 outer_cache.disable = tauros2_disable;
 228                 outer_cache.resume = tauros2_resume;
 229         }
 230 #endif
 231
 232 #ifdef CONFIG_CPU_32v6
 233         /*
 234          * Check whether this CPU lacks support for the v7 hierarchical
 235          * cache ops.  (PJ4 is in its v6 personality mode if the MMFR3
 236          * register indicates no support for the v7 hierarchical cache
 237          * ops.)
 238          */
 239         if (cpuid_scheme() && (read_mmfr3() & 0xf) == 0) {
 240                 /*
 241                  * When Tauros2 is used in an ARMv6 system, the L2
 242                  * enable bit is in the ARMv6 ARM-mandated position
 243                  * (bit [26] of the System Control Register).
 244                  */
 245                 if (!(get_cr() & 0x04000000)) {
 246                         printk(KERN_INFO "Tauros2: Enabling L2 cache.\n");
 247                         adjust_cr(0x04000000, 0x04000000);
 248                 }
 249
 250                 mode = "ARMv6";
 251                 outer_cache.inv_range = tauros2_inv_range;
 252                 outer_cache.clean_range = tauros2_clean_range;
 253                 outer_cache.flush_range = tauros2_flush_range;
 254                 outer_cache.disable = tauros2_disable;
 255                 outer_cache.resume = tauros2_resume;
 256         }
 257 #endif
 258
 259 #ifdef CONFIG_CPU_32v7
 260         /*
 261          * Check whether this CPU has support for the v7 hierarchical
 262          * cache ops.  (PJ4 is in its v7 personality mode if the MMFR3
 263          * register indicates support for the v7 hierarchical cache
 264          * ops.)
 265          *
 266          * (Although strictly speaking there may exist CPUs that
 267          * implement the v7 cache ops but are only ARMv6 CPUs (due to
 268          * not complying with all of the other ARMv7 requirements),
 269          * there are no real-life examples of Tauros2 being used on
 270          * such CPUs as of yet.)
 271          */
 272         if (cpuid_scheme() && (read_mmfr3() & 0xf) == 1) {
 273                 u32 actlr;
 274
 275                 /*
 276                  * When Tauros2 is used in an ARMv7 system, the L2
 277                  * enable bit is located in the Auxiliary System Control
 278                  * Register (which is the only register allowed by the
 279                  * ARMv7 spec to contain fine-grained cache control bits).
 280                  */
 281                 actlr = read_actlr();
 282                 if (!(actlr & 0x00000002)) {
 283                         printk(KERN_INFO "Tauros2: Enabling L2 cache.\n");
 284                         write_actlr(actlr | 0x00000002);
 285                 }
 286
 287                 mode = "ARMv7";
 288         }
 289 #endif
 290
 291         if (mode == NULL) {
 292                 printk(KERN_CRIT "Tauros2: Unable to detect CPU mode.\n");
 293                 return;
 294         }
 295
 296         printk(KERN_INFO "Tauros2: L2 cache support initialised "
 297                          "in %s mode.\n", mode);
 298 }
 299
 300 #ifdef CONFIG_OF
 301 static const struct of_device_id tauros2_ids[] __initconst = {
 302         { .compatible = "marvell,tauros2-cache"},
 303         {}
 304 };
 305 #endif
 306
 307 void __init tauros2_init(unsigned int features)
 308 {
 309 #ifdef CONFIG_OF
 310         struct device_node *node;
 311         int ret;
 312         unsigned int f;
 313
 314         node = of_find_matching_node(NULL, tauros2_ids);
 315         if (!node) {
 316                 pr_info("Not found marvell,tauros2-cache, disable it\n");
 317                 return;
 318         }
 319
 320         ret = of_property_read_u32(node, "marvell,tauros2-cache-features", &f);
 321         if (ret) {
 322                 pr_info("Not found marvell,tauros-cache-features property, "
 323                         "disable extra features\n");
 324                 features = 0;
 325         } else
 326                 features = f;
 327 #endif
 328         tauros2_internal_init(features);
 329 }