arch/arm/mm/pmsa-v8.c

   1 /*
   2  * Based on linux/arch/arm/pmsa-v7.c
   3  *
   4  * ARM PMSAv8 supporting functions.
   5  */
   6
   7 #include <linux/memblock.h>
   8 #include <linux/range.h>
   9
  10 #include <asm/cp15.h>
  11 #include <asm/cputype.h>
  12 #include <asm/mpu.h>
  13
  14 #include <asm/memory.h>
  15 #include <asm/sections.h>
  16
  17 #include "mm.h"
  18
  19 #ifndef CONFIG_CPU_V7M
  20
  21 #define PRSEL   __ACCESS_CP15(c6, 0, c2, 1)
  22 #define PRBAR   __ACCESS_CP15(c6, 0, c3, 0)
  23 #define PRLAR   __ACCESS_CP15(c6, 0, c3, 1)
  24
  25 static inline u32 prlar_read(void)
  26 {
  27         return read_sysreg(PRLAR);
  28 }
  29
  30 static inline u32 prbar_read(void)
  31 {
  32         return read_sysreg(PRBAR);
  33 }
  34
  35 static inline void prsel_write(u32 v)
  36 {
  37         write_sysreg(v, PRSEL);
  38 }
  39
  40 static inline void prbar_write(u32 v)
  41 {
  42         write_sysreg(v, PRBAR);
  43 }
  44
  45 static inline void prlar_write(u32 v)
  46 {
  47         write_sysreg(v, PRLAR);
  48 }
  49 #else
  50
  51 static inline u32 prlar_read(void)
  52 {
  53         return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RLAR);
  54 }
  55
  56 static inline u32 prbar_read(void)
  57 {
  58         return readl_relaxed(BASEADDR_V7M_SCB + PMSAv8_RBAR);
  59 }
  60
  61 static inline void prsel_write(u32 v)
  62 {
  63         writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RNR);
  64 }
  65
  66 static inline void prbar_write(u32 v)
  67 {
  68         writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RBAR);
  69 }
  70
  71 static inline void prlar_write(u32 v)
  72 {
  73         writel_relaxed(v, BASEADDR_V7M_SCB + PMSAv8_RLAR);
  74 }
  75
  76 #endif
  77
  78 static struct range __initdata io[MPU_MAX_REGIONS];
  79 static struct range __initdata mem[MPU_MAX_REGIONS];
  80
  81 static unsigned int __initdata mpu_max_regions;
  82
  83 static __init bool is_region_fixed(int number)
  84 {
  85         switch (number) {
  86         case PMSAv8_XIP_REGION:
  87         case PMSAv8_KERNEL_REGION:
  88                 return true;
  89         default:
  90                 return false;
  91         }
  92 }
  93
  94 void __init pmsav8_adjust_lowmem_bounds(void)
  95 {
  96         phys_addr_t mem_end;
  97         struct memblock_region *reg;
  98         bool first = true;
  99
 100         for_each_memblock(memory, reg) {
 101                 if (first) {
 102                         phys_addr_t phys_offset = PHYS_OFFSET;
 103
 104                         /*
 105                          * Initially only use memory continuous from
 106                          * PHYS_OFFSET */
 107                         if (reg->base != phys_offset)
 108                                 panic("First memory bank must be contiguous from PHYS_OFFSET");
 109                         mem_end = reg->base + reg->size;
 110                         first = false;
 111                 } else {
 112                         /*
 113                          * memblock auto merges contiguous blocks, remove
 114                          * all blocks afterwards in one go (we can't remove
 115                          * blocks separately while iterating)
 116                          */
 117                         pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n",
 118                                   &mem_end, &reg->base);
 119                         memblock_remove(reg->base, 0 - reg->base);
 120                         break;
 121                 }
 122         }
 123 }
 124
 125 static int __init __mpu_max_regions(void)
 126 {
 127         static int max_regions;
 128         u32 mpuir;
 129
 130         if (max_regions)
 131                 return max_regions;
 132
 133         mpuir = read_cpuid_mputype();
 134
 135         max_regions  = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION;
 136
 137         return max_regions;
 138 }
 139
 140 static int __init __pmsav8_setup_region(unsigned int number, u32 bar, u32 lar)
 141 {
 142         if (number > mpu_max_regions
 143             || number >= MPU_MAX_REGIONS)
 144                 return -ENOENT;
 145
 146         dsb();
 147         prsel_write(number);
 148         isb();
 149         prbar_write(bar);
 150         prlar_write(lar);
 151
 152         mpu_rgn_info.rgns[number].prbar = bar;
 153         mpu_rgn_info.rgns[number].prlar = lar;
 154
 155         mpu_rgn_info.used++;
 156
 157         return 0;
 158 }
 159
 160 static int __init pmsav8_setup_ram(unsigned int number, phys_addr_t start,phys_addr_t end)
 161 {
 162         u32 bar, lar;
 163
 164         if (is_region_fixed(number))
 165                 return -EINVAL;
 166
 167         bar = start;
 168         lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);;
 169
 170         bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED;
 171         lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
 172
 173         return __pmsav8_setup_region(number, bar, lar);
 174 }
 175
 176 static int __init pmsav8_setup_io(unsigned int number, phys_addr_t start,phys_addr_t end)
 177 {
 178         u32 bar, lar;
 179
 180         if (is_region_fixed(number))
 181                 return -EINVAL;
 182
 183         bar = start;
 184         lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);;
 185
 186         bar |= PMSAv8_AP_PL1RW_PL0RW | PMSAv8_RGN_SHARED | PMSAv8_BAR_XN;
 187         lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_DEVICE_nGnRnE) | PMSAv8_LAR_EN;
 188
 189         return __pmsav8_setup_region(number, bar, lar);
 190 }
 191
 192 static int __init pmsav8_setup_fixed(unsigned int number, phys_addr_t start,phys_addr_t end)
 193 {
 194         u32 bar, lar;
 195
 196         if (!is_region_fixed(number))
 197                 return -EINVAL;
 198
 199         bar = start;
 200         lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
 201
 202         bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
 203         lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
 204
 205         prsel_write(number);
 206         isb();
 207
 208         if (prbar_read() != bar || prlar_read() != lar)
 209                 return -EINVAL;
 210
 211         /* Reserved region was set up early, we just need a record for secondaries */
 212         mpu_rgn_info.rgns[number].prbar = bar;
 213         mpu_rgn_info.rgns[number].prlar = lar;
 214
 215         mpu_rgn_info.used++;
 216
 217         return 0;
 218 }
 219
 220 #ifndef CONFIG_CPU_V7M
 221 static int __init pmsav8_setup_vector(unsigned int number, phys_addr_t start,phys_addr_t end)
 222 {
 223         u32 bar, lar;
 224
 225         if (number == PMSAv8_KERNEL_REGION)
 226                 return -EINVAL;
 227
 228         bar = start;
 229         lar = (end - 1) & ~(PMSAv8_MINALIGN - 1);
 230
 231         bar |= PMSAv8_AP_PL1RW_PL0NA | PMSAv8_RGN_SHARED;
 232         lar |= PMSAv8_LAR_IDX(PMSAv8_RGN_NORMAL) | PMSAv8_LAR_EN;
 233
 234         return __pmsav8_setup_region(number, bar, lar);
 235 }
 236 #endif
 237
 238 void __init pmsav8_setup(void)
 239 {
 240         int i, err = 0;
 241         int region = PMSAv8_KERNEL_REGION;
 242
 243         /* How many regions are supported ? */
 244         mpu_max_regions = __mpu_max_regions();
 245
 246         /* RAM: single chunk of memory */
 247         add_range(mem,  ARRAY_SIZE(mem), 0,  memblock.memory.regions[0].base,
 248                   memblock.memory.regions[0].base + memblock.memory.regions[0].size);
 249
 250         /* IO: cover full 4G range */
 251         add_range(io, ARRAY_SIZE(io), 0, 0, 0xffffffff);
 252
 253         /* RAM and IO: exclude kernel */
 254         subtract_range(mem, ARRAY_SIZE(mem), __pa(KERNEL_START), __pa(KERNEL_END));
 255         subtract_range(io, ARRAY_SIZE(io),  __pa(KERNEL_START), __pa(KERNEL_END));
 256
 257 #ifdef CONFIG_XIP_KERNEL
 258         /* RAM and IO: exclude xip */
 259         subtract_range(mem, ARRAY_SIZE(mem), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
 260         subtract_range(io, ARRAY_SIZE(io), CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
 261 #endif
 262
 263 #ifndef CONFIG_CPU_V7M
 264         /* RAM and IO: exclude vectors */
 265         subtract_range(mem, ARRAY_SIZE(mem),  vectors_base, vectors_base + 2 * PAGE_SIZE);
 266         subtract_range(io, ARRAY_SIZE(io),  vectors_base, vectors_base + 2 * PAGE_SIZE);
 267 #endif
 268         /* IO: exclude RAM */
 269         for (i = 0; i < ARRAY_SIZE(mem); i++)
 270                 subtract_range(io, ARRAY_SIZE(io), mem[i].start, mem[i].end);
 271
 272         /* Now program MPU */
 273
 274 #ifdef CONFIG_XIP_KERNEL
 275         /* ROM */
 276         err |= pmsav8_setup_fixed(PMSAv8_XIP_REGION, CONFIG_XIP_PHYS_ADDR, __pa(_exiprom));
 277 #endif
 278         /* Kernel */
 279         err |= pmsav8_setup_fixed(region++, __pa(KERNEL_START), __pa(KERNEL_END));
 280
 281
 282         /* IO */
 283         for (i = 0; i < ARRAY_SIZE(io); i++) {
 284                 if (!io[i].end)
 285                         continue;
 286
 287                 err |= pmsav8_setup_io(region++, io[i].start, io[i].end);
 288         }
 289
 290         /* RAM */
 291         for (i = 0; i < ARRAY_SIZE(mem); i++) {
 292                 if (!mem[i].end)
 293                         continue;
 294
 295                 err |= pmsav8_setup_ram(region++, mem[i].start, mem[i].end);
 296         }
 297
 298         /* Vectors */
 299 #ifndef CONFIG_CPU_V7M
 300         err |= pmsav8_setup_vector(region++, vectors_base, vectors_base + 2 * PAGE_SIZE);
 301 #endif
 302         if (err)
 303                 pr_warn("MPU region initialization failure! %d", err);
 304         else
 305                 pr_info("Using ARM PMSAv8 Compliant MPU. Used %d of %d regions\n",
 306                         mpu_rgn_info.used, mpu_max_regions);
 307 }