arch/arm/mm/proc-arm940.S

   1 /*
   2  *  linux/arch/arm/mm/arm940.S: utility functions for ARM940T
   3  *
   4  *  Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/linkage.h>
  12 #include <linux/init.h>
  13 #include <asm/assembler.h>
  14 #include <asm/hwcap.h>
  15 #include <asm/pgtable-hwdef.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/ptrace.h>
  18 #include "proc-macros.S"
  19
  20 /* ARM940T has a 4KB DCache comprising 256 lines of 4 words */
  21 #define CACHE_DLINESIZE 16
  22 #define CACHE_DSEGMENTS 4
  23 #define CACHE_DENTRIES  64
  24
  25         .text
  26 /*
  27  * cpu_arm940_proc_init()
  28  * cpu_arm940_switch_mm()
  29  *
  30  * These are not required.
  31  */
  32 ENTRY(cpu_arm940_proc_init)
  33 ENTRY(cpu_arm940_switch_mm)
  34         ret     lr
  35
  36 /*
  37  * cpu_arm940_proc_fin()
  38  */
  39 ENTRY(cpu_arm940_proc_fin)
  40         mrc     p15, 0, r0, c1, c0, 0           @ ctrl register
  41         bic     r0, r0, #0x00001000             @ i-cache
  42         bic     r0, r0, #0x00000004             @ d-cache
  43         mcr     p15, 0, r0, c1, c0, 0           @ disable caches
  44         ret     lr
  45
  46 /*
  47  * cpu_arm940_reset(loc)
  48  * Params  : r0 = address to jump to
  49  * Notes   : This sets up everything for a reset
  50  */
  51         .pushsection    .idmap.text, "ax"
  52 ENTRY(cpu_arm940_reset)
  53         mov     ip, #0
  54         mcr     p15, 0, ip, c7, c5, 0           @ flush I cache
  55         mcr     p15, 0, ip, c7, c6, 0           @ flush D cache
  56         mcr     p15, 0, ip, c7, c10, 4          @ drain WB
  57         mrc     p15, 0, ip, c1, c0, 0           @ ctrl register
  58         bic     ip, ip, #0x00000005             @ .............c.p
  59         bic     ip, ip, #0x00001000             @ i-cache
  60         mcr     p15, 0, ip, c1, c0, 0           @ ctrl register
  61         ret     r0
  62 ENDPROC(cpu_arm940_reset)
  63         .popsection
  64
  65 /*
  66  * cpu_arm940_do_idle()
  67  */
  68         .align  5
  69 ENTRY(cpu_arm940_do_idle)
  70         mcr     p15, 0, r0, c7, c0, 4           @ Wait for interrupt
  71         ret     lr
  72
  73 /*
  74  *      flush_icache_all()
  75  *
  76  *      Unconditionally clean and invalidate the entire icache.
  77  */
  78 ENTRY(arm940_flush_icache_all)
  79         mov     r0, #0
  80         mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
  81         ret     lr
  82 ENDPROC(arm940_flush_icache_all)
  83
  84 /*
  85  *      flush_user_cache_all()
  86  */
  87 ENTRY(arm940_flush_user_cache_all)
  88         /* FALLTHROUGH */
  89
  90 /*
  91  *      flush_kern_cache_all()
  92  *
  93  *      Clean and invalidate the entire cache.
  94  */
  95 ENTRY(arm940_flush_kern_cache_all)
  96         mov     r2, #VM_EXEC
  97         /* FALLTHROUGH */
  98
  99 /*
 100  *      flush_user_cache_range(start, end, flags)
 101  *
 102  *      There is no efficient way to flush a range of cache entries
 103  *      in the specified address range. Thus, flushes all.
 104  *
 105  *      - start - start address (inclusive)
 106  *      - end   - end address (exclusive)
 107  *      - flags - vm_flags describing address space
 108  */
 109 ENTRY(arm940_flush_user_cache_range)
 110         mov     ip, #0
 111 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
 112         mcr     p15, 0, ip, c7, c6, 0           @ flush D cache
 113 #else
 114         mov     r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
 115 1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
 116 2:      mcr     p15, 0, r3, c7, c14, 2          @ clean/flush D index
 117         subs    r3, r3, #1 << 26
 118         bcs     2b                              @ entries 63 to 0
 119         subs    r1, r1, #1 << 4
 120         bcs     1b                              @ segments 3 to 0
 121 #endif
 122         tst     r2, #VM_EXEC
 123         mcrne   p15, 0, ip, c7, c5, 0           @ invalidate I cache
 124         mcrne   p15, 0, ip, c7, c10, 4          @ drain WB
 125         ret     lr
 126
 127 /*
 128  *      coherent_kern_range(start, end)
 129  *
 130  *      Ensure coherency between the Icache and the Dcache in the
 131  *      region described by start, end.  If you have non-snooping
 132  *      Harvard caches, you need to implement this function.
 133  *
 134  *      - start - virtual start address
 135  *      - end   - virtual end address
 136  */
 137 ENTRY(arm940_coherent_kern_range)
 138         /* FALLTHROUGH */
 139
 140 /*
 141  *      coherent_user_range(start, end)
 142  *
 143  *      Ensure coherency between the Icache and the Dcache in the
 144  *      region described by start, end.  If you have non-snooping
 145  *      Harvard caches, you need to implement this function.
 146  *
 147  *      - start - virtual start address
 148  *      - end   - virtual end address
 149  */
 150 ENTRY(arm940_coherent_user_range)
 151         /* FALLTHROUGH */
 152
 153 /*
 154  *      flush_kern_dcache_area(void *addr, size_t size)
 155  *
 156  *      Ensure no D cache aliasing occurs, either with itself or
 157  *      the I cache
 158  *
 159  *      - addr  - kernel address
 160  *      - size  - region size
 161  */
 162 ENTRY(arm940_flush_kern_dcache_area)
 163         mov     r0, #0
 164         mov     r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
 165 1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
 166 2:      mcr     p15, 0, r3, c7, c14, 2          @ clean/flush D index
 167         subs    r3, r3, #1 << 26
 168         bcs     2b                              @ entries 63 to 0
 169         subs    r1, r1, #1 << 4
 170         bcs     1b                              @ segments 7 to 0
 171         mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
 172         mcr     p15, 0, r0, c7, c10, 4          @ drain WB
 173         ret     lr
 174
 175 /*
 176  *      dma_inv_range(start, end)
 177  *
 178  *      There is no efficient way to invalidate a specifid virtual
 179  *      address range. Thus, invalidates all.
 180  *
 181  *      - start - virtual start address
 182  *      - end   - virtual end address
 183  */
 184 arm940_dma_inv_range:
 185         mov     ip, #0
 186         mov     r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
 187 1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
 188 2:      mcr     p15, 0, r3, c7, c6, 2           @ flush D entry
 189         subs    r3, r3, #1 << 26
 190         bcs     2b                              @ entries 63 to 0
 191         subs    r1, r1, #1 << 4
 192         bcs     1b                              @ segments 7 to 0
 193         mcr     p15, 0, ip, c7, c10, 4          @ drain WB
 194         ret     lr
 195
 196 /*
 197  *      dma_clean_range(start, end)
 198  *
 199  *      There is no efficient way to clean a specifid virtual
 200  *      address range. Thus, cleans all.
 201  *
 202  *      - start - virtual start address
 203  *      - end   - virtual end address
 204  */
 205 arm940_dma_clean_range:
 206 ENTRY(cpu_arm940_dcache_clean_area)
 207         mov     ip, #0
 208 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
 209         mov     r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
 210 1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
 211 2:      mcr     p15, 0, r3, c7, c10, 2          @ clean D entry
 212         subs    r3, r3, #1 << 26
 213         bcs     2b                              @ entries 63 to 0
 214         subs    r1, r1, #1 << 4
 215         bcs     1b                              @ segments 7 to 0
 216 #endif
 217         mcr     p15, 0, ip, c7, c10, 4          @ drain WB
 218         ret     lr
 219
 220 /*
 221  *      dma_flush_range(start, end)
 222  *
 223  *      There is no efficient way to clean and invalidate a specifid
 224  *      virtual address range.
 225  *
 226  *      - start - virtual start address
 227  *      - end   - virtual end address
 228  */
 229 ENTRY(arm940_dma_flush_range)
 230         mov     ip, #0
 231         mov     r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
 232 1:      orr     r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
 233 2:
 234 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
 235         mcr     p15, 0, r3, c7, c14, 2          @ clean/flush D entry
 236 #else
 237         mcr     p15, 0, r3, c7, c6, 2           @ invalidate D entry
 238 #endif
 239         subs    r3, r3, #1 << 26
 240         bcs     2b                              @ entries 63 to 0
 241         subs    r1, r1, #1 << 4
 242         bcs     1b                              @ segments 7 to 0
 243         mcr     p15, 0, ip, c7, c10, 4          @ drain WB
 244         ret     lr
 245
 246 /*
 247  *      dma_map_area(start, size, dir)
 248  *      - start - kernel virtual start address
 249  *      - size  - size of region
 250  *      - dir   - DMA direction
 251  */
 252 ENTRY(arm940_dma_map_area)
 253         add     r1, r1, r0
 254         cmp     r2, #DMA_TO_DEVICE
 255         beq     arm940_dma_clean_range
 256         bcs     arm940_dma_inv_range
 257         b       arm940_dma_flush_range
 258 ENDPROC(arm940_dma_map_area)
 259
 260 /*
 261  *      dma_unmap_area(start, size, dir)
 262  *      - start - kernel virtual start address
 263  *      - size  - size of region
 264  *      - dir   - DMA direction
 265  */
 266 ENTRY(arm940_dma_unmap_area)
 267         ret     lr
 268 ENDPROC(arm940_dma_unmap_area)
 269
 270         .globl  arm940_flush_kern_cache_louis
 271         .equ    arm940_flush_kern_cache_louis, arm940_flush_kern_cache_all
 272
 273         @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
 274         define_cache_functions arm940
 275
 276         .type   __arm940_setup, #function
 277 __arm940_setup:
 278         mov     r0, #0
 279         mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
 280         mcr     p15, 0, r0, c7, c6, 0           @ invalidate D cache
 281         mcr     p15, 0, r0, c7, c10, 4          @ drain WB
 282
 283         mcr     p15, 0, r0, c6, c3, 0           @ disable data area 3~7
 284         mcr     p15, 0, r0, c6, c4, 0
 285         mcr     p15, 0, r0, c6, c5, 0
 286         mcr     p15, 0, r0, c6, c6, 0
 287         mcr     p15, 0, r0, c6, c7, 0
 288
 289         mcr     p15, 0, r0, c6, c3, 1           @ disable instruction area 3~7
 290         mcr     p15, 0, r0, c6, c4, 1
 291         mcr     p15, 0, r0, c6, c5, 1
 292         mcr     p15, 0, r0, c6, c6, 1
 293         mcr     p15, 0, r0, c6, c7, 1
 294
 295         mov     r0, #0x0000003F                 @ base = 0, size = 4GB
 296         mcr     p15, 0, r0, c6, c0, 0           @ set area 0, default
 297         mcr     p15, 0, r0, c6, c0, 1
 298
 299         ldr     r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
 300         ldr     r1, =(CONFIG_DRAM_SIZE >> 12)   @ size of RAM (must be >= 4KB)
 301         mov     r2, #10                         @ 11 is the minimum (4KB)
 302 1:      add     r2, r2, #1                      @ area size *= 2
 303         mov     r1, r1, lsr #1
 304         bne     1b                              @ count not zero r-shift
 305         orr     r0, r0, r2, lsl #1              @ the area register value
 306         orr     r0, r0, #1                      @ set enable bit
 307         mcr     p15, 0, r0, c6, c1, 0           @ set area 1, RAM
 308         mcr     p15, 0, r0, c6, c1, 1
 309
 310         ldr     r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
 311         ldr     r1, =(CONFIG_FLASH_SIZE >> 12)  @ size of FLASH (must be >= 4KB)
 312         mov     r2, #10                         @ 11 is the minimum (4KB)
 313 1:      add     r2, r2, #1                      @ area size *= 2
 314         mov     r1, r1, lsr #1
 315         bne     1b                              @ count not zero r-shift
 316         orr     r0, r0, r2, lsl #1              @ the area register value
 317         orr     r0, r0, #1                      @ set enable bit
 318         mcr     p15, 0, r0, c6, c2, 0           @ set area 2, ROM/FLASH
 319         mcr     p15, 0, r0, c6, c2, 1
 320
 321         mov     r0, #0x06
 322         mcr     p15, 0, r0, c2, c0, 0           @ Region 1&2 cacheable
 323         mcr     p15, 0, r0, c2, c0, 1
 324 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
 325         mov     r0, #0x00                       @ disable whole write buffer
 326 #else
 327         mov     r0, #0x02                       @ Region 1 write bufferred
 328 #endif
 329         mcr     p15, 0, r0, c3, c0, 0
 330
 331         mov     r0, #0x10000
 332         sub     r0, r0, #1                      @ r0 = 0xffff
 333         mcr     p15, 0, r0, c5, c0, 0           @ all read/write access
 334         mcr     p15, 0, r0, c5, c0, 1
 335
 336         mrc     p15, 0, r0, c1, c0              @ get control register
 337         orr     r0, r0, #0x00001000             @ I-cache
 338         orr     r0, r0, #0x00000005             @ MPU/D-cache
 339
 340         ret     lr
 341
 342         .size   __arm940_setup, . - __arm940_setup
 343
 344         __INITDATA
 345
 346         @ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
 347         define_processor_functions arm940, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
 348
 349         .section ".rodata"
 350
 351         string  cpu_arch_name, "armv4t"
 352         string  cpu_elf_name, "v4"
 353         string  cpu_arm940_name, "ARM940T"
 354
 355         .align
 356
 357         .section ".proc.info.init", #alloc, #execinstr
 358
 359         .type   __arm940_proc_info,#object
 360 __arm940_proc_info:
 361         .long   0x41009400
 362         .long   0xff00fff0
 363         .long   0
 364         b       __arm940_setup
 365         .long   cpu_arch_name
 366         .long   cpu_elf_name
 367         .long   HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
 368         .long   cpu_arm940_name
 369         .long   arm940_processor_functions
 370         .long   0
 371         .long   0
 372         .long   arm940_cache_fns
 373         .size   __arm940_proc_info, . - __arm940_proc_info
 374