arch/blackfin/lib/string.c

   1 /*
   2  * U-Boot - string.c Contains library routines.
   3  *
   4  * Copyright (c) 2005-2008 Analog Devices Inc.
   5  *
   6  * (C) Copyright 2000-2004
   7  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <config.h>
  14 #include <asm/blackfin.h>
  15 #include <asm/io.h>
  16 #include <asm/dma.h>
  17
  18 char *strcpy(char *dest, const char *src)
  19 {
  20         char *xdest = dest;
  21         char temp = 0;
  22
  23         __asm__ __volatile__ (
  24                 "1:\t%2 = B [%1++] (Z);\n\t"
  25                 "B [%0++] = %2;\n\t"
  26                 "CC = %2;\n\t"
  27                 "if cc jump 1b (bp);\n"
  28                 : "=a"(dest), "=a"(src), "=d"(temp)
  29                 : "0"(dest), "1"(src), "2"(temp)
  30                 : "memory");
  31
  32         return xdest;
  33 }
  34
  35 char *strncpy(char *dest, const char *src, size_t n)
  36 {
  37         char *xdest = dest;
  38         char temp = 0;
  39
  40         if (n == 0)
  41                 return xdest;
  42
  43         __asm__ __volatile__ (
  44                 "1:\t%3 = B [%1++] (Z);\n\t"
  45                 "B [%0++] = %3;\n\t"
  46                 "CC = %3;\n\t"
  47                 "if ! cc jump 2f;\n\t"
  48                 "%2 += -1;\n\t"
  49                 "CC = %2 == 0;\n\t"
  50                 "if ! cc jump 1b (bp);\n"
  51                 "2:\n"
  52                 : "=a"(dest), "=a"(src), "=da"(n), "=d"(temp)
  53                 : "0"(dest), "1"(src), "2"(n), "3"(temp)
  54                 : "memory");
  55
  56         return xdest;
  57 }
  58
  59 int strcmp(const char *cs, const char *ct)
  60 {
  61         char __res1, __res2;
  62
  63         __asm__ (
  64                 "1:\t%2 = B[%0++] (Z);\n\t"     /* get *cs */
  65                 "%3 = B[%1++] (Z);\n\t" /* get *ct */
  66                 "CC = %2 == %3;\n\t"    /* compare a byte */
  67                 "if ! cc jump 2f;\n\t"  /* not equal, break out */
  68                 "CC = %2;\n\t"  /* at end of cs? */
  69                 "if cc jump 1b (bp);\n\t"       /* no, keep going */
  70                 "jump.s 3f;\n"  /* strings are equal */
  71                 "2:\t%2 = %2 - %3;\n"   /* *cs - *ct */
  72                 "3:\n"
  73                 : "=a"(cs), "=a"(ct), "=d"(__res1), "=d"(__res2)
  74                 : "0"(cs), "1"(ct));
  75
  76         return __res1;
  77 }
  78
  79 int strncmp(const char *cs, const char *ct, size_t count)
  80 {
  81         char __res1, __res2;
  82
  83         if (!count)
  84                 return 0;
  85
  86         __asm__(
  87                 "1:\t%3 = B[%0++] (Z);\n\t"     /* get *cs */
  88                 "%4 = B[%1++] (Z);\n\t" /* get *ct */
  89                 "CC = %3 == %4;\n\t"    /* compare a byte */
  90                 "if ! cc jump 3f;\n\t"  /* not equal, break out */
  91                 "CC = %3;\n\t"  /* at end of cs? */
  92                 "if ! cc jump 4f;\n\t"  /* yes, all done */
  93                 "%2 += -1;\n\t" /* no, adjust count */
  94                 "CC = %2 == 0;\n\t" "if ! cc jump 1b;\n"        /* more to do, keep going */
  95                 "2:\t%3 = 0;\n\t"       /* strings are equal */
  96                 "jump.s    4f;\n" "3:\t%3 = %3 - %4;\n" /* *cs - *ct */
  97                 "4:"
  98                 : "=a"(cs), "=a"(ct), "=da"(count), "=d"(__res1), "=d"(__res2)
  99                 : "0"(cs), "1"(ct), "2"(count));
 100
 101         return __res1;
 102 }
 103
 104 #ifdef MDMA1_D0_NEXT_DESC_PTR
 105 # define MDMA_D0_NEXT_DESC_PTR MDMA1_D0_NEXT_DESC_PTR
 106 # define MDMA_S0_NEXT_DESC_PTR MDMA1_S0_NEXT_DESC_PTR
 107 #endif
 108
 109 static void dma_calc_size(unsigned long ldst, unsigned long lsrc, size_t count,
 110                         unsigned long *dshift, unsigned long *bpos)
 111 {
 112         unsigned long limit;
 113
 114 #ifdef MSIZE
 115         /* The max memory DMA memory transfer size is 32 bytes. */
 116         limit = 5;
 117         *dshift = MSIZE_P;
 118 #else
 119         /* The max memory DMA memory transfer size is 4 bytes. */
 120         limit = 2;
 121         *dshift = WDSIZE_P;
 122 #endif
 123
 124         *bpos = min(limit, (unsigned long)ffs(ldst | lsrc | count)) - 1;
 125 }
 126
 127 /* This version misbehaves for count values of 0 and 2^16+.
 128  * Perhaps we should detect that ?  Nowhere do we actually
 129  * use dma memcpy for those types of lengths though ...
 130  */
 131 void dma_memcpy_nocache(void *dst, const void *src, size_t count)
 132 {
 133         struct dma_register *mdma_d0 = (void *)MDMA_D0_NEXT_DESC_PTR;
 134         struct dma_register *mdma_s0 = (void *)MDMA_S0_NEXT_DESC_PTR;
 135         unsigned long ldst = (unsigned long)dst;
 136         unsigned long lsrc = (unsigned long)src;
 137         unsigned long dshift, bpos;
 138         uint32_t dsize, mod;
 139
 140         /* Disable DMA in case it's still running (older u-boot's did not
 141          * always turn them off).  Do it before the if statement below so
 142          * we can be cheap and not do a SSYNC() due to the forced abort.
 143          */
 144         bfin_write(&mdma_d0->config, 0);
 145         bfin_write(&mdma_s0->config, 0);
 146         bfin_write(&mdma_d0->status, DMA_RUN | DMA_DONE | DMA_ERR);
 147
 148         /* Scratchpad cannot be a DMA source or destination */
 149         if ((lsrc >= L1_SRAM_SCRATCH && lsrc < L1_SRAM_SCRATCH_END) ||
 150             (ldst >= L1_SRAM_SCRATCH && ldst < L1_SRAM_SCRATCH_END))
 151                 hang();
 152
 153         dma_calc_size(ldst, lsrc, count, &dshift, &bpos);
 154         dsize = bpos << dshift;
 155         count >>= bpos;
 156         mod = 1 << bpos;
 157
 158 #ifdef PSIZE
 159         /* The max memory DMA peripheral transfer size is 4 bytes. */
 160         dsize |= min(2UL, bpos) << PSIZE_P;
 161 #endif
 162
 163         /* Copy sram functions from sdram to sram */
 164         /* Setup destination start address */
 165         bfin_write(&mdma_d0->start_addr, ldst);
 166         /* Setup destination xcount */
 167         bfin_write(&mdma_d0->x_count, count);
 168         /* Setup destination xmodify */
 169         bfin_write(&mdma_d0->x_modify, mod);
 170
 171         /* Setup Source start address */
 172         bfin_write(&mdma_s0->start_addr, lsrc);
 173         /* Setup Source xcount */
 174         bfin_write(&mdma_s0->x_count, count);
 175         /* Setup Source xmodify */
 176         bfin_write(&mdma_s0->x_modify, mod);
 177
 178         /* Enable source DMA */
 179         bfin_write(&mdma_s0->config, dsize | DMAEN);
 180         bfin_write(&mdma_d0->config, dsize | DMAEN | WNR | DI_EN);
 181         SSYNC();
 182
 183         while (!(bfin_read(&mdma_d0->status) & DMA_DONE))
 184                 continue;
 185
 186         bfin_write(&mdma_d0->status, DMA_RUN | DMA_DONE | DMA_ERR);
 187         bfin_write(&mdma_d0->config, 0);
 188         bfin_write(&mdma_s0->config, 0);
 189 }
 190 /* We should do a dcache invalidate on the destination after the dma, but since
 191  * we lack such hardware capability, we'll flush/invalidate the destination
 192  * before the dma and bank on the idea that u-boot is single threaded.
 193  */
 194 void *dma_memcpy(void *dst, const void *src, size_t count)
 195 {
 196         if (dcache_status()) {
 197                 blackfin_dcache_flush_range(src, src + count);
 198                 blackfin_dcache_flush_invalidate_range(dst, dst + count);
 199         }
 200
 201         dma_memcpy_nocache(dst, src, count);
 202
 203         if (icache_status())
 204                 blackfin_icache_flush_range(dst, dst + count);
 205
 206         return dst;
 207 }
 208
 209 /*
 210  * memcpy - Copy one area of memory to another
 211  * @dest: Where to copy to
 212  * @src: Where to copy from
 213  * @count: The size of the area.
 214  *
 215  * We need to have this wrapper in memcpy() as common code may call memcpy()
 216  * to load up L1 regions.  Consider loading an ELF which has sections with
 217  * LMA's pointing to L1.  The common code ELF loader will simply use memcpy()
 218  * to move the ELF's sections into the right place.  We need to catch that
 219  * here and redirect to dma_memcpy().
 220  */
 221 extern void *memcpy_ASM(void *dst, const void *src, size_t count);
 222 void *memcpy(void *dst, const void *src, size_t count)
 223 {
 224         if (!count)
 225                 return dst;
 226
 227 #ifdef CONFIG_CMD_KGDB
 228         if (src >= (void *)SYSMMR_BASE) {
 229                 if (count == 2 && (unsigned long)src % 2 == 0) {
 230                         u16 mmr = bfin_read16(src);
 231                         memcpy(dst, &mmr, sizeof(mmr));
 232                         return dst;
 233                 }
 234                 if (count == 4 && (unsigned long)src % 4 == 0) {
 235                         u32 mmr = bfin_read32(src);
 236                         memcpy(dst, &mmr, sizeof(mmr));
 237                         return dst;
 238                 }
 239                 /* Failed for some reason */
 240                 memset(dst, 0xad, count);
 241                 return dst;
 242         }
 243         if (dst >= (void *)SYSMMR_BASE) {
 244                 if (count == 2 && (unsigned long)dst % 2 == 0) {
 245                         u16 mmr;
 246                         memcpy(&mmr, src, sizeof(mmr));
 247                         bfin_write16(dst, mmr);
 248                         return dst;
 249                 }
 250                 if (count == 4 && (unsigned long)dst % 4 == 0) {
 251                         u32 mmr;
 252                         memcpy(&mmr, src, sizeof(mmr));
 253                         bfin_write32(dst, mmr);
 254                         return dst;
 255                 }
 256                 /* Failed for some reason */
 257                 memset(dst, 0xad, count);
 258                 return dst;
 259         }
 260 #endif
 261
 262         /* if L1 is the source or dst, use DMA */
 263         if (addr_bfin_on_chip_mem(dst) || addr_bfin_on_chip_mem(src))
 264                 return dma_memcpy(dst, src, count);
 265         else
 266                 /* No L1 is involved, so just call regular memcpy */
 267                 return memcpy_ASM(dst, src, count);
 268 }