arch/powerpc/cpu/mpc83xx/law.c

   1 /*
   2  * Copyright 2011 Freescale Semiconductor, Inc.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0
   5  */
   6
   7 #include <common.h>
   8 #include <asm/fsl_law.h>
   9 #include <asm/mmu.h>
  10 #include <linux/log2.h>
  11
  12 int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id)
  13 {
  14         immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
  15         law83xx_t *ecm = &immap->sysconf.ddrlaw[0];
  16         u64 start_align, law_sz;
  17         int law_sz_enc;
  18
  19         if (start == 0)
  20                 start_align = 1ull << (LAW_SIZE_2G + 1);
  21         else
  22                 start_align = 1ull << (__ffs64(start) - 1);
  23         law_sz = min(start_align, sz);
  24         law_sz_enc = __ilog2_u64(law_sz) - 1;
  25
  26         /*
  27          * Set up LAWBAR for all of DDR.
  28          */
  29         ecm->bar = start & 0xfffff000;
  30         ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
  31         debug("DDR:bar=0x%08x\n", ecm->bar);
  32         debug("DDR:ar=0x%08x\n", ecm->ar);
  33
  34         /* recalculate size based on what was actually covered by the law */
  35         law_sz = 1ull << __ilog2_u64(law_sz);
  36
  37         /* do we still have anything to map */
  38         sz = sz - law_sz;
  39         if (sz) {
  40                 start += law_sz;
  41
  42                 start_align = 1ull << (__ffs64(start) - 1);
  43                 law_sz = min(start_align, sz);
  44                 law_sz_enc = __ilog2_u64(law_sz) - 1;
  45                 ecm = &immap->sysconf.ddrlaw[1];
  46                 ecm->bar = start & 0xfffff000;
  47                 ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
  48                 debug("DDR:bar=0x%08x\n", ecm->bar);
  49                 debug("DDR:ar=0x%08x\n", ecm->ar);
  50         } else {
  51                 return 0;
  52         }
  53
  54         /* do we still have anything to map */
  55         sz = sz - law_sz;
  56         if (sz)
  57                 return 1;
  58
  59         return 0;
  60 }