uboot/arch/powerpc/cpu/mpc83xx/law.c
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   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
  12int 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));
  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));
  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}
  61