LXR linux/arch/riscv/kernel/soc.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2020 Western Digital Corporation or its affiliates.
   4 */
   5#include <linux/init.h>
   6#include <linux/libfdt.h>
   7#include <linux/pgtable.h>
   8#include <asm/soc.h>
   9
  10/*
  11 * This is called extremly early, before parse_dtb(), to allow initializing
  12 * SoC hardware before memory or any device driver initialization.
  13 */
  14void __init soc_early_init(void)
  15{
  16        void (*early_fn)(const void *fdt);
  17        const struct of_device_id *s;
  18        const void *fdt = dtb_early_va;
  19
  20        for (s = (void *)&__soc_early_init_table_start;
  21             (void *)s < (void *)&__soc_early_init_table_end; s++) {
  22                if (!fdt_node_check_compatible(fdt, 0, s->compatible)) {
  23                        early_fn = s->data;
  24                        early_fn(fdt);
  25                        return;
  26                }
  27        }
  28}
  29
  30static bool soc_builtin_dtb_match(unsigned long vendor_id,
  31                                unsigned long arch_id, unsigned long imp_id,
  32                                const struct soc_builtin_dtb *entry)
  33{
  34        return entry->vendor_id == vendor_id &&
  35               entry->arch_id == arch_id &&
  36               entry->imp_id == imp_id;
  37}
  38
  39void * __init soc_lookup_builtin_dtb(void)
  40{
  41        unsigned long vendor_id, arch_id, imp_id;
  42        const struct soc_builtin_dtb *s;
  43
  44        __asm__ ("csrr %0, mvendorid" : "=r"(vendor_id));
  45        __asm__ ("csrr %0, marchid" : "=r"(arch_id));
  46        __asm__ ("csrr %0, mimpid" : "=r"(imp_id));
  47
  48        for (s = (void *)&__soc_builtin_dtb_table_start;
  49             (void *)s < (void *)&__soc_builtin_dtb_table_end; s++) {
  50                if (soc_builtin_dtb_match(vendor_id, arch_id, imp_id, s))
  51                        return s->dtb_func();
  52        }
  53
  54        return NULL;
  55}
  56