LXR linux/arch/powerpc/platforms/pseries/rng.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright 2013, Michael Ellerman, IBM Corporation.
   4 */
   5
   6#define pr_fmt(fmt)     "pseries-rng: " fmt
   7
   8#include <linux/kernel.h>
   9#include <linux/of.h>
  10#include <asm/archrandom.h>
  11#include <asm/machdep.h>
  12#include <asm/plpar_wrappers.h>
  13
  14
  15static int pseries_get_random_long(unsigned long *v)
  16{
  17        unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  18
  19        if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) {
  20                *v = retbuf[0];
  21                return 1;
  22        }
  23
  24        return 0;
  25}
  26
  27static __init int rng_init(void)
  28{
  29        struct device_node *dn;
  30
  31        dn = of_find_compatible_node(NULL, NULL, "ibm,random");
  32        if (!dn)
  33                return -ENODEV;
  34
  35        pr_info("Registering arch random hook.\n");
  36
  37        ppc_md.get_random_seed = pseries_get_random_long;
  38
  39        return 0;
  40}
  41machine_subsys_initcall(pseries, rng_init);
  42