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 #include "pseries.h"
  14
  15
  16 static int pseries_get_random_long(unsigned long *v)
  17 {
  18         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
  19
  20         if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) {
  21                 *v = retbuf[0];
  22                 return 1;
  23         }
  24
  25         return 0;
  26 }
  27
  28 void __init pseries_rng_init(void)
  29 {
  30         struct device_node *dn;
  31
  32         dn = of_find_compatible_node(NULL, NULL, "ibm,random");
  33         if (!dn)
  34                 return;
  35         ppc_md.get_random_seed = pseries_get_random_long;
  36         of_node_put(dn);
  37 }