162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later
262306a36Sopenharmony_ci/*
362306a36Sopenharmony_ci * Copyright 2013, Michael Ellerman, IBM Corporation.
462306a36Sopenharmony_ci */
562306a36Sopenharmony_ci
662306a36Sopenharmony_ci#define pr_fmt(fmt)	"pseries-rng: " fmt
762306a36Sopenharmony_ci
862306a36Sopenharmony_ci#include <linux/kernel.h>
962306a36Sopenharmony_ci#include <linux/of.h>
1062306a36Sopenharmony_ci#include <asm/archrandom.h>
1162306a36Sopenharmony_ci#include <asm/machdep.h>
1262306a36Sopenharmony_ci#include <asm/plpar_wrappers.h>
1362306a36Sopenharmony_ci#include "pseries.h"
1462306a36Sopenharmony_ci
1562306a36Sopenharmony_ci
1662306a36Sopenharmony_cistatic int pseries_get_random_long(unsigned long *v)
1762306a36Sopenharmony_ci{
1862306a36Sopenharmony_ci	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
1962306a36Sopenharmony_ci
2062306a36Sopenharmony_ci	if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) {
2162306a36Sopenharmony_ci		*v = retbuf[0];
2262306a36Sopenharmony_ci		return 1;
2362306a36Sopenharmony_ci	}
2462306a36Sopenharmony_ci
2562306a36Sopenharmony_ci	return 0;
2662306a36Sopenharmony_ci}
2762306a36Sopenharmony_ci
2862306a36Sopenharmony_civoid __init pseries_rng_init(void)
2962306a36Sopenharmony_ci{
3062306a36Sopenharmony_ci	struct device_node *dn;
3162306a36Sopenharmony_ci
3262306a36Sopenharmony_ci	dn = of_find_compatible_node(NULL, NULL, "ibm,random");
3362306a36Sopenharmony_ci	if (!dn)
3462306a36Sopenharmony_ci		return;
3562306a36Sopenharmony_ci	ppc_md.get_random_seed = pseries_get_random_long;
3662306a36Sopenharmony_ci	of_node_put(dn);
3762306a36Sopenharmony_ci}
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