hwrng: Add a driver for the hwrng found in power7+ systems (66548e40) · Commits · 戴 / test

drivers/char/hw_random/Kconfig

+13 −0

Original line number	Diff line number	Diff line
		@@ -290,6 +290,19 @@ config HW_RANDOM_PSERIES

		If unsure, say Y.

		config HW_RANDOM_POWERNV
		tristate "PowerNV Random Number Generator support"
		depends on HW_RANDOM && PPC_POWERNV
		default HW_RANDOM
		---help---
		This is the driver for Random Number Generator hardware found
		in POWER7+ and above machines for PowerNV platform.

		To compile this driver as a module, choose M here: the
		module will be called powernv-rng.

		If unsure, say Y.

		config HW_RANDOM_EXYNOS
		tristate "EXYNOS HW random number generator support"
		depends on HW_RANDOM && HAS_IOMEM && HAVE_CLK

drivers/char/hw_random/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
		obj-$(CONFIG_HW_RANDOM_PICOXCELL) += picoxcell-rng.o
		obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
		obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
		obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
		obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
		obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
		obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o

drivers/char/hw_random/powernv-rng.c

0 → 100644

+81 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2013 Michael Ellerman, Guo Chao, IBM Corp.
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU General Public License
		* as published by the Free Software Foundation; either version
		* 2 of the License, or (at your option) any later version.
		*/

		#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

		#include <linux/module.h>
		#include <linux/kernel.h>
		#include <linux/platform_device.h>
		#include <linux/random.h>
		#include <linux/hw_random.h>

		static int powernv_rng_read(struct hwrng rng, void data, size_t max, bool wait)
		{
		unsigned long *buf;
		int i, len;

		/* We rely on rng_buffer_size() being >= sizeof(unsigned long) */
		len = max / sizeof(unsigned long);

		buf = (unsigned long *)data;

		for (i = 0; i < len; i++)
		powernv_get_random_long(buf++);

		return len * sizeof(unsigned long);
		}

		static struct hwrng powernv_hwrng = {
		.name = "powernv-rng",
		.read = powernv_rng_read,
		};

		static int powernv_rng_remove(struct platform_device *pdev)
		{
		hwrng_unregister(&powernv_hwrng);

		return 0;
		}

		static int powernv_rng_probe(struct platform_device *pdev)
		{
		int rc;

		rc = hwrng_register(&powernv_hwrng);
		if (rc) {
		/* We only register one device, ignore any others */
		if (rc == -EEXIST)
		rc = -ENODEV;

		return rc;
		}

		pr_info("Registered powernv hwrng.\n");

		return 0;
		}

		static struct of_device_id powernv_rng_match[] = {
		{ .compatible = "ibm,power-rng",},
		{},
		};
		MODULE_DEVICE_TABLE(of, powernv_rng_match);

		static struct platform_driver powernv_rng_driver = {
		.driver = {
		.name = "powernv_rng",
		.of_match_table = powernv_rng_match,
		},
		.probe = powernv_rng_probe,
		.remove = powernv_rng_remove,
		};
		module_platform_driver(powernv_rng_driver);

		MODULE_LICENSE("GPL");
		MODULE_DESCRIPTION("Bare metal HWRNG driver for POWER7+ and above");

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