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Commit a064eb98 authored by Zhen Kong's avatar Zhen Kong
Browse files

hwrng: Add QRNG driver snapshot for kona 



This is a snapshot of the qrng driver as of msm-4.19
commit e74173d56eb2c869 ("hwrng: Add QRNG driver
snapshot for kona") with changes to comply with
msm-5.4 format requirement.

Change-Id: I930b0dfd70db8b2c1ffcb98965aabe45bffbd0ba
Signed-off-by: default avatarZhen Kong <zkong@codeaurora.org>
parent 77a29a8c

drivers/char/hw_random/Kconfig

+14 −0
Original line number Diff line number Diff line
@@ -308,6 +308,20 @@ config HW_RANDOM_HISI 


	  If unsure, say Y.



config HW_RANDOM_MSM_LEGACY

	tristate "QTI MSM Random Number Generator support (LEGACY)"

	depends on HW_RANDOM && ARCH_QCOM

	select CRYPTO_AES

	select CRYPTO_ECB

	help

	  This driver provides kernel-side support for the Random Number

	  Generator hardware found on QTI MSM SoCs.



	  To compile this driver as a module, choose M here: the

	  module will be called msm_rng.



	  If unsure, say Y.



config HW_RANDOM_ST

	tristate "ST Microelectronics HW Random Number Generator support"

	depends on HW_RANDOM && ARCH_STI

drivers/char/hw_random/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o 
obj-$(CONFIG_HW_RANDOM_HISI)	+= hisi-rng.o

obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o

obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o

obj-$(CONFIG_HW_RANDOM_MSM_LEGACY) += msm_rng.o

obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o

obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o

obj-$(CONFIG_HW_RANDOM_STM32) += stm32-rng.o

drivers/char/hw_random/msm_rng.c

0 → 100644
+484 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (c) 2011-2013, 2015, 2017-2019 The Linux Foundation. All rights

 * reserved.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/hw_random.h>

#include <linux/clk.h>

#include <linux/slab.h>

#include <linux/io.h>

#include <linux/err.h>

#include <linux/types.h>

#include <linux/of.h>

#include <linux/qrng.h>

#include <linux/fs.h>

#include <linux/cdev.h>

#include <linux/delay.h>

#include <linux/crypto.h>

#include <crypto/internal/rng.h>

#include <linux/interconnect.h>

#include <linux/sched/signal.h>



#define DRIVER_NAME "msm_rng"



/* Device specific register offsets */

#define PRNG_DATA_OUT_OFFSET    0x0000

#define PRNG_STATUS_OFFSET	0x0004

#define PRNG_LFSR_CFG_OFFSET	0x0100

#define PRNG_CONFIG_OFFSET	0x0104



/* Device specific register masks and config values */

#define PRNG_LFSR_CFG_MASK	0xFFFF0000

#define PRNG_LFSR_CFG_CLOCKS	0x0000DDDD

#define PRNG_CONFIG_MASK	0xFFFFFFFD

#define PRNG_HW_ENABLE		0x00000002



#define MAX_HW_FIFO_DEPTH 16                     /* FIFO is 16 words deep */

#define MAX_HW_FIFO_SIZE (MAX_HW_FIFO_DEPTH * 4) /* FIFO is 32 bits wide  */



#define RETRY_MAX_CNT		5	/* max retry times to read register */

#define RETRY_DELAY_INTERVAL	440	/* retry delay interval in us */



struct msm_rng_device {

	struct platform_device *pdev;

	void __iomem *base;

	struct clk *prng_clk;

	struct mutex rng_lock;

	struct icc_path *icc_path;

};



static struct msm_rng_device msm_rng_device_info;

static struct msm_rng_device *msm_rng_dev_cached;

static struct mutex cached_rng_lock;

static long msm_rng_ioctl(struct file *filp, unsigned int cmd,

				unsigned long arg)

{

	long ret = 0;



	switch (cmd) {

	case QRNG_IOCTL_RESET_BUS_BANDWIDTH:

		pr_debug("calling msm_rng_bus_scale(LOW)\n");

		ret = icc_set_bw(msm_rng_device_info.icc_path, 0, 0);

		if (ret)

			pr_err("failed qrng_reset_bus_bw, ret = %ld\n", ret);

		break;

	default:

		pr_err("Unsupported IOCTL call\n");

		break;

	}

	return ret;

}



/*

 *

 *  This function calls hardware random bit generator directory and retuns it

 *  back to caller

 *

 */

static int msm_rng_direct_read(struct msm_rng_device *msm_rng_dev,

					void *data, size_t max)

{

	struct platform_device *pdev;

	void __iomem *base;

	size_t currsize = 0;

	u32 val = 0;

	u32 *retdata = data;

	int ret;

	int failed = 0;



	pdev = msm_rng_dev->pdev;

	base = msm_rng_dev->base;



	/* no room for word data */

	if (max < 4)

		return 0;



	mutex_lock(&msm_rng_dev->rng_lock);



	if (msm_rng_dev->icc_path) {

		ret = icc_set_bw(msm_rng_dev->icc_path, 0, 300000);

		if (ret) {

			pr_err("bus_scale_client_update_req failed\n");

			goto bus_err;

		}

	}

	/* enable PRNG clock */

	if (msm_rng_dev->prng_clk) {

		ret = clk_prepare_enable(msm_rng_dev->prng_clk);

		if (ret) {

			pr_err("failed to enable prng clock\n");

			goto err;

		}

	}

	/* read random data from h/w */

	do {

		/* check status bit if data is available */

		if (!(readl_relaxed(base + PRNG_STATUS_OFFSET)

				& 0x00000001)) {

			if (failed++ == RETRY_MAX_CNT) {

				if (currsize == 0)

					pr_err("Data not available\n");

				break;

			}

			udelay(RETRY_DELAY_INTERVAL);

		} else {



			/* read FIFO */

			val = readl_relaxed(base + PRNG_DATA_OUT_OFFSET);



			/* write data back to callers pointer */

			*(retdata++) = val;

			currsize += 4;

			/* make sure we stay on 32bit boundary */

			if ((max - currsize) < 4)

				break;

		}



	} while (currsize < max);



	/* vote to turn off clock */

	if (msm_rng_dev->prng_clk)

		clk_disable_unprepare(msm_rng_dev->prng_clk);

err:

	if (msm_rng_dev->icc_path) {

		ret = icc_set_bw(msm_rng_dev->icc_path, 0, 0);

		if (ret)

			pr_err("bus_scale_client_update_req failed\n");

	}

bus_err:

	mutex_unlock(&msm_rng_dev->rng_lock);



	val = 0L;

	return currsize;

}

static int msm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)

{

	struct msm_rng_device *msm_rng_dev;

	int rv = 0;



	msm_rng_dev = (struct msm_rng_device *)rng->priv;

	rv = msm_rng_direct_read(msm_rng_dev, data, max);



	return rv;

}





static struct hwrng msm_rng = {

	.name = DRIVER_NAME,

	.read = msm_rng_read,

	.quality = 1024,

};



static int msm_rng_enable_hw(struct msm_rng_device *msm_rng_dev)

{

	unsigned long val = 0;

	unsigned long reg_val = 0;

	int ret = 0;



	if (msm_rng_dev->icc_path) {

		ret = icc_set_bw(msm_rng_dev->icc_path, 0, 30000);

		if (ret)

			pr_err("bus_scale_client_update_req failed\n");

	}

	/* Enable the PRNG CLK */

	if (msm_rng_dev->prng_clk) {

		ret = clk_prepare_enable(msm_rng_dev->prng_clk);

		if (ret) {

			dev_err(&(msm_rng_dev->pdev)->dev,

				"failed to enable clock in probe\n");

			return -EPERM;

		}

	}



	/* Enable PRNG h/w only if it is NOT ON */

	val = readl_relaxed(msm_rng_dev->base + PRNG_CONFIG_OFFSET) &

					PRNG_HW_ENABLE;

	/* PRNG H/W is not ON */

	if (val != PRNG_HW_ENABLE) {

		val = readl_relaxed(msm_rng_dev->base + PRNG_LFSR_CFG_OFFSET);

		val &= PRNG_LFSR_CFG_MASK;

		val |= PRNG_LFSR_CFG_CLOCKS;

		writel_relaxed(val, msm_rng_dev->base + PRNG_LFSR_CFG_OFFSET);



		/* The PRNG CONFIG register should be first written */

		mb();



		reg_val = readl_relaxed(msm_rng_dev->base + PRNG_CONFIG_OFFSET)

						& PRNG_CONFIG_MASK;

		reg_val |= PRNG_HW_ENABLE;

		writel_relaxed(reg_val, msm_rng_dev->base + PRNG_CONFIG_OFFSET);



		/* The PRNG clk should be disabled only after we enable the

		 * PRNG h/w by writing to the PRNG CONFIG register.

		 */

		mb();

	}

	if (msm_rng_dev->prng_clk)

		clk_disable_unprepare(msm_rng_dev->prng_clk);



	if (msm_rng_dev->icc_path) {

		ret = icc_set_bw(msm_rng_dev->icc_path, 0, 0);

		if (ret)

			pr_err("bus_scale_client_update_req failed\n");

	}



	return 0;

}



static const struct file_operations msm_rng_fops = {

	.unlocked_ioctl = msm_rng_ioctl,

};

static struct class *msm_rng_class;

static struct cdev msm_rng_cdev;



static int msm_rng_probe(struct platform_device *pdev)

{

	struct resource *res;

	struct msm_rng_device *msm_rng_dev = NULL;

	void __iomem *base = NULL;

	bool configure_qrng = true;

	int error = 0;

	struct device *dev;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (res == NULL) {

		dev_err(&pdev->dev, "invalid address\n");

		error = -EFAULT;

		goto err_exit;

	}



	msm_rng_dev = kzalloc(sizeof(struct msm_rng_device), GFP_KERNEL);

	if (!msm_rng_dev) {

		error = -ENOMEM;

		goto err_exit;

	}



	base = ioremap(res->start, resource_size(res));

	if (!base) {

		dev_err(&pdev->dev, "ioremap failed\n");

		error = -ENOMEM;

		goto err_iomap;

	}

	msm_rng_dev->base = base;



	/* create a handle for clock control */

	if (pdev->dev.of_node) {

		if (of_property_read_bool(pdev->dev.of_node,

					"qcom,no-clock-support"))

			msm_rng_dev->prng_clk = NULL;

		else

			msm_rng_dev->prng_clk = clk_get(&pdev->dev,

							"km_clk_src");

	}



	if (IS_ERR(msm_rng_dev->prng_clk)) {

		dev_err(&pdev->dev, "failed to register clock source\n");

		error = -ENODEV;

		goto err_clk_get;

	}



	/* save away pdev and register driver data */

	msm_rng_dev->pdev = pdev;

	platform_set_drvdata(pdev, msm_rng_dev);



	if (pdev->dev.of_node) {

		msm_rng_dev->icc_path = of_icc_get(&pdev->dev, "data_path");

		msm_rng_device_info.icc_path = msm_rng_dev->icc_path;

		if (IS_ERR(msm_rng_dev->icc_path)) {

			error = PTR_ERR(msm_rng_dev->icc_path);

			dev_err(&pdev->dev, "get icc path err %d\n", error);

			goto err_icc_get;

		}

	}



	/* Enable rng h/w for the targets which can access the entire

	 * address space of PRNG.

	 */

	if ((pdev->dev.of_node) && (of_property_read_bool(pdev->dev.of_node,

					"qcom,no-qrng-config")))

		configure_qrng = false;

	if (configure_qrng) {

		error = msm_rng_enable_hw(msm_rng_dev);

		if (error)

			goto err_icc_get;

	}



	mutex_init(&msm_rng_dev->rng_lock);

	mutex_init(&cached_rng_lock);



	/* register with hwrng framework */

	msm_rng.priv = (unsigned long) msm_rng_dev;

	error = hwrng_register(&msm_rng);

	if (error) {

		dev_err(&pdev->dev, "failed to register hwrng\n");

		goto err_reg_hwrng;

	}

	error = register_chrdev(QRNG_IOC_MAGIC, DRIVER_NAME, &msm_rng_fops);

	if (error) {

		dev_err(&pdev->dev, "failed to register chrdev\n");

		goto err_reg_chrdev;

	}



	msm_rng_class = class_create(THIS_MODULE, "msm-rng");

	if (IS_ERR(msm_rng_class)) {

		pr_err("class_create failed\n");

		error = PTR_ERR(msm_rng_class);

		goto err_create_cls;

	}



	dev = device_create(msm_rng_class, NULL, MKDEV(QRNG_IOC_MAGIC, 0),

				NULL, "msm-rng");

	if (IS_ERR(dev)) {

		pr_err("Device create failed\n");

		error = PTR_ERR(dev);

		goto err_create_dev;

	}

	cdev_init(&msm_rng_cdev, &msm_rng_fops);

	msm_rng_dev_cached = msm_rng_dev;

	return error;



err_create_dev:

	class_destroy(msm_rng_class);

err_create_cls:

	unregister_chrdev(QRNG_IOC_MAGIC, DRIVER_NAME);

err_reg_chrdev:

	hwrng_unregister(&msm_rng);

err_reg_hwrng:

	if (msm_rng_dev->icc_path)

		icc_put(msm_rng_dev->icc_path);

err_icc_get:

	if (msm_rng_dev->prng_clk)

		clk_put(msm_rng_dev->prng_clk);

err_clk_get:

	iounmap(msm_rng_dev->base);

err_iomap:

	kzfree(msm_rng_dev);

err_exit:

	return error;

}



static int msm_rng_remove(struct platform_device *pdev)

{

	struct msm_rng_device *msm_rng_dev = platform_get_drvdata(pdev);



	unregister_chrdev(QRNG_IOC_MAGIC, DRIVER_NAME);

	hwrng_unregister(&msm_rng);

	if (msm_rng_dev->prng_clk)

		clk_put(msm_rng_dev->prng_clk);

	iounmap(msm_rng_dev->base);

	platform_set_drvdata(pdev, NULL);

	if (msm_rng_dev->icc_path)

		icc_put(msm_rng_dev->icc_path);



	kzfree(msm_rng_dev);

	msm_rng_dev_cached = NULL;

	return 0;

}



static int qrng_get_random(struct crypto_rng *tfm, const u8 *src,

				unsigned int slen, u8 *rdata,

				unsigned int dlen)

{

	int sizeread = 0;

	int rv = -EFAULT;



	if (!msm_rng_dev_cached) {

		pr_err("%s: msm_rng_dev is not initialized\n", __func__);

		rv = -ENODEV;

		goto err_exit;

	}



	if (!rdata) {

		pr_err("%s: data buffer is null\n", __func__);

		rv = -EINVAL;

		goto err_exit;

	}



	if (signal_pending(current) ||

		mutex_lock_interruptible(&cached_rng_lock)) {

		pr_err("%s: mutex lock interrupted\n", __func__);

		rv = -ERESTARTSYS;

		goto err_exit;

	}

	sizeread = msm_rng_direct_read(msm_rng_dev_cached, rdata, dlen);



	if (sizeread == dlen)

		rv = 0;



	mutex_unlock(&cached_rng_lock);

err_exit:

	return rv;



}



static int qrng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)

{

	return 0;

}



static struct rng_alg rng_algs[] = { {

	.generate	= qrng_get_random,

	.seed		= qrng_reset,

	.seedsize	= 0,

	.base		= {

		.cra_name		= "qrng",

		.cra_driver_name	= "fips_hw_qrng",

		.cra_priority		= 300,

		.cra_ctxsize		= 0,

		.cra_module		= THIS_MODULE,

	}

} };



static const struct of_device_id qrng_match[] = {

	{.compatible = "qcom,msm-rng"},

	{},

};



static struct platform_driver rng_driver = {

	.probe      = msm_rng_probe,

	.remove     = msm_rng_remove,

	.driver     = {

		.name   = DRIVER_NAME,

		.of_match_table = qrng_match,

	},

};



static int __init msm_rng_init(void)

{

	int ret;



	msm_rng_dev_cached = NULL;

	ret = platform_driver_register(&rng_driver);

	if (ret) {

		pr_err("%s: platform_driver_register error:%d\n",

			__func__, ret);

		goto err_exit;

	}

	ret = crypto_register_rngs(rng_algs, ARRAY_SIZE(rng_algs));

	if (ret) {

		pr_err("%s: crypto_register_algs error:%d\n",

			__func__, ret);

		goto err_exit;

	}



err_exit:

	return ret;

}



module_init(msm_rng_init);



static void __exit msm_rng_exit(void)

{

	crypto_unregister_rngs(rng_algs, ARRAY_SIZE(rng_algs));

	platform_driver_unregister(&rng_driver);

}



module_exit(msm_rng_exit);



MODULE_DESCRIPTION("QTI MSM Random Number Driver");

MODULE_LICENSE("GPL v2");

include/uapi/linux/qrng.h

0 → 100644
+13 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */

#ifndef _UAPI_QRNG_H_

#define _UAPI_QRNG_H_



#include <linux/types.h>

#include <linux/ioctl.h>



#define QRNG_IOC_MAGIC    0x100



#define QRNG_IOCTL_RESET_BUS_BANDWIDTH\

	_IO(QRNG_IOC_MAGIC, 1)



#endif /* _UAPI_QRNG_H_ */