crypto: exynos-rng - Remove exynos-rng driver

This driver has no purpose. It doesn't feed into the Linux RNG, nor does it implement the hwrng interface. It is accessible only via the "rng" algorithm type of AF_ALG, which isn't used in practice. Everyone uses either the Linux RNG, or rarely /dev/hwrng.

Moreover, this is a PRNG whose only source of entropy is the 160-bit seed the user passes in. So this can be used only by a user who already has a source of cryptographically secure random numbers, such as /dev/random. Which they can, and do, just use in the first place.

This driver has no purpose. It doesn't feed into the Linux RNG, nor does it implement the hwrng interface. It is accessible only via the "rng" algorithm type of AF_ALG, which isn't used in practice. Everyone uses either the Linux RNG, or rarely /dev/hwrng.

Moreover, this is a PRNG whose only source of entropy is the 160-bit seed the user passes in. So this can be used only by a user who already has a source of cryptographically secure random numbers, such as /dev/random. Which they can, and do, just use in the first place.

Just remove this driver. There's no need to keep useless code around.

Note that the other crypto_rng drivers in drivers/crypto/ are similarly unused and are being removed too. This commit just handles exynos-rng.

Signed-off-by Eric Biggers <[email protected]>

---

 MAINTAINERS                         |   8 -
 arch/arm/configs/exynos_defconfig   |   1 -
 arch/arm/configs/multi_v7_defconfig |   1 -
 drivers/crypto/Kconfig              |  18 --
 drivers/crypto/Makefile             |   1 -
 drivers/crypto/exynos-rng.c         | 399 ----------------------------
 6 files changed, 428 deletions(-)
 delete mode 100644 drivers/crypto/exynos-rng.c

MAINTAINERS +0 -8

index 882214b0e7db..a7f2762baac1 100644
@@ -23701,18 +23701,10 @@ L:    [email protected]
 S:     Supported
 F:     Documentation/devicetree/bindings/mailbox/google,gs101-mbox.yaml
 F:     drivers/mailbox/exynos-mailbox.c
 F:     include/linux/mailbox/exynos-message.h
 
-SAMSUNG EXYNOS PSEUDO RANDOM NUMBER GENERATOR (RNG) DRIVER
-M:     Krzysztof Kozlowski <[email protected]>
-L:     [email protected]
-L:     [email protected]
-S:     Maintained
-F:     Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml
-F:     drivers/crypto/exynos-rng.c
-
 SAMSUNG EXYNOS TRUE RANDOM NUMBER GENERATOR (TRNG) DRIVER
 M:     Łukasz Stelmach <[email protected]>
 L:     [email protected]
 S:     Maintained
 F:     Documentation/devicetree/bindings/rng/samsung,exynos5250-trng.yaml

arch/arm/configs/exynos_defconfig +0 -1

index 84070e9698e8..8b072a5c0a5e 100644
@@ -362,11 +362,10 @@ CONFIG_CRYPTO_LZ4=m
 CONFIG_CRYPTO_USER_API_HASH=m
 CONFIG_CRYPTO_USER_API_SKCIPHER=m
 CONFIG_CRYPTO_USER_API_RNG=m
 CONFIG_CRYPTO_USER_API_AEAD=m
 CONFIG_CRYPTO_AES_ARM_BS=m
-CONFIG_CRYPTO_DEV_EXYNOS_RNG=y
 CONFIG_CRYPTO_DEV_S5P=y
 CONFIG_DMA_CMA=y
 CONFIG_CMA_SIZE_MBYTES=96
 CONFIG_FONTS=y
 CONFIG_FONT_7x14=y

arch/arm/configs/multi_v7_defconfig +0 -1

index bcc9aabc1202..3672dd12df60 100644
@@ -1327,11 +1327,10 @@ CONFIG_CRYPTO_GHASH_ARM_CE=m
 CONFIG_CRYPTO_AES=m
 CONFIG_CRYPTO_AES_ARM_BS=m
 CONFIG_CRYPTO_AES_ARM_CE=m
 CONFIG_CRYPTO_DEV_SUN4I_SS=m
 CONFIG_CRYPTO_DEV_FSL_CAAM=m
-CONFIG_CRYPTO_DEV_EXYNOS_RNG=m
 CONFIG_CRYPTO_DEV_S5P=m
 CONFIG_CRYPTO_DEV_ATMEL_AES=m
 CONFIG_CRYPTO_DEV_ATMEL_TDES=m
 CONFIG_CRYPTO_DEV_ATMEL_SHA=m
 CONFIG_CRYPTO_DEV_MARVELL_CESA=m

drivers/crypto/Kconfig +0 -18

index 3449b3c9c6ad..39c7b195bb33 100644
@@ -373,25 +373,10 @@ config CRYPTO_DEV_SAHARA
        select CRYPTO_ENGINE
        help
          This option enables support for the SAHARA HW crypto accelerator
          found in some Freescale i.MX chips.
 
-config CRYPTO_DEV_EXYNOS_RNG
-       tristate "Exynos HW pseudo random number generator support"
-       depends on ARCH_EXYNOS || COMPILE_TEST
-       depends on HAS_IOMEM
-       select CRYPTO_RNG
-       help
-         This driver provides kernel-side support through the
-         cryptographic API for the pseudo random number generator hardware
-         found on Exynos SoCs.
-
-         To compile this driver as a module, choose M here: the
-         module will be called exynos-rng.
-
-         If unsure, say Y.
-
 config CRYPTO_DEV_S5P
        tristate "Support for Samsung S5PV210/Exynos crypto accelerator"
        depends on ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
        depends on HAS_IOMEM
        select CRYPTO_AES

@@ -402,20 +387,17 @@ config CRYPTO_DEV_S5P
          algorithms execution.
 
 config CRYPTO_DEV_EXYNOS_HASH
        bool "Support for Samsung Exynos HASH accelerator"
        depends on CRYPTO_DEV_S5P
-       depends on !CRYPTO_DEV_EXYNOS_RNG && CRYPTO_DEV_EXYNOS_RNG!=m
        select CRYPTO_SHA1
        select CRYPTO_MD5
        select CRYPTO_SHA256
        help
          Select this to offload Exynos from HASH MD5/SHA1/SHA256.
          This will select software SHA1, MD5 and SHA256 as they are
          needed for small and zero-size messages.
-         HASH algorithms will be disabled if EXYNOS_RNG
-         is enabled due to hw conflict.
 
 config CRYPTO_DEV_NX
        bool "Support for IBM PowerPC Nest (NX) cryptographic acceleration"
        depends on PPC64
        help

drivers/crypto/Makefile +0 -1

index 283bbc650b5b..e141ab0dd741 100644
@@ -9,11 +9,10 @@ obj-$(CONFIG_CRYPTO_DEV_ATMEL_I2C) += atmel-i2c.o
 obj-$(CONFIG_CRYPTO_DEV_ATMEL_ECC) += atmel-ecc.o
 obj-$(CONFIG_CRYPTO_DEV_ATMEL_SHA204A) += atmel-sha204a.o
 obj-$(CONFIG_CRYPTO_DEV_CCP) += ccp/
 obj-$(CONFIG_CRYPTO_DEV_CCREE) += ccree/
 obj-$(CONFIG_CRYPTO_DEV_CHELSIO) += chelsio/
-obj-$(CONFIG_CRYPTO_DEV_EXYNOS_RNG) += exynos-rng.o
 obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_COMMON) += caam/
 obj-$(CONFIG_CRYPTO_DEV_GEODE) += geode-aes.o
 obj-$(CONFIG_CRYPTO_DEV_HIFN_795X) += hifn_795x.o
 obj-$(CONFIG_CRYPTO_DEV_IMGTEC_HASH) += img-hash.o
 obj-$(CONFIG_CRYPTO_DEV_MARVELL) += marvell/

drivers/crypto/exynos-rng.c deleted +0 -399

deleted file mode 100644
index 2aaa98f9b44e..000000000000
@@ -1,399 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * exynos-rng.c - Random Number Generator driver for the Exynos
- *
- * Copyright (c) 2017 Krzysztof Kozlowski <[email protected]>
- *
- * Loosely based on old driver from drivers/char/hw_random/exynos-rng.c:
- * Copyright (C) 2012 Samsung Electronics
- * Jonghwa Lee <[email protected]>
- */
-
-#include <linux/clk.h>
-#include <linux/crypto.h>
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-
-#include <crypto/internal/rng.h>
-
-#define EXYNOS_RNG_CONTROL             0x0
-#define EXYNOS_RNG_STATUS              0x10
-
-#define EXYNOS_RNG_SEED_CONF           0x14
-#define EXYNOS_RNG_GEN_PRNG            BIT(1)
-
-#define EXYNOS_RNG_SEED_BASE           0x140
-#define EXYNOS_RNG_SEED(n)             (EXYNOS_RNG_SEED_BASE + (n * 0x4))
-#define EXYNOS_RNG_OUT_BASE            0x160
-#define EXYNOS_RNG_OUT(n)              (EXYNOS_RNG_OUT_BASE + (n * 0x4))
-
-/* EXYNOS_RNG_CONTROL bit fields */
-#define EXYNOS_RNG_CONTROL_START       0x18
-/* EXYNOS_RNG_STATUS bit fields */
-#define EXYNOS_RNG_STATUS_SEED_SETTING_DONE    BIT(1)
-#define EXYNOS_RNG_STATUS_RNG_DONE             BIT(5)
-
-/* Five seed and output registers, each 4 bytes */
-#define EXYNOS_RNG_SEED_REGS           5
-#define EXYNOS_RNG_SEED_SIZE           (EXYNOS_RNG_SEED_REGS * 4)
-
-enum exynos_prng_type {
-       EXYNOS_PRNG_UNKNOWN = 0,
-       EXYNOS_PRNG_EXYNOS4,
-       EXYNOS_PRNG_EXYNOS5,
-};
-
-/*
- * Driver re-seeds itself with generated random numbers to hinder
- * backtracking of the original seed.
- *
- * Time for next re-seed in ms.
- */
-#define EXYNOS_RNG_RESEED_TIME         1000
-#define EXYNOS_RNG_RESEED_BYTES                65536
-
-/*
- * In polling mode, do not wait infinitely for the engine to finish the work.
- */
-#define EXYNOS_RNG_WAIT_RETRIES                100
-
-/* Context for crypto */
-struct exynos_rng_ctx {
-       struct exynos_rng_dev           *rng;
-};
-
-/* Device associated memory */
-struct exynos_rng_dev {
-       struct device                   *dev;
-       enum exynos_prng_type           type;
-       void __iomem                    *mem;
-       struct clk                      *clk;
-       struct mutex                    lock;
-       /* Generated numbers stored for seeding during resume */
-       u8                              seed_save[EXYNOS_RNG_SEED_SIZE];
-       unsigned int                    seed_save_len;
-       /* Time of last seeding in jiffies */
-       unsigned long                   last_seeding;
-       /* Bytes generated since last seeding */
-       unsigned long                   bytes_seeding;
-};
-
-static struct exynos_rng_dev *exynos_rng_dev;
-
-static u32 exynos_rng_readl(struct exynos_rng_dev *rng, u32 offset)
-{
-       return readl_relaxed(rng->mem + offset);
-}
-
-static void exynos_rng_writel(struct exynos_rng_dev *rng, u32 val, u32 offset)
-{
-       writel_relaxed(val, rng->mem + offset);
-}
-
-static int exynos_rng_set_seed(struct exynos_rng_dev *rng,
-                              const u8 *seed, unsigned int slen)
-{
-       u32 val;
-       int i;
-
-       /* Round seed length because loop iterates over full register size */
-       slen = ALIGN_DOWN(slen, 4);
-
-       if (slen < EXYNOS_RNG_SEED_SIZE)
-               return -EINVAL;
-
-       for (i = 0; i < slen ; i += 4) {
-               unsigned int seed_reg = (i / 4) % EXYNOS_RNG_SEED_REGS;
-
-               val = seed[i] << 24;
-               val |= seed[i + 1] << 16;
-               val |= seed[i + 2] << 8;
-               val |= seed[i + 3] << 0;
-
-               exynos_rng_writel(rng, val, EXYNOS_RNG_SEED(seed_reg));
-       }
-
-       val = exynos_rng_readl(rng, EXYNOS_RNG_STATUS);
-       if (!(val & EXYNOS_RNG_STATUS_SEED_SETTING_DONE)) {
-               dev_warn(rng->dev, "Seed setting not finished\n");
-               return -EIO;
-       }
-
-       rng->last_seeding = jiffies;
-       rng->bytes_seeding = 0;
-
-       return 0;
-}
-
-/*
- * Start the engine and poll for finish.  Then read from output registers
- * filling the 'dst' buffer up to 'dlen' bytes or up to size of generated
- * random data (EXYNOS_RNG_SEED_SIZE).
- *
- * On success: return 0 and store number of read bytes under 'read' address.
- * On error: return -ERRNO.
- */
-static int exynos_rng_get_random(struct exynos_rng_dev *rng,
-                                u8 *dst, unsigned int dlen,
-                                unsigned int *read)
-{
-       int retry = EXYNOS_RNG_WAIT_RETRIES;
-
-       if (rng->type == EXYNOS_PRNG_EXYNOS4) {
-               exynos_rng_writel(rng, EXYNOS_RNG_CONTROL_START,
-                                 EXYNOS_RNG_CONTROL);
-       } else if (rng->type == EXYNOS_PRNG_EXYNOS5) {
-               exynos_rng_writel(rng, EXYNOS_RNG_GEN_PRNG,
-                                 EXYNOS_RNG_SEED_CONF);
-       }
-
-       while (!(exynos_rng_readl(rng,
-                       EXYNOS_RNG_STATUS) & EXYNOS_RNG_STATUS_RNG_DONE) && --retry)
-               cpu_relax();
-
-       if (!retry)
-               return -ETIMEDOUT;
-
-       /* Clear status bit */
-       exynos_rng_writel(rng, EXYNOS_RNG_STATUS_RNG_DONE,
-                         EXYNOS_RNG_STATUS);
-       *read = min_t(size_t, dlen, EXYNOS_RNG_SEED_SIZE);
-       memcpy_fromio(dst, rng->mem + EXYNOS_RNG_OUT_BASE, *read);
-       rng->bytes_seeding += *read;
-
-       return 0;
-}
-
-/* Re-seed itself from time to time */
-static void exynos_rng_reseed(struct exynos_rng_dev *rng)
-{
-       unsigned long next_seeding = rng->last_seeding + \
-                                    msecs_to_jiffies(EXYNOS_RNG_RESEED_TIME);
-       unsigned long now = jiffies;
-       unsigned int read = 0;
-       u8 seed[EXYNOS_RNG_SEED_SIZE];
-
-       if (time_before(now, next_seeding) &&
-           rng->bytes_seeding < EXYNOS_RNG_RESEED_BYTES)
-               return;
-
-       if (exynos_rng_get_random(rng, seed, sizeof(seed), &read))
-               return;
-
-       exynos_rng_set_seed(rng, seed, read);
-
-       /* Let others do some of their job. */
-       mutex_unlock(&rng->lock);
-       mutex_lock(&rng->lock);
-}
-
-static int exynos_rng_generate(struct crypto_rng *tfm,
-                              const u8 *src, unsigned int slen,
-                              u8 *dst, unsigned int dlen)
-{
-       struct exynos_rng_ctx *ctx = crypto_rng_ctx(tfm);
-       struct exynos_rng_dev *rng = ctx->rng;
-       unsigned int read = 0;
-       int ret;
-
-       ret = clk_prepare_enable(rng->clk);
-       if (ret)
-               return ret;
-
-       mutex_lock(&rng->lock);
-       do {
-               ret = exynos_rng_get_random(rng, dst, dlen, &read);
-               if (ret)
-                       break;
-
-               dlen -= read;
-               dst += read;
-
-               exynos_rng_reseed(rng);
-       } while (dlen > 0);
-       mutex_unlock(&rng->lock);
-
-       clk_disable_unprepare(rng->clk);
-
-       return ret;
-}
-
-static int exynos_rng_seed(struct crypto_rng *tfm, const u8 *seed,
-                          unsigned int slen)
-{
-       struct exynos_rng_ctx *ctx = crypto_rng_ctx(tfm);
-       struct exynos_rng_dev *rng = ctx->rng;
-       int ret;
-
-       ret = clk_prepare_enable(rng->clk);
-       if (ret)
-               return ret;
-
-       mutex_lock(&rng->lock);
-       ret = exynos_rng_set_seed(ctx->rng, seed, slen);
-       mutex_unlock(&rng->lock);
-
-       clk_disable_unprepare(rng->clk);
-
-       return ret;
-}
-
-static int exynos_rng_kcapi_init(struct crypto_tfm *tfm)
-{
-       struct exynos_rng_ctx *ctx = crypto_tfm_ctx(tfm);
-
-       ctx->rng = exynos_rng_dev;
-
-       return 0;
-}
-
-static struct rng_alg exynos_rng_alg = {
-       .generate               = exynos_rng_generate,
-       .seed                   = exynos_rng_seed,
-       .seedsize               = EXYNOS_RNG_SEED_SIZE,
-       .base                   = {
-               .cra_name               = "stdrng",
-               .cra_driver_name        = "exynos_rng",
-               .cra_priority           = 300,
-               .cra_ctxsize            = sizeof(struct exynos_rng_ctx),
-               .cra_module             = THIS_MODULE,
-               .cra_init               = exynos_rng_kcapi_init,
-       }
-};
-
-static int exynos_rng_probe(struct platform_device *pdev)
-{
-       struct exynos_rng_dev *rng;
-       int ret;
-
-       if (exynos_rng_dev)
-               return -EEXIST;
-
-       rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
-       if (!rng)
-               return -ENOMEM;
-
-       rng->type = (uintptr_t)of_device_get_match_data(&pdev->dev);
-
-       mutex_init(&rng->lock);
-
-       rng->dev = &pdev->dev;
-       rng->clk = devm_clk_get(&pdev->dev, "secss");
-       if (IS_ERR(rng->clk)) {
-               dev_err(&pdev->dev, "Couldn't get clock.\n");
-               return PTR_ERR(rng->clk);
-       }
-
-       rng->mem = devm_platform_ioremap_resource(pdev, 0);
-       if (IS_ERR(rng->mem))
-               return PTR_ERR(rng->mem);
-
-       platform_set_drvdata(pdev, rng);
-
-       exynos_rng_dev = rng;
-
-       ret = crypto_register_rng(&exynos_rng_alg);
-       if (ret) {
-               dev_err(&pdev->dev,
-                       "Couldn't register rng crypto alg: %d\n", ret);
-               exynos_rng_dev = NULL;
-       }
-
-       return ret;
-}
-
-static void exynos_rng_remove(struct platform_device *pdev)
-{
-       crypto_unregister_rng(&exynos_rng_alg);
-
-       exynos_rng_dev = NULL;
-}
-
-static int __maybe_unused exynos_rng_suspend(struct device *dev)
-{
-       struct exynos_rng_dev *rng = dev_get_drvdata(dev);
-       int ret;
-
-       /* If we were never seeded then after resume it will be the same */
-       if (!rng->last_seeding)
-               return 0;
-
-       rng->seed_save_len = 0;
-       ret = clk_prepare_enable(rng->clk);
-       if (ret)
-               return ret;
-
-       mutex_lock(&rng->lock);
-
-       /* Get new random numbers and store them for seeding on resume. */
-       exynos_rng_get_random(rng, rng->seed_save, sizeof(rng->seed_save),
-                             &(rng->seed_save_len));
-
-       mutex_unlock(&rng->lock);
-
-       dev_dbg(rng->dev, "Stored %u bytes for seeding on system resume\n",
-               rng->seed_save_len);
-
-       clk_disable_unprepare(rng->clk);
-
-       return 0;
-}
-
-static int __maybe_unused exynos_rng_resume(struct device *dev)
-{
-       struct exynos_rng_dev *rng = dev_get_drvdata(dev);
-       int ret;
-
-       /* Never seeded so nothing to do */
-       if (!rng->last_seeding)
-               return 0;
-
-       ret = clk_prepare_enable(rng->clk);
-       if (ret)
-               return ret;
-
-       mutex_lock(&rng->lock);
-
-       ret = exynos_rng_set_seed(rng, rng->seed_save, rng->seed_save_len);
-
-       mutex_unlock(&rng->lock);
-
-       clk_disable_unprepare(rng->clk);
-
-       return ret;
-}
-
-static SIMPLE_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_suspend,
-                        exynos_rng_resume);
-
-static const struct of_device_id exynos_rng_dt_match[] = {
-       {
-               .compatible = "samsung,exynos4-rng",
-               .data = (const void *)EXYNOS_PRNG_EXYNOS4,
-       }, {
-               .compatible = "samsung,exynos5250-prng",
-               .data = (const void *)EXYNOS_PRNG_EXYNOS5,
-       },
-       { },
-};
-MODULE_DEVICE_TABLE(of, exynos_rng_dt_match);
-
-static struct platform_driver exynos_rng_driver = {
-       .driver         = {
-               .name   = "exynos-rng",
-               .pm     = &exynos_rng_pm_ops,
-               .of_match_table = exynos_rng_dt_match,
-       },
-       .probe          = exynos_rng_probe,
-       .remove         = exynos_rng_remove,
-};
-
-module_platform_driver(exynos_rng_driver);
-
-MODULE_DESCRIPTION("Exynos H/W Random Number Generator driver");
-MODULE_AUTHOR("Krzysztof Kozlowski <[email protected]>");
-MODULE_LICENSE("GPL v2");

base-commit: 5624ea54f3ba5c83d2e5503411a31a8be0278c1e --
2.54.0

Hi Eric,

Quoted 16 lines · Eric Biggers

This driver has no purpose. It doesn't feed into the Linux RNG, nor does it implement the hwrng interface. It is accessible only via the "rng" algorithm type of AF_ALG, which isn't used in practice. Everyone uses either the Linux RNG, or rarely /dev/hwrng.

Moreover, this is a PRNG whose only source of entropy is the 160-bit seed the user passes in. So this can be used only by a user who already has a source of cryptographically secure random numbers, such as /dev/random. Which they can, and do, just use in the first place.

Just remove this driver. There's no need to keep useless code around.

Note that the other crypto_rng drivers in drivers/crypto/ are similarly unused and are being removed too. This commit just handles exynos-rng.

Quoted 2 lines

Signed-off-by Eric Biggers <[email protected]>

---

If the driver is being removed, should the binding documentation for this driver not also be deleted (see Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml)?

Peter

Quoted 26 lines · Peter Griffin

Hi Eric,

Quoted 11 lines · Eric Biggers

This driver has no purpose. It doesn't feed into the Linux RNG, nor does it implement the hwrng interface. It is accessible only via the "rng" algorithm type of AF_ALG, which isn't used in practice. Everyone uses either the Linux RNG, or rarely /dev/hwrng.

Moreover, this is a PRNG whose only source of entropy is the 160-bit seed the user passes in. So this can be used only by a user who already has a source of cryptographically secure random numbers, such as /dev/random. Which they can, and do, just use in the first place.

Quoted 7 lines

Just remove this driver. There's no need to keep useless code around.

Note that the other crypto_rng drivers in drivers/crypto/ are similarly unused and are being removed too. This commit just handles exynos-rng.

Signed-off-by Eric Biggers <[email protected]>

---

If the driver is being removed, should the binding documentation for this driver not also be deleted (see Documentation/devicetree/bindings/rng/samsung,exynos4-rng.yaml)?

Quoted 1 line

Peter

In other discussions I've been told that devicetree bindings are hardware descriptions that should still exist even if there is no driver. It doesn't make a lot of sense, but it seems to be what the devicetree people want. I expect there would be objections to removing this binding.

This driver has no purpose. It doesn't feed into the Linux RNG, nor does it implement the hwrng interface. It is accessible only via the "rng" algorithm type of AF_ALG, which isn't used in practice. Everyone uses either the Linux RNG, or rarely /dev/hwrng.

Moreover, this is a PRNG whose only source of entropy is the 160-bit seed the user passes in. So this can be used only by a user who already has a source of cryptographically secure random numbers, such as /dev/random. Which they can, and do, just use in the first place.

Just remove this driver. There's no need to keep useless code around.

Note that the other crypto_rng drivers in drivers/crypto/ are similarly unused and are being removed too. This commit just handles exynos-rng.

Signed-off-by Eric Biggers <[email protected]>

---
 MAINTAINERS                         |   8 -
 arch/arm/configs/exynos_defconfig   |   1 -
 arch/arm/configs/multi_v7_defconfig |   1 -
 drivers/crypto/Kconfig              |  18 --
 drivers/crypto/Makefile             |   1 -
 drivers/crypto/exynos-rng.c         | 399 ----------------------------
 6 files changed, 428 deletions(-)
 delete mode 100644 drivers/crypto/exynos-rng.c