[PATCH 3/4] crypto: hisilicon/trng - add support for PRNG
From: Weili Qian
Date: Fri Nov 20 2020 - 04:06:20 EST
This patch adds support for pseudo random number generator(PRNG)
in Crypto subsystem.
Signed-off-by: Weili Qian <qianweili@xxxxxxxxxx>
Reviewed-by: Zaibo Xu <xuzaibo@xxxxxxxxxx>
---
drivers/crypto/hisilicon/Kconfig | 1 +
drivers/crypto/hisilicon/trng/trng.c | 241 ++++++++++++++++++++++++++++++++++-
2 files changed, 239 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index 2cd3298..8431926 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -76,5 +76,6 @@ config CRYPTO_DEV_HISI_TRNG
tristate "Support for HISI TRNG Driver"
depends on ARM64 && ACPI
select HW_RANDOM
+ select CRYPTO_RNG
help
Support for HiSilicon TRNG Driver.
diff --git a/drivers/crypto/hisilicon/trng/trng.c b/drivers/crypto/hisilicon/trng/trng.c
index 6a65b82..a5033cf 100644
--- a/drivers/crypto/hisilicon/trng/trng.c
+++ b/drivers/crypto/hisilicon/trng/trng.c
@@ -2,26 +2,181 @@
/* Copyright (c) 2019 HiSilicon Limited. */
#include <linux/acpi.h>
+#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/hw_random.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/random.h>
+#include <crypto/internal/rng.h>
#define HISI_TRNG_REG 0x00F0
#define HISI_TRNG_BYTES 4
#define HISI_TRNG_QUALITY 512
#define SLEEP_US 10
#define TIMEOUT_US 10000
+#define SW_DRBG_NUM_SHIFT 2
+#define SW_DRBG_KEY_BASE 0x082C
+#define SW_DRBG_SEED(n) (SW_DRBG_KEY_BASE - ((n) << SW_DRBG_NUM_SHIFT))
+#define SW_DRBG_SEED_REGS_NUM 12
+#define SW_DRBG_SEED_SIZE 48
+#define SW_DRBG_BLOCKS 0x0830
+#define SW_DRBG_INIT 0x0834
+#define SW_DRBG_GEN 0x083c
+#define SW_DRBG_STATUS 0x0840
+#define SW_DRBG_BLOCKS_NUM 4095
+#define SW_DRBG_DATA_BASE 0x0850
+#define SW_DRBG_DATA_NUM 4
+#define SW_DRBG_DATA(n) (SW_DRBG_DATA_BASE - ((n) << SW_DRBG_NUM_SHIFT))
+#define SW_DRBG_BYTES 16
+#define SW_DRBG_ENABLE_SHIFT 12
+#define SEED_SHIFT_24 24
+#define SEED_SHIFT_16 16
+#define SEED_SHIFT_8 8
+
+struct hisi_trng_list {
+ struct mutex lock;
+ struct list_head list;
+ bool is_init;
+};
struct hisi_trng {
void __iomem *base;
+ struct hisi_trng_list *trng_list;
+ struct list_head list;
struct hwrng rng;
+ bool is_used;
+ struct mutex mutex;
+};
+
+struct hisi_trng_ctx {
+ struct hisi_trng *trng;
};
+static atomic_t trng_active_devs;
+static struct hisi_trng_list trng_devices;
+
+static void hisi_trng_set_seed(struct hisi_trng *trng, const u8 *seed)
+{
+ u32 val, seed_reg, i;
+
+ for (i = 0; i < SW_DRBG_SEED_SIZE;
+ i += SW_DRBG_SEED_SIZE / SW_DRBG_SEED_REGS_NUM) {
+ val = seed[i] << SEED_SHIFT_24;
+ val |= seed[i + 1UL] << SEED_SHIFT_16;
+ val |= seed[i + 2UL] << SEED_SHIFT_8;
+ val |= seed[i + 3UL];
+
+ seed_reg = (i >> SW_DRBG_NUM_SHIFT) % SW_DRBG_SEED_REGS_NUM;
+ writel(val, trng->base + SW_DRBG_SEED(seed_reg));
+ }
+}
+
+static int hisi_trng_seed(struct crypto_rng *tfm, const u8 *seed,
+ unsigned int slen)
+{
+ struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);
+ struct hisi_trng *trng = ctx->trng;
+ u32 val = 0;
+ int ret = 0;
+
+ if (slen < SW_DRBG_SEED_SIZE) {
+ pr_err("slen(%u) is not matched with trng(%d)\n", slen,
+ SW_DRBG_SEED_SIZE);
+ return -EINVAL;
+ }
+
+ writel(0x0, trng->base + SW_DRBG_BLOCKS);
+ hisi_trng_set_seed(trng, seed);
+
+ writel(SW_DRBG_BLOCKS_NUM | (0x1 << SW_DRBG_ENABLE_SHIFT),
+ trng->base + SW_DRBG_BLOCKS);
+ writel(0x1, trng->base + SW_DRBG_INIT);
+
+ ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,
+ val, val & BIT(0), SLEEP_US, TIMEOUT_US);
+ if (ret)
+ pr_err("fail to init trng(%d)\n", ret);
+
+ return ret;
+}
+
+static int hisi_trng_generate(struct crypto_rng *tfm, const u8 *src,
+ unsigned int slen, u8 *dstn, unsigned int dlen)
+{
+ struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);
+ struct hisi_trng *trng = ctx->trng;
+ u32 data[SW_DRBG_DATA_NUM];
+ u32 currsize = 0;
+ u32 val = 0;
+ int ret;
+ u32 i;
+
+ if (dlen > SW_DRBG_BLOCKS_NUM * SW_DRBG_BYTES || dlen == 0) {
+ pr_err("dlen(%d) exceeds limit(%d)!\n", dlen,
+ SW_DRBG_BLOCKS_NUM * SW_DRBG_BYTES);
+ return -EINVAL;
+ }
+
+ do {
+ ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,
+ val, val & BIT(1), SLEEP_US, TIMEOUT_US);
+ if (ret) {
+ pr_err("fail to generate random number(%d)!\n", ret);
+ break;
+ }
+
+ for (i = 0; i < SW_DRBG_DATA_NUM; i++)
+ data[i] = readl(trng->base + SW_DRBG_DATA(i));
+
+ if (dlen - currsize >= SW_DRBG_BYTES) {
+ memcpy(dstn + currsize, data, SW_DRBG_BYTES);
+ currsize += SW_DRBG_BYTES;
+ } else {
+ memcpy(dstn + currsize, data, dlen - currsize);
+ currsize = dlen;
+ }
+
+ writel(0x1, trng->base + SW_DRBG_GEN);
+ } while (currsize < dlen);
+
+ return ret;
+}
+
+static int hisi_trng_init(struct crypto_tfm *tfm)
+{
+ struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct hisi_trng *trng;
+ int ret = -EBUSY;
+
+ mutex_lock(&trng_devices.lock);
+ list_for_each_entry(trng, &trng_devices.list, list) {
+ if (!trng->is_used) {
+ trng->is_used = true;
+ ctx->trng = trng;
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&trng_devices.lock);
+
+ return ret;
+}
+
+static void hisi_trng_exit(struct crypto_tfm *tfm)
+{
+ struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ mutex_lock(&trng_devices.lock);
+ ctx->trng->is_used = false;
+ mutex_unlock(&trng_devices.lock);
+}
+
static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
{
struct hisi_trng *trng;
@@ -53,6 +208,42 @@ static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
return currsize;
}
+static struct rng_alg hisi_trng_alg = {
+ .generate = hisi_trng_generate,
+ .seed = hisi_trng_seed,
+ .seedsize = SW_DRBG_SEED_SIZE,
+ .base = {
+ .cra_name = "stdrng",
+ .cra_driver_name = "hisi_stdrng",
+ .cra_priority = 300,
+ .cra_ctxsize = sizeof(struct hisi_trng_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = hisi_trng_init,
+ .cra_exit = hisi_trng_exit,
+ },
+};
+
+static void hisi_trng_add_to_list(struct hisi_trng *trng)
+{
+ mutex_lock(&trng_devices.lock);
+ list_add_tail(&trng->list, &trng_devices.list);
+ mutex_unlock(&trng_devices.lock);
+}
+
+static int hisi_trng_del_from_list(struct hisi_trng *trng)
+{
+ int ret = -EBUSY;
+
+ mutex_lock(&trng_devices.lock);
+ if (!trng->is_used) {
+ list_del(&trng->list);
+ ret = 0;
+ }
+ mutex_unlock(&trng_devices.lock);
+
+ return ret;
+}
+
static int hisi_trng_probe(struct platform_device *pdev)
{
struct hisi_trng *trng;
@@ -62,19 +253,62 @@ static int hisi_trng_probe(struct platform_device *pdev)
if (!trng)
return -ENOMEM;
+ platform_set_drvdata(pdev, trng);
+
trng->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(trng->base))
return PTR_ERR(trng->base);
+ trng->is_used = false;
+ if (!trng_devices.is_init) {
+ INIT_LIST_HEAD(&trng_devices.list);
+ mutex_init(&trng_devices.lock);
+ trng_devices.is_init = true;
+ }
+
+ hisi_trng_add_to_list(trng);
+ if (atomic_add_return(1, &trng_active_devs) == 1) {
+ ret = crypto_register_rng(&hisi_trng_alg);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "failed to register crypto(%d)\n", ret);
+ atomic_sub_return(1, &trng_active_devs);
+ goto err_remove_from_list;
+ }
+ }
+
trng->rng.name = pdev->name;
trng->rng.read = hisi_trng_read;
trng->rng.quality = HISI_TRNG_QUALITY;
-
ret = devm_hwrng_register(&pdev->dev, &trng->rng);
- if (ret)
- dev_err(&pdev->dev, "failed to register hwrng!\n");
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register hwrng: %d!\n", ret);
+ goto err_crypto_unregister;
+ }
return ret;
+
+err_crypto_unregister:
+ if (atomic_sub_return(1, &trng_active_devs) == 0)
+ crypto_unregister_rng(&hisi_trng_alg);
+
+err_remove_from_list:
+ hisi_trng_del_from_list(trng);
+ return ret;
+}
+
+static int hisi_trng_remove(struct platform_device *pdev)
+{
+ struct hisi_trng *trng = platform_get_drvdata(pdev);
+
+ /* Wait until the task is finished */
+ while (hisi_trng_del_from_list(trng))
+ ;
+
+ if (atomic_sub_return(1, &trng_active_devs) == 0)
+ crypto_unregister_rng(&hisi_trng_alg);
+
+ return 0;
}
static const struct acpi_device_id hisi_trng_acpi_match[] = {
@@ -85,6 +319,7 @@ MODULE_DEVICE_TABLE(acpi, hisi_trng_acpi_match);
static struct platform_driver hisi_trng_driver = {
.probe = hisi_trng_probe,
+ .remove = hisi_trng_remove,
.driver = {
.name = "hisi-trng-v2",
.acpi_match_table = ACPI_PTR(hisi_trng_acpi_match),
--
2.8.1