// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 HiSilicon Limited. */
-#include <crypto/internal/rng.h>
#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>
#define HISI_TRNG_REG 0x00F0
#define HISI_TRNG_BYTES 4
#define HISI_TRNG_QUALITY 512
-#define HISI_TRNG_VERSION 0x01B8
-#define HISI_TRNG_VER_V1 GENMASK(31, 0)
#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
-#define SW_MAX_RANDOM_BYTES 65520
-
-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;
- u32 ver;
- u32 ctx_num;
- /* The bytes of the random number generated since the last seeding. */
- u32 random_bytes;
- struct mutex lock;
-};
-
-struct hisi_trng_ctx {
- struct hisi_trng *trng;
};
-static atomic_t trng_active_devs;
-static struct hisi_trng_list trng_devices;
-static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait);
-
-static int hisi_trng_set_seed(struct hisi_trng *trng, const u8 *seed)
-{
- u32 val, seed_reg, i;
- int ret;
-
- writel(0x0, trng->base + SW_DRBG_BLOCKS);
-
- 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));
- }
-
- 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("failed to init trng(%d)\n", ret);
- return -EIO;
- }
-
- trng->random_bytes = 0;
-
- return 0;
-}
-
-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;
- int ret;
-
- if (slen < SW_DRBG_SEED_SIZE) {
- pr_err("slen(%u) is not matched with trng(%d)\n", slen,
- SW_DRBG_SEED_SIZE);
- return -EINVAL;
- }
-
- mutex_lock(&trng->lock);
- ret = hisi_trng_set_seed(trng, seed);
- mutex_unlock(&trng->lock);
-
- return ret;
-}
-
-static int hisi_trng_reseed(struct hisi_trng *trng)
-{
- u8 seed[SW_DRBG_SEED_SIZE];
- int size;
-
- if (!trng->random_bytes)
- return 0;
-
- size = hisi_trng_read(&trng->rng, seed, SW_DRBG_SEED_SIZE, false);
- if (size != SW_DRBG_SEED_SIZE)
- return -EIO;
-
- return hisi_trng_set_seed(trng, seed);
-}
-
-static int hisi_trng_get_bytes(struct hisi_trng *trng, u8 *dstn, unsigned int dlen)
-{
- u32 data[SW_DRBG_DATA_NUM];
- u32 currsize = 0;
- u32 val = 0;
- int ret;
- u32 i;
-
- ret = hisi_trng_reseed(trng);
- if (ret)
- return ret;
-
- do {
- ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,
- val, val & BIT(1), SLEEP_US, TIMEOUT_US);
- if (ret) {
- pr_err("failed 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;
- }
-
- trng->random_bytes += SW_DRBG_BYTES;
- writel(0x1, trng->base + SW_DRBG_GEN);
- } while (currsize < dlen);
-
- 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;
- unsigned int currsize = 0;
- unsigned int block_size;
- int ret;
-
- if (!dstn || !dlen) {
- pr_err("output is error, dlen %u!\n", dlen);
- return -EINVAL;
- }
-
- do {
- block_size = min_t(unsigned int, dlen - currsize, SW_MAX_RANDOM_BYTES);
- mutex_lock(&trng->lock);
- ret = hisi_trng_get_bytes(trng, dstn + currsize, block_size);
- mutex_unlock(&trng->lock);
- if (ret)
- return ret;
- currsize += block_size;
- } while (currsize < dlen);
-
- return 0;
-}
-
-static int hisi_trng_init(struct crypto_tfm *tfm)
-{
- struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);
- struct hisi_trng *trng;
- u32 ctx_num = ~0;
-
- mutex_lock(&trng_devices.lock);
- list_for_each_entry(trng, &trng_devices.list, list) {
- if (trng->ctx_num < ctx_num) {
- ctx_num = trng->ctx_num;
- ctx->trng = trng;
- }
- }
- ctx->trng->ctx_num++;
- mutex_unlock(&trng_devices.lock);
-
- return 0;
-}
-
-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->ctx_num--;
- mutex_unlock(&trng_devices.lock);
-}
-
static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
{
struct hisi_trng *trng;
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->ctx_num) {
- 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;
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->ctx_num = 0;
- trng->random_bytes = SW_MAX_RANDOM_BYTES;
- mutex_init(&trng->lock);
- trng->ver = readl(trng->base + HISI_TRNG_VERSION);
- 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 (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_inc_return(&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_dec_return(&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) {
+ if (ret)
dev_err(&pdev->dev, "failed to register hwrng: %d!\n", ret);
- goto err_crypto_unregister;
- }
-
- return ret;
-
-err_crypto_unregister:
- if (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_dec_return(&trng_active_devs) == 0)
- crypto_unregister_rng(&hisi_trng_alg);
-
-err_remove_from_list:
- hisi_trng_del_from_list(trng);
return ret;
}
-static void 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 (trng->ver != HISI_TRNG_VER_V1 &&
- atomic_dec_return(&trng_active_devs) == 0)
- crypto_unregister_rng(&hisi_trng_alg);
-}
-
static const struct acpi_device_id hisi_trng_acpi_match[] = {
{ "HISI02B3", 0 },
{ }
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),
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