diff options
Diffstat (limited to 'drivers/crypto/hisilicon/trng/trng.c')
| -rw-r--r-- | drivers/crypto/hisilicon/trng/trng.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/crypto/hisilicon/trng/trng.c b/drivers/crypto/hisilicon/trng/trng.c new file mode 100644 index 000000000..97e500db0 --- /dev/null +++ b/drivers/crypto/hisilicon/trng/trng.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0 +/* 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 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 + +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; + 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; + int currsize = 0; + u32 val = 0; + int ret; + + trng = container_of(rng, struct hisi_trng, rng); + + do { + ret = readl_poll_timeout(trng->base + HISI_TRNG_REG, val, + val, SLEEP_US, TIMEOUT_US); + if (ret) + return currsize; + + if (max - currsize >= HISI_TRNG_BYTES) { + memcpy(buf + currsize, &val, HISI_TRNG_BYTES); + currsize += HISI_TRNG_BYTES; + if (currsize == max) + return currsize; + continue; + } + + /* copy remaining bytes */ + memcpy(buf + currsize, &val, max - currsize); + currsize = max; + } while (currsize < max); + + 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; + int ret; + + trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL); + 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; + 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) { + 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 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 (trng->ver != HISI_TRNG_VER_V1 && + atomic_dec_return(&trng_active_devs) == 0) + crypto_unregister_rng(&hisi_trng_alg); + + return 0; +} + +static const struct acpi_device_id hisi_trng_acpi_match[] = { + { "HISI02B3", 0 }, + { } +}; +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), + }, +}; + +module_platform_driver(hisi_trng_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Weili Qian <qianweili@huawei.com>"); +MODULE_AUTHOR("Zaibo Xu <xuzaibo@huawei.com>"); +MODULE_DESCRIPTION("HiSilicon true random number generator V2 driver"); |