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1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2019 HiSilicon Limited. */3 4#include <crypto/internal/rng.h>5#include <linux/acpi.h>6#include <linux/crypto.h>7#include <linux/err.h>8#include <linux/hw_random.h>9#include <linux/io.h>10#include <linux/iopoll.h>11#include <linux/kernel.h>12#include <linux/list.h>13#include <linux/module.h>14#include <linux/mutex.h>15#include <linux/platform_device.h>16#include <linux/random.h>17 18#define HISI_TRNG_REG 0x00F019#define HISI_TRNG_BYTES 420#define HISI_TRNG_QUALITY 51221#define HISI_TRNG_VERSION 0x01B822#define HISI_TRNG_VER_V1 GENMASK(31, 0)23#define SLEEP_US 1024#define TIMEOUT_US 1000025#define SW_DRBG_NUM_SHIFT 226#define SW_DRBG_KEY_BASE 0x082C27#define SW_DRBG_SEED(n) (SW_DRBG_KEY_BASE - ((n) << SW_DRBG_NUM_SHIFT))28#define SW_DRBG_SEED_REGS_NUM 1229#define SW_DRBG_SEED_SIZE 4830#define SW_DRBG_BLOCKS 0x083031#define SW_DRBG_INIT 0x083432#define SW_DRBG_GEN 0x083c33#define SW_DRBG_STATUS 0x084034#define SW_DRBG_BLOCKS_NUM 409535#define SW_DRBG_DATA_BASE 0x085036#define SW_DRBG_DATA_NUM 437#define SW_DRBG_DATA(n) (SW_DRBG_DATA_BASE - ((n) << SW_DRBG_NUM_SHIFT))38#define SW_DRBG_BYTES 1639#define SW_DRBG_ENABLE_SHIFT 1240#define SEED_SHIFT_24 2441#define SEED_SHIFT_16 1642#define SEED_SHIFT_8 843 44struct hisi_trng_list {45 struct mutex lock;46 struct list_head list;47 bool is_init;48};49 50struct hisi_trng {51 void __iomem *base;52 struct hisi_trng_list *trng_list;53 struct list_head list;54 struct hwrng rng;55 u32 ver;56 bool is_used;57 struct mutex mutex;58};59 60struct hisi_trng_ctx {61 struct hisi_trng *trng;62};63 64static atomic_t trng_active_devs;65static struct hisi_trng_list trng_devices;66 67static void hisi_trng_set_seed(struct hisi_trng *trng, const u8 *seed)68{69 u32 val, seed_reg, i;70 71 for (i = 0; i < SW_DRBG_SEED_SIZE;72 i += SW_DRBG_SEED_SIZE / SW_DRBG_SEED_REGS_NUM) {73 val = seed[i] << SEED_SHIFT_24;74 val |= seed[i + 1UL] << SEED_SHIFT_16;75 val |= seed[i + 2UL] << SEED_SHIFT_8;76 val |= seed[i + 3UL];77 78 seed_reg = (i >> SW_DRBG_NUM_SHIFT) % SW_DRBG_SEED_REGS_NUM;79 writel(val, trng->base + SW_DRBG_SEED(seed_reg));80 }81}82 83static int hisi_trng_seed(struct crypto_rng *tfm, const u8 *seed,84 unsigned int slen)85{86 struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);87 struct hisi_trng *trng = ctx->trng;88 u32 val = 0;89 int ret = 0;90 91 if (slen < SW_DRBG_SEED_SIZE) {92 pr_err("slen(%u) is not matched with trng(%d)\n", slen,93 SW_DRBG_SEED_SIZE);94 return -EINVAL;95 }96 97 writel(0x0, trng->base + SW_DRBG_BLOCKS);98 hisi_trng_set_seed(trng, seed);99 100 writel(SW_DRBG_BLOCKS_NUM | (0x1 << SW_DRBG_ENABLE_SHIFT),101 trng->base + SW_DRBG_BLOCKS);102 writel(0x1, trng->base + SW_DRBG_INIT);103 104 ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,105 val, val & BIT(0), SLEEP_US, TIMEOUT_US);106 if (ret)107 pr_err("fail to init trng(%d)\n", ret);108 109 return ret;110}111 112static int hisi_trng_generate(struct crypto_rng *tfm, const u8 *src,113 unsigned int slen, u8 *dstn, unsigned int dlen)114{115 struct hisi_trng_ctx *ctx = crypto_rng_ctx(tfm);116 struct hisi_trng *trng = ctx->trng;117 u32 data[SW_DRBG_DATA_NUM];118 u32 currsize = 0;119 u32 val = 0;120 int ret;121 u32 i;122 123 if (dlen > SW_DRBG_BLOCKS_NUM * SW_DRBG_BYTES || dlen == 0) {124 pr_err("dlen(%u) exceeds limit(%d)!\n", dlen,125 SW_DRBG_BLOCKS_NUM * SW_DRBG_BYTES);126 return -EINVAL;127 }128 129 do {130 ret = readl_relaxed_poll_timeout(trng->base + SW_DRBG_STATUS,131 val, val & BIT(1), SLEEP_US, TIMEOUT_US);132 if (ret) {133 pr_err("fail to generate random number(%d)!\n", ret);134 break;135 }136 137 for (i = 0; i < SW_DRBG_DATA_NUM; i++)138 data[i] = readl(trng->base + SW_DRBG_DATA(i));139 140 if (dlen - currsize >= SW_DRBG_BYTES) {141 memcpy(dstn + currsize, data, SW_DRBG_BYTES);142 currsize += SW_DRBG_BYTES;143 } else {144 memcpy(dstn + currsize, data, dlen - currsize);145 currsize = dlen;146 }147 148 writel(0x1, trng->base + SW_DRBG_GEN);149 } while (currsize < dlen);150 151 return ret;152}153 154static int hisi_trng_init(struct crypto_tfm *tfm)155{156 struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);157 struct hisi_trng *trng;158 int ret = -EBUSY;159 160 mutex_lock(&trng_devices.lock);161 list_for_each_entry(trng, &trng_devices.list, list) {162 if (!trng->is_used) {163 trng->is_used = true;164 ctx->trng = trng;165 ret = 0;166 break;167 }168 }169 mutex_unlock(&trng_devices.lock);170 171 return ret;172}173 174static void hisi_trng_exit(struct crypto_tfm *tfm)175{176 struct hisi_trng_ctx *ctx = crypto_tfm_ctx(tfm);177 178 mutex_lock(&trng_devices.lock);179 ctx->trng->is_used = false;180 mutex_unlock(&trng_devices.lock);181}182 183static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)184{185 struct hisi_trng *trng;186 int currsize = 0;187 u32 val = 0;188 int ret;189 190 trng = container_of(rng, struct hisi_trng, rng);191 192 do {193 ret = readl_poll_timeout(trng->base + HISI_TRNG_REG, val,194 val, SLEEP_US, TIMEOUT_US);195 if (ret)196 return currsize;197 198 if (max - currsize >= HISI_TRNG_BYTES) {199 memcpy(buf + currsize, &val, HISI_TRNG_BYTES);200 currsize += HISI_TRNG_BYTES;201 if (currsize == max)202 return currsize;203 continue;204 }205 206 /* copy remaining bytes */207 memcpy(buf + currsize, &val, max - currsize);208 currsize = max;209 } while (currsize < max);210 211 return currsize;212}213 214static struct rng_alg hisi_trng_alg = {215 .generate = hisi_trng_generate,216 .seed = hisi_trng_seed,217 .seedsize = SW_DRBG_SEED_SIZE,218 .base = {219 .cra_name = "stdrng",220 .cra_driver_name = "hisi_stdrng",221 .cra_priority = 300,222 .cra_ctxsize = sizeof(struct hisi_trng_ctx),223 .cra_module = THIS_MODULE,224 .cra_init = hisi_trng_init,225 .cra_exit = hisi_trng_exit,226 },227};228 229static void hisi_trng_add_to_list(struct hisi_trng *trng)230{231 mutex_lock(&trng_devices.lock);232 list_add_tail(&trng->list, &trng_devices.list);233 mutex_unlock(&trng_devices.lock);234}235 236static int hisi_trng_del_from_list(struct hisi_trng *trng)237{238 int ret = -EBUSY;239 240 mutex_lock(&trng_devices.lock);241 if (!trng->is_used) {242 list_del(&trng->list);243 ret = 0;244 }245 mutex_unlock(&trng_devices.lock);246 247 return ret;248}249 250static int hisi_trng_probe(struct platform_device *pdev)251{252 struct hisi_trng *trng;253 int ret;254 255 trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);256 if (!trng)257 return -ENOMEM;258 259 platform_set_drvdata(pdev, trng);260 261 trng->base = devm_platform_ioremap_resource(pdev, 0);262 if (IS_ERR(trng->base))263 return PTR_ERR(trng->base);264 265 trng->is_used = false;266 trng->ver = readl(trng->base + HISI_TRNG_VERSION);267 if (!trng_devices.is_init) {268 INIT_LIST_HEAD(&trng_devices.list);269 mutex_init(&trng_devices.lock);270 trng_devices.is_init = true;271 }272 273 hisi_trng_add_to_list(trng);274 if (trng->ver != HISI_TRNG_VER_V1 &&275 atomic_inc_return(&trng_active_devs) == 1) {276 ret = crypto_register_rng(&hisi_trng_alg);277 if (ret) {278 dev_err(&pdev->dev,279 "failed to register crypto(%d)\n", ret);280 atomic_dec_return(&trng_active_devs);281 goto err_remove_from_list;282 }283 }284 285 trng->rng.name = pdev->name;286 trng->rng.read = hisi_trng_read;287 trng->rng.quality = HISI_TRNG_QUALITY;288 ret = devm_hwrng_register(&pdev->dev, &trng->rng);289 if (ret) {290 dev_err(&pdev->dev, "failed to register hwrng: %d!\n", ret);291 goto err_crypto_unregister;292 }293 294 return ret;295 296err_crypto_unregister:297 if (trng->ver != HISI_TRNG_VER_V1 &&298 atomic_dec_return(&trng_active_devs) == 0)299 crypto_unregister_rng(&hisi_trng_alg);300 301err_remove_from_list:302 hisi_trng_del_from_list(trng);303 return ret;304}305 306static void hisi_trng_remove(struct platform_device *pdev)307{308 struct hisi_trng *trng = platform_get_drvdata(pdev);309 310 /* Wait until the task is finished */311 while (hisi_trng_del_from_list(trng))312 ;313 314 if (trng->ver != HISI_TRNG_VER_V1 &&315 atomic_dec_return(&trng_active_devs) == 0)316 crypto_unregister_rng(&hisi_trng_alg);317}318 319static const struct acpi_device_id hisi_trng_acpi_match[] = {320 { "HISI02B3", 0 },321 { }322};323MODULE_DEVICE_TABLE(acpi, hisi_trng_acpi_match);324 325static struct platform_driver hisi_trng_driver = {326 .probe = hisi_trng_probe,327 .remove_new = hisi_trng_remove,328 .driver = {329 .name = "hisi-trng-v2",330 .acpi_match_table = ACPI_PTR(hisi_trng_acpi_match),331 },332};333 334module_platform_driver(hisi_trng_driver);335 336MODULE_LICENSE("GPL v2");337MODULE_AUTHOR("Weili Qian <qianweili@huawei.com>");338MODULE_AUTHOR("Zaibo Xu <xuzaibo@huawei.com>");339MODULE_DESCRIPTION("HiSilicon true random number generator V2 driver");340