diff options
Diffstat (limited to 'drivers/crypto/stm32/stm32-crc32.c')
| -rw-r--r-- | drivers/crypto/stm32/stm32-crc32.c | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c new file mode 100644 index 000000000..90a920e7f --- /dev/null +++ b/drivers/crypto/stm32/stm32-crc32.c @@ -0,0 +1,487 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) STMicroelectronics SA 2017 + * Author: Fabien Dessenne <fabien.dessenne@st.com> + */ + +#include <linux/bitrev.h> +#include <linux/clk.h> +#include <linux/crc32.h> +#include <linux/crc32poly.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> + +#include <crypto/internal/hash.h> + +#include <asm/unaligned.h> + +#define DRIVER_NAME "stm32-crc32" +#define CHKSUM_DIGEST_SIZE 4 +#define CHKSUM_BLOCK_SIZE 1 + +/* Registers */ +#define CRC_DR 0x00000000 +#define CRC_CR 0x00000008 +#define CRC_INIT 0x00000010 +#define CRC_POL 0x00000014 + +/* Registers values */ +#define CRC_CR_RESET BIT(0) +#define CRC_CR_REV_IN_WORD (BIT(6) | BIT(5)) +#define CRC_CR_REV_IN_BYTE BIT(5) +#define CRC_CR_REV_OUT BIT(7) +#define CRC32C_INIT_DEFAULT 0xFFFFFFFF + +#define CRC_AUTOSUSPEND_DELAY 50 + +static unsigned int burst_size; +module_param(burst_size, uint, 0644); +MODULE_PARM_DESC(burst_size, "Select burst byte size (0 unlimited)"); + +struct stm32_crc { + struct list_head list; + struct device *dev; + void __iomem *regs; + struct clk *clk; + spinlock_t lock; +}; + +struct stm32_crc_list { + struct list_head dev_list; + spinlock_t lock; /* protect dev_list */ +}; + +static struct stm32_crc_list crc_list = { + .dev_list = LIST_HEAD_INIT(crc_list.dev_list), + .lock = __SPIN_LOCK_UNLOCKED(crc_list.lock), +}; + +struct stm32_crc_ctx { + u32 key; + u32 poly; +}; + +struct stm32_crc_desc_ctx { + u32 partial; /* crc32c: partial in first 4 bytes of that struct */ +}; + +static int stm32_crc32_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = 0; + mctx->poly = CRC32_POLY_LE; + return 0; +} + +static int stm32_crc32c_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = CRC32C_INIT_DEFAULT; + mctx->poly = CRC32C_POLY_LE; + return 0; +} + +static int stm32_crc_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen) +{ + struct stm32_crc_ctx *mctx = crypto_shash_ctx(tfm); + + if (keylen != sizeof(u32)) + return -EINVAL; + + mctx->key = get_unaligned_le32(key); + return 0; +} + +static struct stm32_crc *stm32_crc_get_next_crc(void) +{ + struct stm32_crc *crc; + + spin_lock_bh(&crc_list.lock); + crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list); + if (crc) + list_move_tail(&crc->list, &crc_list.dev_list); + spin_unlock_bh(&crc_list.lock); + + return crc; +} + +static int stm32_crc_init(struct shash_desc *desc) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); + struct stm32_crc *crc; + unsigned long flags; + + crc = stm32_crc_get_next_crc(); + if (!crc) + return -ENODEV; + + pm_runtime_get_sync(crc->dev); + + spin_lock_irqsave(&crc->lock, flags); + + /* Reset, set key, poly and configure in bit reverse mode */ + writel_relaxed(bitrev32(mctx->key), crc->regs + CRC_INIT); + writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL); + writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, + crc->regs + CRC_CR); + + /* Store partial result */ + ctx->partial = readl_relaxed(crc->regs + CRC_DR); + + spin_unlock_irqrestore(&crc->lock, flags); + + pm_runtime_mark_last_busy(crc->dev); + pm_runtime_put_autosuspend(crc->dev); + + return 0; +} + +static int burst_update(struct shash_desc *desc, const u8 *d8, + size_t length) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); + struct stm32_crc *crc; + + crc = stm32_crc_get_next_crc(); + if (!crc) + return -ENODEV; + + pm_runtime_get_sync(crc->dev); + + if (!spin_trylock(&crc->lock)) { + /* Hardware is busy, calculate crc32 by software */ + if (mctx->poly == CRC32_POLY_LE) + ctx->partial = crc32_le(ctx->partial, d8, length); + else + ctx->partial = __crc32c_le(ctx->partial, d8, length); + + goto pm_out; + } + + /* + * Restore previously calculated CRC for this context as init value + * Restore polynomial configuration + * Configure in register for word input data, + * Configure out register in reversed bit mode data. + */ + writel_relaxed(bitrev32(ctx->partial), crc->regs + CRC_INIT); + writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL); + writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, + crc->regs + CRC_CR); + + if (d8 != PTR_ALIGN(d8, sizeof(u32))) { + /* Configure for byte data */ + writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT, + crc->regs + CRC_CR); + while (d8 != PTR_ALIGN(d8, sizeof(u32)) && length) { + writeb_relaxed(*d8++, crc->regs + CRC_DR); + length--; + } + /* Configure for word data */ + writel_relaxed(CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, + crc->regs + CRC_CR); + } + + for (; length >= sizeof(u32); d8 += sizeof(u32), length -= sizeof(u32)) + writel_relaxed(*((u32 *)d8), crc->regs + CRC_DR); + + if (length) { + /* Configure for byte data */ + writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT, + crc->regs + CRC_CR); + while (length--) + writeb_relaxed(*d8++, crc->regs + CRC_DR); + } + + /* Store partial result */ + ctx->partial = readl_relaxed(crc->regs + CRC_DR); + + spin_unlock(&crc->lock); + +pm_out: + pm_runtime_mark_last_busy(crc->dev); + pm_runtime_put_autosuspend(crc->dev); + + return 0; +} + +static int stm32_crc_update(struct shash_desc *desc, const u8 *d8, + unsigned int length) +{ + const unsigned int burst_sz = burst_size; + unsigned int rem_sz; + const u8 *cur; + size_t size; + int ret; + + if (!burst_sz) + return burst_update(desc, d8, length); + + /* Digest first bytes not 32bit aligned at first pass in the loop */ + size = min_t(size_t, length, burst_sz + (size_t)d8 - + ALIGN_DOWN((size_t)d8, sizeof(u32))); + for (rem_sz = length, cur = d8; rem_sz; + rem_sz -= size, cur += size, size = min(rem_sz, burst_sz)) { + ret = burst_update(desc, cur, size); + if (ret) + return ret; + } + + return 0; +} + +static int stm32_crc_final(struct shash_desc *desc, u8 *out) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); + + /* Send computed CRC */ + put_unaligned_le32(mctx->poly == CRC32C_POLY_LE ? + ~ctx->partial : ctx->partial, out); + + return 0; +} + +static int stm32_crc_finup(struct shash_desc *desc, const u8 *data, + unsigned int length, u8 *out) +{ + return stm32_crc_update(desc, data, length) ?: + stm32_crc_final(desc, out); +} + +static int stm32_crc_digest(struct shash_desc *desc, const u8 *data, + unsigned int length, u8 *out) +{ + return stm32_crc_init(desc) ?: stm32_crc_finup(desc, data, length, out); +} + +static unsigned int refcnt; +static DEFINE_MUTEX(refcnt_lock); +static struct shash_alg algs[] = { + /* CRC-32 */ + { + .setkey = stm32_crc_setkey, + .init = stm32_crc_init, + .update = stm32_crc_update, + .final = stm32_crc_final, + .finup = stm32_crc_finup, + .digest = stm32_crc_digest, + .descsize = sizeof(struct stm32_crc_desc_ctx), + .digestsize = CHKSUM_DIGEST_SIZE, + .base = { + .cra_name = "crc32", + .cra_driver_name = "stm32-crc32-crc32", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_alignmask = 3, + .cra_ctxsize = sizeof(struct stm32_crc_ctx), + .cra_module = THIS_MODULE, + .cra_init = stm32_crc32_cra_init, + } + }, + /* CRC-32Castagnoli */ + { + .setkey = stm32_crc_setkey, + .init = stm32_crc_init, + .update = stm32_crc_update, + .final = stm32_crc_final, + .finup = stm32_crc_finup, + .digest = stm32_crc_digest, + .descsize = sizeof(struct stm32_crc_desc_ctx), + .digestsize = CHKSUM_DIGEST_SIZE, + .base = { + .cra_name = "crc32c", + .cra_driver_name = "stm32-crc32-crc32c", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_alignmask = 3, + .cra_ctxsize = sizeof(struct stm32_crc_ctx), + .cra_module = THIS_MODULE, + .cra_init = stm32_crc32c_cra_init, + } + } +}; + +static int stm32_crc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_crc *crc; + int ret; + + crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL); + if (!crc) + return -ENOMEM; + + crc->dev = dev; + + crc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(crc->regs)) { + dev_err(dev, "Cannot map CRC IO\n"); + return PTR_ERR(crc->regs); + } + + crc->clk = devm_clk_get(dev, NULL); + if (IS_ERR(crc->clk)) { + dev_err(dev, "Could not get clock\n"); + return PTR_ERR(crc->clk); + } + + ret = clk_prepare_enable(crc->clk); + if (ret) { + dev_err(crc->dev, "Failed to enable clock\n"); + return ret; + } + + pm_runtime_set_autosuspend_delay(dev, CRC_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(dev); + + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_irq_safe(dev); + pm_runtime_enable(dev); + + spin_lock_init(&crc->lock); + + platform_set_drvdata(pdev, crc); + + spin_lock(&crc_list.lock); + list_add(&crc->list, &crc_list.dev_list); + spin_unlock(&crc_list.lock); + + mutex_lock(&refcnt_lock); + if (!refcnt) { + ret = crypto_register_shashes(algs, ARRAY_SIZE(algs)); + if (ret) { + mutex_unlock(&refcnt_lock); + dev_err(dev, "Failed to register\n"); + clk_disable_unprepare(crc->clk); + return ret; + } + } + refcnt++; + mutex_unlock(&refcnt_lock); + + dev_info(dev, "Initialized\n"); + + pm_runtime_put_sync(dev); + + return 0; +} + +static int stm32_crc_remove(struct platform_device *pdev) +{ + struct stm32_crc *crc = platform_get_drvdata(pdev); + int ret = pm_runtime_get_sync(crc->dev); + + if (ret < 0) { + pm_runtime_put_noidle(crc->dev); + return ret; + } + + spin_lock(&crc_list.lock); + list_del(&crc->list); + spin_unlock(&crc_list.lock); + + mutex_lock(&refcnt_lock); + if (!--refcnt) + crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); + mutex_unlock(&refcnt_lock); + + pm_runtime_disable(crc->dev); + pm_runtime_put_noidle(crc->dev); + + clk_disable_unprepare(crc->clk); + + return 0; +} + +static int __maybe_unused stm32_crc_suspend(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + int ret; + + ret = pm_runtime_force_suspend(dev); + if (ret) + return ret; + + clk_unprepare(crc->clk); + + return 0; +} + +static int __maybe_unused stm32_crc_resume(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare(crc->clk); + if (ret) { + dev_err(crc->dev, "Failed to prepare clock\n"); + return ret; + } + + return pm_runtime_force_resume(dev); +} + +static int __maybe_unused stm32_crc_runtime_suspend(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + + clk_disable(crc->clk); + + return 0; +} + +static int __maybe_unused stm32_crc_runtime_resume(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + int ret; + + ret = clk_enable(crc->clk); + if (ret) { + dev_err(crc->dev, "Failed to enable clock\n"); + return ret; + } + + return 0; +} + +static const struct dev_pm_ops stm32_crc_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(stm32_crc_suspend, + stm32_crc_resume) + SET_RUNTIME_PM_OPS(stm32_crc_runtime_suspend, + stm32_crc_runtime_resume, NULL) +}; + +static const struct of_device_id stm32_dt_ids[] = { + { .compatible = "st,stm32f7-crc", }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_dt_ids); + +static struct platform_driver stm32_crc_driver = { + .probe = stm32_crc_probe, + .remove = stm32_crc_remove, + .driver = { + .name = DRIVER_NAME, + .pm = &stm32_crc_pm_ops, + .of_match_table = stm32_dt_ids, + }, +}; + +module_platform_driver(stm32_crc_driver); + +MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>"); +MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver"); +MODULE_LICENSE("GPL"); |