This module registers a CRC32 ("Ethernet") and a CRC32C (Castagnoli) algorithm that make use of the STMicroelectronics STM32 crypto hardware. Theses algorithms are compatible with the little-endian generic ones. Both algorithms use ~0 as default seed (key). With CRC32C the output is xored with ~0. Using TCRYPT CRC32C speed test, this shows up to 900% speedup compared to the crc32c-generic algorithm. Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxx> --- drivers/crypto/Kconfig | 2 + drivers/crypto/Makefile | 1 + drivers/crypto/stm32/Kconfig | 8 + drivers/crypto/stm32/Makefile | 2 + drivers/crypto/stm32/stm32_crc32.c | 324 +++++++++++++++++++++++++++++++++++++ 5 files changed, 337 insertions(+) create mode 100644 drivers/crypto/stm32/Kconfig create mode 100644 drivers/crypto/stm32/Makefile create mode 100644 drivers/crypto/stm32/stm32_crc32.c diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 473d312..922b323 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -619,4 +619,6 @@ config CRYPTO_DEV_BCM_SPU Secure Processing Unit (SPU). The SPU driver registers ablkcipher, ahash, and aead algorithms with the kernel cryptographic API. +source "drivers/crypto/stm32/Kconfig" + endif # CRYPTO_HW diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile index 7396094..95bf2f9 100644 --- a/drivers/crypto/Makefile +++ b/drivers/crypto/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_CRYPTO_DEV_QCE) += qce/ obj-$(CONFIG_CRYPTO_DEV_ROCKCHIP) += rockchip/ obj-$(CONFIG_CRYPTO_DEV_S5P) += s5p-sss.o obj-$(CONFIG_CRYPTO_DEV_SAHARA) += sahara.o +obj-$(CONFIG_CRYPTO_DEV_STM32) += stm32/ obj-$(CONFIG_CRYPTO_DEV_SUN4I_SS) += sunxi-ss/ obj-$(CONFIG_CRYPTO_DEV_TALITOS) += talitos.o obj-$(CONFIG_CRYPTO_DEV_UX500) += ux500/ diff --git a/drivers/crypto/stm32/Kconfig b/drivers/crypto/stm32/Kconfig new file mode 100644 index 0000000..792335b --- /dev/null +++ b/drivers/crypto/stm32/Kconfig @@ -0,0 +1,8 @@ +config CRYPTO_DEV_STM32 + tristate "Support for STM32 crypto accelerators" + depends on ARCH_STM32 + select CRYPTO_HASH + help + This enables support for the CRC32 hw accelerator which can be found + on STMicroelectronis STM32 SOC. + diff --git a/drivers/crypto/stm32/Makefile b/drivers/crypto/stm32/Makefile new file mode 100644 index 0000000..73b4c6e --- /dev/null +++ b/drivers/crypto/stm32/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_CRYPTO_DEV_STM32) += stm32_cryp.o +stm32_cryp-objs := stm32_crc32.o diff --git a/drivers/crypto/stm32/stm32_crc32.c b/drivers/crypto/stm32/stm32_crc32.c new file mode 100644 index 0000000..7652822 --- /dev/null +++ b/drivers/crypto/stm32/stm32_crc32.c @@ -0,0 +1,324 @@ +/* + * Copyright (C) STMicroelectronics SA 2017 + * Author: Fabien Dessenne <fabien.dessenne@xxxxxx> + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/bitrev.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/platform_device.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_REVERSE (BIT(7) | BIT(6) | BIT(5)) +#define CRC_INIT_DEFAULT 0xFFFFFFFF + +/* Polynomial reversed */ +#define POLY_CRC32 0xEDB88320 +#define POLY_CRC32C 0x82F63B78 + +struct stm32_crc { + struct list_head list; + struct device *dev; + void __iomem *regs; + struct clk *clk; + u8 pending_data[sizeof(u32)]; + size_t nb_pending_bytes; +}; + +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 */ + struct stm32_crc *crc; +}; + +static int stm32_crc32_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = CRC_INIT_DEFAULT; + mctx->poly = POLY_CRC32; + return 0; +} + +static int stm32_crc32c_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = CRC_INIT_DEFAULT; + mctx->poly = POLY_CRC32C; + 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)) { + crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + + mctx->key = get_unaligned_le32(key); + return 0; +} + +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; + + spin_lock_bh(&crc_list.lock); + list_for_each_entry(crc, &crc_list.dev_list, list) { + ctx->crc = crc; + break; + } + spin_unlock_bh(&crc_list.lock); + + /* Reset, set key, poly and configure in bit reverse mode */ + writel(bitrev32(mctx->key), ctx->crc->regs + CRC_INIT); + writel(bitrev32(mctx->poly), ctx->crc->regs + CRC_POL); + writel(CRC_CR_RESET | CRC_CR_REVERSE, ctx->crc->regs + CRC_CR); + + /* Store partial result */ + ctx->partial = readl(ctx->crc->regs + CRC_DR); + ctx->crc->nb_pending_bytes = 0; + + return 0; +} + +static int stm32_crc_update(struct shash_desc *desc, const u8 *d8, + unsigned int length) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc *crc = ctx->crc; + u32 *d32; + unsigned int i; + + if (unlikely(crc->nb_pending_bytes)) { + while (crc->nb_pending_bytes != sizeof(u32) && length) { + /* Fill in pending data */ + crc->pending_data[crc->nb_pending_bytes++] = *(d8++); + length--; + } + + if (crc->nb_pending_bytes == sizeof(u32)) { + /* Process completed pending data */ + writel(*(u32 *)crc->pending_data, crc->regs + CRC_DR); + crc->nb_pending_bytes = 0; + } + } + + d32 = (u32 *)d8; + for (i = 0; i < length >> 2; i++) + /* Process 32 bits data */ + writel(*(d32++), crc->regs + CRC_DR); + + /* Store partial result */ + ctx->partial = readl(crc->regs + CRC_DR); + + /* Check for pending data (non 32 bits) */ + length &= 3; + if (likely(!length)) + return 0; + + if ((crc->nb_pending_bytes + length) >= sizeof(u32)) { + /* Shall not happen */ + dev_err(crc->dev, "Pending data overflow\n"); + return -EINVAL; + } + + d8 = (const u8 *)d32; + for (i = 0; i < length; i++) + /* Store pending data */ + crc->pending_data[crc->nb_pending_bytes++] = *(d8++); + + 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 == POLY_CRC32C ? + ~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 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 = DRIVER_NAME, + .cra_priority = 200, + .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 = DRIVER_NAME, + .cra_priority = 200, + .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; + struct resource *res; + int ret; + + crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL); + if (!crc) + return -ENOMEM; + + crc->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + crc->regs = devm_ioremap_resource(dev, res); + 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; + } + + platform_set_drvdata(pdev, crc); + + spin_lock(&crc_list.lock); + list_add(&crc->list, &crc_list.dev_list); + spin_unlock(&crc_list.lock); + + ret = crypto_register_shashes(algs, ARRAY_SIZE(algs)); + if (ret) { + dev_err(dev, "Failed to register\n"); + clk_disable_unprepare(crc->clk); + return ret; + } + + dev_info(dev, "Initialized\n"); + + return 0; +} + +static int stm32_crc_remove(struct platform_device *pdev) +{ + struct stm32_crc *crc = platform_get_drvdata(pdev); + + spin_lock(&crc_list.lock); + list_del(&crc->list); + spin_unlock(&crc_list.lock); + + crypto_unregister_shash(algs); + + clk_disable_unprepare(crc->clk); + + return 0; +} + +static const struct of_device_id stm32_dt_ids[] = { + { .compatible = "st,stm32f7-crc", }, + {}, +}; +MODULE_DEVICE_TABLE(of, sti_dt_ids); + +static struct platform_driver stm32_crc_driver = { + .probe = stm32_crc_probe, + .remove = stm32_crc_remove, + .driver = { + .name = DRIVER_NAME, + .of_match_table = stm32_dt_ids, + }, +}; + +module_platform_driver(stm32_crc_driver); + +MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@xxxxxx>"); +MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver"); +MODULE_LICENSE("GPL"); -- 2.7.4