From: Eric Biggers Date: Sun, 1 Jun 2025 19:34:41 +0000 (-0700) Subject: crypto: stm32 - remove crc32 and crc32c support X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b019bb25fbfde0b148895a1676f4bfe7a264156;p=thirdparty%2Flinux.git crypto: stm32 - remove crc32 and crc32c support Remove the crc32 and crc32c support from the stm32 driver. Since it's not wired up to the CRC library, almost no CRC user in the kernel can actually be taking advantage of it, so it's effectively dead code. Support for this hardware could be migrated to the CRC library, but there doesn't seem to be much point. This CRC engine is present only on a couple older SoCs that lacked CRC instructions. Even for those SoCs, it probably wouldn't be worthwhile. This driver has to deal with things like locking and runtime power management that do not exist in software CRC code and are a source of bugs (as is clear from the commit log) and add significant overhead to the processing of short messages, which are common. The patch that added this driver seemed to justify it based purely on a microbenchmark on Cortex-M7 on long messages, not a real use case. These days, if this driver were to be used at all it would likely be on Cortex-A7 instead. This CRC engine is also not supported by QEMU, making the driver not easily testable. Acked-by: Ard Biesheuvel Acked-by: Arnd Bergmann Cc: Alexandre Torgue Cc: Fabien Dessenne Cc: Lionel Debieve Cc: Maxime Coquelin Cc: linux-stm32@st-md-mailman.stormreply.com Link: https://lore.kernel.org/r/20250601193441.6913-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig index 50c170b4619f7..c79495e113c85 100644 --- a/arch/arm/configs/multi_v7_defconfig +++ b/arch/arm/configs/multi_v7_defconfig @@ -1298,7 +1298,6 @@ CONFIG_CRYPTO_DEV_MARVELL_CESA=m CONFIG_CRYPTO_DEV_QCE=m CONFIG_CRYPTO_DEV_QCOM_RNG=m CONFIG_CRYPTO_DEV_ROCKCHIP=m -CONFIG_CRYPTO_DEV_STM32_CRC=m CONFIG_CRYPTO_DEV_STM32_HASH=m CONFIG_CRYPTO_DEV_STM32_CRYP=m CONFIG_CMA_SIZE_MBYTES=64 diff --git a/drivers/crypto/stm32/Kconfig b/drivers/crypto/stm32/Kconfig index 49dfd161e9b9e..d6dc848c82eee 100644 --- a/drivers/crypto/stm32/Kconfig +++ b/drivers/crypto/stm32/Kconfig @@ -1,13 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -config CRYPTO_DEV_STM32_CRC - tristate "Support for STM32 crc accelerators" - depends on ARCH_STM32 - select CRYPTO_HASH - select CRC32 - help - This enables support for the CRC32 hw accelerator which can be found - on STMicroelectronics STM32 SOC. - config CRYPTO_DEV_STM32_HASH tristate "Support for STM32 hash accelerators" depends on ARCH_STM32 || ARCH_U8500 diff --git a/drivers/crypto/stm32/Makefile b/drivers/crypto/stm32/Makefile index 518e0e0b11a9e..c63004026afb8 100644 --- a/drivers/crypto/stm32/Makefile +++ b/drivers/crypto/stm32/Makefile @@ -1,4 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_CRYPTO_DEV_STM32_CRC) += stm32-crc32.o obj-$(CONFIG_CRYPTO_DEV_STM32_HASH) += stm32-hash.o obj-$(CONFIG_CRYPTO_DEV_STM32_CRYP) += stm32-cryp.o diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c deleted file mode 100644 index fd29785a3ecf3..0000000000000 --- a/drivers/crypto/stm32/stm32-crc32.c +++ /dev/null @@ -1,480 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) STMicroelectronics SA 2017 - * Author: Fabien Dessenne - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -#include - -#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_or_null(&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(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_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_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 void stm32_crc_remove(struct platform_device *pdev) -{ - struct stm32_crc *crc = platform_get_drvdata(pdev); - int ret = pm_runtime_get_sync(crc->dev); - - 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); - - if (ret >= 0) - clk_disable(crc->clk); - clk_unprepare(crc->clk); -} - -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 "); -MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver"); -MODULE_LICENSE("GPL");