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Diffstat (limited to 'drivers/crypto/stm32/stm32-crc32.c')
-rw-r--r--drivers/crypto/stm32/stm32-crc32.c487
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 0000000000..90a920e7f6
--- /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");