root/drivers/crypto/gemini/sl3516-ce-core.c
// SPDX-License-Identifier: GPL-2.0
/*
 * sl3516-ce-core.c - hardware cryptographic offloader for Storlink SL3516 SoC
 *
 * Copyright (C) 2021 Corentin Labbe <clabbe@baylibre.com>
 *
 * Core file which registers crypto algorithms supported by the CryptoEngine
 */

#include <crypto/engine.h>
#include <crypto/internal/rng.h>
#include <crypto/internal/skcipher.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/dev_printk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#include "sl3516-ce.h"

static int sl3516_ce_desc_init(struct sl3516_ce_dev *ce)
{
        const size_t sz = sizeof(struct descriptor) * MAXDESC;
        int i;

        ce->tx = dma_alloc_coherent(ce->dev, sz, &ce->dtx, GFP_KERNEL);
        if (!ce->tx)
                return -ENOMEM;
        ce->rx = dma_alloc_coherent(ce->dev, sz, &ce->drx, GFP_KERNEL);
        if (!ce->rx)
                goto err_rx;

        for (i = 0; i < MAXDESC; i++) {
                ce->tx[i].frame_ctrl.bits.own = CE_CPU;
                ce->tx[i].next_desc.next_descriptor = ce->dtx + (i + 1) * sizeof(struct descriptor);
        }
        ce->tx[MAXDESC - 1].next_desc.next_descriptor = ce->dtx;

        for (i = 0; i < MAXDESC; i++) {
                ce->rx[i].frame_ctrl.bits.own = CE_CPU;
                ce->rx[i].next_desc.next_descriptor = ce->drx + (i + 1) * sizeof(struct descriptor);
        }
        ce->rx[MAXDESC - 1].next_desc.next_descriptor = ce->drx;

        ce->pctrl = dma_alloc_coherent(ce->dev, sizeof(struct pkt_control_ecb),
                                       &ce->dctrl, GFP_KERNEL);
        if (!ce->pctrl)
                goto err_pctrl;

        return 0;
err_pctrl:
        dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
err_rx:
        dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
        return -ENOMEM;
}

static void sl3516_ce_free_descs(struct sl3516_ce_dev *ce)
{
        const size_t sz = sizeof(struct descriptor) * MAXDESC;

        dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
        dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
        dma_free_coherent(ce->dev, sizeof(struct pkt_control_ecb), ce->pctrl,
                          ce->dctrl);
}

static void start_dma_tx(struct sl3516_ce_dev *ce)
{
        u32 v;

        v = TXDMA_CTRL_START | TXDMA_CTRL_CHAIN_MODE | TXDMA_CTRL_CONTINUE | \
                TXDMA_CTRL_INT_FAIL | TXDMA_CTRL_INT_PERR | TXDMA_CTRL_BURST_UNK;

        writel(v, ce->base + IPSEC_TXDMA_CTRL);
}

static void start_dma_rx(struct sl3516_ce_dev *ce)
{
        u32 v;

        v = RXDMA_CTRL_START | RXDMA_CTRL_CHAIN_MODE | RXDMA_CTRL_CONTINUE | \
                RXDMA_CTRL_BURST_UNK | RXDMA_CTRL_INT_FINISH | \
                RXDMA_CTRL_INT_FAIL | RXDMA_CTRL_INT_PERR | \
                RXDMA_CTRL_INT_EOD | RXDMA_CTRL_INT_EOF;

        writel(v, ce->base + IPSEC_RXDMA_CTRL);
}

static struct descriptor *get_desc_tx(struct sl3516_ce_dev *ce)
{
        struct descriptor *dd;

        dd = &ce->tx[ce->ctx];
        ce->ctx++;
        if (ce->ctx >= MAXDESC)
                ce->ctx = 0;
        return dd;
}

static struct descriptor *get_desc_rx(struct sl3516_ce_dev *ce)
{
        struct descriptor *rdd;

        rdd = &ce->rx[ce->crx];
        ce->crx++;
        if (ce->crx >= MAXDESC)
                ce->crx = 0;
        return rdd;
}

int sl3516_ce_run_task(struct sl3516_ce_dev *ce, struct sl3516_ce_cipher_req_ctx *rctx,
                       const char *name)
{
        struct descriptor *dd, *rdd = NULL;
        u32 v;
        int i, err = 0;

        ce->stat_req++;

        reinit_completion(&ce->complete);
        ce->status = 0;

        for (i = 0; i < rctx->nr_sgd; i++) {
                dev_dbg(ce->dev, "%s handle DST SG %d/%d len=%d\n", __func__,
                        i, rctx->nr_sgd, rctx->t_dst[i].len);
                rdd = get_desc_rx(ce);
                rdd->buf_adr = rctx->t_dst[i].addr;
                rdd->frame_ctrl.bits.buffer_size = rctx->t_dst[i].len;
                rdd->frame_ctrl.bits.own = CE_DMA;
        }
        rdd->next_desc.bits.eofie = 1;

        for (i = 0; i < rctx->nr_sgs; i++) {
                dev_dbg(ce->dev, "%s handle SRC SG %d/%d len=%d\n", __func__,
                        i, rctx->nr_sgs, rctx->t_src[i].len);
                rctx->h->algorithm_len = rctx->t_src[i].len;

                dd = get_desc_tx(ce);
                dd->frame_ctrl.raw = 0;
                dd->flag_status.raw = 0;
                dd->frame_ctrl.bits.buffer_size = rctx->pctrllen;
                dd->buf_adr = ce->dctrl;
                dd->flag_status.tx_flag.tqflag = rctx->tqflag;
                dd->next_desc.bits.eofie = 0;
                dd->next_desc.bits.dec = 0;
                dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
                dd->frame_ctrl.bits.own = CE_DMA;

                dd = get_desc_tx(ce);
                dd->frame_ctrl.raw = 0;
                dd->flag_status.raw = 0;
                dd->frame_ctrl.bits.buffer_size = rctx->t_src[i].len;
                dd->buf_adr = rctx->t_src[i].addr;
                dd->flag_status.tx_flag.tqflag = 0;
                dd->next_desc.bits.eofie = 0;
                dd->next_desc.bits.dec = 0;
                dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
                dd->frame_ctrl.bits.own = CE_DMA;
                start_dma_tx(ce);
                start_dma_rx(ce);
        }
        wait_for_completion_interruptible_timeout(&ce->complete,
                                                  msecs_to_jiffies(5000));
        if (ce->status == 0) {
                dev_err(ce->dev, "DMA timeout for %s\n", name);
                err = -EFAULT;
        }
        v = readl(ce->base + IPSEC_STATUS_REG);
        if (v & 0xFFF) {
                dev_err(ce->dev, "IPSEC_STATUS_REG %x\n", v);
                err = -EFAULT;
        }

        return err;
}

static irqreturn_t ce_irq_handler(int irq, void *data)
{
        struct sl3516_ce_dev *ce = (struct sl3516_ce_dev *)data;
        u32 v;

        ce->stat_irq++;

        v = readl(ce->base + IPSEC_DMA_STATUS);
        writel(v, ce->base + IPSEC_DMA_STATUS);

        if (v & DMA_STATUS_TS_DERR)
                dev_err(ce->dev, "AHB bus Error While Tx !!!\n");
        if (v & DMA_STATUS_TS_PERR)
                dev_err(ce->dev, "Tx Descriptor Protocol Error !!!\n");
        if (v & DMA_STATUS_RS_DERR)
                dev_err(ce->dev, "AHB bus Error While Rx !!!\n");
        if (v & DMA_STATUS_RS_PERR)
                dev_err(ce->dev, "Rx Descriptor Protocol Error !!!\n");

        if (v & DMA_STATUS_TS_EOFI)
                ce->stat_irq_tx++;
        if (v & DMA_STATUS_RS_EOFI) {
                ce->status = 1;
                complete(&ce->complete);
                ce->stat_irq_rx++;
                return IRQ_HANDLED;
        }

        return IRQ_HANDLED;
}

static struct sl3516_ce_alg_template ce_algs[] = {
{
        .type = CRYPTO_ALG_TYPE_SKCIPHER,
        .mode = ECB_AES,
        .alg.skcipher.base = {
                .base = {
                        .cra_name = "ecb(aes)",
                        .cra_driver_name = "ecb-aes-sl3516",
                        .cra_priority = 400,
                        .cra_blocksize = AES_BLOCK_SIZE,
                        .cra_flags = CRYPTO_ALG_TYPE_SKCIPHER |
                                CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
                        .cra_ctxsize = sizeof(struct sl3516_ce_cipher_tfm_ctx),
                        .cra_module = THIS_MODULE,
                        .cra_alignmask = 0xf,
                        .cra_init = sl3516_ce_cipher_init,
                        .cra_exit = sl3516_ce_cipher_exit,
                },
                .min_keysize    = AES_MIN_KEY_SIZE,
                .max_keysize    = AES_MAX_KEY_SIZE,
                .setkey         = sl3516_ce_aes_setkey,
                .encrypt        = sl3516_ce_skencrypt,
                .decrypt        = sl3516_ce_skdecrypt,
        },
        .alg.skcipher.op = {
                .do_one_request = sl3516_ce_handle_cipher_request,
        },
},
};

static int sl3516_ce_debugfs_show(struct seq_file *seq, void *v)
{
        struct sl3516_ce_dev *ce = seq->private;
        unsigned int i;

        seq_printf(seq, "HWRNG %lu %lu\n",
                   ce->hwrng_stat_req, ce->hwrng_stat_bytes);
        seq_printf(seq, "IRQ %lu\n", ce->stat_irq);
        seq_printf(seq, "IRQ TX %lu\n", ce->stat_irq_tx);
        seq_printf(seq, "IRQ RX %lu\n", ce->stat_irq_rx);
        seq_printf(seq, "nreq %lu\n", ce->stat_req);
        seq_printf(seq, "fallback SG count TX %lu\n", ce->fallback_sg_count_tx);
        seq_printf(seq, "fallback SG count RX %lu\n", ce->fallback_sg_count_rx);
        seq_printf(seq, "fallback modulo16 %lu\n", ce->fallback_mod16);
        seq_printf(seq, "fallback align16 %lu\n", ce->fallback_align16);
        seq_printf(seq, "fallback not same len %lu\n", ce->fallback_not_same_len);

        for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
                if (!ce_algs[i].ce)
                        continue;
                switch (ce_algs[i].type) {
                case CRYPTO_ALG_TYPE_SKCIPHER:
                        seq_printf(seq, "%s %s reqs=%lu fallback=%lu\n",
                                   ce_algs[i].alg.skcipher.base.base.cra_driver_name,
                                   ce_algs[i].alg.skcipher.base.base.cra_name,
                                   ce_algs[i].stat_req, ce_algs[i].stat_fb);
                        break;
                }
        }
        return 0;
}

DEFINE_SHOW_ATTRIBUTE(sl3516_ce_debugfs);

static int sl3516_ce_register_algs(struct sl3516_ce_dev *ce)
{
        int err;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
                ce_algs[i].ce = ce;
                switch (ce_algs[i].type) {
                case CRYPTO_ALG_TYPE_SKCIPHER:
                        dev_info(ce->dev, "DEBUG: Register %s\n",
                                 ce_algs[i].alg.skcipher.base.base.cra_name);
                        err = crypto_engine_register_skcipher(&ce_algs[i].alg.skcipher);
                        if (err) {
                                dev_err(ce->dev, "Fail to register %s\n",
                                        ce_algs[i].alg.skcipher.base.base.cra_name);
                                ce_algs[i].ce = NULL;
                                return err;
                        }
                        break;
                default:
                        ce_algs[i].ce = NULL;
                        dev_err(ce->dev, "ERROR: tried to register an unknown algo\n");
                }
        }
        return 0;
}

static void sl3516_ce_unregister_algs(struct sl3516_ce_dev *ce)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
                if (!ce_algs[i].ce)
                        continue;
                switch (ce_algs[i].type) {
                case CRYPTO_ALG_TYPE_SKCIPHER:
                        dev_info(ce->dev, "Unregister %d %s\n", i,
                                 ce_algs[i].alg.skcipher.base.base.cra_name);
                        crypto_engine_unregister_skcipher(&ce_algs[i].alg.skcipher);
                        break;
                }
        }
}

static void sl3516_ce_start(struct sl3516_ce_dev *ce)
{
        ce->ctx = 0;
        ce->crx = 0;
        writel(ce->dtx, ce->base + IPSEC_TXDMA_CURR_DESC);
        writel(ce->drx, ce->base + IPSEC_RXDMA_CURR_DESC);
        writel(0, ce->base + IPSEC_DMA_STATUS);
}

/*
 * Power management strategy: The device is suspended unless a TFM exists for
 * one of the algorithms proposed by this driver.
 */
static int sl3516_ce_pm_suspend(struct device *dev)
{
        struct sl3516_ce_dev *ce = dev_get_drvdata(dev);

        reset_control_assert(ce->reset);
        clk_disable_unprepare(ce->clks);
        return 0;
}

static int sl3516_ce_pm_resume(struct device *dev)
{
        struct sl3516_ce_dev *ce = dev_get_drvdata(dev);
        int err;

        err = clk_prepare_enable(ce->clks);
        if (err) {
                dev_err(ce->dev, "Cannot prepare_enable\n");
                goto error;
        }
        err = reset_control_deassert(ce->reset);
        if (err) {
                dev_err(ce->dev, "Cannot deassert reset control\n");
                goto error;
        }

        sl3516_ce_start(ce);

        return 0;
error:
        sl3516_ce_pm_suspend(dev);
        return err;
}

static const struct dev_pm_ops sl3516_ce_pm_ops = {
        SET_RUNTIME_PM_OPS(sl3516_ce_pm_suspend, sl3516_ce_pm_resume, NULL)
};

static int sl3516_ce_pm_init(struct sl3516_ce_dev *ce)
{
        int err;

        pm_runtime_use_autosuspend(ce->dev);
        pm_runtime_set_autosuspend_delay(ce->dev, 2000);

        err = pm_runtime_set_suspended(ce->dev);
        if (err)
                return err;
        pm_runtime_enable(ce->dev);
        return err;
}

static void sl3516_ce_pm_exit(struct sl3516_ce_dev *ce)
{
        pm_runtime_disable(ce->dev);
}

static int sl3516_ce_probe(struct platform_device *pdev)
{
        struct sl3516_ce_dev *ce;
        int err, irq;
        u32 v;

        ce = devm_kzalloc(&pdev->dev, sizeof(*ce), GFP_KERNEL);
        if (!ce)
                return -ENOMEM;

        ce->dev = &pdev->dev;
        platform_set_drvdata(pdev, ce);

        ce->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(ce->base))
                return PTR_ERR(ce->base);

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        err = devm_request_irq(&pdev->dev, irq, ce_irq_handler, 0, "crypto", ce);
        if (err) {
                dev_err(ce->dev, "Cannot request Crypto Engine IRQ (err=%d)\n", err);
                return err;
        }

        ce->reset = devm_reset_control_get(&pdev->dev, NULL);
        if (IS_ERR(ce->reset))
                return dev_err_probe(&pdev->dev, PTR_ERR(ce->reset),
                                     "No reset control found\n");
        ce->clks = devm_clk_get(ce->dev, NULL);
        if (IS_ERR(ce->clks)) {
                err = PTR_ERR(ce->clks);
                dev_err(ce->dev, "Cannot get clock err=%d\n", err);
                return err;
        }

        err = sl3516_ce_desc_init(ce);
        if (err)
                return err;

        err = sl3516_ce_pm_init(ce);
        if (err)
                goto error_pm;

        init_completion(&ce->complete);

        ce->engine = crypto_engine_alloc_init(ce->dev, true);
        if (!ce->engine) {
                dev_err(ce->dev, "Cannot allocate engine\n");
                err = -ENOMEM;
                goto error_engine;
        }

        err = crypto_engine_start(ce->engine);
        if (err) {
                dev_err(ce->dev, "Cannot start engine\n");
                goto error_engine;
        }

        err = sl3516_ce_register_algs(ce);
        if (err)
                goto error_alg;

        err = sl3516_ce_rng_register(ce);
        if (err)
                goto error_rng;

        err = pm_runtime_resume_and_get(ce->dev);
        if (err < 0)
                goto error_pmuse;

        v = readl(ce->base + IPSEC_ID);
        dev_info(ce->dev, "SL3516 dev %lx rev %lx\n",
                 v & GENMASK(31, 4),
                 v & GENMASK(3, 0));
        v = readl(ce->base + IPSEC_DMA_DEVICE_ID);
        dev_info(ce->dev, "SL3516 DMA dev %lx rev %lx\n",
                 v & GENMASK(15, 4),
                 v & GENMASK(3, 0));

        pm_runtime_put_sync(ce->dev);

        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SL3516_DEBUG)) {
                struct dentry *dbgfs_dir __maybe_unused;
                struct dentry *dbgfs_stats __maybe_unused;

                /* Ignore error of debugfs */
                dbgfs_dir = debugfs_create_dir("sl3516", NULL);
                dbgfs_stats = debugfs_create_file("stats", 0444,
                                                  dbgfs_dir, ce,
                                                  &sl3516_ce_debugfs_fops);
#ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
                ce->dbgfs_dir = dbgfs_dir;
                ce->dbgfs_stats = dbgfs_stats;
#endif
        }

        return 0;
error_pmuse:
        sl3516_ce_rng_unregister(ce);
error_rng:
        sl3516_ce_unregister_algs(ce);
error_alg:
        crypto_engine_exit(ce->engine);
error_engine:
        sl3516_ce_pm_exit(ce);
error_pm:
        sl3516_ce_free_descs(ce);
        return err;
}

static void sl3516_ce_remove(struct platform_device *pdev)
{
        struct sl3516_ce_dev *ce = platform_get_drvdata(pdev);

        sl3516_ce_rng_unregister(ce);
        sl3516_ce_unregister_algs(ce);
        crypto_engine_exit(ce->engine);
        sl3516_ce_pm_exit(ce);
        sl3516_ce_free_descs(ce);

#ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
        debugfs_remove_recursive(ce->dbgfs_dir);
#endif
}

static const struct of_device_id sl3516_ce_crypto_of_match_table[] = {
        { .compatible = "cortina,sl3516-crypto"},
        {}
};
MODULE_DEVICE_TABLE(of, sl3516_ce_crypto_of_match_table);

static struct platform_driver sl3516_ce_driver = {
        .probe           = sl3516_ce_probe,
        .remove          = sl3516_ce_remove,
        .driver          = {
                .name           = "sl3516-crypto",
                .pm             = &sl3516_ce_pm_ops,
                .of_match_table = sl3516_ce_crypto_of_match_table,
        },
};

module_platform_driver(sl3516_ce_driver);

MODULE_DESCRIPTION("SL3516 cryptographic offloader");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Corentin Labbe <clabbe@baylibre.com>");