From 27aa9f97887f599267c345075e61979de785c770 Mon Sep 17 00:00:00 2001
From: Peng Ma <peng.ma@nxp.com>
Date: Thu, 11 Oct 2018 16:49:41 +0800
Subject: [PATCH] dma: caam: add dma memcpy driver
MIME-Version: 1.0
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This module introduces a memcpy DMA driver based on the DMA capabilities
of the CAAM hardware block. CAAM DMA is a platform driver that is only
probed if the device is defined in the device tree. The driver creates
a DMA channel for each JR of the CAAM. This introduces a dependency on
the JR driver. Therefore a defering mechanism was used to ensure that
the CAAM DMA driver is probed only after the JR driver.

Signed-off-by: Radu Alexe <radu.alexe@nxp.com>
Signed-off-by: Tudor Ambarus <tudor-dan.ambarus@nxp.com>
Signed-off-by: Rajiv Vishwakarma <rajiv.vishwakarma@nxp.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
[rebase]
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
 drivers/dma/Kconfig    |  19 +-
 drivers/dma/Makefile   |   1 +
 drivers/dma/caam_dma.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 481 insertions(+), 1 deletion(-)
 create mode 100644 drivers/dma/caam_dma.c

--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -132,6 +132,24 @@ config COH901318
 	help
 	  Enable support for ST-Ericsson COH 901 318 DMA.
 
+config CRYPTO_DEV_FSL_CAAM_DMA
+	tristate "CAAM DMA engine support"
+	depends on CRYPTO_DEV_FSL_CAAM_JR
+	default n
+	select DMA_ENGINE
+	select ASYNC_CORE
+	select ASYNC_TX_ENABLE_CHANNEL_SWITCH
+	help
+	  Selecting this will offload the DMA operations for users of
+	  the scatter gather memcopy API to the CAAM via job rings. The
+	  CAAM is a hardware module that provides hardware acceleration to
+	  cryptographic operations. It has a built-in DMA controller that can
+	  be programmed to read/write cryptographic data. This module defines
+	  a DMA driver that uses the DMA capabilities of the CAAM.
+
+	  To compile this as a module, choose M here: the module
+	  will be called caam_dma.
+
 config DMA_BCM2835
 	tristate "BCM2835 DMA engine support"
 	depends on ARCH_BCM2835
@@ -663,7 +681,6 @@ config ZX_DMA
 	help
 	  Support the DMA engine for ZTE ZX family platform devices.
 
-
 # driver files
 source "drivers/dma/bestcomm/Kconfig"
 
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
 obj-$(CONFIG_ZX_DMA) += zx_dma.o
 obj-$(CONFIG_ST_FDMA) += st_fdma.o
 obj-$(CONFIG_FSL_DPAA2_QDMA) += fsl-dpaa2-qdma/
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_DMA) += caam_dma.o
 
 obj-y += mediatek/
 obj-y += qcom/
--- /dev/null
+++ b/drivers/dma/caam_dma.c
@@ -0,0 +1,462 @@
+/*
+ * caam support for SG DMA
+ *
+ * Copyright 2016 Freescale Semiconductor, Inc
+ * Copyright 2017 NXP
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the names of the above-listed copyright holders nor the
+ *       names of any contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "dmaengine.h"
+
+#include "../crypto/caam/regs.h"
+#include "../crypto/caam/jr.h"
+#include "../crypto/caam/error.h"
+#include "../crypto/caam/desc_constr.h"
+
+#define DESC_DMA_MEMCPY_LEN	((CAAM_DESC_BYTES_MAX - DESC_JOB_IO_LEN) / \
+				 CAAM_CMD_SZ)
+
+/*
+ * This is max chunk size of a DMA transfer. If a buffer is larger than this
+ * value it is internally broken into chunks of max CAAM_DMA_CHUNK_SIZE bytes
+ * and for each chunk a DMA transfer request is issued.
+ * This value is the largest number on 16 bits that is a multiple of 256 bytes
+ * (the largest configurable CAAM DMA burst size).
+ */
+#define CAAM_DMA_CHUNK_SIZE	65280
+
+struct caam_dma_sh_desc {
+	u32 desc[DESC_DMA_MEMCPY_LEN] ____cacheline_aligned;
+	dma_addr_t desc_dma;
+};
+
+/* caam dma extended descriptor */
+struct caam_dma_edesc {
+	struct dma_async_tx_descriptor async_tx;
+	struct list_head node;
+	struct caam_dma_ctx *ctx;
+	dma_addr_t src_dma;
+	dma_addr_t dst_dma;
+	unsigned int src_len;
+	unsigned int dst_len;
+	u32 jd[] ____cacheline_aligned;
+};
+
+/*
+ * caam_dma_ctx - per jr/channel context
+ * @chan: dma channel used by async_tx API
+ * @node: list_head used to attach to the global dma_ctx_list
+ * @jrdev: Job Ring device
+ * @pending_q: queue of pending (submitted, but not enqueued) jobs
+ * @done_not_acked: jobs that have been completed by jr, but maybe not acked
+ * @edesc_lock: protects extended descriptor
+ */
+struct caam_dma_ctx {
+	struct dma_chan chan;
+	struct list_head node;
+	struct device *jrdev;
+	struct list_head pending_q;
+	struct list_head done_not_acked;
+	spinlock_t edesc_lock;
+};
+
+static struct dma_device *dma_dev;
+static struct caam_dma_sh_desc *dma_sh_desc;
+static LIST_HEAD(dma_ctx_list);
+
+static dma_cookie_t caam_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct caam_dma_edesc *edesc = NULL;
+	struct caam_dma_ctx *ctx = NULL;
+	dma_cookie_t cookie;
+
+	edesc = container_of(tx, struct caam_dma_edesc, async_tx);
+	ctx = container_of(tx->chan, struct caam_dma_ctx, chan);
+
+	spin_lock_bh(&ctx->edesc_lock);
+
+	cookie = dma_cookie_assign(tx);
+	list_add_tail(&edesc->node, &ctx->pending_q);
+
+	spin_unlock_bh(&ctx->edesc_lock);
+
+	return cookie;
+}
+
+static void caam_jr_chan_free_edesc(struct caam_dma_edesc *edesc)
+{
+	struct caam_dma_ctx *ctx = edesc->ctx;
+	struct caam_dma_edesc *_edesc = NULL;
+
+	spin_lock_bh(&ctx->edesc_lock);
+
+	list_add_tail(&edesc->node, &ctx->done_not_acked);
+	list_for_each_entry_safe(edesc, _edesc, &ctx->done_not_acked, node) {
+		if (async_tx_test_ack(&edesc->async_tx)) {
+			list_del(&edesc->node);
+			kfree(edesc);
+		}
+	}
+
+	spin_unlock_bh(&ctx->edesc_lock);
+}
+
+static void caam_dma_done(struct device *dev, u32 *hwdesc, u32 err,
+			  void *context)
+{
+	struct caam_dma_edesc *edesc = context;
+	struct caam_dma_ctx *ctx = edesc->ctx;
+	dma_async_tx_callback callback;
+	void *callback_param;
+
+	if (err)
+		caam_jr_strstatus(ctx->jrdev, err);
+
+	dma_run_dependencies(&edesc->async_tx);
+
+	spin_lock_bh(&ctx->edesc_lock);
+	dma_cookie_complete(&edesc->async_tx);
+	spin_unlock_bh(&ctx->edesc_lock);
+
+	callback = edesc->async_tx.callback;
+	callback_param = edesc->async_tx.callback_param;
+
+	dma_descriptor_unmap(&edesc->async_tx);
+
+	caam_jr_chan_free_edesc(edesc);
+
+	if (callback)
+		callback(callback_param);
+}
+
+static void caam_dma_memcpy_init_job_desc(struct caam_dma_edesc *edesc)
+{
+	u32 *jd = edesc->jd;
+	u32 *sh_desc = dma_sh_desc->desc;
+	dma_addr_t desc_dma = dma_sh_desc->desc_dma;
+
+	/* init the job descriptor */
+	init_job_desc_shared(jd, desc_dma, desc_len(sh_desc), HDR_REVERSE);
+
+	/* set SEQIN PTR */
+	append_seq_in_ptr(jd, edesc->src_dma, edesc->src_len, 0);
+
+	/* set SEQOUT PTR */
+	append_seq_out_ptr(jd, edesc->dst_dma, edesc->dst_len, 0);
+
+	print_hex_dump_debug("caam dma desc@" __stringify(__LINE__) ": ",
+			     DUMP_PREFIX_ADDRESS, 16, 4, jd, desc_bytes(jd), 1);
+}
+
+static struct dma_async_tx_descriptor *
+caam_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
+		     size_t len, unsigned long flags)
+{
+	struct caam_dma_edesc *edesc;
+	struct caam_dma_ctx *ctx = container_of(chan, struct caam_dma_ctx,
+						chan);
+
+	edesc = kzalloc(sizeof(*edesc) + DESC_JOB_IO_LEN, GFP_DMA | GFP_NOWAIT);
+	if (!edesc)
+		return ERR_PTR(-ENOMEM);
+
+	dma_async_tx_descriptor_init(&edesc->async_tx, chan);
+	edesc->async_tx.tx_submit = caam_dma_tx_submit;
+	edesc->async_tx.flags = flags;
+	edesc->async_tx.cookie = -EBUSY;
+
+	edesc->src_dma = src;
+	edesc->src_len = len;
+	edesc->dst_dma = dst;
+	edesc->dst_len = len;
+	edesc->ctx = ctx;
+
+	caam_dma_memcpy_init_job_desc(edesc);
+
+	return &edesc->async_tx;
+}
+
+/* This function can be called in an interrupt context */
+static void caam_dma_issue_pending(struct dma_chan *chan)
+{
+	struct caam_dma_ctx *ctx = container_of(chan, struct caam_dma_ctx,
+						chan);
+	struct caam_dma_edesc *edesc, *_edesc;
+
+	spin_lock_bh(&ctx->edesc_lock);
+	list_for_each_entry_safe(edesc, _edesc, &ctx->pending_q, node) {
+		if (caam_jr_enqueue(ctx->jrdev, edesc->jd,
+				    caam_dma_done, edesc) < 0)
+			break;
+		list_del(&edesc->node);
+	}
+	spin_unlock_bh(&ctx->edesc_lock);
+}
+
+static void caam_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct caam_dma_ctx *ctx = container_of(chan, struct caam_dma_ctx,
+						chan);
+	struct caam_dma_edesc *edesc, *_edesc;
+
+	spin_lock_bh(&ctx->edesc_lock);
+	list_for_each_entry_safe(edesc, _edesc, &ctx->pending_q, node) {
+		list_del(&edesc->node);
+		kfree(edesc);
+	}
+	list_for_each_entry_safe(edesc, _edesc, &ctx->done_not_acked, node) {
+		list_del(&edesc->node);
+		kfree(edesc);
+	}
+	spin_unlock_bh(&ctx->edesc_lock);
+}
+
+static int caam_dma_jr_chan_bind(void)
+{
+	struct device *jrdev;
+	struct caam_dma_ctx *ctx;
+	int bonds = 0;
+	int i;
+
+	for (i = 0; i < caam_jr_driver_probed(); i++) {
+		jrdev = caam_jridx_alloc(i);
+		if (IS_ERR(jrdev)) {
+			pr_err("job ring device %d allocation failed\n", i);
+			continue;
+		}
+
+		ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+		if (!ctx) {
+			caam_jr_free(jrdev);
+			continue;
+		}
+
+		ctx->chan.device = dma_dev;
+		ctx->chan.private = ctx;
+
+		ctx->jrdev = jrdev;
+
+		INIT_LIST_HEAD(&ctx->pending_q);
+		INIT_LIST_HEAD(&ctx->done_not_acked);
+		INIT_LIST_HEAD(&ctx->node);
+		spin_lock_init(&ctx->edesc_lock);
+
+		dma_cookie_init(&ctx->chan);
+
+		/* add the context of this channel to the context list */
+		list_add_tail(&ctx->node, &dma_ctx_list);
+
+		/* add this channel to the device chan list */
+		list_add_tail(&ctx->chan.device_node, &dma_dev->channels);
+
+		bonds++;
+	}
+
+	return bonds;
+}
+
+static inline void caam_jr_dma_free(struct dma_chan *chan)
+{
+	struct caam_dma_ctx *ctx = container_of(chan, struct caam_dma_ctx,
+						chan);
+
+	list_del(&ctx->node);
+	list_del(&chan->device_node);
+	caam_jr_free(ctx->jrdev);
+	kfree(ctx);
+}
+
+static void set_caam_dma_desc(u32 *desc)
+{
+	u32 *jmp_cmd;
+
+	/* dma shared descriptor */
+	init_sh_desc(desc, HDR_SHARE_NEVER | (1 << HDR_START_IDX_SHIFT));
+
+	/* REG1 = CAAM_DMA_CHUNK_SIZE */
+	append_math_add_imm_u32(desc, REG1, ZERO, IMM, CAAM_DMA_CHUNK_SIZE);
+
+	/* REG0 = SEQINLEN - CAAM_DMA_CHUNK_SIZE */
+	append_math_sub_imm_u32(desc, REG0, SEQINLEN, IMM, CAAM_DMA_CHUNK_SIZE);
+
+	/*
+	 * if (REG0 > 0)
+	 *	jmp to LABEL1
+	 */
+	jmp_cmd = append_jump(desc, JUMP_TEST_INVALL | JUMP_COND_MATH_N |
+			      JUMP_COND_MATH_Z);
+
+	/* REG1 = SEQINLEN */
+	append_math_sub(desc, REG1, SEQINLEN, ZERO, CAAM_CMD_SZ);
+
+	/* LABEL1 */
+	set_jump_tgt_here(desc, jmp_cmd);
+
+	/* VARSEQINLEN = REG1 */
+	append_math_add(desc, VARSEQINLEN, REG1, ZERO, CAAM_CMD_SZ);
+
+	/* VARSEQOUTLEN = REG1 */
+	append_math_add(desc, VARSEQOUTLEN, REG1, ZERO, CAAM_CMD_SZ);
+
+	/* do FIFO STORE */
+	append_seq_fifo_store(desc, 0, FIFOST_TYPE_METADATA | LDST_VLF);
+
+	/* do FIFO LOAD */
+	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 |
+			     FIFOLD_TYPE_IFIFO | LDST_VLF);
+
+	/*
+	 * if (REG0 > 0)
+	 *	jmp 0xF8 (after shared desc header)
+	 */
+	append_jump(desc, JUMP_TEST_INVALL | JUMP_COND_MATH_N |
+		    JUMP_COND_MATH_Z | 0xF8);
+
+	print_hex_dump_debug("caam dma shdesc@" __stringify(__LINE__) ": ",
+			     DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc),
+			     1);
+}
+
+static int caam_dma_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *ctrldev = dev->parent;
+	struct dma_chan *chan, *_chan;
+	u32 *sh_desc;
+	int err = -ENOMEM;
+	int bonds;
+
+	if (!caam_jr_driver_probed()) {
+		dev_info(dev, "Defer probing after JR driver probing\n");
+		return -EPROBE_DEFER;
+	}
+
+	dma_dev = kzalloc(sizeof(*dma_dev), GFP_KERNEL);
+	if (!dma_dev)
+		return -ENOMEM;
+
+	dma_sh_desc = kzalloc(sizeof(*dma_sh_desc), GFP_KERNEL | GFP_DMA);
+	if (!dma_sh_desc)
+		goto desc_err;
+
+	sh_desc = dma_sh_desc->desc;
+	set_caam_dma_desc(sh_desc);
+	dma_sh_desc->desc_dma = dma_map_single(ctrldev, sh_desc,
+					       desc_bytes(sh_desc),
+					       DMA_TO_DEVICE);
+	if (dma_mapping_error(ctrldev, dma_sh_desc->desc_dma)) {
+		dev_err(dev, "unable to map dma descriptor\n");
+		goto map_err;
+	}
+
+	INIT_LIST_HEAD(&dma_dev->channels);
+
+	bonds = caam_dma_jr_chan_bind();
+	if (!bonds) {
+		err = -ENODEV;
+		goto jr_bind_err;
+	}
+
+	dma_dev->dev = dev;
+	dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
+	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+	dma_dev->device_tx_status = dma_cookie_status;
+	dma_dev->device_issue_pending = caam_dma_issue_pending;
+	dma_dev->device_prep_dma_memcpy = caam_dma_prep_memcpy;
+	dma_dev->device_free_chan_resources = caam_dma_free_chan_resources;
+
+	err = dma_async_device_register(dma_dev);
+	if (err) {
+		dev_err(dev, "Failed to register CAAM DMA engine\n");
+		goto jr_bind_err;
+	}
+
+	dev_info(dev, "caam dma support with %d job rings\n", bonds);
+
+	return err;
+
+jr_bind_err:
+	list_for_each_entry_safe(chan, _chan, &dma_dev->channels, device_node)
+		caam_jr_dma_free(chan);
+
+	dma_unmap_single(ctrldev, dma_sh_desc->desc_dma, desc_bytes(sh_desc),
+			 DMA_TO_DEVICE);
+map_err:
+	kfree(dma_sh_desc);
+desc_err:
+	kfree(dma_dev);
+	return err;
+}
+
+static int caam_dma_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *ctrldev = dev->parent;
+	struct caam_dma_ctx *ctx, *_ctx;
+
+	dma_async_device_unregister(dma_dev);
+
+	list_for_each_entry_safe(ctx, _ctx, &dma_ctx_list, node) {
+		list_del(&ctx->node);
+		caam_jr_free(ctx->jrdev);
+		kfree(ctx);
+	}
+
+	dma_unmap_single(ctrldev, dma_sh_desc->desc_dma,
+			 desc_bytes(dma_sh_desc->desc), DMA_TO_DEVICE);
+
+	kfree(dma_sh_desc);
+	kfree(dma_dev);
+
+	dev_info(dev, "caam dma support disabled\n");
+	return 0;
+}
+
+static struct platform_driver caam_dma_driver = {
+	.driver = {
+		.name = "caam-dma",
+	},
+	.probe  = caam_dma_probe,
+	.remove = caam_dma_remove,
+};
+module_platform_driver(caam_dma_driver);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("NXP CAAM support for DMA engine");
+MODULE_AUTHOR("NXP Semiconductors");
+MODULE_ALIAS("platform:caam-dma");
