From: Radu Alexe <radu.alexe@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Tudor Ambarus <tudor-dan.ambarus@xxxxxxx>
Signed-off-by: Rajiv Vishwakarma <rajiv.vishwakarma@xxxxxxx>
---
drivers/dma/Kconfig | 17 ++
drivers/dma/Makefile | 1 +
drivers/dma/caam_dma.c | 444 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 462 insertions(+)
create mode 100644 drivers/dma/caam_dma.c
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index fadc4d8783bd..0df48307dac1 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -600,6 +600,23 @@ config ZX_DMA
help
Support the DMA engine for ZTE ZX family platform devices.
+config CRYPTO_DEV_FSL_CAAM_DMA
+ tristate "CAAM DMA engine support"
+ depends on CRYPTO_DEV_FSL_CAAM_JR
+ default y
+ 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.
# driver files
source "drivers/dma/bestcomm/Kconfig"
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index f08f8de1b567..37563454d624 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_TI_EDMA) += edma.o
obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
obj-$(CONFIG_ZX_DMA) += zx_dma.o
obj-$(CONFIG_ST_FDMA) += st_fdma.o
+obj-$(CONFIG_CRYPTO_DEV_FSL_CAAM_DMA) += caam_dma.o
obj-y += qcom/
obj-y += xilinx/
diff --git a/drivers/dma/caam_dma.c b/drivers/dma/caam_dma.c
new file mode 100644
index 000000000000..dfd5409864b0
--- /dev/null
+++ b/drivers/dma/caam_dma.c
@@ -0,0 +1,444 @@
+/*
+ * caam support for SG DMA
+ *
+ * Copyright 2016 Freescale Semiconductor, Inc
+ * Copyright 2017 NXP
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+
+#include <linux/dmaengine.h>
+#include "dmaengine.h"
+
+#include "../crypto/caam/regs.h"
+#include "../crypto/caam/jr.h"
+#include "../crypto/caam/error.h"
+#include "../crypto/caam/intern.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
+ * @submit_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 submit_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->submit_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);
+
+#ifdef DEBUG
+ print_hex_dump(KERN_ERR, "caam dma desc@" __stringify(__LINE__) ": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, jd, desc_bytes(jd), 1);
+#endif
+}
+
+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->submit_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->submit_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->submit_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);
+
+#ifdef DEBUG
+ print_hex_dump(KERN_ERR, "caam dma shdesc@" __stringify(__LINE__) ": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
+#endif
+}
+
+static int __init 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 const struct of_device_id caam_dma_match[] = {
+ { .compatible = "fsl,sec-v5.4-dma", },
+ { .compatible = "fsl,sec-v5.0-dma", },
+ { .compatible = "fsl,sec-v4.0-dma", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, caam_dma_match);
+
+static struct platform_driver caam_dma_driver = {
+ .driver = {
+ .name = "caam-dma",
+ .of_match_table = caam_dma_match,
+ },
+ .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 SG DMA");
+MODULE_AUTHOR("NXP Semiconductors");
--
2.14.2.606.g7451fcd
