2013-05-08 18:41:45

by Tobias Rauter

[permalink] [raw]
Subject: [RFC] Freescale DCP crypto acceleration

Hi!

I am working on a driver for the data co processor of freescale's
imx28 (should also work on mx23 and mx5). I noticed that Christoph
sent a patch for this device some days ago to the crypto mailing
list. As far as I see this is basically the Freescale-SDK driver with
some modifications for mainline. This was also my first
approach. Since this driver has some problems (duplicated code, mutex in
atomic context) I decided to get the reference manual and write the
driver from scratch. To prevent double work (in case Christoph or
someone else does the same thing), I want to share my work here now.

This is my first real kernel driver so it would be nice if someone
could take some time to find the noob-mistakes and send me feedback.

Things I'm working on:
- get rid of the global device
- at the moment the number of entries of the in/out scatterlist is
limited to 20. I am working on a ringbuffer where the CPU fills the
co-processors buffer while it iterates through the pages.
- overall performance
- ATM each scatterlist entry of the request has to be aligned to
AES_BLOCK_SIZE. Since I was not able to find a documentation, I
want to ask if my idea is the right approach to solve this problem:
use a ablkcipher walk ,iterate through this walk and do
dma_map_single for each buffer instead of the whole scatterlist.

regards,
Tobias


2013-05-08 18:41:50

by Tobias Rauter

[permalink] [raw]
Subject: [PATCH 1/1] crypto: Added support for Freescale's DCP co-processor


Signed-off-by: Tobias Rauter <[email protected]>
---
arch/arm/boot/dts/imx28.dtsi | 2 +-
drivers/crypto/Kconfig | 10 +
drivers/crypto/Makefile | 1 +
drivers/crypto/dcp.c | 752 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 764 insertions(+), 1 deletion(-)
create mode 100644 drivers/crypto/dcp.c

diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi
index 7ba4966..cd428d6 100644
--- a/arch/arm/boot/dts/imx28.dtsi
+++ b/arch/arm/boot/dts/imx28.dtsi
@@ -666,7 +666,7 @@
[email protected] {
reg = <0x80028000 0x2000>;
interrupts = <52 53 54>;
- status = "disabled";
+ compatible = "fsl-dcp";
};

[email protected] {
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 87ec4d0..1f98eca 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -276,6 +276,16 @@ config CRYPTO_DEV_PICOXCELL

Saying m here will build a module named pipcoxcell_crypto.

+config CRYPTO_DEV_DCP
+ tristate "Support for the DCP engine"
+ depends on ARCH_MXS && OF
+ select CRYPTO_BLKCIPHER
+ select CRYPTO_AES
+ select CRYPTO_CBC
+ help
+ This options enables support for the hardware crypto-acceleration
+ capabilities of the DCP co-processor
+
config CRYPTO_DEV_S5P
tristate "Support for Samsung S5PV210 crypto accelerator"
depends on ARCH_S5PV210
diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
index 880a47b..603b92e 100644
--- a/drivers/crypto/Makefile
+++ b/drivers/crypto/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_CRYPTO_DEV_PPC4XX) += amcc/
obj-$(CONFIG_CRYPTO_DEV_OMAP_SHAM) += omap-sham.o
obj-$(CONFIG_CRYPTO_DEV_OMAP_AES) += omap-aes.o
obj-$(CONFIG_CRYPTO_DEV_PICOXCELL) += picoxcell_crypto.o
+obj-$(CONFIG_CRYPTO_DEV_DCP) += dcp.o
obj-$(CONFIG_CRYPTO_DEV_S5P) += s5p-sss.o
obj-$(CONFIG_CRYPTO_DEV_TEGRA_AES) += tegra-aes.o
obj-$(CONFIG_CRYPTO_DEV_UX500) += ux500/
diff --git a/drivers/crypto/dcp.c b/drivers/crypto/dcp.c
new file mode 100644
index 0000000..ad0bae5
--- /dev/null
+++ b/drivers/crypto/dcp.c
@@ -0,0 +1,752 @@
+/*
+ * Cryptographic API.
+ *
+ * Support for DCP cryptographic accelerator.
+ *
+ * Copyright (c) 2013
+ * Author: Tobias Rauter <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Based on tegra-aes.c, dcp.c (from freescale SDK) and sahara.c
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/crypto.h>
+
+#include <crypto/scatterwalk.h>
+#include <crypto/aes.h>
+
+
+/* DCP CHANNEL USED FOR AES */
+#define USED_CHANNEL 1
+#define DCP_MAX_PKG 20
+
+/* Control Register */
+#define DCP_REG_CTRL 0x000
+#define DCP_CTRL_SFRST (1<<31)
+#define DCP_CTRL_CLKGATE (1<<30)
+#define DCP_CTRL_CRYPTO_PRESENT (1<<29)
+#define DCP_CTRL_SHA_PRESENT (1<<28)
+#define DCP_CTRL_GATHER_RES_WRITE (1<<23)
+#define DCP_CTRL_ENABLE_CONTEXT_CACHE (1<<22)
+#define DCP_CTRL_ENABLE_CONTEXT_SWITCH (1<<21)
+#define DCP_CTRL_CH_IRQ_E_0 0x01
+#define DCP_CTRL_CH_IRQ_E_1 0x02
+#define DCP_CTRL_CH_IRQ_E_2 0x04
+#define DCP_CTRL_CH_IRQ_E_3 0x08
+
+/* Status register */
+#define DCP_REG_STAT 0x010
+#define DCP_STAT_OTP_KEY_READY (1<<28)
+#define DCP_STAT_CUR_CHANNEL(stat) ((stat>>24)&0x0F)
+#define DCP_STAT_READY_CHANNEL(stat) ((stat>>16)&0x0F)
+#define DCP_STAT_IRQ(stat) (stat&0x0F)
+#define DCP_STAT_CHAN_0 (0x01)
+#define DCP_STAT_CHAN_1 (0x02)
+#define DCP_STAT_CHAN_2 (0x04)
+#define DCP_STAT_CHAN_3 (0x08)
+
+/* Channel Control Register */
+#define DCP_REG_CHAN_CTRL 0x020
+#define DCP_CHAN_CTRL_CH0_IRQ_MERGED (1<<16)
+#define DCP_CHAN_CTRL_HIGH_PRIO_0 (0x0100)
+#define DCP_CHAN_CTRL_HIGH_PRIO_1 (0x0200)
+#define DCP_CHAN_CTRL_HIGH_PRIO_2 (0x0400)
+#define DCP_CHAN_CTRL_HIGH_PRIO_3 (0x0800)
+#define DCP_CHAN_CTRL_ENABLE_0 (0x01)
+#define DCP_CHAN_CTRL_ENABLE_1 (0x02)
+#define DCP_CHAN_CTRL_ENABLE_2 (0x04)
+#define DCP_CHAN_CTRL_ENABLE_3 (0x08)
+
+/*
+ * Channel Registers:
+ * The DCP has 4 channels. Each of this channels
+ * has 4 registers (command pointer, semaphore, status and options).
+ * The address of register REG of channel CHAN is obtained by
+ * dcp_chan_reg(REG, CHAN)
+ */
+#define DCP_REG_CHAN_PTR 0x00000100
+#define DCP_REG_CHAN_SEMA 0x00000110
+#define DCP_REG_CHAN_STAT 0x00000120
+#define DCP_REG_CHAN_OPT 0x00000130
+
+#define DCP_CHAN_STAT_NEXT_CHAIN_IS_0 0x010000
+#define DCP_CHAN_STAT_NO_CHAIN 0x020000
+#define DCP_CHAN_STAT_CONTEXT_ERROR 0x030000
+#define DCP_CHAN_STAT_PAYLOAD_ERROR 0x040000
+#define DCP_CHAN_STAT_INVALID_MODE 0x050000
+#define DCP_CHAN_STAT_PAGEFAULT 0x40
+#define DCP_CHAN_STAT_DST 0x20
+#define DCP_CHAN_STAT_SRC 0x10
+#define DCP_CHAN_STAT_PACKET 0x08
+#define DCP_CHAN_STAT_SETUP 0x04
+#define DCP_CHAN_STAT_MISMATCH 0x02
+
+/* hw packet control*/
+
+#define DCP_PKT_PAYLOAD_KEY (1<<11)
+#define DCP_PKT_CIPHER_INIT (1<<9)
+#define DCP_PKG_CIPHER_ENCRYPT (1<<8)
+#define DCP_PKT_CIPHER_ENABLE (1<<5)
+#define DCP_PKT_DECR_SEM (1<<1)
+#define DCP_PKT_CHAIN (1<<2)
+#define DCP_PKT_IRQ 1
+
+#define CIPHER_MODE_CBC (1<<4)
+
+/* cipher flags */
+#define DCP_ENC 0x0001
+#define DCP_DEC 0x0002
+#define DCP_ECB 0x0004
+#define DCP_CBC 0x0008
+#define DCP_CBC_INIT 0x0010
+#define DCP_NEW_KEY 0x0020
+#define DCP_AES 0x1000
+
+/* clock defines */
+#define CLOCK_ON 1
+#define CLOCK_OFF 0
+
+struct dcp_dev_req_ctx {
+ int mode;
+};
+
+struct dcp_op {
+ unsigned int flags;
+ u8 key[AES_KEYSIZE_128];
+ int keylen;
+
+ struct scatterlist *in_sg;
+ struct scatterlist *out_sg;
+ int sg_in_nents;
+ int sg_out_nents;
+
+ void *iv;
+ int nbytes;
+
+ struct crypto_ablkcipher *fallback;
+};
+
+struct dcp_dev {
+ struct device *dev;
+ void __iomem *dcp_regs_base;
+
+ int dcp_vmi_irq;
+ int dcp_irq;
+
+ spinlock_t queue_lock;
+ struct crypto_queue queue;
+
+ struct mutex op_mutex;
+ struct completion op_completion;
+ struct dcp_dev_hw_packet *hw_pkg[DCP_MAX_PKG];
+ dma_addr_t hw_phys_pkg[DCP_MAX_PKG];
+
+ /* [KEY][IV] Both with 16 Bytes*/
+ u8 *key_iv_base;
+ dma_addr_t key_iv_phys_base;
+
+ struct dcp_op *ctx;
+};
+
+struct dcp_dev_hw_packet {
+ uint32_t next;
+ uint32_t pkt1;
+ uint32_t pkt2;
+ uint32_t src;
+ uint32_t dst;
+ uint32_t size;
+ uint32_t payload;
+ uint32_t stat;
+};
+
+/*FIXME: get rid of globals */
+static void dcp_workqueue_handler(struct work_struct *work);
+static DECLARE_WORK(dcp_work, dcp_workqueue_handler);
+static struct workqueue_struct *dcp_wq;
+struct dcp_dev *global_dev;
+
+static inline u32 dcp_chan_reg(u32 reg, int chan)
+{
+ return reg + (chan) * 0x40;
+}
+
+static inline void dcp_write(struct dcp_dev *dev, u32 data, u32 reg)
+{
+ writel(data, dev->dcp_regs_base + reg);
+}
+
+static inline void dcp_set(struct dcp_dev *dev, u32 data, u32 reg)
+{
+ writel(data, dev->dcp_regs_base + (reg | 0x04));
+}
+
+static inline void dcp_clear(struct dcp_dev *dev, u32 data, u32 reg)
+{
+ writel(data, dev->dcp_regs_base + (reg | 0x08));
+}
+
+static inline void dcp_toggle(struct dcp_dev *dev, u32 data, u32 reg)
+{
+ writel(data, dev->dcp_regs_base + (reg | 0x0C));
+}
+
+static inline unsigned int dcp_read(struct dcp_dev *dev, u32 reg)
+{
+ return readl(dev->dcp_regs_base + reg);
+}
+
+static int dcp_perform_op(struct dcp_dev *dev, int nbytes)
+{
+ struct dcp_op *ctx = dev->ctx;
+ struct dcp_dev_hw_packet *pkt;
+ struct scatterlist *in_sg, *out_sg;
+ int in_off, out_off;
+ int act_packet = 0;
+ u32 pkt1, pkt2;
+ u32 stat = 0;
+
+ if (ctx->flags & DCP_NEW_KEY) {
+ memcpy(dev->key_iv_base, ctx->key, ctx->keylen);
+ ctx->flags &= ~DCP_NEW_KEY;
+ }
+
+ pkt1 = 0;
+ pkt1 |= DCP_PKT_CIPHER_ENABLE;
+ pkt1 |= DCP_PKT_PAYLOAD_KEY;
+
+ if (ctx->flags & DCP_ENC)
+ pkt1 |= DCP_PKG_CIPHER_ENCRYPT;
+
+ pkt2 = 0;
+ if (ctx->flags & DCP_CBC)
+ pkt2 |= CIPHER_MODE_CBC;
+
+ pkt = dev->hw_pkg[act_packet];
+ in_sg = ctx->in_sg;
+ out_sg = ctx->out_sg;
+ in_off = 0;
+ out_off = 0;
+
+ while (nbytes > 0) {
+ int len = min(in_sg->length - in_off, out_sg->length - out_off);
+
+ pkt->pkt1 = pkt1;
+ pkt->pkt2 = pkt2;
+
+ pkt->payload = (u32) dev->key_iv_phys_base;
+ pkt->stat = 0;
+
+ if (ctx->flags & DCP_CBC_INIT) {
+ pkt->pkt1 |= DCP_PKT_CIPHER_INIT;
+ ctx->flags &= ~DCP_CBC_INIT;
+ }
+
+ pkt->src = in_sg->dma_address + in_off;
+ pkt->dst = out_sg->dma_address + out_off;
+ pkt->size = len;
+ nbytes -= len;
+
+ if (nbytes <= 0) {
+ pkt->next = 0;
+ pkt->pkt1 |= DCP_PKT_IRQ;
+ pkt->pkt1 |= DCP_PKT_DECR_SEM;
+ } else {
+ pkt->next = dev->hw_phys_pkg[++act_packet];
+ pkt->pkt1 |= DCP_PKT_CHAIN;
+ pkt = dev->hw_pkg[act_packet];
+ in_off += len;
+ out_off += len;
+ if (in_sg->length == in_off) {
+ in_off = 0;
+ in_sg = sg_next(in_sg);
+ }
+ if (out_sg->length == out_off) {
+ out_off = 0;
+ out_sg = sg_next(out_sg);
+ }
+ }
+ }
+
+ dcp_clear(dev, -1, dcp_chan_reg(DCP_REG_CHAN_STAT, USED_CHANNEL));
+
+ dcp_write(dev, (u32) dev->hw_phys_pkg[0],
+ dcp_chan_reg(DCP_REG_CHAN_PTR, USED_CHANNEL));
+
+
+ dcp_write(dev, 1, dcp_chan_reg(DCP_REG_CHAN_SEMA, USED_CHANNEL));
+
+ wait_for_completion_timeout(&dev->op_completion,
+ msecs_to_jiffies(1000));
+
+ stat = dcp_read(dev, dcp_chan_reg(DCP_REG_CHAN_STAT, USED_CHANNEL));
+
+ if (stat)
+ dev_err(dev->dev, "Channel stat error 0x%x\n", stat);
+
+ return stat;
+}
+
+
+static irqreturn_t dcp_common_irq(int irq, void *context)
+{
+ u32 msk;
+ struct dcp_dev *dev = (struct dcp_dev *) context;
+
+ msk = DCP_STAT_IRQ(dcp_read(dev, DCP_REG_STAT));
+ dcp_clear(dev, msk, DCP_REG_STAT);
+
+ if (msk == 0)
+ return IRQ_NONE;
+
+ if (msk & DCP_STAT_CHAN_1)
+ complete(&dev->op_completion);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t dcp_vmi_irq(int irq, void *context)
+{
+ return dcp_common_irq(irq, context);
+}
+
+static irqreturn_t dcp_irq(int irq, void *context)
+{
+ return dcp_common_irq(irq, context);
+}
+
+static int dcp_sg_nents(struct scatterlist *sg, int nbytes)
+{
+ int nents;
+ for (nents = 0; sg && nbytes > 0; sg = sg_next(sg)) {
+ nbytes -= sg->length;
+ nents++;
+ }
+ return nents;
+}
+
+static int dcp_crypt(struct dcp_dev *dev, struct dcp_op *ctx)
+{
+ int ret = 0;
+
+ ctx->sg_in_nents = dcp_sg_nents(ctx->in_sg, ctx->nbytes);
+ ctx->sg_out_nents = dcp_sg_nents(ctx->out_sg, ctx->nbytes);
+
+ mutex_lock(&dev->op_mutex);
+ dev->ctx = ctx;
+
+ if ((ctx->flags & DCP_CBC) && ctx->iv) {
+ ctx->flags |= DCP_CBC_INIT;
+ memcpy(dev->key_iv_base + AES_KEYSIZE_128,
+ ctx->iv, AES_KEYSIZE_128);
+ }
+
+ ret = dma_map_sg(dev->dev, ctx->in_sg, ctx->sg_in_nents, DMA_TO_DEVICE);
+ if (ret != ctx->sg_in_nents) {
+ dev_err(dev->dev, "couldn't map src sg\n");
+ goto out;
+ }
+
+ ret = dma_map_sg(dev->dev, ctx->out_sg, ctx->sg_out_nents,
+ DMA_FROM_DEVICE);
+ if (ret != ctx->sg_out_nents) {
+ dev_err(dev->dev, "couldn't map dest sg\n");
+ goto unmap_in;
+ }
+
+ ret = dcp_perform_op(dev, ctx->nbytes);
+
+ dma_unmap_sg(dev->dev, ctx->out_sg, ctx->sg_out_nents, DMA_FROM_DEVICE);
+unmap_in:
+ dma_unmap_sg(dev->dev, ctx->in_sg, ctx->sg_in_nents, DMA_TO_DEVICE);
+out:
+
+ mutex_unlock(&dev->op_mutex);
+
+ return ret;
+
+}
+
+static void dcp_workqueue_handler(struct work_struct *work)
+{
+ struct dcp_dev *dev = global_dev;
+ struct crypto_async_request *async_req, *backlog;
+ struct crypto_ablkcipher *tfm;
+ struct dcp_op *ctx;
+ struct dcp_dev_req_ctx *rctx;
+ struct ablkcipher_request *req;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->queue_lock, flags);
+
+ backlog = crypto_get_backlog(&dev->queue);
+ async_req = crypto_dequeue_request(&dev->queue);
+
+ spin_unlock_irqrestore(&dev->queue_lock, flags);
+
+ if (!async_req)
+ return;
+
+ if (backlog)
+ backlog->complete(backlog, -EINPROGRESS);
+
+ req = ablkcipher_request_cast(async_req);
+ tfm = crypto_ablkcipher_reqtfm(req);
+ rctx = ablkcipher_request_ctx(req);
+ ctx = crypto_ablkcipher_ctx(tfm);
+
+ if (!req->src || !req->dst)
+ return;
+
+ ctx->nbytes = req->nbytes;
+ ctx->in_sg = req->src;
+ ctx->out_sg = req->dst;
+ ctx->iv = req->info;
+ ctx->flags |= rctx->mode;
+
+ async_req->complete(async_req, dcp_crypt(dev, ctx));
+}
+
+
+static int dcp_cra_init(struct crypto_tfm *tfm)
+{
+ const char *name = tfm->__crt_alg->cra_name;
+ struct dcp_op *ctx = crypto_tfm_ctx(tfm);
+
+ tfm->crt_ablkcipher.reqsize = sizeof(struct dcp_dev_req_ctx);
+
+ ctx->fallback = crypto_alloc_ablkcipher(name, 0,
+ CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
+
+ if (IS_ERR(ctx->fallback)) {
+ dev_err(global_dev->dev, "Error allocating fallback algo %s\n",
+ name);
+ return PTR_ERR(ctx->fallback);
+ }
+
+ return 0;
+}
+
+static void dcp_cra_exit(struct crypto_tfm *tfm)
+{
+ struct dcp_op *ctx = crypto_tfm_ctx(tfm);
+
+ if (ctx->fallback)
+ crypto_free_ablkcipher(ctx->fallback);
+
+ ctx->fallback = NULL;
+}
+
+/* async interface */
+static int dcp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+ unsigned int len)
+{
+ struct dcp_op *ctx = crypto_ablkcipher_ctx(tfm);
+ unsigned int ret = 0;
+ ctx->keylen = len;
+ ctx->flags = 0;
+ if (len == AES_KEYSIZE_128) {
+ memcpy(ctx->key, key, len);
+ ctx->flags |= DCP_NEW_KEY;
+ return 0;
+ }
+
+ dev_dbg(global_dev->dev, "key size %d not supported, using fallback ",
+ len);
+
+ ctx->fallback->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
+ ctx->fallback->base.crt_flags |=
+ (tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+ ret = crypto_ablkcipher_setkey(ctx->fallback, key, len);
+ if (ret) {
+ struct crypto_tfm *tfm_aux = crypto_ablkcipher_tfm(tfm);
+
+ tfm_aux->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+ tfm_aux->crt_flags |=
+ (ctx->fallback->base.crt_flags & CRYPTO_TFM_RES_MASK);
+ }
+ return ret;
+}
+
+static int dcp_aes_cbc_crypt(struct ablkcipher_request *req, int mode)
+{
+ struct dcp_dev_req_ctx *rctx = ablkcipher_request_ctx(req);
+ struct dcp_dev *dcp = global_dev;
+ unsigned long flags;
+ int err = 0;
+ rctx->mode = mode;
+ spin_lock_irqsave(&dcp->queue_lock, flags);
+ err = ablkcipher_enqueue_request(&dcp->queue, req);
+ spin_unlock_irqrestore(&dcp->queue_lock, flags);
+
+ if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE))
+ return -EINVAL;
+
+ queue_work(dcp_wq, &dcp_work);
+
+ return err;
+}
+
+static int dcp_aes_cbc_encrypt(struct ablkcipher_request *req)
+{
+ struct crypto_tfm *tfm =
+ crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
+ struct dcp_op *ctx = crypto_ablkcipher_ctx(
+ crypto_ablkcipher_reqtfm(req));
+
+ if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
+ int err = 0;
+ ablkcipher_request_set_tfm(req, ctx->fallback);
+ err = crypto_ablkcipher_encrypt(req);
+ ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
+ return err;
+ }
+
+ return dcp_aes_cbc_crypt(req, DCP_AES | DCP_ENC | DCP_CBC);
+}
+
+static int dcp_aes_cbc_decrypt(struct ablkcipher_request *req)
+{
+ struct crypto_tfm *tfm =
+ crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
+ struct dcp_op *ctx = crypto_ablkcipher_ctx(
+ crypto_ablkcipher_reqtfm(req));
+
+ if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
+ int err = 0;
+ ablkcipher_request_set_tfm(req, ctx->fallback);
+ err = crypto_ablkcipher_decrypt(req);
+ ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
+ return err;
+ }
+ return dcp_aes_cbc_crypt(req, DCP_AES | DCP_DEC | DCP_CBC);
+}
+
+static struct crypto_alg algs[] = {
+{
+ .cra_name = "cbc(aes)",
+ .cra_driver_name = "dcp-cbc-aes",
+ .cra_alignmask = 15,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
+ CRYPTO_ALG_NEED_FALLBACK,
+ .cra_blocksize = AES_KEYSIZE_128,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_priority = 300,
+ .cra_u.ablkcipher = {
+ .min_keysize = AES_KEYSIZE_128,
+ .max_keysize = AES_KEYSIZE_128,
+ .setkey = dcp_aes_setkey,
+ .encrypt = dcp_aes_cbc_encrypt,
+ .decrypt = dcp_aes_cbc_decrypt,
+ .ivsize = AES_KEYSIZE_128,
+ }
+
+},
+};
+
+static int dcp_probe(struct platform_device *pdev)
+{
+ struct dcp_dev *dev = NULL;
+ struct resource *r;
+ int i, ret, j;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (dev == NULL) {
+ dev_err(&pdev->dev, "Failed to allocate structure\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+ global_dev = dev;
+ dev->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, dev);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "failed to get IORESOURCE_MEM\n");
+ ret = -ENXIO;
+ goto err_dev;
+ }
+ dev->dcp_regs_base = ioremap(r->start, resource_size(r));
+
+
+ dcp_set(dev, DCP_CTRL_SFRST, DCP_REG_CTRL);
+ udelay(10);
+ dcp_clear(dev, DCP_CTRL_SFRST | DCP_CTRL_CLKGATE, DCP_REG_CTRL);
+
+ dcp_write(dev, DCP_CTRL_GATHER_RES_WRITE |
+ DCP_CTRL_ENABLE_CONTEXT_CACHE | DCP_CTRL_CH_IRQ_E_1,
+ DCP_REG_CTRL);
+
+ dcp_write(dev, DCP_CHAN_CTRL_ENABLE_1, DCP_REG_CHAN_CTRL);
+
+ for (i = 0; i < 4; i++)
+ dcp_clear(dev, -1, dcp_chan_reg(DCP_REG_CHAN_STAT, i));
+
+ dcp_clear(dev, -1, DCP_REG_STAT);
+
+
+ r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "can't get IRQ resource (0)\n");
+ ret = -EIO;
+ goto err_unmap_mem;
+ }
+ dev->dcp_vmi_irq = r->start;
+ ret = request_irq(dev->dcp_vmi_irq, dcp_vmi_irq, 0, "dcp", dev);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "can't request_irq (0)\n");
+ ret = -EIO;
+ goto err_unmap_mem;
+ }
+
+ r = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+ if (!r) {
+ dev_err(&pdev->dev, "can't get IRQ resource (1)\n");
+ ret = -EIO;
+ goto err_free_irq0;
+ }
+ dev->dcp_irq = r->start;
+ ret = request_irq(dev->dcp_irq, dcp_irq, 0, "dcp", dev);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "can't request_irq (1)\n");
+ ret = -EIO;
+ goto err_free_irq0;
+ }
+
+ dev->hw_pkg[0] = dma_alloc_coherent(&pdev->dev,
+ DCP_MAX_PKG * sizeof(struct dcp_dev_hw_packet),
+ &dev->hw_phys_pkg[0],
+ GFP_KERNEL);
+ if (!dev->hw_pkg[0]) {
+ dev_err(&pdev->dev, "Could not allocate hw descriptors\n");
+ ret = -ENOMEM;
+ goto err_free_irq1;
+ }
+
+ for (i = 1; i < DCP_MAX_PKG; i++) {
+ dev->hw_phys_pkg[i] = dev->hw_phys_pkg[i - 1]
+ + sizeof(struct dcp_dev_hw_packet);
+ dev->hw_pkg[i] = dev->hw_pkg[i - 1] + 1;
+
+ }
+
+ dev->key_iv_base = dma_alloc_coherent(&pdev->dev, 2 * AES_KEYSIZE_128,
+ &dev->key_iv_phys_base, GFP_KERNEL);
+ if (!dev->key_iv_base) {
+ dev_err(&pdev->dev, "Could not allocate memory for key\n");
+ ret = -ENOMEM;
+ goto err_free_hw_packet;
+ }
+
+ spin_lock_init(&dev->queue_lock);
+ crypto_init_queue(&dev->queue, 10);
+ mutex_init(&dev->op_mutex);
+ init_completion(&dev->op_completion);
+
+ dcp_wq = alloc_workqueue("dcp_wq", WQ_HIGHPRI | WQ_UNBOUND, 1);
+ if (!dcp_wq) {
+ dev_err(&pdev->dev, "alloc_workqueue failed\n");
+ ret = -ENOMEM;
+ goto err_free_key_iv;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(algs); i++) {
+ algs[i].cra_priority = 500;
+ algs[i].cra_ctxsize = sizeof(struct dcp_op);
+ algs[i].cra_module = THIS_MODULE;
+ algs[i].cra_init = dcp_cra_init;
+ algs[i].cra_exit = dcp_cra_exit;
+ if (crypto_register_alg(&algs[i])) {
+ dev_err(&pdev->dev, "register algorithm failed\n");
+ ret = -ENOMEM;
+ goto err_unregister;
+ }
+ }
+ dev_notice(&pdev->dev, "DCP crypto enabled.!\n");
+
+ return 0;
+
+err_unregister:
+ for (j = 0; j < i; j++)
+ crypto_unregister_alg(&algs[j]);
+err_free_key_iv:
+ dma_free_coherent(&pdev->dev, 2 * AES_KEYSIZE_128, dev->key_iv_base,
+ dev->key_iv_phys_base);
+err_free_hw_packet:
+ dma_free_coherent(&pdev->dev, DCP_MAX_PKG *
+ sizeof(struct dcp_dev_hw_packet), dev->hw_pkg[0],
+ dev->hw_phys_pkg[0]);
+err_free_irq1:
+ free_irq(dev->dcp_irq, dev);
+err_free_irq0:
+ free_irq(dev->dcp_vmi_irq, dev);
+err_unmap_mem:
+ iounmap((void *) dev->dcp_regs_base);
+err_dev:
+ kfree(dev);
+err:
+ return ret;
+}
+
+static int dcp_remove(struct platform_device *pdev)
+{
+ struct dcp_dev *dev;
+ int j;
+ dev = platform_get_drvdata(pdev);
+ platform_set_drvdata(pdev, NULL);
+
+ dma_free_coherent(&pdev->dev,
+ DCP_MAX_PKG * sizeof(struct dcp_dev_hw_packet),
+ dev->hw_pkg[0], dev->hw_phys_pkg[0]);
+
+ dma_free_coherent(&pdev->dev, 2 * AES_KEYSIZE_128, dev->key_iv_base,
+ dev->key_iv_phys_base);
+
+ free_irq(dev->dcp_irq, dev);
+ free_irq(dev->dcp_vmi_irq, dev);
+
+ iounmap((void *) dev->dcp_regs_base);
+
+ for (j = 0; j < ARRAY_SIZE(algs); j++)
+ crypto_unregister_alg(&algs[j]);
+
+ kfree(dev);
+ return 0;
+}
+
+static struct of_device_id fs_dcp_of_match[] = {
+ { .compatible = "fsl-dcp"},
+ {},
+};
+
+static struct platform_driver fs_dcp_driver = {
+ .probe = dcp_probe,
+ .remove = dcp_remove,
+ .driver = {
+ .name = "fsl-dcp",
+ .owner = THIS_MODULE,
+ .of_match_table = fs_dcp_of_match
+ }
+};
+
+module_platform_driver(fs_dcp_driver);
+
+
+MODULE_AUTHOR("Tobias Rauter <[email protected]>");
+MODULE_DESCRIPTION("Freescale DCP Crypto Driver");
+MODULE_LICENSE("GPL");
--
1.8.1.2

2013-05-10 06:27:50

by Christoph G. Baumann

[permalink] [raw]
Subject: Re: [RFC] Freescale DCP crypto acceleration

Hello Tobias,

good to see that someone else is also working on this. As I don't have the time
to do a complete rewrite it's all yours :-)
Two remarks:
1. don't forget the SHA hashes
2. try to keep it compatible with the "old" IOCTL interface as tools like
kobs-ng rely on it

Regards
Christoph