[PATCH v6 0/2] crypto: driver for Tegra AES hardware

[PATCH v6 0/2] crypto: driver for Tegra AES hardware

[Varun Wadekar]

The tegra crypto driver uses the tegra_chip_uid API for the RNG
calculation. If one wants to build tegra-aes as a module, then
tegra_chip_uid needs to be exported.

I have also posted "arm: tegra: export tegra_chip_uid" to the mach-tegra
maintainers to get this patch into their tree, but for compiling the
"crypto: driver for Tegra AES hardware" patch, "arm: tegra: export tegra_chip_uid"
has to be present.

I leave it to the linux-crypto maintainers to decide how they want to
tackle this situation. In order to facilitate smooth compilation of the
actual crytpo driver patch sending the tegra_chip_uid patch as well.

v7:
---
Changed the memset/memcpy logic for copying of the key. Now memset and
memcpy work on mutually exclusive addresses.

v6:
---
Fixed the subject line in the cover letter and removed the
'Change-Id: xxxx' lines from the commits

v5:
---
Specifically mention the dependancy between "arm: tegra: export tegra_chip_uid"
and "crypto: driver for Tegra AES hardware"

v4:
---
Mentioned the dependancy on the "arm: tegra: export tegra_chip_uid"
patch

v3:
---
Add the following code from KimP in tegra_aes_handle_req

tfm = crypto_ablkcipher_reqtfm(req);
...
ctx = crypto_ablkcipher_ctx(tfm);
...
dd->ivlen = crypto_ablkcipher_ivsize(tfm); 

v2:
---
Fixed the enable/disable irq related comments from Kim Phillips and some
other cosmetic changes.

v1:
---
Fixed the compilation issues that Henning reported. The driver now
builds as a module. Use devm_* apis. Fixed other comments from StephenW
and KimP.

Henning Heinold (1):
  arm: tegra: export tegra_chip_uid

Varun Wadekar (1):
  crypto: driver for Tegra AES hardware

 arch/arm/mach-tegra/fuse.c |    2 +
 drivers/crypto/Kconfig     |   11 +
 drivers/crypto/Makefile    |    1 +
 drivers/crypto/tegra-aes.c | 1102 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/crypto/tegra-aes.h |  103 ++++
 5 files changed, 1219 insertions(+), 0 deletions(-)
 create mode 100644 drivers/crypto/tegra-aes.c
 create mode 100644 drivers/crypto/tegra-aes.h

[PATCH v7 1/2] arm: tegra: export tegra_chip_uid

[Varun Wadekar]

From: Henning Heinold <heinold-cPcqOTmdTlv31zTM6d8ziw@public.gmane.org>

The crypto driver will need this api to use
it in the RNG calculations. In order to build
the crypto driver as a module, tegra_chip_uid
has to be exported.

Signed-off-by: Henning Heinold <heinold-cPcqOTmdTlv31zTM6d8ziw@public.gmane.org>
Signed-off-by: Varun Wadekar <vwadekar-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 arch/arm/mach-tegra/fuse.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-tegra/fuse.c b/arch/arm/mach-tegra/fuse.c
index 1fa26d9..ea49bd9 100644
--- a/arch/arm/mach-tegra/fuse.c
+++ b/arch/arm/mach-tegra/fuse.c
@@ -19,6 +19,7 @@
 
 #include <linux/kernel.h>
 #include <linux/io.h>
+#include <linux/module.h>
 
 #include <mach/iomap.h>
 
@@ -58,6 +59,7 @@ unsigned long long tegra_chip_uid(void)
 	hi = fuse_readl(FUSE_UID_HIGH);
 	return (hi << 32ull) | lo;
 }
+EXPORT_SYMBOL(tegra_chip_uid);
 
 int tegra_sku_id(void)
 {
-- 
1.7.1

Re: [PATCH v7 1/2] arm: tegra: export tegra_chip_uid

[Olof Johansson]

On Thu, Nov 17, 2011 at 9:42 PM, Varun Wadekar <vwadekar-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:
> From: Henning Heinold <heinold-cPcqOTmdTlv31zTM6d8ziw@public.gmane.org>
>
> The crypto driver will need this api to use
> it in the RNG calculations. In order to build
> the crypto driver as a module, tegra_chip_uid
> has to be exported.
>
> Signed-off-by: Henning Heinold <heinold-cPcqOTmdTlv31zTM6d8ziw@public.gmane.org>
> Signed-off-by: Varun Wadekar <vwadekar-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

Acked-by: Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>

[PATCH v7 2/2] crypto: driver for Tegra AES hardware

[Varun Wadekar]

driver supports ecb/cbc/ofb/ansi_x9.31rng modes,
128, 192 and 256-bit key sizes

Signed-off-by: Varun Wadekar <vwadekar-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/crypto/Kconfig     |   11 +
 drivers/crypto/Makefile    |    1 +
 drivers/crypto/tegra-aes.c | 1102 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/crypto/tegra-aes.h |  103 ++++
 4 files changed, 1217 insertions(+), 0 deletions(-)
 create mode 100644 drivers/crypto/tegra-aes.c
 create mode 100644 drivers/crypto/tegra-aes.h

diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 6d16b4b..e707979 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -293,4 +293,15 @@ config CRYPTO_DEV_S5P
 	  Select this to offload Samsung S5PV210 or S5PC110 from AES
 	  algorithms execution.
 
+config CRYPTO_DEV_TEGRA_AES
+	tristate "Support for TEGRA AES hw engine"
+	depends on ARCH_TEGRA
+	select CRYPTO_AES
+	help
+	  TEGRA processors have AES module accelerator. Select this if you
+	  want to use the TEGRA module for AES algorithms.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called tegra-aes.
+
 endif # CRYPTO_HW
diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
index 53ea501..f3e64ea 100644
--- a/drivers/crypto/Makefile
+++ b/drivers/crypto/Makefile
@@ -13,3 +13,4 @@ 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_S5P) += s5p-sss.o
+obj-$(CONFIG_CRYPTO_DEV_TEGRA_AES) += tegra-aes.o
diff --git a/drivers/crypto/tegra-aes.c b/drivers/crypto/tegra-aes.c
new file mode 100644
index 0000000..914eb6e
--- /dev/null
+++ b/drivers/crypto/tegra-aes.c
@@ -0,0 +1,1102 @@
+/*
+ * drivers/crypto/tegra-aes.c
+ *
+ * Driver for NVIDIA Tegra AES hardware engine residing inside the
+ * Bit Stream Engine for Video (BSEV) hardware block.
+ *
+ * The programming sequence for this engine is with the help
+ * of commands which travel via a command queue residing between the
+ * CPU and the BSEV block. The BSEV engine has an internal RAM (VRAM)
+ * where the final input plaintext, keys and the IV have to be copied
+ * before starting the encrypt/decrypt operation.
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.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 <mach/clk.h>
+
+#include <crypto/scatterwalk.h>
+#include <crypto/aes.h>
+#include <crypto/internal/rng.h>
+
+#include "tegra-aes.h"
+
+#define FLAGS_MODE_MASK			0x00FF
+#define FLAGS_ENCRYPT			BIT(0)
+#define FLAGS_CBC			BIT(1)
+#define FLAGS_GIV			BIT(2)
+#define FLAGS_RNG			BIT(3)
+#define FLAGS_OFB			BIT(4)
+#define FLAGS_NEW_KEY			BIT(5)
+#define FLAGS_NEW_IV			BIT(6)
+#define FLAGS_INIT			BIT(7)
+#define FLAGS_FAST			BIT(8)
+#define FLAGS_BUSY			9
+
+/*
+ * Defines AES engine Max process bytes size in one go, which takes 1 msec.
+ * AES engine spends about 176 cycles/16-bytes or 11 cycles/byte
+ * The duration CPU can use the BSE to 1 msec, then the number of available
+ * cycles of AVP/BSE is 216K. In this duration, AES can process 216/11 ~= 19KB
+ * Based on this AES_HW_DMA_BUFFER_SIZE_BYTES is configured to 16KB.
+ */
+#define AES_HW_DMA_BUFFER_SIZE_BYTES 0x4000
+
+/*
+ * The key table length is 64 bytes
+ * (This includes first upto 32 bytes key + 16 bytes original initial vector
+ * and 16 bytes updated initial vector)
+ */
+#define AES_HW_KEY_TABLE_LENGTH_BYTES 64
+
+/*
+ * The memory being used is divides as follows:
+ * 1. Key - 32 bytes
+ * 2. Original IV - 16 bytes
+ * 3. Updated IV - 16 bytes
+ * 4. Key schedule - 256 bytes
+ *
+ * 1+2+3 constitute the hw key table.
+ */
+#define AES_HW_IV_SIZE 16
+#define AES_HW_KEYSCHEDULE_LEN 256
+#define AES_IVKEY_SIZE (AES_HW_KEY_TABLE_LENGTH_BYTES + AES_HW_KEYSCHEDULE_LEN)
+
+/* Define commands required for AES operation */
+enum {
+	CMD_BLKSTARTENGINE = 0x0E,
+	CMD_DMASETUP = 0x10,
+	CMD_DMACOMPLETE = 0x11,
+	CMD_SETTABLE = 0x15,
+	CMD_MEMDMAVD = 0x22,
+};
+
+/* Define sub-commands */
+enum {
+	SUBCMD_VRAM_SEL = 0x1,
+	SUBCMD_CRYPTO_TABLE_SEL = 0x3,
+	SUBCMD_KEY_TABLE_SEL = 0x8,
+};
+
+/* memdma_vd command */
+#define MEMDMA_DIR_DTOVRAM		0 /* sdram -> vram */
+#define MEMDMA_DIR_VTODRAM		1 /* vram -> sdram */
+#define MEMDMA_DIR_SHIFT		25
+#define MEMDMA_NUM_WORDS_SHIFT		12
+
+/* command queue bit shifts */
+enum {
+	CMDQ_KEYTABLEADDR_SHIFT = 0,
+	CMDQ_KEYTABLEID_SHIFT = 17,
+	CMDQ_VRAMSEL_SHIFT = 23,
+	CMDQ_TABLESEL_SHIFT = 24,
+	CMDQ_OPCODE_SHIFT = 26,
+};
+
+/*
+ * The secure key slot contains a unique secure key generated
+ * and loaded by the bootloader. This slot is marked as non-accessible
+ * to the kernel.
+ */
+#define SSK_SLOT_NUM		4
+
+#define AES_NR_KEYSLOTS		8
+#define TEGRA_AES_QUEUE_LENGTH	50
+#define DEFAULT_RNG_BLK_SZ	16
+
+/* The command queue depth */
+#define AES_HW_MAX_ICQ_LENGTH	5
+
+struct tegra_aes_slot {
+	struct list_head node;
+	int slot_num;
+	bool available;
+};
+
+static struct tegra_aes_slot ssk = {
+	.slot_num = SSK_SLOT_NUM,
+	.available = true,
+};
+
+struct tegra_aes_reqctx {
+	unsigned long mode;
+};
+
+struct tegra_aes_dev {
+	struct device *dev;
+	void __iomem *io_base;
+	dma_addr_t ivkey_phys_base;
+	void __iomem *ivkey_base;
+	struct clk *aes_clk;
+	struct tegra_aes_ctx *ctx;
+	int irq;
+	unsigned long flags;
+	struct completion op_complete;
+	u32 *buf_in;
+	dma_addr_t dma_buf_in;
+	u32 *buf_out;
+	dma_addr_t dma_buf_out;
+	u8 *iv;
+	u8 dt[DEFAULT_RNG_BLK_SZ];
+	int ivlen;
+	u64 ctr;
+	spinlock_t lock;
+	struct crypto_queue queue;
+	struct tegra_aes_slot *slots;
+	struct ablkcipher_request *req;
+	size_t total;
+	struct scatterlist *in_sg;
+	size_t in_offset;
+	struct scatterlist *out_sg;
+	size_t out_offset;
+};
+
+static struct tegra_aes_dev *aes_dev;
+
+struct tegra_aes_ctx {
+	struct tegra_aes_dev *dd;
+	unsigned long flags;
+	struct tegra_aes_slot *slot;
+	u8 key[AES_MAX_KEY_SIZE];
+	int keylen;
+};
+
+static struct tegra_aes_ctx rng_ctx = {
+	.flags = FLAGS_NEW_KEY,
+	.keylen = AES_KEYSIZE_128,
+};
+
+/* keep registered devices data here */
+static LIST_HEAD(dev_list);
+static DEFINE_SPINLOCK(list_lock);
+static DEFINE_MUTEX(aes_lock);
+
+static void aes_workqueue_handler(struct work_struct *work);
+static DECLARE_WORK(aes_work, aes_workqueue_handler);
+static struct workqueue_struct *aes_wq;
+
+extern unsigned long long tegra_chip_uid(void);
+
+static inline u32 aes_readl(struct tegra_aes_dev *dd, u32 offset)
+{
+	return readl(dd->io_base + offset);
+}
+
+static inline void aes_writel(struct tegra_aes_dev *dd, u32 val, u32 offset)
+{
+	writel(val, dd->io_base + offset);
+}
+
+static int aes_start_crypt(struct tegra_aes_dev *dd, u32 in_addr, u32 out_addr,
+	int nblocks, int mode, bool upd_iv)
+{
+	u32 cmdq[AES_HW_MAX_ICQ_LENGTH];
+	int i, eng_busy, icq_empty, ret;
+	u32 value;
+
+	/* reset all the interrupt bits */
+	aes_writel(dd, 0xFFFFFFFF, TEGRA_AES_INTR_STATUS);
+
+	/* enable error, dma xfer complete interrupts */
+	aes_writel(dd, 0x33, TEGRA_AES_INT_ENB);
+
+	cmdq[0] = CMD_DMASETUP << CMDQ_OPCODE_SHIFT;
+	cmdq[1] = in_addr;
+	cmdq[2] = CMD_BLKSTARTENGINE << CMDQ_OPCODE_SHIFT | (nblocks-1);
+	cmdq[3] = CMD_DMACOMPLETE << CMDQ_OPCODE_SHIFT;
+
+	value = aes_readl(dd, TEGRA_AES_CMDQUE_CONTROL);
+	/* access SDRAM through AHB */
+	value &= ~TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD;
+	value &= ~TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD;
+	value |= TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD |
+		 TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD |
+		 TEGRA_AES_CMDQ_CTRL_ICMDQEN_FIELD;
+	aes_writel(dd, value, TEGRA_AES_CMDQUE_CONTROL);
+	dev_dbg(dd->dev, "cmd_q_ctrl=0x%x", value);
+
+	value = (0x1 << TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT) |
+		((dd->ctx->keylen * 8) <<
+			TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT) |
+		((u32)upd_iv << TEGRA_AES_SECURE_IV_SELECT_SHIFT);
+
+	if (mode & FLAGS_CBC) {
+		value |= ((((mode & FLAGS_ENCRYPT) ? 2 : 3)
+				<< TEGRA_AES_SECURE_XOR_POS_SHIFT) |
+			(((mode & FLAGS_ENCRYPT) ? 2 : 3)
+				<< TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT) |
+			((mode & FLAGS_ENCRYPT) ? 1 : 0)
+				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT);
+	} else if (mode & FLAGS_OFB) {
+		value |= ((TEGRA_AES_SECURE_XOR_POS_FIELD) |
+			(2 << TEGRA_AES_SECURE_INPUT_SEL_SHIFT) |
+			(TEGRA_AES_SECURE_CORE_SEL_FIELD));
+	} else if (mode & FLAGS_RNG) {
+		value |= (((mode & FLAGS_ENCRYPT) ? 1 : 0)
+				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT |
+			  TEGRA_AES_SECURE_RNG_ENB_FIELD);
+	} else {
+		value |= (((mode & FLAGS_ENCRYPT) ? 1 : 0)
+				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT);
+	}
+
+	dev_dbg(dd->dev, "secure_in_sel=0x%x", value);
+	aes_writel(dd, value, TEGRA_AES_SECURE_INPUT_SELECT);
+
+	aes_writel(dd, out_addr, TEGRA_AES_SECURE_DEST_ADDR);
+	INIT_COMPLETION(dd->op_complete);
+
+	for (i = 0; i < AES_HW_MAX_ICQ_LENGTH - 1; i++) {
+		do {
+			value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
+			eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
+			icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
+		} while (eng_busy & (!icq_empty));
+		aes_writel(dd, cmdq[i], TEGRA_AES_ICMDQUE_WR);
+	}
+
+	ret = wait_for_completion_timeout(&dd->op_complete,
+					  msecs_to_jiffies(150));
+	if (ret == 0) {
+		dev_err(dd->dev, "timed out (0x%x)\n",
+			aes_readl(dd, TEGRA_AES_INTR_STATUS));
+		return -ETIMEDOUT;
+	}
+
+	aes_writel(dd, cmdq[AES_HW_MAX_ICQ_LENGTH - 1], TEGRA_AES_ICMDQUE_WR);
+	return 0;
+}
+
+static void aes_release_key_slot(struct tegra_aes_ctx *ctx)
+{
+	spin_lock(&list_lock);
+	ctx->slot->available = true;
+	ctx->slot = NULL;
+	spin_unlock(&list_lock);
+}
+
+static struct tegra_aes_slot *aes_find_key_slot(struct tegra_aes_dev *dd)
+{
+	struct tegra_aes_slot *slot = NULL;
+	bool found = false;
+
+	spin_lock(&list_lock);
+	list_for_each_entry(slot, &dev_list, node) {
+		dev_dbg(dd->dev, "empty:%d, num:%d\n", slot->available,
+			slot->slot_num);
+		if (slot->available) {
+			slot->available = false;
+			found = true;
+			break;
+		}
+	}
+	spin_unlock(&list_lock);
+
+	return found ? slot : NULL;
+}
+
+static int aes_set_key(struct tegra_aes_dev *dd)
+{
+	u32 value, cmdq[2];
+	struct tegra_aes_ctx *ctx = dd->ctx;
+	int eng_busy, icq_empty, dma_busy;
+	bool use_ssk = false;
+
+	/* use ssk? */
+	if (!dd->ctx->slot) {
+		dev_dbg(dd->dev, "using ssk");
+		dd->ctx->slot = &ssk;
+		use_ssk = true;
+	}
+
+	/* enable key schedule generation in hardware */
+	value = aes_readl(dd, TEGRA_AES_SECURE_CONFIG_EXT);
+	value &= ~TEGRA_AES_SECURE_KEY_SCH_DIS_FIELD;
+	aes_writel(dd, value, TEGRA_AES_SECURE_CONFIG_EXT);
+
+	/* select the key slot */
+	value = aes_readl(dd, TEGRA_AES_SECURE_CONFIG);
+	value &= ~TEGRA_AES_SECURE_KEY_INDEX_FIELD;
+	value |= (ctx->slot->slot_num << TEGRA_AES_SECURE_KEY_INDEX_SHIFT);
+	aes_writel(dd, value, TEGRA_AES_SECURE_CONFIG);
+
+	if (use_ssk)
+		return 0;
+
+	/* copy the key table from sdram to vram */
+	cmdq[0] = CMD_MEMDMAVD << CMDQ_OPCODE_SHIFT |
+		MEMDMA_DIR_DTOVRAM << MEMDMA_DIR_SHIFT |
+		AES_HW_KEY_TABLE_LENGTH_BYTES / sizeof(u32) <<
+			MEMDMA_NUM_WORDS_SHIFT;
+	cmdq[1] = (u32)dd->ivkey_phys_base;
+
+	aes_writel(dd, cmdq[0], TEGRA_AES_ICMDQUE_WR);
+	aes_writel(dd, cmdq[1], TEGRA_AES_ICMDQUE_WR);
+
+	do {
+		value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
+		eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
+		icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
+		dma_busy = value & TEGRA_AES_DMA_BUSY_FIELD;
+	} while (eng_busy & (!icq_empty) & dma_busy);
+
+	/* settable command to get key into internal registers */
+	value = CMD_SETTABLE << CMDQ_OPCODE_SHIFT |
+		SUBCMD_CRYPTO_TABLE_SEL << CMDQ_TABLESEL_SHIFT |
+		SUBCMD_VRAM_SEL << CMDQ_VRAMSEL_SHIFT |
+		(SUBCMD_KEY_TABLE_SEL | ctx->slot->slot_num) <<
+			CMDQ_KEYTABLEID_SHIFT;
+	aes_writel(dd, value, TEGRA_AES_ICMDQUE_WR);
+
+	do {
+		value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
+		eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
+		icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
+	} while (eng_busy & (!icq_empty));
+
+	return 0;
+}
+
+static int tegra_aes_handle_req(struct tegra_aes_dev *dd)
+{
+	struct crypto_async_request *async_req, *backlog;
+	struct crypto_ablkcipher *tfm;
+	struct tegra_aes_ctx *ctx;
+	struct tegra_aes_reqctx *rctx;
+	struct ablkcipher_request *req;
+	unsigned long flags;
+	int dma_max = AES_HW_DMA_BUFFER_SIZE_BYTES;
+	int ret = 0, nblocks, total;
+	int count = 0;
+	dma_addr_t addr_in, addr_out;
+	struct scatterlist *in_sg, *out_sg;
+
+	if (!dd)
+		return -EINVAL;
+
+	spin_lock_irqsave(&dd->lock, flags);
+	backlog = crypto_get_backlog(&dd->queue);
+	async_req = crypto_dequeue_request(&dd->queue);
+	if (!async_req)
+		clear_bit(FLAGS_BUSY, &dd->flags);
+	spin_unlock_irqrestore(&dd->lock, flags);
+
+	if (!async_req)
+		return -ENODATA;
+
+	if (backlog)
+		backlog->complete(backlog, -EINPROGRESS);
+
+	req = ablkcipher_request_cast(async_req);
+
+	dev_dbg(dd->dev, "%s: get new req\n", __func__);
+
+	if (!req->src || !req->dst)
+		return -EINVAL;
+
+	/* take mutex to access the aes hw */
+	mutex_lock(&aes_lock);
+
+	/* assign new request to device */
+	dd->req = req;
+	dd->total = req->nbytes;
+	dd->in_offset = 0;
+	dd->in_sg = req->src;
+	dd->out_offset = 0;
+	dd->out_sg = req->dst;
+
+	in_sg = dd->in_sg;
+	out_sg = dd->out_sg;
+
+	total = dd->total;
+
+	tfm = crypto_ablkcipher_reqtfm(req);
+	rctx = ablkcipher_request_ctx(req);
+	ctx = crypto_ablkcipher_ctx(tfm);
+	rctx->mode &= FLAGS_MODE_MASK;
+	dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode;
+
+	dd->iv = (u8 *)req->info;
+	dd->ivlen = crypto_ablkcipher_ivsize(tfm);
+
+	/* assign new context to device */
+	ctx->dd = dd;
+	dd->ctx = ctx;
+
+	if (ctx->flags & FLAGS_NEW_KEY) {
+		/* copy the key */
+		memcpy(dd->ivkey_base, ctx->key, ctx->keylen);
+		memset(dd->ivkey_base + ctx->keylen, 0, AES_HW_KEY_TABLE_LENGTH_BYTES - ctx->keylen);
+		aes_set_key(dd);
+		ctx->flags &= ~FLAGS_NEW_KEY;
+	}
+
+	if (((dd->flags & FLAGS_CBC) || (dd->flags & FLAGS_OFB)) && dd->iv) {
+		/* set iv to the aes hw slot
+		 * Hw generates updated iv only after iv is set in slot.
+		 * So key and iv is passed asynchronously.
+		 */
+		memcpy(dd->buf_in, dd->iv, dd->ivlen);
+
+		ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
+				      dd->dma_buf_out, 1, FLAGS_CBC, false);
+		if (ret < 0) {
+			dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
+			goto out;
+		}
+	}
+
+	while (total) {
+		dev_dbg(dd->dev, "remain: %d\n", total);
+		ret = dma_map_sg(dd->dev, in_sg, 1, DMA_TO_DEVICE);
+		if (!ret) {
+			dev_err(dd->dev, "dma_map_sg() error\n");
+			goto out;
+		}
+
+		ret = dma_map_sg(dd->dev, out_sg, 1, DMA_FROM_DEVICE);
+		if (!ret) {
+			dev_err(dd->dev, "dma_map_sg() error\n");
+			dma_unmap_sg(dd->dev, dd->in_sg,
+				1, DMA_TO_DEVICE);
+			goto out;
+		}
+
+		addr_in = sg_dma_address(in_sg);
+		addr_out = sg_dma_address(out_sg);
+		dd->flags |= FLAGS_FAST;
+		count = min_t(int, sg_dma_len(in_sg), dma_max);
+		WARN_ON(sg_dma_len(in_sg) != sg_dma_len(out_sg));
+		nblocks = DIV_ROUND_UP(count, AES_BLOCK_SIZE);
+
+		ret = aes_start_crypt(dd, addr_in, addr_out, nblocks,
+			dd->flags, true);
+
+		dma_unmap_sg(dd->dev, out_sg, 1, DMA_FROM_DEVICE);
+		dma_unmap_sg(dd->dev, in_sg, 1, DMA_TO_DEVICE);
+
+		if (ret < 0) {
+			dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
+			goto out;
+		}
+		dd->flags &= ~FLAGS_FAST;
+
+		dev_dbg(dd->dev, "out: copied %d\n", count);
+		total -= count;
+		in_sg = sg_next(in_sg);
+		out_sg = sg_next(out_sg);
+		WARN_ON(((total != 0) && (!in_sg || !out_sg)));
+	}
+
+out:
+	mutex_unlock(&aes_lock);
+
+	dd->total = total;
+
+	if (dd->req->base.complete)
+		dd->req->base.complete(&dd->req->base, ret);
+
+	dev_dbg(dd->dev, "%s: exit\n", __func__);
+	return ret;
+}
+
+static int tegra_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	struct tegra_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	struct tegra_aes_dev *dd = aes_dev;
+	struct tegra_aes_slot *key_slot;
+
+	if ((keylen != AES_KEYSIZE_128) && (keylen != AES_KEYSIZE_192) &&
+		(keylen != AES_KEYSIZE_256)) {
+		dev_err(dd->dev, "unsupported key size\n");
+		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	dev_dbg(dd->dev, "keylen: %d\n", keylen);
+
+	ctx->dd = dd;
+
+	if (key) {
+		if (!ctx->slot) {
+			key_slot = aes_find_key_slot(dd);
+			if (!key_slot) {
+				dev_err(dd->dev, "no empty slot\n");
+				return -ENOMEM;
+			}
+
+			ctx->slot = key_slot;
+		}
+
+		memcpy(ctx->key, key, keylen);
+		ctx->keylen = keylen;
+	}
+
+	ctx->flags |= FLAGS_NEW_KEY;
+	dev_dbg(dd->dev, "done\n");
+	return 0;
+}
+
+static void aes_workqueue_handler(struct work_struct *work)
+{
+	struct tegra_aes_dev *dd = aes_dev;
+	int ret;
+
+	clk_enable(dd->aes_clk);
+
+	/* empty the crypto queue and then return */
+	do {
+		ret = tegra_aes_handle_req(dd);
+	} while (!ret);
+
+	clk_disable(dd->aes_clk);
+}
+
+static irqreturn_t aes_irq(int irq, void *dev_id)
+{
+	struct tegra_aes_dev *dd = (struct tegra_aes_dev *)dev_id;
+	u32 value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
+	int busy = test_bit(FLAGS_BUSY, &dd->flags);
+
+	if (!busy) {
+		dev_dbg(dd->dev, "spurious interrupt\n");
+		return IRQ_NONE;
+	}
+
+	dev_dbg(dd->dev, "irq_stat: 0x%x\n", value);
+	if (value & TEGRA_AES_INT_ERROR_MASK)
+		aes_writel(dd, TEGRA_AES_INT_ERROR_MASK, TEGRA_AES_INTR_STATUS);
+
+	if (!(value & TEGRA_AES_ENGINE_BUSY_FIELD))
+		complete(&dd->op_complete);
+	else
+		return IRQ_NONE;
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
+{
+	struct tegra_aes_reqctx *rctx = ablkcipher_request_ctx(req);
+	struct tegra_aes_dev *dd = aes_dev;
+	unsigned long flags;
+	int err = 0;
+	int busy;
+
+	dev_dbg(dd->dev, "nbytes: %d, enc: %d, cbc: %d, ofb: %d\n",
+		req->nbytes, !!(mode & FLAGS_ENCRYPT),
+		!!(mode & FLAGS_CBC), !!(mode & FLAGS_OFB));
+
+	rctx->mode = mode;
+
+	spin_lock_irqsave(&dd->lock, flags);
+	err = ablkcipher_enqueue_request(&dd->queue, req);
+	busy = test_and_set_bit(FLAGS_BUSY, &dd->flags);
+	spin_unlock_irqrestore(&dd->lock, flags);
+
+	if (!busy)
+		queue_work(aes_wq, &aes_work);
+
+	return err;
+}
+
+static int tegra_aes_ecb_encrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, FLAGS_ENCRYPT);
+}
+
+static int tegra_aes_ecb_decrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, 0);
+}
+
+static int tegra_aes_cbc_encrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC);
+}
+
+static int tegra_aes_cbc_decrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, FLAGS_CBC);
+}
+
+static int tegra_aes_ofb_encrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_OFB);
+}
+
+static int tegra_aes_ofb_decrypt(struct ablkcipher_request *req)
+{
+	return tegra_aes_crypt(req, FLAGS_OFB);
+}
+
+static int tegra_aes_get_random(struct crypto_rng *tfm, u8 *rdata,
+				unsigned int dlen)
+{
+	struct tegra_aes_dev *dd = aes_dev;
+	struct tegra_aes_ctx *ctx = &rng_ctx;
+	int ret, i;
+	u8 *dest = rdata, *dt = dd->dt;
+
+	/* take mutex to access the aes hw */
+	mutex_lock(&aes_lock);
+
+	clk_enable(dd->aes_clk);
+
+	ctx->dd = dd;
+	dd->ctx = ctx;
+	dd->flags = FLAGS_ENCRYPT | FLAGS_RNG;
+
+	memcpy(dd->buf_in, dt, DEFAULT_RNG_BLK_SZ);
+
+	ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
+			      (u32)dd->dma_buf_out, 1, dd->flags, true);
+	if (ret < 0) {
+		dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
+		dlen = ret;
+		goto out;
+	}
+	memcpy(dest, dd->buf_out, dlen);
+
+	/* update the DT */
+	for (i = DEFAULT_RNG_BLK_SZ - 1; i >= 0; i--) {
+		dt[i] += 1;
+		if (dt[i] != 0)
+			break;
+	}
+
+out:
+	clk_disable(dd->aes_clk);
+	mutex_unlock(&aes_lock);
+
+	dev_dbg(dd->dev, "%s: done\n", __func__);
+	return dlen;
+}
+
+static int tegra_aes_rng_reset(struct crypto_rng *tfm, u8 *seed,
+			       unsigned int slen)
+{
+	struct tegra_aes_dev *dd = aes_dev;
+	struct tegra_aes_ctx *ctx = &rng_ctx;
+	struct tegra_aes_slot *key_slot;
+	struct timespec ts;
+	int ret = 0;
+	u64 nsec, tmp[2];
+	u8 *dt;
+
+	if (!ctx || !dd) {
+		dev_err(dd->dev, "ctx=0x%x, dd=0x%x\n",
+			(unsigned int)ctx, (unsigned int)dd);
+		return -EINVAL;
+	}
+
+	if (slen < (DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128)) {
+		dev_err(dd->dev, "seed size invalid");
+		return -ENOMEM;
+	}
+
+	/* take mutex to access the aes hw */
+	mutex_lock(&aes_lock);
+
+	if (!ctx->slot) {
+		key_slot = aes_find_key_slot(dd);
+		if (!key_slot) {
+			dev_err(dd->dev, "no empty slot\n");
+			mutex_unlock(&aes_lock);
+			return -ENOMEM;
+		}
+		ctx->slot = key_slot;
+	}
+
+	ctx->dd = dd;
+	dd->ctx = ctx;
+	dd->ctr = 0;
+
+	ctx->keylen = AES_KEYSIZE_128;
+	ctx->flags |= FLAGS_NEW_KEY;
+
+	/* copy the key to the key slot */
+	memcpy(dd->ivkey_base, seed + DEFAULT_RNG_BLK_SZ, AES_KEYSIZE_128);
+	memset(dd->ivkey_base + AES_KEYSIZE_128, 0, AES_HW_KEY_TABLE_LENGTH_BYTES - AES_KEYSIZE_128);
+
+	dd->iv = seed;
+	dd->ivlen = slen;
+
+	dd->flags = FLAGS_ENCRYPT | FLAGS_RNG;
+
+	clk_enable(dd->aes_clk);
+
+	aes_set_key(dd);
+
+	/* set seed to the aes hw slot */
+	memcpy(dd->buf_in, dd->iv, DEFAULT_RNG_BLK_SZ);
+	ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
+			      dd->dma_buf_out, 1, FLAGS_CBC, false);
+	if (ret < 0) {
+		dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
+		goto out;
+	}
+
+	if (dd->ivlen >= (2 * DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128)) {
+		dt = dd->iv + DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128;
+	} else {
+		getnstimeofday(&ts);
+		nsec = timespec_to_ns(&ts);
+		do_div(nsec, 1000);
+		nsec ^= dd->ctr << 56;
+		dd->ctr++;
+		tmp[0] = nsec;
+		tmp[1] = tegra_chip_uid();
+		dt = (u8 *)tmp;
+	}
+	memcpy(dd->dt, dt, DEFAULT_RNG_BLK_SZ);
+
+out:
+	clk_disable(dd->aes_clk);
+	mutex_unlock(&aes_lock);
+
+	dev_dbg(dd->dev, "%s: done\n", __func__);
+	return ret;
+}
+
+static int tegra_aes_cra_init(struct crypto_tfm *tfm)
+{
+	tfm->crt_ablkcipher.reqsize = sizeof(struct tegra_aes_reqctx);
+
+	return 0;
+}
+
+void tegra_aes_cra_exit(struct crypto_tfm *tfm)
+{
+	struct tegra_aes_ctx *ctx =
+		crypto_ablkcipher_ctx((struct crypto_ablkcipher *)tfm);
+
+	if (ctx && ctx->slot)
+		aes_release_key_slot(ctx);
+}
+
+static struct crypto_alg algs[] = {
+	{
+		.cra_name = "ecb(aes)",
+		.cra_driver_name = "ecb-aes-tegra",
+		.cra_priority = 300,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_u.ablkcipher = {
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.setkey = tegra_aes_setkey,
+			.encrypt = tegra_aes_ecb_encrypt,
+			.decrypt = tegra_aes_ecb_decrypt,
+		},
+	}, {
+		.cra_name = "cbc(aes)",
+		.cra_driver_name = "cbc-aes-tegra",
+		.cra_priority = 300,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_u.ablkcipher = {
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.ivsize = AES_MIN_KEY_SIZE,
+			.setkey = tegra_aes_setkey,
+			.encrypt = tegra_aes_cbc_encrypt,
+			.decrypt = tegra_aes_cbc_decrypt,
+		}
+	}, {
+		.cra_name = "ofb(aes)",
+		.cra_driver_name = "ofb-aes-tegra",
+		.cra_priority = 300,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_alignmask = 3,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_u.ablkcipher = {
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.ivsize = AES_MIN_KEY_SIZE,
+			.setkey = tegra_aes_setkey,
+			.encrypt = tegra_aes_ofb_encrypt,
+			.decrypt = tegra_aes_ofb_decrypt,
+		}
+	}, {
+		.cra_name = "ansi_cprng",
+		.cra_driver_name = "rng-aes-tegra",
+		.cra_flags = CRYPTO_ALG_TYPE_RNG,
+		.cra_ctxsize = sizeof(struct tegra_aes_ctx),
+		.cra_type = &crypto_rng_type,
+		.cra_u.rng = {
+			.rng_make_random = tegra_aes_get_random,
+			.rng_reset = tegra_aes_rng_reset,
+			.seedsize = AES_KEYSIZE_128 + (2 * DEFAULT_RNG_BLK_SZ),
+		}
+	}
+};
+
+static int tegra_aes_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tegra_aes_dev *dd;
+	struct resource *res;
+	int err = -ENOMEM, i = 0, j;
+
+	dd = devm_kzalloc(dev, sizeof(struct tegra_aes_dev), GFP_KERNEL);
+	if (dd == NULL) {
+		dev_err(dev, "unable to alloc data struct.\n");
+		return err;
+	}
+
+	dd->dev = dev;
+	platform_set_drvdata(pdev, dd);
+
+	dd->slots = devm_kzalloc(dev, sizeof(struct tegra_aes_slot) *
+				 AES_NR_KEYSLOTS, GFP_KERNEL);
+	if (dd->slots == NULL) {
+		dev_err(dev, "unable to alloc slot struct.\n");
+		goto out;
+	}
+
+	spin_lock_init(&dd->lock);
+	crypto_init_queue(&dd->queue, TEGRA_AES_QUEUE_LENGTH);
+
+	/* Get the module base address */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "invalid resource type: base\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	if (!devm_request_mem_region(&pdev->dev, res->start,
+				     resource_size(res),
+				     dev_name(&pdev->dev))) {
+		dev_err(&pdev->dev, "Couldn't request MEM resource\n");
+		return -ENODEV;
+	}
+
+	dd->io_base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!dd->io_base) {
+		dev_err(dev, "can't ioremap register space\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* Initialize the vde clock */
+	dd->aes_clk = clk_get(dev, "vde");
+	if (IS_ERR(dd->aes_clk)) {
+		dev_err(dev, "iclock intialization failed.\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	err = clk_set_rate(dd->aes_clk, ULONG_MAX);
+	if (err) {
+		dev_err(dd->dev, "iclk set_rate fail(%d)\n", err);
+		goto out;
+	}
+
+	/*
+	 * the foll contiguous memory is allocated as follows -
+	 * - hardware key table
+	 * - key schedule
+	 */
+	dd->ivkey_base = dma_alloc_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
+					    &dd->ivkey_phys_base,
+		GFP_KERNEL);
+	if (!dd->ivkey_base) {
+		dev_err(dev, "can not allocate iv/key buffer\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	dd->buf_in = dma_alloc_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+					&dd->dma_buf_in, GFP_KERNEL);
+	if (!dd->buf_in) {
+		dev_err(dev, "can not allocate dma-in buffer\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	dd->buf_out = dma_alloc_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+					 &dd->dma_buf_out, GFP_KERNEL);
+	if (!dd->buf_out) {
+		dev_err(dev, "can not allocate dma-out buffer\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	init_completion(&dd->op_complete);
+	aes_wq = alloc_workqueue("tegra_aes_wq", WQ_HIGHPRI | WQ_UNBOUND, 1);
+	if (!aes_wq) {
+		dev_err(dev, "alloc_workqueue failed\n");
+		goto out;
+	}
+
+	/* get the irq */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev, "invalid resource type: base\n");
+		err = -ENODEV;
+		goto out;
+	}
+	dd->irq = res->start;
+
+	err = request_irq(dd->irq, aes_irq, IRQF_TRIGGER_HIGH |
+			  IRQF_SHARED, "tegra-aes", dd);
+	if (err) {
+		dev_err(dev, "request_irq failed\n");
+		goto out;
+	}
+
+	spin_lock_init(&list_lock);
+	spin_lock(&list_lock);
+	for (i = 0; i < AES_NR_KEYSLOTS; i++) {
+		if (i == SSK_SLOT_NUM)
+			continue;
+		dd->slots[i].available = true;
+		dd->slots[i].slot_num = i;
+		INIT_LIST_HEAD(&dd->slots[i].node);
+		list_add_tail(&dd->slots[i].node, &dev_list);
+	}
+	spin_unlock(&list_lock);
+
+	aes_dev = dd;
+	for (i = 0; i < ARRAY_SIZE(algs); i++) {
+		INIT_LIST_HEAD(&algs[i].cra_list);
+
+		algs[i].cra_priority = 300;
+		algs[i].cra_ctxsize = sizeof(struct tegra_aes_ctx);
+		algs[i].cra_module = THIS_MODULE;
+		algs[i].cra_init = tegra_aes_cra_init;
+		algs[i].cra_exit = tegra_aes_cra_exit;
+
+		err = crypto_register_alg(&algs[i]);
+		if (err)
+			goto out;
+	}
+
+	dev_info(dev, "registered");
+	return 0;
+
+out:
+	for (j = 0; j < i; j++)
+		crypto_unregister_alg(&algs[j]);
+	if (dd->ivkey_base)
+		dma_free_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
+			dd->ivkey_base, dd->ivkey_phys_base);
+	if (dd->buf_in)
+		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+			dd->buf_in, dd->dma_buf_in);
+	if (dd->buf_out)
+		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+			dd->buf_out, dd->dma_buf_out);
+	if (dd->aes_clk)
+		clk_put(dd->aes_clk);
+	if (aes_wq)
+		destroy_workqueue(aes_wq);
+	free_irq(dd->irq, dd);
+	spin_lock(&list_lock);
+	list_del(&dev_list);
+	spin_unlock(&list_lock);
+
+	aes_dev = NULL;
+
+	dev_err(dev, "%s: initialization failed.\n", __func__);
+	return err;
+}
+
+static int __devexit tegra_aes_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tegra_aes_dev *dd = platform_get_drvdata(pdev);
+	int i;
+
+	cancel_work_sync(&aes_work);
+	destroy_workqueue(aes_wq);
+	free_irq(dd->irq, dd);
+	spin_lock(&list_lock);
+	list_del(&dev_list);
+	spin_unlock(&list_lock);
+
+	for (i = 0; i < ARRAY_SIZE(algs); i++)
+		crypto_unregister_alg(&algs[i]);
+
+	dma_free_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
+			  dd->ivkey_base, dd->ivkey_phys_base);
+	dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+			  dd->buf_in, dd->dma_buf_in);
+	dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
+			  dd->buf_out, dd->dma_buf_out);
+	clk_put(dd->aes_clk);
+	aes_dev = NULL;
+
+	return 0;
+}
+
+static struct of_device_id tegra_aes_of_match[] __devinitdata = {
+	{ .compatible = "nvidia,tegra20-aes", },
+	{ .compatible = "nvidia,tegra30-aes", },
+	{ },
+};
+
+static struct platform_driver tegra_aes_driver = {
+	.probe  = tegra_aes_probe,
+	.remove = __devexit_p(tegra_aes_remove),
+	.driver = {
+		.name   = "tegra-aes",
+		.owner  = THIS_MODULE,
+		.of_match_table = tegra_aes_of_match,
+	},
+};
+
+static int __init tegra_aes_module_init(void)
+{
+	mutex_init(&aes_lock);
+	INIT_LIST_HEAD(&dev_list);
+	return  platform_driver_register(&tegra_aes_driver);
+}
+
+static void __exit tegra_aes_module_exit(void)
+{
+	platform_driver_unregister(&tegra_aes_driver);
+}
+
+module_init(tegra_aes_module_init);
+module_exit(tegra_aes_module_exit);
+
+MODULE_DESCRIPTION("Tegra AES/OFB/CPRNG hw acceleration support.");
+MODULE_AUTHOR("NVIDIA Corporation");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/crypto/tegra-aes.h b/drivers/crypto/tegra-aes.h
new file mode 100644
index 0000000..6006333
--- /dev/null
+++ b/drivers/crypto/tegra-aes.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef __CRYPTODEV_TEGRA_AES_H
+#define __CRYPTODEV_TEGRA_AES_H
+
+#define TEGRA_AES_ICMDQUE_WR			0x1000
+#define TEGRA_AES_CMDQUE_CONTROL		0x1008
+#define TEGRA_AES_INTR_STATUS			0x1018
+#define TEGRA_AES_INT_ENB			0x1040
+#define TEGRA_AES_CONFIG			0x1044
+#define TEGRA_AES_IRAM_ACCESS_CFG		0x10A0
+#define TEGRA_AES_SECURE_DEST_ADDR		0x1100
+#define TEGRA_AES_SECURE_INPUT_SELECT		0x1104
+#define TEGRA_AES_SECURE_CONFIG			0x1108
+#define TEGRA_AES_SECURE_CONFIG_EXT		0x110C
+#define TEGRA_AES_SECURE_SECURITY		0x1110
+#define TEGRA_AES_SECURE_HASH_RESULT0		0x1120
+#define TEGRA_AES_SECURE_HASH_RESULT1		0x1124
+#define TEGRA_AES_SECURE_HASH_RESULT2		0x1128
+#define TEGRA_AES_SECURE_HASH_RESULT3		0x112C
+#define TEGRA_AES_SECURE_SEC_SEL0		0x1140
+#define TEGRA_AES_SECURE_SEC_SEL1		0x1144
+#define TEGRA_AES_SECURE_SEC_SEL2		0x1148
+#define TEGRA_AES_SECURE_SEC_SEL3		0x114C
+#define TEGRA_AES_SECURE_SEC_SEL4		0x1150
+#define TEGRA_AES_SECURE_SEC_SEL5		0x1154
+#define TEGRA_AES_SECURE_SEC_SEL6		0x1158
+#define TEGRA_AES_SECURE_SEC_SEL7		0x115C
+
+/* interrupt status reg masks and shifts */
+#define TEGRA_AES_ENGINE_BUSY_FIELD		BIT(0)
+#define TEGRA_AES_ICQ_EMPTY_FIELD		BIT(3)
+#define TEGRA_AES_DMA_BUSY_FIELD		BIT(23)
+
+/* secure select reg masks and shifts */
+#define TEGRA_AES_SECURE_SEL0_KEYREAD_ENB0_FIELD	BIT(0)
+
+/* secure config ext masks and shifts */
+#define TEGRA_AES_SECURE_KEY_SCH_DIS_FIELD	BIT(15)
+
+/* secure config masks and shifts */
+#define TEGRA_AES_SECURE_KEY_INDEX_SHIFT	20
+#define TEGRA_AES_SECURE_KEY_INDEX_FIELD	(0x1F << TEGRA_AES_SECURE_KEY_INDEX_SHIFT)
+#define TEGRA_AES_SECURE_BLOCK_CNT_SHIFT	0
+#define TEGRA_AES_SECURE_BLOCK_CNT_FIELD	(0xFFFFF << TEGRA_AES_SECURE_BLOCK_CNT_SHIFT)
+
+/* stream interface select masks and shifts */
+#define TEGRA_AES_CMDQ_CTRL_UCMDQEN_FIELD	BIT(0)
+#define TEGRA_AES_CMDQ_CTRL_ICMDQEN_FIELD	BIT(1)
+#define TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD	BIT(4)
+#define TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD	BIT(5)
+
+/* config register masks and shifts */
+#define TEGRA_AES_CONFIG_ENDIAN_ENB_FIELD	BIT(10)
+#define TEGRA_AES_CONFIG_MODE_SEL_SHIFT		0
+#define TEGRA_AES_CONFIG_MODE_SEL_FIELD		(0x1F << TEGRA_AES_CONFIG_MODE_SEL_SHIFT)
+
+/* extended config */
+#define TEGRA_AES_SECURE_OFFSET_CNT_SHIFT	24
+#define TEGRA_AES_SECURE_OFFSET_CNT_FIELD	(0xFF << TEGRA_AES_SECURE_OFFSET_CNT_SHIFT)
+#define TEGRA_AES_SECURE_KEYSCHED_GEN_FIELD	BIT(15)
+
+/* init vector select */
+#define TEGRA_AES_SECURE_IV_SELECT_SHIFT	10
+#define TEGRA_AES_SECURE_IV_SELECT_FIELD	BIT(10)
+
+/* secure engine input */
+#define TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT	28
+#define TEGRA_AES_SECURE_INPUT_ALG_SEL_FIELD	(0xF << TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT)
+#define TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT	16
+#define TEGRA_AES_SECURE_INPUT_KEY_LEN_FIELD	(0xFFF << TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT)
+#define TEGRA_AES_SECURE_RNG_ENB_FIELD		BIT(11)
+#define TEGRA_AES_SECURE_CORE_SEL_SHIFT		9
+#define TEGRA_AES_SECURE_CORE_SEL_FIELD		BIT(9)
+#define TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT	7
+#define TEGRA_AES_SECURE_VCTRAM_SEL_FIELD	(0x3 << TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT)
+#define TEGRA_AES_SECURE_INPUT_SEL_SHIFT	5
+#define TEGRA_AES_SECURE_INPUT_SEL_FIELD	(0x3 << TEGRA_AES_SECURE_INPUT_SEL_SHIFT)
+#define TEGRA_AES_SECURE_XOR_POS_SHIFT		3
+#define TEGRA_AES_SECURE_XOR_POS_FIELD		(0x3 << TEGRA_AES_SECURE_XOR_POS_SHIFT)
+#define TEGRA_AES_SECURE_HASH_ENB_FIELD		BIT(2)
+#define TEGRA_AES_SECURE_ON_THE_FLY_FIELD	BIT(0)
+
+/* interrupt error mask */
+#define TEGRA_AES_INT_ERROR_MASK		0xFFF000
+
+#endif
-- 
1.7.1

Re: [PATCH v7 2/2] crypto: driver for Tegra AES hardware

[Jamie Iles]

Hi Varun,

Just a couple of nitpicks inline, otherwise looks good to me.

Jamie

On Fri, Nov 18, 2011 at 11:12:33AM +0530, Varun Wadekar wrote:
> driver supports ecb/cbc/ofb/ansi_x9.31rng modes,
> 128, 192 and 256-bit key sizes
> 
> Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
> ---
>  drivers/crypto/Kconfig     |   11 +
>  drivers/crypto/Makefile    |    1 +
>  drivers/crypto/tegra-aes.c | 1102 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/crypto/tegra-aes.h |  103 ++++
>  4 files changed, 1217 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/crypto/tegra-aes.c
>  create mode 100644 drivers/crypto/tegra-aes.h
> 
> diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> index 6d16b4b..e707979 100644
> --- a/drivers/crypto/Kconfig
> +++ b/drivers/crypto/Kconfig
> @@ -293,4 +293,15 @@ config CRYPTO_DEV_S5P
>  	  Select this to offload Samsung S5PV210 or S5PC110 from AES
>  	  algorithms execution.
>  
> +config CRYPTO_DEV_TEGRA_AES
> +	tristate "Support for TEGRA AES hw engine"
> +	depends on ARCH_TEGRA
> +	select CRYPTO_AES
> +	help
> +	  TEGRA processors have AES module accelerator. Select this if you
> +	  want to use the TEGRA module for AES algorithms.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called tegra-aes.
> +
>  endif # CRYPTO_HW
> diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
> index 53ea501..f3e64ea 100644
> --- a/drivers/crypto/Makefile
> +++ b/drivers/crypto/Makefile
> @@ -13,3 +13,4 @@ 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_S5P) += s5p-sss.o
> +obj-$(CONFIG_CRYPTO_DEV_TEGRA_AES) += tegra-aes.o
> diff --git a/drivers/crypto/tegra-aes.c b/drivers/crypto/tegra-aes.c
> new file mode 100644
> index 0000000..914eb6e
> --- /dev/null
> +++ b/drivers/crypto/tegra-aes.c
> @@ -0,0 +1,1102 @@
> +/*
> + * drivers/crypto/tegra-aes.c
> + *
> + * Driver for NVIDIA Tegra AES hardware engine residing inside the
> + * Bit Stream Engine for Video (BSEV) hardware block.
> + *
> + * The programming sequence for this engine is with the help
> + * of commands which travel via a command queue residing between the
> + * CPU and the BSEV block. The BSEV engine has an internal RAM (VRAM)
> + * where the final input plaintext, keys and the IV have to be copied
> + * before starting the encrypt/decrypt operation.
> + *
> + * Copyright (c) 2010, NVIDIA Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/clk.h>
> +#include <linux/platform_device.h>
> +#include <linux/scatterlist.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 <mach/clk.h>
> +
> +#include <crypto/scatterwalk.h>
> +#include <crypto/aes.h>
> +#include <crypto/internal/rng.h>
> +
> +#include "tegra-aes.h"
> +
> +#define FLAGS_MODE_MASK			0x00FF
> +#define FLAGS_ENCRYPT			BIT(0)
> +#define FLAGS_CBC			BIT(1)
> +#define FLAGS_GIV			BIT(2)
> +#define FLAGS_RNG			BIT(3)
> +#define FLAGS_OFB			BIT(4)
> +#define FLAGS_NEW_KEY			BIT(5)
> +#define FLAGS_NEW_IV			BIT(6)
> +#define FLAGS_INIT			BIT(7)
> +#define FLAGS_FAST			BIT(8)
> +#define FLAGS_BUSY			9
> +
> +/*
> + * Defines AES engine Max process bytes size in one go, which takes 1 msec.
> + * AES engine spends about 176 cycles/16-bytes or 11 cycles/byte
> + * The duration CPU can use the BSE to 1 msec, then the number of available
> + * cycles of AVP/BSE is 216K. In this duration, AES can process 216/11 ~= 19KB
> + * Based on this AES_HW_DMA_BUFFER_SIZE_BYTES is configured to 16KB.
> + */
> +#define AES_HW_DMA_BUFFER_SIZE_BYTES 0x4000
> +
> +/*
> + * The key table length is 64 bytes
> + * (This includes first upto 32 bytes key + 16 bytes original initial vector
> + * and 16 bytes updated initial vector)
> + */
> +#define AES_HW_KEY_TABLE_LENGTH_BYTES 64
> +
> +/*
> + * The memory being used is divides as follows:
> + * 1. Key - 32 bytes
> + * 2. Original IV - 16 bytes
> + * 3. Updated IV - 16 bytes
> + * 4. Key schedule - 256 bytes
> + *
> + * 1+2+3 constitute the hw key table.
> + */
> +#define AES_HW_IV_SIZE 16
> +#define AES_HW_KEYSCHEDULE_LEN 256
> +#define AES_IVKEY_SIZE (AES_HW_KEY_TABLE_LENGTH_BYTES + AES_HW_KEYSCHEDULE_LEN)
> +
> +/* Define commands required for AES operation */
> +enum {
> +	CMD_BLKSTARTENGINE = 0x0E,
> +	CMD_DMASETUP = 0x10,
> +	CMD_DMACOMPLETE = 0x11,
> +	CMD_SETTABLE = 0x15,
> +	CMD_MEMDMAVD = 0x22,
> +};
> +
> +/* Define sub-commands */
> +enum {
> +	SUBCMD_VRAM_SEL = 0x1,
> +	SUBCMD_CRYPTO_TABLE_SEL = 0x3,
> +	SUBCMD_KEY_TABLE_SEL = 0x8,
> +};
> +
> +/* memdma_vd command */
> +#define MEMDMA_DIR_DTOVRAM		0 /* sdram -> vram */
> +#define MEMDMA_DIR_VTODRAM		1 /* vram -> sdram */
> +#define MEMDMA_DIR_SHIFT		25
> +#define MEMDMA_NUM_WORDS_SHIFT		12
> +
> +/* command queue bit shifts */
> +enum {
> +	CMDQ_KEYTABLEADDR_SHIFT = 0,
> +	CMDQ_KEYTABLEID_SHIFT = 17,
> +	CMDQ_VRAMSEL_SHIFT = 23,
> +	CMDQ_TABLESEL_SHIFT = 24,
> +	CMDQ_OPCODE_SHIFT = 26,
> +};
> +
> +/*
> + * The secure key slot contains a unique secure key generated
> + * and loaded by the bootloader. This slot is marked as non-accessible
> + * to the kernel.
> + */
> +#define SSK_SLOT_NUM		4
> +
> +#define AES_NR_KEYSLOTS		8
> +#define TEGRA_AES_QUEUE_LENGTH	50
> +#define DEFAULT_RNG_BLK_SZ	16
> +
> +/* The command queue depth */
> +#define AES_HW_MAX_ICQ_LENGTH	5
> +
> +struct tegra_aes_slot {
> +	struct list_head node;
> +	int slot_num;
> +	bool available;
> +};
> +
> +static struct tegra_aes_slot ssk = {
> +	.slot_num = SSK_SLOT_NUM,
> +	.available = true,
> +};
> +
> +struct tegra_aes_reqctx {
> +	unsigned long mode;
> +};
> +
> +struct tegra_aes_dev {
> +	struct device *dev;
> +	void __iomem *io_base;
> +	dma_addr_t ivkey_phys_base;
> +	void __iomem *ivkey_base;
> +	struct clk *aes_clk;
> +	struct tegra_aes_ctx *ctx;
> +	int irq;
> +	unsigned long flags;
> +	struct completion op_complete;
> +	u32 *buf_in;
> +	dma_addr_t dma_buf_in;
> +	u32 *buf_out;
> +	dma_addr_t dma_buf_out;
> +	u8 *iv;
> +	u8 dt[DEFAULT_RNG_BLK_SZ];
> +	int ivlen;
> +	u64 ctr;
> +	spinlock_t lock;
> +	struct crypto_queue queue;
> +	struct tegra_aes_slot *slots;
> +	struct ablkcipher_request *req;
> +	size_t total;
> +	struct scatterlist *in_sg;
> +	size_t in_offset;
> +	struct scatterlist *out_sg;
> +	size_t out_offset;
> +};
> +
> +static struct tegra_aes_dev *aes_dev;
> +
> +struct tegra_aes_ctx {
> +	struct tegra_aes_dev *dd;
> +	unsigned long flags;
> +	struct tegra_aes_slot *slot;
> +	u8 key[AES_MAX_KEY_SIZE];
> +	int keylen;

size_t?

> +};
> +
> +static struct tegra_aes_ctx rng_ctx = {
> +	.flags = FLAGS_NEW_KEY,
> +	.keylen = AES_KEYSIZE_128,
> +};
> +
> +/* keep registered devices data here */
> +static LIST_HEAD(dev_list);
> +static DEFINE_SPINLOCK(list_lock);
> +static DEFINE_MUTEX(aes_lock);
> +
> +static void aes_workqueue_handler(struct work_struct *work);
> +static DECLARE_WORK(aes_work, aes_workqueue_handler);
> +static struct workqueue_struct *aes_wq;
> +
> +extern unsigned long long tegra_chip_uid(void);
> +
> +static inline u32 aes_readl(struct tegra_aes_dev *dd, u32 offset)
> +{
> +	return readl(dd->io_base + offset);
> +}
> +
> +static inline void aes_writel(struct tegra_aes_dev *dd, u32 val, u32 offset)
> +{
> +	writel(val, dd->io_base + offset);
> +}
> +
> +static int aes_start_crypt(struct tegra_aes_dev *dd, u32 in_addr, u32 out_addr,
> +	int nblocks, int mode, bool upd_iv)
> +{
> +	u32 cmdq[AES_HW_MAX_ICQ_LENGTH];
> +	int i, eng_busy, icq_empty, ret;
> +	u32 value;
> +
> +	/* reset all the interrupt bits */
> +	aes_writel(dd, 0xFFFFFFFF, TEGRA_AES_INTR_STATUS);
> +
> +	/* enable error, dma xfer complete interrupts */
> +	aes_writel(dd, 0x33, TEGRA_AES_INT_ENB);
> +
> +	cmdq[0] = CMD_DMASETUP << CMDQ_OPCODE_SHIFT;
> +	cmdq[1] = in_addr;
> +	cmdq[2] = CMD_BLKSTARTENGINE << CMDQ_OPCODE_SHIFT | (nblocks-1);
> +	cmdq[3] = CMD_DMACOMPLETE << CMDQ_OPCODE_SHIFT;
> +
> +	value = aes_readl(dd, TEGRA_AES_CMDQUE_CONTROL);
> +	/* access SDRAM through AHB */
> +	value &= ~TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD;
> +	value &= ~TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD;
> +	value |= TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD |
> +		 TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD |
> +		 TEGRA_AES_CMDQ_CTRL_ICMDQEN_FIELD;
> +	aes_writel(dd, value, TEGRA_AES_CMDQUE_CONTROL);
> +	dev_dbg(dd->dev, "cmd_q_ctrl=0x%x", value);
> +
> +	value = (0x1 << TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT) |
> +		((dd->ctx->keylen * 8) <<
> +			TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT) |
> +		((u32)upd_iv << TEGRA_AES_SECURE_IV_SELECT_SHIFT);
> +
> +	if (mode & FLAGS_CBC) {
> +		value |= ((((mode & FLAGS_ENCRYPT) ? 2 : 3)
> +				<< TEGRA_AES_SECURE_XOR_POS_SHIFT) |
> +			(((mode & FLAGS_ENCRYPT) ? 2 : 3)
> +				<< TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT) |
> +			((mode & FLAGS_ENCRYPT) ? 1 : 0)
> +				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT);
> +	} else if (mode & FLAGS_OFB) {
> +		value |= ((TEGRA_AES_SECURE_XOR_POS_FIELD) |
> +			(2 << TEGRA_AES_SECURE_INPUT_SEL_SHIFT) |
> +			(TEGRA_AES_SECURE_CORE_SEL_FIELD));
> +	} else if (mode & FLAGS_RNG) {
> +		value |= (((mode & FLAGS_ENCRYPT) ? 1 : 0)
> +				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT |
> +			  TEGRA_AES_SECURE_RNG_ENB_FIELD);
> +	} else {
> +		value |= (((mode & FLAGS_ENCRYPT) ? 1 : 0)
> +				<< TEGRA_AES_SECURE_CORE_SEL_SHIFT);
> +	}
> +
> +	dev_dbg(dd->dev, "secure_in_sel=0x%x", value);
> +	aes_writel(dd, value, TEGRA_AES_SECURE_INPUT_SELECT);
> +
> +	aes_writel(dd, out_addr, TEGRA_AES_SECURE_DEST_ADDR);
> +	INIT_COMPLETION(dd->op_complete);
> +
> +	for (i = 0; i < AES_HW_MAX_ICQ_LENGTH - 1; i++) {
> +		do {
> +			value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
> +			eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
> +			icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
> +		} while (eng_busy & (!icq_empty));
> +		aes_writel(dd, cmdq[i], TEGRA_AES_ICMDQUE_WR);
> +	}
> +
> +	ret = wait_for_completion_timeout(&dd->op_complete,
> +					  msecs_to_jiffies(150));
> +	if (ret == 0) {
> +		dev_err(dd->dev, "timed out (0x%x)\n",
> +			aes_readl(dd, TEGRA_AES_INTR_STATUS));
> +		return -ETIMEDOUT;
> +	}
> +
> +	aes_writel(dd, cmdq[AES_HW_MAX_ICQ_LENGTH - 1], TEGRA_AES_ICMDQUE_WR);
> +	return 0;
> +}
> +
> +static void aes_release_key_slot(struct tegra_aes_ctx *ctx)
> +{
> +	spin_lock(&list_lock);
> +	ctx->slot->available = true;
> +	ctx->slot = NULL;
> +	spin_unlock(&list_lock);
> +}
> +
> +static struct tegra_aes_slot *aes_find_key_slot(struct tegra_aes_dev *dd)
> +{
> +	struct tegra_aes_slot *slot = NULL;
> +	bool found = false;
> +
> +	spin_lock(&list_lock);
> +	list_for_each_entry(slot, &dev_list, node) {
> +		dev_dbg(dd->dev, "empty:%d, num:%d\n", slot->available,
> +			slot->slot_num);
> +		if (slot->available) {
> +			slot->available = false;
> +			found = true;
> +			break;
> +		}
> +	}
> +	spin_unlock(&list_lock);
> +
> +	return found ? slot : NULL;
> +}

I wonder if rather than doing this search each time if it would be worth 
just having a list of available slots, then allocating one is just an 
empty test and delete.  Releasing just adds to the list.

> +
> +static int aes_set_key(struct tegra_aes_dev *dd)
> +{
> +	u32 value, cmdq[2];
> +	struct tegra_aes_ctx *ctx = dd->ctx;
> +	int eng_busy, icq_empty, dma_busy;
> +	bool use_ssk = false;
> +
> +	/* use ssk? */
> +	if (!dd->ctx->slot) {
> +		dev_dbg(dd->dev, "using ssk");
> +		dd->ctx->slot = &ssk;
> +		use_ssk = true;
> +	}
> +
> +	/* enable key schedule generation in hardware */
> +	value = aes_readl(dd, TEGRA_AES_SECURE_CONFIG_EXT);
> +	value &= ~TEGRA_AES_SECURE_KEY_SCH_DIS_FIELD;
> +	aes_writel(dd, value, TEGRA_AES_SECURE_CONFIG_EXT);
> +
> +	/* select the key slot */
> +	value = aes_readl(dd, TEGRA_AES_SECURE_CONFIG);
> +	value &= ~TEGRA_AES_SECURE_KEY_INDEX_FIELD;
> +	value |= (ctx->slot->slot_num << TEGRA_AES_SECURE_KEY_INDEX_SHIFT);
> +	aes_writel(dd, value, TEGRA_AES_SECURE_CONFIG);
> +
> +	if (use_ssk)
> +		return 0;
> +
> +	/* copy the key table from sdram to vram */
> +	cmdq[0] = CMD_MEMDMAVD << CMDQ_OPCODE_SHIFT |
> +		MEMDMA_DIR_DTOVRAM << MEMDMA_DIR_SHIFT |
> +		AES_HW_KEY_TABLE_LENGTH_BYTES / sizeof(u32) <<
> +			MEMDMA_NUM_WORDS_SHIFT;
> +	cmdq[1] = (u32)dd->ivkey_phys_base;
> +
> +	aes_writel(dd, cmdq[0], TEGRA_AES_ICMDQUE_WR);
> +	aes_writel(dd, cmdq[1], TEGRA_AES_ICMDQUE_WR);
> +
> +	do {
> +		value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
> +		eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
> +		icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
> +		dma_busy = value & TEGRA_AES_DMA_BUSY_FIELD;
> +	} while (eng_busy & (!icq_empty) & dma_busy);
> +
> +	/* settable command to get key into internal registers */
> +	value = CMD_SETTABLE << CMDQ_OPCODE_SHIFT |
> +		SUBCMD_CRYPTO_TABLE_SEL << CMDQ_TABLESEL_SHIFT |
> +		SUBCMD_VRAM_SEL << CMDQ_VRAMSEL_SHIFT |
> +		(SUBCMD_KEY_TABLE_SEL | ctx->slot->slot_num) <<
> +			CMDQ_KEYTABLEID_SHIFT;
> +	aes_writel(dd, value, TEGRA_AES_ICMDQUE_WR);
> +
> +	do {
> +		value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
> +		eng_busy = value & TEGRA_AES_ENGINE_BUSY_FIELD;
> +		icq_empty = value & TEGRA_AES_ICQ_EMPTY_FIELD;
> +	} while (eng_busy & (!icq_empty));
> +
> +	return 0;
> +}
> +
> +static int tegra_aes_handle_req(struct tegra_aes_dev *dd)
> +{
> +	struct crypto_async_request *async_req, *backlog;
> +	struct crypto_ablkcipher *tfm;
> +	struct tegra_aes_ctx *ctx;
> +	struct tegra_aes_reqctx *rctx;
> +	struct ablkcipher_request *req;
> +	unsigned long flags;
> +	int dma_max = AES_HW_DMA_BUFFER_SIZE_BYTES;
> +	int ret = 0, nblocks, total;
> +	int count = 0;
> +	dma_addr_t addr_in, addr_out;
> +	struct scatterlist *in_sg, *out_sg;
> +
> +	if (!dd)
> +		return -EINVAL;
> +
> +	spin_lock_irqsave(&dd->lock, flags);
> +	backlog = crypto_get_backlog(&dd->queue);
> +	async_req = crypto_dequeue_request(&dd->queue);
> +	if (!async_req)
> +		clear_bit(FLAGS_BUSY, &dd->flags);
> +	spin_unlock_irqrestore(&dd->lock, flags);
> +
> +	if (!async_req)
> +		return -ENODATA;
> +
> +	if (backlog)
> +		backlog->complete(backlog, -EINPROGRESS);
> +
> +	req = ablkcipher_request_cast(async_req);
> +
> +	dev_dbg(dd->dev, "%s: get new req\n", __func__);
> +
> +	if (!req->src || !req->dst)
> +		return -EINVAL;
> +
> +	/* take mutex to access the aes hw */
> +	mutex_lock(&aes_lock);
> +
> +	/* assign new request to device */
> +	dd->req = req;
> +	dd->total = req->nbytes;
> +	dd->in_offset = 0;
> +	dd->in_sg = req->src;
> +	dd->out_offset = 0;
> +	dd->out_sg = req->dst;
> +
> +	in_sg = dd->in_sg;
> +	out_sg = dd->out_sg;
> +
> +	total = dd->total;
> +
> +	tfm = crypto_ablkcipher_reqtfm(req);
> +	rctx = ablkcipher_request_ctx(req);
> +	ctx = crypto_ablkcipher_ctx(tfm);
> +	rctx->mode &= FLAGS_MODE_MASK;
> +	dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode;
> +
> +	dd->iv = (u8 *)req->info;
> +	dd->ivlen = crypto_ablkcipher_ivsize(tfm);
> +
> +	/* assign new context to device */
> +	ctx->dd = dd;
> +	dd->ctx = ctx;
> +
> +	if (ctx->flags & FLAGS_NEW_KEY) {
> +		/* copy the key */
> +		memcpy(dd->ivkey_base, ctx->key, ctx->keylen);
> +		memset(dd->ivkey_base + ctx->keylen, 0, AES_HW_KEY_TABLE_LENGTH_BYTES - ctx->keylen);
> +		aes_set_key(dd);
> +		ctx->flags &= ~FLAGS_NEW_KEY;
> +	}
> +
> +	if (((dd->flags & FLAGS_CBC) || (dd->flags & FLAGS_OFB)) && dd->iv) {
> +		/* set iv to the aes hw slot
> +		 * Hw generates updated iv only after iv is set in slot.
> +		 * So key and iv is passed asynchronously.
> +		 */
> +		memcpy(dd->buf_in, dd->iv, dd->ivlen);
> +
> +		ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
> +				      dd->dma_buf_out, 1, FLAGS_CBC, false);
> +		if (ret < 0) {
> +			dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
> +			goto out;
> +		}
> +	}
> +
> +	while (total) {
> +		dev_dbg(dd->dev, "remain: %d\n", total);
> +		ret = dma_map_sg(dd->dev, in_sg, 1, DMA_TO_DEVICE);
> +		if (!ret) {
> +			dev_err(dd->dev, "dma_map_sg() error\n");
> +			goto out;
> +		}
> +
> +		ret = dma_map_sg(dd->dev, out_sg, 1, DMA_FROM_DEVICE);
> +		if (!ret) {
> +			dev_err(dd->dev, "dma_map_sg() error\n");
> +			dma_unmap_sg(dd->dev, dd->in_sg,
> +				1, DMA_TO_DEVICE);
> +			goto out;
> +		}
> +
> +		addr_in = sg_dma_address(in_sg);
> +		addr_out = sg_dma_address(out_sg);
> +		dd->flags |= FLAGS_FAST;
> +		count = min_t(int, sg_dma_len(in_sg), dma_max);
> +		WARN_ON(sg_dma_len(in_sg) != sg_dma_len(out_sg));
> +		nblocks = DIV_ROUND_UP(count, AES_BLOCK_SIZE);
> +
> +		ret = aes_start_crypt(dd, addr_in, addr_out, nblocks,
> +			dd->flags, true);
> +
> +		dma_unmap_sg(dd->dev, out_sg, 1, DMA_FROM_DEVICE);
> +		dma_unmap_sg(dd->dev, in_sg, 1, DMA_TO_DEVICE);
> +
> +		if (ret < 0) {
> +			dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
> +			goto out;
> +		}
> +		dd->flags &= ~FLAGS_FAST;
> +
> +		dev_dbg(dd->dev, "out: copied %d\n", count);
> +		total -= count;
> +		in_sg = sg_next(in_sg);
> +		out_sg = sg_next(out_sg);
> +		WARN_ON(((total != 0) && (!in_sg || !out_sg)));
> +	}
> +
> +out:
> +	mutex_unlock(&aes_lock);
> +
> +	dd->total = total;
> +
> +	if (dd->req->base.complete)
> +		dd->req->base.complete(&dd->req->base, ret);
> +
> +	dev_dbg(dd->dev, "%s: exit\n", __func__);
> +	return ret;
> +}
> +
> +static int tegra_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
> +			    unsigned int keylen)
> +{
> +	struct tegra_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm);
> +	struct tegra_aes_dev *dd = aes_dev;
> +	struct tegra_aes_slot *key_slot;
> +
> +	if ((keylen != AES_KEYSIZE_128) && (keylen != AES_KEYSIZE_192) &&
> +		(keylen != AES_KEYSIZE_256)) {
> +		dev_err(dd->dev, "unsupported key size\n");
> +		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
> +		return -EINVAL;
> +	}
> +
> +	dev_dbg(dd->dev, "keylen: %d\n", keylen);
> +
> +	ctx->dd = dd;
> +
> +	if (key) {
> +		if (!ctx->slot) {
> +			key_slot = aes_find_key_slot(dd);
> +			if (!key_slot) {
> +				dev_err(dd->dev, "no empty slot\n");
> +				return -ENOMEM;
> +			}
> +
> +			ctx->slot = key_slot;
> +		}
> +
> +		memcpy(ctx->key, key, keylen);
> +		ctx->keylen = keylen;
> +	}
> +
> +	ctx->flags |= FLAGS_NEW_KEY;
> +	dev_dbg(dd->dev, "done\n");
> +	return 0;
> +}
> +
> +static void aes_workqueue_handler(struct work_struct *work)
> +{
> +	struct tegra_aes_dev *dd = aes_dev;
> +	int ret;
> +
> +	clk_enable(dd->aes_clk);

The return value of clk_enable() should really be checked.

> +
> +	/* empty the crypto queue and then return */
> +	do {
> +		ret = tegra_aes_handle_req(dd);
> +	} while (!ret);
> +
> +	clk_disable(dd->aes_clk);
> +}
> +
> +static irqreturn_t aes_irq(int irq, void *dev_id)
> +{
> +	struct tegra_aes_dev *dd = (struct tegra_aes_dev *)dev_id;
> +	u32 value = aes_readl(dd, TEGRA_AES_INTR_STATUS);
> +	int busy = test_bit(FLAGS_BUSY, &dd->flags);
> +
> +	if (!busy) {
> +		dev_dbg(dd->dev, "spurious interrupt\n");
> +		return IRQ_NONE;
> +	}
> +
> +	dev_dbg(dd->dev, "irq_stat: 0x%x\n", value);
> +	if (value & TEGRA_AES_INT_ERROR_MASK)
> +		aes_writel(dd, TEGRA_AES_INT_ERROR_MASK, TEGRA_AES_INTR_STATUS);
> +
> +	if (!(value & TEGRA_AES_ENGINE_BUSY_FIELD))
> +		complete(&dd->op_complete);
> +	else
> +		return IRQ_NONE;
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int tegra_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
> +{
> +	struct tegra_aes_reqctx *rctx = ablkcipher_request_ctx(req);
> +	struct tegra_aes_dev *dd = aes_dev;
> +	unsigned long flags;
> +	int err = 0;
> +	int busy;
> +
> +	dev_dbg(dd->dev, "nbytes: %d, enc: %d, cbc: %d, ofb: %d\n",
> +		req->nbytes, !!(mode & FLAGS_ENCRYPT),
> +		!!(mode & FLAGS_CBC), !!(mode & FLAGS_OFB));
> +
> +	rctx->mode = mode;
> +
> +	spin_lock_irqsave(&dd->lock, flags);
> +	err = ablkcipher_enqueue_request(&dd->queue, req);
> +	busy = test_and_set_bit(FLAGS_BUSY, &dd->flags);
> +	spin_unlock_irqrestore(&dd->lock, flags);
> +
> +	if (!busy)
> +		queue_work(aes_wq, &aes_work);
> +
> +	return err;
> +}
> +
> +static int tegra_aes_ecb_encrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, FLAGS_ENCRYPT);
> +}
> +
> +static int tegra_aes_ecb_decrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, 0);
> +}
> +
> +static int tegra_aes_cbc_encrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC);
> +}
> +
> +static int tegra_aes_cbc_decrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, FLAGS_CBC);
> +}
> +
> +static int tegra_aes_ofb_encrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_OFB);
> +}
> +
> +static int tegra_aes_ofb_decrypt(struct ablkcipher_request *req)
> +{
> +	return tegra_aes_crypt(req, FLAGS_OFB);
> +}
> +
> +static int tegra_aes_get_random(struct crypto_rng *tfm, u8 *rdata,
> +				unsigned int dlen)
> +{
> +	struct tegra_aes_dev *dd = aes_dev;
> +	struct tegra_aes_ctx *ctx = &rng_ctx;
> +	int ret, i;
> +	u8 *dest = rdata, *dt = dd->dt;
> +
> +	/* take mutex to access the aes hw */
> +	mutex_lock(&aes_lock);
> +
> +	clk_enable(dd->aes_clk);
> +
> +	ctx->dd = dd;
> +	dd->ctx = ctx;
> +	dd->flags = FLAGS_ENCRYPT | FLAGS_RNG;
> +
> +	memcpy(dd->buf_in, dt, DEFAULT_RNG_BLK_SZ);
> +
> +	ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
> +			      (u32)dd->dma_buf_out, 1, dd->flags, true);
> +	if (ret < 0) {
> +		dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
> +		dlen = ret;
> +		goto out;
> +	}
> +	memcpy(dest, dd->buf_out, dlen);
> +
> +	/* update the DT */
> +	for (i = DEFAULT_RNG_BLK_SZ - 1; i >= 0; i--) {
> +		dt[i] += 1;
> +		if (dt[i] != 0)
> +			break;
> +	}
> +
> +out:
> +	clk_disable(dd->aes_clk);
> +	mutex_unlock(&aes_lock);
> +
> +	dev_dbg(dd->dev, "%s: done\n", __func__);
> +	return dlen;
> +}
> +
> +static int tegra_aes_rng_reset(struct crypto_rng *tfm, u8 *seed,
> +			       unsigned int slen)
> +{
> +	struct tegra_aes_dev *dd = aes_dev;
> +	struct tegra_aes_ctx *ctx = &rng_ctx;
> +	struct tegra_aes_slot *key_slot;
> +	struct timespec ts;
> +	int ret = 0;
> +	u64 nsec, tmp[2];
> +	u8 *dt;
> +
> +	if (!ctx || !dd) {
> +		dev_err(dd->dev, "ctx=0x%x, dd=0x%x\n",
> +			(unsigned int)ctx, (unsigned int)dd);
> +		return -EINVAL;
> +	}
> +
> +	if (slen < (DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128)) {
> +		dev_err(dd->dev, "seed size invalid");
> +		return -ENOMEM;
> +	}
> +
> +	/* take mutex to access the aes hw */
> +	mutex_lock(&aes_lock);
> +
> +	if (!ctx->slot) {
> +		key_slot = aes_find_key_slot(dd);
> +		if (!key_slot) {
> +			dev_err(dd->dev, "no empty slot\n");
> +			mutex_unlock(&aes_lock);
> +			return -ENOMEM;
> +		}
> +		ctx->slot = key_slot;
> +	}
> +
> +	ctx->dd = dd;
> +	dd->ctx = ctx;
> +	dd->ctr = 0;
> +
> +	ctx->keylen = AES_KEYSIZE_128;
> +	ctx->flags |= FLAGS_NEW_KEY;
> +
> +	/* copy the key to the key slot */
> +	memcpy(dd->ivkey_base, seed + DEFAULT_RNG_BLK_SZ, AES_KEYSIZE_128);
> +	memset(dd->ivkey_base + AES_KEYSIZE_128, 0, AES_HW_KEY_TABLE_LENGTH_BYTES - AES_KEYSIZE_128);
> +
> +	dd->iv = seed;
> +	dd->ivlen = slen;
> +
> +	dd->flags = FLAGS_ENCRYPT | FLAGS_RNG;
> +
> +	clk_enable(dd->aes_clk);
> +
> +	aes_set_key(dd);
> +
> +	/* set seed to the aes hw slot */
> +	memcpy(dd->buf_in, dd->iv, DEFAULT_RNG_BLK_SZ);
> +	ret = aes_start_crypt(dd, (u32)dd->dma_buf_in,
> +			      dd->dma_buf_out, 1, FLAGS_CBC, false);
> +	if (ret < 0) {
> +		dev_err(dd->dev, "aes_start_crypt fail(%d)\n", ret);
> +		goto out;
> +	}
> +
> +	if (dd->ivlen >= (2 * DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128)) {
> +		dt = dd->iv + DEFAULT_RNG_BLK_SZ + AES_KEYSIZE_128;
> +	} else {
> +		getnstimeofday(&ts);
> +		nsec = timespec_to_ns(&ts);
> +		do_div(nsec, 1000);
> +		nsec ^= dd->ctr << 56;
> +		dd->ctr++;
> +		tmp[0] = nsec;
> +		tmp[1] = tegra_chip_uid();
> +		dt = (u8 *)tmp;
> +	}
> +	memcpy(dd->dt, dt, DEFAULT_RNG_BLK_SZ);
> +
> +out:
> +	clk_disable(dd->aes_clk);
> +	mutex_unlock(&aes_lock);
> +
> +	dev_dbg(dd->dev, "%s: done\n", __func__);
> +	return ret;
> +}
> +
> +static int tegra_aes_cra_init(struct crypto_tfm *tfm)
> +{
> +	tfm->crt_ablkcipher.reqsize = sizeof(struct tegra_aes_reqctx);
> +
> +	return 0;
> +}
> +
> +void tegra_aes_cra_exit(struct crypto_tfm *tfm)
> +{
> +	struct tegra_aes_ctx *ctx =
> +		crypto_ablkcipher_ctx((struct crypto_ablkcipher *)tfm);
> +
> +	if (ctx && ctx->slot)
> +		aes_release_key_slot(ctx);
> +}
> +
> +static struct crypto_alg algs[] = {
> +	{
> +		.cra_name = "ecb(aes)",
> +		.cra_driver_name = "ecb-aes-tegra",
> +		.cra_priority = 300,
> +		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
> +		.cra_blocksize = AES_BLOCK_SIZE,
> +		.cra_alignmask = 3,
> +		.cra_type = &crypto_ablkcipher_type,
> +		.cra_u.ablkcipher = {
> +			.min_keysize = AES_MIN_KEY_SIZE,
> +			.max_keysize = AES_MAX_KEY_SIZE,
> +			.setkey = tegra_aes_setkey,
> +			.encrypt = tegra_aes_ecb_encrypt,
> +			.decrypt = tegra_aes_ecb_decrypt,
> +		},
> +	}, {
> +		.cra_name = "cbc(aes)",
> +		.cra_driver_name = "cbc-aes-tegra",
> +		.cra_priority = 300,
> +		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
> +		.cra_blocksize = AES_BLOCK_SIZE,
> +		.cra_alignmask = 3,
> +		.cra_type = &crypto_ablkcipher_type,
> +		.cra_u.ablkcipher = {
> +			.min_keysize = AES_MIN_KEY_SIZE,
> +			.max_keysize = AES_MAX_KEY_SIZE,
> +			.ivsize = AES_MIN_KEY_SIZE,
> +			.setkey = tegra_aes_setkey,
> +			.encrypt = tegra_aes_cbc_encrypt,
> +			.decrypt = tegra_aes_cbc_decrypt,
> +		}
> +	}, {
> +		.cra_name = "ofb(aes)",
> +		.cra_driver_name = "ofb-aes-tegra",
> +		.cra_priority = 300,
> +		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
> +		.cra_blocksize = AES_BLOCK_SIZE,
> +		.cra_alignmask = 3,
> +		.cra_type = &crypto_ablkcipher_type,
> +		.cra_u.ablkcipher = {
> +			.min_keysize = AES_MIN_KEY_SIZE,
> +			.max_keysize = AES_MAX_KEY_SIZE,
> +			.ivsize = AES_MIN_KEY_SIZE,
> +			.setkey = tegra_aes_setkey,
> +			.encrypt = tegra_aes_ofb_encrypt,
> +			.decrypt = tegra_aes_ofb_decrypt,
> +		}
> +	}, {
> +		.cra_name = "ansi_cprng",
> +		.cra_driver_name = "rng-aes-tegra",
> +		.cra_flags = CRYPTO_ALG_TYPE_RNG,
> +		.cra_ctxsize = sizeof(struct tegra_aes_ctx),
> +		.cra_type = &crypto_rng_type,
> +		.cra_u.rng = {
> +			.rng_make_random = tegra_aes_get_random,
> +			.rng_reset = tegra_aes_rng_reset,
> +			.seedsize = AES_KEYSIZE_128 + (2 * DEFAULT_RNG_BLK_SZ),
> +		}
> +	}
> +};
> +
> +static int tegra_aes_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct tegra_aes_dev *dd;
> +	struct resource *res;
> +	int err = -ENOMEM, i = 0, j;
> +
> +	dd = devm_kzalloc(dev, sizeof(struct tegra_aes_dev), GFP_KERNEL);
> +	if (dd == NULL) {
> +		dev_err(dev, "unable to alloc data struct.\n");
> +		return err;
> +	}
> +
> +	dd->dev = dev;
> +	platform_set_drvdata(pdev, dd);
> +
> +	dd->slots = devm_kzalloc(dev, sizeof(struct tegra_aes_slot) *
> +				 AES_NR_KEYSLOTS, GFP_KERNEL);
> +	if (dd->slots == NULL) {
> +		dev_err(dev, "unable to alloc slot struct.\n");
> +		goto out;
> +	}
> +
> +	spin_lock_init(&dd->lock);
> +	crypto_init_queue(&dd->queue, TEGRA_AES_QUEUE_LENGTH);
> +
> +	/* Get the module base address */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "invalid resource type: base\n");
> +		err = -ENODEV;
> +		goto out;
> +	}
> +
> +	if (!devm_request_mem_region(&pdev->dev, res->start,
> +				     resource_size(res),
> +				     dev_name(&pdev->dev))) {
> +		dev_err(&pdev->dev, "Couldn't request MEM resource\n");
> +		return -ENODEV;
> +	}
> +
> +	dd->io_base = devm_ioremap(dev, res->start, resource_size(res));
> +	if (!dd->io_base) {
> +		dev_err(dev, "can't ioremap register space\n");
> +		err = -ENOMEM;
> +		goto out;
> +	}
> +
> +	/* Initialize the vde clock */
> +	dd->aes_clk = clk_get(dev, "vde");
> +	if (IS_ERR(dd->aes_clk)) {
> +		dev_err(dev, "iclock intialization failed.\n");
> +		err = -ENODEV;
> +		goto out;
> +	}
> +
> +	err = clk_set_rate(dd->aes_clk, ULONG_MAX);
> +	if (err) {
> +		dev_err(dd->dev, "iclk set_rate fail(%d)\n", err);
> +		goto out;
> +	}
> +
> +	/*
> +	 * the foll contiguous memory is allocated as follows -
> +	 * - hardware key table
> +	 * - key schedule
> +	 */
> +	dd->ivkey_base = dma_alloc_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
> +					    &dd->ivkey_phys_base,
> +		GFP_KERNEL);
> +	if (!dd->ivkey_base) {
> +		dev_err(dev, "can not allocate iv/key buffer\n");
> +		err = -ENOMEM;
> +		goto out;
> +	}
> +
> +	dd->buf_in = dma_alloc_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +					&dd->dma_buf_in, GFP_KERNEL);
> +	if (!dd->buf_in) {
> +		dev_err(dev, "can not allocate dma-in buffer\n");
> +		err = -ENOMEM;
> +		goto out;
> +	}
> +
> +	dd->buf_out = dma_alloc_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +					 &dd->dma_buf_out, GFP_KERNEL);
> +	if (!dd->buf_out) {
> +		dev_err(dev, "can not allocate dma-out buffer\n");
> +		err = -ENOMEM;
> +		goto out;
> +	}
> +
> +	init_completion(&dd->op_complete);
> +	aes_wq = alloc_workqueue("tegra_aes_wq", WQ_HIGHPRI | WQ_UNBOUND, 1);
> +	if (!aes_wq) {
> +		dev_err(dev, "alloc_workqueue failed\n");
> +		goto out;
> +	}
> +
> +	/* get the irq */
> +	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +	if (!res) {
> +		dev_err(dev, "invalid resource type: base\n");
> +		err = -ENODEV;
> +		goto out;
> +	}
> +	dd->irq = res->start;
> +
> +	err = request_irq(dd->irq, aes_irq, IRQF_TRIGGER_HIGH |
> +			  IRQF_SHARED, "tegra-aes", dd);

devm_request_irq()?

> +	if (err) {
> +		dev_err(dev, "request_irq failed\n");
> +		goto out;
> +	}
> +
> +	spin_lock_init(&list_lock);
> +	spin_lock(&list_lock);
> +	for (i = 0; i < AES_NR_KEYSLOTS; i++) {
> +		if (i == SSK_SLOT_NUM)
> +			continue;
> +		dd->slots[i].available = true;
> +		dd->slots[i].slot_num = i;
> +		INIT_LIST_HEAD(&dd->slots[i].node);
> +		list_add_tail(&dd->slots[i].node, &dev_list);
> +	}
> +	spin_unlock(&list_lock);
> +
> +	aes_dev = dd;
> +	for (i = 0; i < ARRAY_SIZE(algs); i++) {
> +		INIT_LIST_HEAD(&algs[i].cra_list);
> +
> +		algs[i].cra_priority = 300;
> +		algs[i].cra_ctxsize = sizeof(struct tegra_aes_ctx);
> +		algs[i].cra_module = THIS_MODULE;
> +		algs[i].cra_init = tegra_aes_cra_init;
> +		algs[i].cra_exit = tegra_aes_cra_exit;
> +
> +		err = crypto_register_alg(&algs[i]);
> +		if (err)
> +			goto out;
> +	}
> +
> +	dev_info(dev, "registered");
> +	return 0;
> +
> +out:
> +	for (j = 0; j < i; j++)
> +		crypto_unregister_alg(&algs[j]);
> +	if (dd->ivkey_base)
> +		dma_free_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
> +			dd->ivkey_base, dd->ivkey_phys_base);
> +	if (dd->buf_in)
> +		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +			dd->buf_in, dd->dma_buf_in);
> +	if (dd->buf_out)
> +		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +			dd->buf_out, dd->dma_buf_out);
> +	if (dd->aes_clk)
> +		clk_put(dd->aes_clk);

Note that clk_get() _can_ return NULL as a valid clk even if it doesn't 
on tegra which makes this check a little difficult.

> +	if (aes_wq)
> +		destroy_workqueue(aes_wq);
> +	free_irq(dd->irq, dd);
> +	spin_lock(&list_lock);
> +	list_del(&dev_list);
> +	spin_unlock(&list_lock);
> +
> +	aes_dev = NULL;
> +
> +	dev_err(dev, "%s: initialization failed.\n", __func__);
> +	return err;
> +}
> +
> +static int __devexit tegra_aes_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct tegra_aes_dev *dd = platform_get_drvdata(pdev);
> +	int i;
> +
> +	cancel_work_sync(&aes_work);
> +	destroy_workqueue(aes_wq);
> +	free_irq(dd->irq, dd);
> +	spin_lock(&list_lock);
> +	list_del(&dev_list);
> +	spin_unlock(&list_lock);
> +
> +	for (i = 0; i < ARRAY_SIZE(algs); i++)
> +		crypto_unregister_alg(&algs[i]);

I think you probably want to unregister the algs before freeing the 
resources in case of a race.

> +
> +	dma_free_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
> +			  dd->ivkey_base, dd->ivkey_phys_base);
> +	dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +			  dd->buf_in, dd->dma_buf_in);
> +	dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> +			  dd->buf_out, dd->dma_buf_out);
> +	clk_put(dd->aes_clk);
> +	aes_dev = NULL;
> +
> +	return 0;
> +}
> +
> +static struct of_device_id tegra_aes_of_match[] __devinitdata = {
> +	{ .compatible = "nvidia,tegra20-aes", },
> +	{ .compatible = "nvidia,tegra30-aes", },
> +	{ },
> +};
> +
> +static struct platform_driver tegra_aes_driver = {
> +	.probe  = tegra_aes_probe,
> +	.remove = __devexit_p(tegra_aes_remove),
> +	.driver = {
> +		.name   = "tegra-aes",
> +		.owner  = THIS_MODULE,
> +		.of_match_table = tegra_aes_of_match,
> +	},
> +};
> +
> +static int __init tegra_aes_module_init(void)
> +{
> +	mutex_init(&aes_lock);
> +	INIT_LIST_HEAD(&dev_list);

I'm not sure that you need these as you have the static initializers.  
If you remove these then you could use module_platform_driver() from 
next to remove some of the boilerplate code.

> +	return  platform_driver_register(&tegra_aes_driver);
> +}
> +
> +static void __exit tegra_aes_module_exit(void)
> +{
> +	platform_driver_unregister(&tegra_aes_driver);
> +}
> +
> +module_init(tegra_aes_module_init);
> +module_exit(tegra_aes_module_exit);
> +
> +MODULE_DESCRIPTION("Tegra AES/OFB/CPRNG hw acceleration support.");
> +MODULE_AUTHOR("NVIDIA Corporation");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/crypto/tegra-aes.h b/drivers/crypto/tegra-aes.h
> new file mode 100644
> index 0000000..6006333
> --- /dev/null
> +++ b/drivers/crypto/tegra-aes.h
> @@ -0,0 +1,103 @@
> +/*
> + * Copyright (c) 2010, NVIDIA Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
> + */
> +
> +#ifndef __CRYPTODEV_TEGRA_AES_H
> +#define __CRYPTODEV_TEGRA_AES_H
> +
> +#define TEGRA_AES_ICMDQUE_WR			0x1000
> +#define TEGRA_AES_CMDQUE_CONTROL		0x1008
> +#define TEGRA_AES_INTR_STATUS			0x1018
> +#define TEGRA_AES_INT_ENB			0x1040
> +#define TEGRA_AES_CONFIG			0x1044
> +#define TEGRA_AES_IRAM_ACCESS_CFG		0x10A0
> +#define TEGRA_AES_SECURE_DEST_ADDR		0x1100
> +#define TEGRA_AES_SECURE_INPUT_SELECT		0x1104
> +#define TEGRA_AES_SECURE_CONFIG			0x1108
> +#define TEGRA_AES_SECURE_CONFIG_EXT		0x110C
> +#define TEGRA_AES_SECURE_SECURITY		0x1110
> +#define TEGRA_AES_SECURE_HASH_RESULT0		0x1120
> +#define TEGRA_AES_SECURE_HASH_RESULT1		0x1124
> +#define TEGRA_AES_SECURE_HASH_RESULT2		0x1128
> +#define TEGRA_AES_SECURE_HASH_RESULT3		0x112C
> +#define TEGRA_AES_SECURE_SEC_SEL0		0x1140
> +#define TEGRA_AES_SECURE_SEC_SEL1		0x1144
> +#define TEGRA_AES_SECURE_SEC_SEL2		0x1148
> +#define TEGRA_AES_SECURE_SEC_SEL3		0x114C
> +#define TEGRA_AES_SECURE_SEC_SEL4		0x1150
> +#define TEGRA_AES_SECURE_SEC_SEL5		0x1154
> +#define TEGRA_AES_SECURE_SEC_SEL6		0x1158
> +#define TEGRA_AES_SECURE_SEC_SEL7		0x115C
> +
> +/* interrupt status reg masks and shifts */
> +#define TEGRA_AES_ENGINE_BUSY_FIELD		BIT(0)
> +#define TEGRA_AES_ICQ_EMPTY_FIELD		BIT(3)
> +#define TEGRA_AES_DMA_BUSY_FIELD		BIT(23)
> +
> +/* secure select reg masks and shifts */
> +#define TEGRA_AES_SECURE_SEL0_KEYREAD_ENB0_FIELD	BIT(0)
> +
> +/* secure config ext masks and shifts */
> +#define TEGRA_AES_SECURE_KEY_SCH_DIS_FIELD	BIT(15)
> +
> +/* secure config masks and shifts */
> +#define TEGRA_AES_SECURE_KEY_INDEX_SHIFT	20
> +#define TEGRA_AES_SECURE_KEY_INDEX_FIELD	(0x1F << TEGRA_AES_SECURE_KEY_INDEX_SHIFT)
> +#define TEGRA_AES_SECURE_BLOCK_CNT_SHIFT	0
> +#define TEGRA_AES_SECURE_BLOCK_CNT_FIELD	(0xFFFFF << TEGRA_AES_SECURE_BLOCK_CNT_SHIFT)
> +
> +/* stream interface select masks and shifts */
> +#define TEGRA_AES_CMDQ_CTRL_UCMDQEN_FIELD	BIT(0)
> +#define TEGRA_AES_CMDQ_CTRL_ICMDQEN_FIELD	BIT(1)
> +#define TEGRA_AES_CMDQ_CTRL_SRC_STM_SEL_FIELD	BIT(4)
> +#define TEGRA_AES_CMDQ_CTRL_DST_STM_SEL_FIELD	BIT(5)
> +
> +/* config register masks and shifts */
> +#define TEGRA_AES_CONFIG_ENDIAN_ENB_FIELD	BIT(10)
> +#define TEGRA_AES_CONFIG_MODE_SEL_SHIFT		0
> +#define TEGRA_AES_CONFIG_MODE_SEL_FIELD		(0x1F << TEGRA_AES_CONFIG_MODE_SEL_SHIFT)
> +
> +/* extended config */
> +#define TEGRA_AES_SECURE_OFFSET_CNT_SHIFT	24
> +#define TEGRA_AES_SECURE_OFFSET_CNT_FIELD	(0xFF << TEGRA_AES_SECURE_OFFSET_CNT_SHIFT)
> +#define TEGRA_AES_SECURE_KEYSCHED_GEN_FIELD	BIT(15)
> +
> +/* init vector select */
> +#define TEGRA_AES_SECURE_IV_SELECT_SHIFT	10
> +#define TEGRA_AES_SECURE_IV_SELECT_FIELD	BIT(10)
> +
> +/* secure engine input */
> +#define TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT	28
> +#define TEGRA_AES_SECURE_INPUT_ALG_SEL_FIELD	(0xF << TEGRA_AES_SECURE_INPUT_ALG_SEL_SHIFT)
> +#define TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT	16
> +#define TEGRA_AES_SECURE_INPUT_KEY_LEN_FIELD	(0xFFF << TEGRA_AES_SECURE_INPUT_KEY_LEN_SHIFT)
> +#define TEGRA_AES_SECURE_RNG_ENB_FIELD		BIT(11)
> +#define TEGRA_AES_SECURE_CORE_SEL_SHIFT		9
> +#define TEGRA_AES_SECURE_CORE_SEL_FIELD		BIT(9)
> +#define TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT	7
> +#define TEGRA_AES_SECURE_VCTRAM_SEL_FIELD	(0x3 << TEGRA_AES_SECURE_VCTRAM_SEL_SHIFT)
> +#define TEGRA_AES_SECURE_INPUT_SEL_SHIFT	5
> +#define TEGRA_AES_SECURE_INPUT_SEL_FIELD	(0x3 << TEGRA_AES_SECURE_INPUT_SEL_SHIFT)
> +#define TEGRA_AES_SECURE_XOR_POS_SHIFT		3
> +#define TEGRA_AES_SECURE_XOR_POS_FIELD		(0x3 << TEGRA_AES_SECURE_XOR_POS_SHIFT)
> +#define TEGRA_AES_SECURE_HASH_ENB_FIELD		BIT(2)
> +#define TEGRA_AES_SECURE_ON_THE_FLY_FIELD	BIT(0)
> +
> +/* interrupt error mask */
> +#define TEGRA_AES_INT_ERROR_MASK		0xFFF000
> +
> +#endif
> -- 
> 1.7.1
> 
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RE: [PATCH v7 2/2] crypto: driver for Tegra AES hardware

[Stephen Warren]

Jamie Iles wrote at Friday, November 18, 2011 3:03 AM:
> On Fri, Nov 18, 2011 at 11:12:33AM +0530, Varun Wadekar wrote:
> > driver supports ecb/cbc/ofb/ansi_x9.31rng modes,
> > 128, 192 and 256-bit key sizes

> > +static int tegra_aes_probe(struct platform_device *pdev)
...
> > +	dev_info(dev, "registered");
> > +	return 0;
> > +
> > +out:
> > +	for (j = 0; j < i; j++)
> > +		crypto_unregister_alg(&algs[j]);
> > +	if (dd->ivkey_base)
> > +		dma_free_coherent(dev, AES_HW_KEY_TABLE_LENGTH_BYTES,
> > +			dd->ivkey_base, dd->ivkey_phys_base);
> > +	if (dd->buf_in)
> > +		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> > +			dd->buf_in, dd->dma_buf_in);
> > +	if (dd->buf_out)
> > +		dma_free_coherent(dev, AES_HW_DMA_BUFFER_SIZE_BYTES,
> > +			dd->buf_out, dd->dma_buf_out);
> > +	if (dd->aes_clk)
> > +		clk_put(dd->aes_clk);
> 
> Note that clk_get() _can_ return NULL as a valid clk even if it doesn't
> on tegra which makes this check a little difficult.

You can use IS_ERR to check for whether the clock was "got" or not, but
of course, you'll have to initialize that field to some error value before
any point where the code can "goto out";

-- 
nvpublic