Re: [PATCH 1/2] Add crypto driver support for some MediaTek chips

[mtk09577 <ryder.lee@mediatek.com>]

Hello,

On Fri, 2016-12-02 at 09:18 +0100, Corentin Labbe wrote:
> Hello
> 
> I have some minor comment inline
> 
> On Fri, Dec 02, 2016 at 11:26:44AM +0800, Ryder Lee wrote:
> > This adds support for the MediaTek hardware accelerator on
> > mt7623/mt2701/mt8521p SoC.
> > 
> > This driver currently implement:
> > - SHA1 and SHA2 family(HMAC) hash alogrithms.
> > - AES block cipher in CBC/ECB mode with 128/196/256 bits keys.
> 
> I see also a PRNG but is seems not really used.

Yes, PRNG is not implemented yet, i will remove it temporarily.

> > 
> > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
> > ---
> >  drivers/crypto/Kconfig                 |   17 +
> >  drivers/crypto/Makefile                |    1 +
> >  drivers/crypto/mediatek/Makefile       |    2 +
> >  drivers/crypto/mediatek/mtk-aes.c      |  734 +++++++++++++++++
> >  drivers/crypto/mediatek/mtk-platform.c |  575 +++++++++++++
> >  drivers/crypto/mediatek/mtk-platform.h |  230 ++++++
> >  drivers/crypto/mediatek/mtk-regs.h     |  194 +++++
> >  drivers/crypto/mediatek/mtk-sha.c      | 1384 ++++++++++++++++++++++++++++++++
> >  8 files changed, 3137 insertions(+)
> >  create mode 100644 drivers/crypto/mediatek/Makefile
> >  create mode 100644 drivers/crypto/mediatek/mtk-aes.c
> >  create mode 100644 drivers/crypto/mediatek/mtk-platform.c
> >  create mode 100644 drivers/crypto/mediatek/mtk-platform.h
> >  create mode 100644 drivers/crypto/mediatek/mtk-regs.h
> >  create mode 100644 drivers/crypto/mediatek/mtk-sha.c
> > 
> > diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> > index 4d2b81f..5d9c803 100644
> > --- a/drivers/crypto/Kconfig
> > +++ b/drivers/crypto/Kconfig
> > @@ -553,6 +553,23 @@ config CRYPTO_DEV_ROCKCHIP
> >  	  This driver interfaces with the hardware crypto accelerator.
> >  	  Supporting cbc/ecb chainmode, and aes/des/des3_ede cipher mode.
> >  
> > +config CRYPTO_DEV_MEDIATEK
> > +	tristate "MediaTek's Cryptographic Engine driver"
> > +	depends on ARM && ARCH_MEDIATEK
> > +	select NEON
> > +	select KERNEL_MODE_NEON
> > +	select ARM_CRYPTO
> > +	select CRYPTO_AES
> > +	select CRYPTO_BLKCIPHER
> > +	select CRYPTO_SHA1_ARM_NEON
> > +	select CRYPTO_SHA256_ARM
> > +	select CRYPTO_SHA512_ARM
> > +	select CRYPTO_HMAC
> 
> Why do you select accelerated algos ?
> Adding COMPILE_TEST could be helpfull also.

Our Hardware has complex procedure on calculate HMAC, and it get a bad
performance.... So i decide to use ARM NEON instruction as fallback to
speedup it.
I will add COMPILE_TEST.

> [...]
> > +
> > +#include <linux/dma-mapping.h>
> > +#include <linux/scatterlist.h>
> > +#include <crypto/scatterwalk.h>
> > +#include <crypto/algapi.h>
> > +#include <crypto/aes.h>
> > +#include "mtk-platform.h"
> > +#include "mtk-regs.h"
> > +
> 
> Sort headers in alphabetical order
> 
> [...]
> > +
> > +	mtk_aes_unregister_algs();
> > +	mtk_aes_record_free(cryp);
> > +}
> > +EXPORT_SYMBOL(mtk_cipher_alg_release);
> 
> Why not EXPORT_SYMBOL_GPL ?
> Furthermore do you really need it to be exported ?

My mistake. I will remove it.

> [...]
> > +
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/clk.h>
> > +#include <linux/platform_device.h>
> > +#include "mtk-platform.h"
> > +#include "mtk-regs.h"
> > +
> 
> Sort headers in alphabetical order
> 
> [...]
> > +
> > +static void mtk_prng_reseed(struct mtk_cryp *cryp)
> > +{
> > +	/* 8 words to seed the PRNG to provide IVs */
> > +	void __iomem *base = cryp->base;
> > +	const u32 prng_key[8] = {0x48c24cfd, 0x6c07f742,
> > +				0xaee75681, 0x0f27c239,
> > +				0x79947198, 0xe2991275,
> > +				0x21ac3c7c, 0xd008c4b4};
> 
> Why do you seed with thoses constant ?
> 
> [...]
> > +
> > +static int mtk_accelerator_init(struct mtk_cryp *cryp)
> > +{
> > +	int i, err;
> > +
> > +	/* Initialize advanced interrupt controller(AIC) */
> > +	for (i = 0; i < 5; i++) {
> 
> I see this 5 for interrupt away, so perhaps a define could be used
> 
> [...]
> 
> here 
> 
> > +	for (i = 0; i < 5; i++) {
> > +		cryp->irq[i] = platform_get_irq(pdev, i);
> > +		if (cryp->irq[i] < 0) {
> > +			dev_err(cryp->dev, "no IRQ:%d resource info\n", i);
> > +			return -ENXIO;
> > +		}
> > +	}
> [...]

> > +#ifndef __MTK_PLATFORM_H_
> > +#define __MTK_PLATFORM_H_
> > +
> > +#include <linux/crypto.h>
> > +#include <crypto/internal/hash.h>
> > +#include <linux/interrupt.h>
> 
> Sort headers in alphabetical order
> 
> [...]
> > +#define MTK_DESC_FIRST		BIT(23)
> > +#define MTK_DESC_BUF_LEN(x)	((x) & 0x1ffff)
> > +#define MTK_DESC_CT_LEN(x)	(((x) & 0xff) << 24)
> > +
> > +#define WORD(x)			((x) >> 2)
> 
> dangerous and ambigous define

I will define a IRQ_NUM and modify ambiguous definition.

> [...]
> > +
> > +#include <linux/dma-mapping.h>
> > +#include <linux/scatterlist.h>
> > +#include <linux/crypto.h>
> > +#include <crypto/scatterwalk.h>
> > +#include <crypto/algapi.h>
> > +#include <crypto/sha.h>
> > +#include <crypto/internal/hash.h>
> 
> Sort headers in alphabetical order
> [...]
> Generally more function comment could be helpfull.

I will sort all header and add more function comment.
Thanks for your review.

> Regards