Re: [PATCH 2/2] scsi: ufs: add inline crypto support to UFS HCD

From: Greg KH
Date: Tue Dec 11 2018 - 07:03:43 EST


On Tue, Dec 11, 2018 at 09:50:27AM +0000, Parshuram Thombare wrote:
> Add real time crypto support to UFS HCD using new device
> mapper 'crypto-ufs'. dmsetup tool can be used to enable
> real time / inline crypto support using device mapper
> 'crypt-ufs'.
>
> Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>

As you cc:ed me, I'll provide some minor review comments:

> +config BLK_DEV_HW_RT_ENCRYPTION
> + bool
> + depends on SCSI_UFSHCD_RT_ENCRYPTION
> + default n

n is always the default, you never need to list that.

> +
> source block/Kconfig.iosched
> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> index 2ddbb26..09a3ec0 100644
> --- a/drivers/scsi/ufs/Kconfig
> +++ b/drivers/scsi/ufs/Kconfig
> @@ -136,3 +136,15 @@ config SCSI_UFS_BSG
>
> Select this if you need a bsg device node for your UFS controller.
> If unsure, say N.
> +
> +config SCSI_UFSHCD_RT_ENCRYPTION
> + bool "Universal Flash Storage Controller RT encryption support"
> + depends on SCSI_UFSHCD
> + default n

Same here.

> + select BLK_DEV_HW_RT_ENCRYPTION if SCSI_UFSHCD_RT_ENCRYPTION
> + select BLK_DEV_DM if SCSI_UFSHCD_RT_ENCRYPTION
> + help
> + Universal Flash Storage Controller RT encryption support
> +
> + Select this if you want to enable real time encryption on UFS controller
> + If unsure, say N.

Don't you need to indent the help lines?

> +int ufshcd_crypto_init(struct ufs_hba *hba);
> +void ufshcd_crypto_remove(struct ufs_hba *hba);
> +void ufshcd_prepare_for_crypto(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
> +#endif

You need to provide inline functions for when your config option is not
enabled here.

That way you don't have to do this mess:

> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 86fe114..a96b038 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -47,6 +47,9 @@
> #include "unipro.h"
> #include "ufs-sysfs.h"
> #include "ufs_bsg.h"
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> +#include "ufshcd-crypto.h"
> +#endif

No need for #ifdefs in .c files at all. Always include the .h file, and
then since your functions are all inline void functions, the code just
compiles away into nothing.


>
> #define CREATE_TRACE_POINTS
> #include <trace/events/ufs.h>
> @@ -2198,6 +2201,14 @@ static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
>
> dword_0 = data_direction | (lrbp->command_type
> << UPIU_COMMAND_TYPE_OFFSET);
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> + if (lrbp->cci >= 0) {
> + dword_0 |= (1 << CRYPTO_UTP_REQ_DESC_DWORD0_CE_SHIFT);
> + dword_0 |= ((lrbp->cci << CRYPTO_UTP_REQ_DESC_DWORD0_CCI_SHIFT)
> + & CRYPTO_UTP_REQ_DESC_DWORD0_CCI_MASK);
> + } else
> + dword_0 &= ~CRYPTO_UTP_REQ_DESC_DWORD0_CE_MASK;
> +#endif

Some comments on what this is trying to do here?


> if (lrbp->intr_cmd)
> dword_0 |= UTP_REQ_DESC_INT_CMD;
>
> @@ -2462,6 +2473,12 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
> lrbp->intr_cmd = !ufshcd_is_intr_aggr_allowed(hba) ? true : false;
> lrbp->req_abort_skip = false;
>
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> + lrbp->cci = -1;

What does -1 mean? You should have a type for it if it is something
"special".

> + /* prepare block for crypto */
> + if (hba->capabilities & MASK_CRYPTO_SUPPORT)
> + ufshcd_prepare_for_crypto(hba, lrbp);
> +#endif

Again, no #ifdefs needed please.


> ufshcd_comp_scsi_upiu(hba, lrbp);
>
> err = ufshcd_map_sg(hba, lrbp);
> @@ -8119,6 +8136,11 @@ void ufshcd_remove(struct ufs_hba *hba)
> ufs_bsg_remove(hba);
> ufs_sysfs_remove_nodes(hba->dev);
> scsi_remove_host(hba->host);
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> + if (hba->capabilities & MASK_CRYPTO_SUPPORT)
> + ufshcd_crypto_remove(hba);
> +#endif

Same ifdef here, and everywhere else in this file.

> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -193,6 +193,9 @@ struct ufshcd_lrb {
> ktime_t compl_time_stamp;
>
> bool req_abort_skip;
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> + int cci;
> +#endif

No need for a #ifdef here. But comment on exactly what "cci" means,
that seems to not make any sense to me.

> };
>
> /**
> @@ -706,6 +709,9 @@ struct ufs_hba {
>
> struct device bsg_dev;
> struct request_queue *bsg_queue;
> +#ifdef CONFIG_SCSI_UFSHCD_RT_ENCRYPTION
> + struct ufshcd_crypto_ctx *cctx;
> +#endif

or here.

> };
>
> /* Returns true if clocks can be gated. Otherwise false */
> diff --git a/drivers/scsi/ufs/ufshci.h b/drivers/scsi/ufs/ufshci.h
> index 6fa889d..fe5a92d 100644
> --- a/drivers/scsi/ufs/ufshci.h
> +++ b/drivers/scsi/ufs/ufshci.h
> @@ -90,6 +90,7 @@ enum {
> MASK_64_ADDRESSING_SUPPORT = 0x01000000,
> MASK_OUT_OF_ORDER_DATA_DELIVERY_SUPPORT = 0x02000000,
> MASK_UIC_DME_TEST_MODE_SUPPORT = 0x04000000,
> + MASK_CRYPTO_SUPPORT = 0x10000000,

Why are you all not using the BIT(N) macro for these?

thanks,

greg k-h