Re: [PATCH v3 15/17] scsi: ufs: ufs-exynos: multi-host configuration for exynosauto

[Inki Dae <inki.dae@samsung.com>]

21. 9. 17. 오후 3:54에 Chanho Park 이(가) 쓴 글:
> UFS controller of ExynosAuto v9 SoC supports multi-host interface for I/O
> virtualization. In general, we're using para-virtualized driver to
> support a block device by several virtual machines. However, it should
> be relayed by backend driver. Multi-host functionality extends the host
> controller by providing register interfaces that can be used by each
> VM's ufs drivers respectively. By this, we can provide direct access to
> the UFS device for multiple VMs. It's similar with SR-IOV of PCIe.
> 
> We divide this M-HCI as PH(Physical Host) and VHs(Virtual Host). The PH
> supports all UFSHCI functions(all SAPs) same as conventional UFSHCI but
> the VH only supports data transfer function. Thus, except UTP_CMD_SAP and
> UTP_TMPSAP, the PH should handle all the physical features.
> 
> This patch provides an initial implementation of PH part. M-HCI can
> support up to four interfaces but this patch initially supports only 1
> PH and 1 VH. For this, we uses TASK_TAG[7:5] field so TASK_TAG[4:0] for
> 32 doorbel will be supported. After the PH is initiated, this will send
> a ready message to VHs through a mailbox register. The message handler
> is not fully implemented yet such as supporting reset / abort cases.
> 
> Cc: Alim Akhtar <alim.akhtar@samsung.com>
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> ---
>  drivers/scsi/ufs/ufs-exynos.c | 45 +++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
> index 28f027d45917..0ca21cd8e76e 100644
> --- a/drivers/scsi/ufs/ufs-exynos.c
> +++ b/drivers/scsi/ufs/ufs-exynos.c
> @@ -83,6 +83,21 @@
>  #define UFS_SHARABLE		(UFS_WR_SHARABLE | UFS_RD_SHARABLE)
>  #define UFS_SHAREABILITY_OFFSET	0x710
>  
> +/* Multi-host registers */
> +#define MHCTRL					0xC4
> +#define MHCTRL_EN_VH_MASK			(0xE)
> +#define MHCTRL_EN_VH(vh)			(vh << 1)
> +#define PH2VH_MBOX				0xD8
> +
> +#define MH_MSG_MASK				(0xFF)
> +
> +#define MH_MSG(id, msg)				((id << 8) | (msg & 0xFF))
> +#define MH_MSG_PH_READY				0x1
> +#define MH_MSG_VH_READY				0x2
> +
> +#define HCI_MH_ALLOWABLE_TRAN_OF_VH		0x30C
> +#define HCI_MH_IID_IN_TASK_TAG			0X308
> +
>  enum {
>  	UNIPRO_L1_5 = 0,/* PHY Adapter */
>  	UNIPRO_L2,	/* Data Link */
> @@ -173,6 +188,20 @@ static int exynosauto_ufs_drv_init(struct device *dev, struct exynos_ufs *ufs)
>  	return 0;
>  }
>  
> +static int exynosauto_ufs_post_hce_enable(struct exynos_ufs *ufs)
> +{
> +	struct ufs_hba *hba = ufs->hba;
> +
> +	/* Enable Virtual Host #1 */
> +	ufshcd_rmwl(hba, MHCTRL_EN_VH_MASK, MHCTRL_EN_VH(1), MHCTRL);
> +	/* Default VH Transfer permissions */
> +	hci_writel(ufs, 0x03FFE1FE, HCI_MH_ALLOWABLE_TRAN_OF_VH);

How about using a defined macro instead of constant value, 0x03FFE1FE for code readability? And maybe 0x03FFE1FE to 0x3FFE1FE.

Thanks,
Inki Dae

> +	/* IID information is replaced in TASKTAG[7:5] instead of IID in UCD */
> +	hci_writel(ufs, 0x1, HCI_MH_IID_IN_TASK_TAG);
> +
> +	return 0;
> +}
> +
>  static int exynosauto_ufs_pre_link(struct exynos_ufs *ufs)
>  {
>  	struct ufs_hba *hba = ufs->hba;
> @@ -231,6 +260,20 @@ static int exynosauto_ufs_pre_pwr_change(struct exynos_ufs *ufs,
>  	return 0;
>  }
>  
> +static int exynosauto_ufs_post_pwr_change(struct exynos_ufs *ufs,
> +					  struct ufs_pa_layer_attr *pwr)
> +{
> +	struct ufs_hba *hba = ufs->hba;
> +	u32 enabled_vh;
> +
> +	enabled_vh = ufshcd_readl(hba, MHCTRL) & MHCTRL_EN_VH_MASK;
> +
> +	/* Send physical host ready message to virtual hosts */
> +	ufshcd_writel(hba, MH_MSG(enabled_vh, MH_MSG_PH_READY), PH2VH_MBOX);
> +
> +	return 0;
> +}
> +
>  static int exynos7_ufs_pre_link(struct exynos_ufs *ufs)
>  {
>  	struct ufs_hba *hba = ufs->hba;
> @@ -1395,8 +1438,10 @@ static struct exynos_ufs_drv_data exynosauto_ufs_drvs = {
>  				  EXYNOS_UFS_OPT_SKIP_CONFIG_PHY_ATTR |
>  				  EXYNOS_UFS_OPT_BROKEN_RX_SEL_IDX,
>  	.drv_init		= exynosauto_ufs_drv_init,
> +	.post_hce_enable	= exynosauto_ufs_post_hce_enable,
>  	.pre_link		= exynosauto_ufs_pre_link,
>  	.pre_pwr_change		= exynosauto_ufs_pre_pwr_change,
> +	.post_pwr_change	= exynosauto_ufs_post_pwr_change,
>  };
>  
>  static struct exynos_ufs_drv_data exynos_ufs_drvs = {
>