Re: [PATCH] iommu/arm-smmu-v3: Fix incorrect fields being passed to prefetch command

[Pratyush Yadav]

On 28/06/19 2:39 PM, Pratyush Yadav wrote:> According to the SMMUv3 spec [0] section 4.2.1, command 0x1
> (CMD_PREFETCH_CONFIG) does not take address and size as parameters. It
> only takes  StreamID, SSec, SubstreamID, and SSV. Address and Size are
> parameters for command 0x2 (CMD_PREFETCH_ADDR).
> 
> Tested on kernel 4.19 on TI J721E SOC.

Even though I only tested on 4.19 because I don't have the setup to run 
mainline master on this SOC, the patch is based on mainline master and I
did compile-test it.

> [0] https://static.docs.arm.com/ihi0070/a/IHI_0070A_SMMUv3.pdf
> 
> Signed-off-by: Pratyush Yadav <p-yadav1@xxxxxx>
> ---
>  drivers/iommu/arm-smmu-v3.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 4d5a694f02c2..2d4dfd909436 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -413,6 +413,7 @@ struct arm_smmu_cmdq_ent {
>  	/* Command-specific fields */
>  	union {
>  		#define CMDQ_OP_PREFETCH_CFG	0x1
> +		#define CMDQ_OP_PREFETCH_ADDR	0x2
>  		struct {
>  			u32			sid;
>  			u8			size;
> @@ -805,10 +806,12 @@ static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent)
>  	case CMDQ_OP_TLBI_EL2_ALL:
>  	case CMDQ_OP_TLBI_NSNH_ALL:
>  		break;
> -	case CMDQ_OP_PREFETCH_CFG:
> -		cmd[0] |= FIELD_PREP(CMDQ_PREFETCH_0_SID, ent->prefetch.sid);
> +	case CMDQ_OP_PREFETCH_ADDR:
>  		cmd[1] |= FIELD_PREP(CMDQ_PREFETCH_1_SIZE, ent->prefetch.size);
>  		cmd[1] |= ent->prefetch.addr & CMDQ_PREFETCH_1_ADDR_MASK;
> +		/* Fallthrough */
> +	case CMDQ_OP_PREFETCH_CFG:
> +		cmd[0] |= FIELD_PREP(CMDQ_PREFETCH_0_SID, ent->prefetch.sid);
>  		break;
>  	case CMDQ_OP_CFGI_STE:
>  		cmd[0] |= FIELD_PREP(CMDQ_CFGI_0_SID, ent->cfgi.sid);
> 
-- 
Regards,
Pratyush Yadav