Re: [PATCH v5 6/6] fpga: m10bmc-sec: add max10 get_hw_errinfo callback func

[Tom Rix <trix@redhat.com>]

On 11/13/20 4:55 PM, Russ Weight wrote:
> Extend the MAX10 BMC Secure Update driver to include
> a function that returns 64 bits of additional HW specific
> data for errors that require additional information.
> This callback function enables the hw_errinfo sysfs
> node in the Intel Security Manager class driver.
>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> ---
> v5:
>   - No change
> v4:
>   - No change
> v3:
>   - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
>   - Changed "MAX10 BMC Secure Engine driver" to "MAX10 BMC Secure Update
>     driver"
> v2:
>   - Implemented HW_ERRINFO_POISON for m10bmc_sec_hw_errinfo() to
>     ensure that corresponding bits are set to 1 if we are unable
>     to read the doorbell or auth_result registers.
>   - Added m10bmc_ prefix to functions in m10bmc_iops structure
> ---
>  drivers/fpga/intel-m10-bmc-secure.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/fpga/intel-m10-bmc-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
> index 4fa8a2256088..a024efb173d3 100644
> --- a/drivers/fpga/intel-m10-bmc-secure.c
> +++ b/drivers/fpga/intel-m10-bmc-secure.c
> @@ -472,11 +472,36 @@ static enum fpga_sec_err m10bmc_sec_cancel(struct fpga_sec_mgr *smgr)
>  	return ret ? FPGA_SEC_ERR_RW_ERROR : FPGA_SEC_ERR_NONE;
>  }
>  
> +#define HW_ERRINFO_POISON	GENMASK(31, 0)
> +static u64 m10bmc_sec_hw_errinfo(struct fpga_sec_mgr *smgr)
> +{
> +	struct m10bmc_sec *sec = smgr->priv;
> +	u32 doorbell, auth_result;

If doorbell and auth_result were poisoned at initialization, the if-checks could be skipped.

Tom

> +
> +	switch (smgr->err_code) {
> +	case FPGA_SEC_ERR_HW_ERROR:
> +	case FPGA_SEC_ERR_TIMEOUT:
> +	case FPGA_SEC_ERR_BUSY:
> +	case FPGA_SEC_ERR_WEAROUT:
> +		if (m10bmc_sys_read(sec->m10bmc, M10BMC_DOORBELL, &doorbell))
> +			doorbell = HW_ERRINFO_POISON;
> +
> +		if (m10bmc_sys_read(sec->m10bmc, M10BMC_AUTH_RESULT,
> +				    &auth_result))
> +			auth_result = HW_ERRINFO_POISON;
> +
> +		return (u64)doorbell << 32 | (u64)auth_result;
> +	default:
> +		return 0;
> +	}
> +}
> +
>  static const struct fpga_sec_mgr_ops m10bmc_sops = {
>  	.prepare = m10bmc_sec_prepare,
>  	.write_blk = m10bmc_sec_write_blk,
>  	.poll_complete = m10bmc_sec_poll_complete,
>  	.cancel = m10bmc_sec_cancel,
> +	.get_hw_errinfo = m10bmc_sec_hw_errinfo,
>  };
>  
>  static int m10bmc_secure_probe(struct platform_device *pdev)