Commit e17f49bb authored by Marco Chiappero's avatar Marco Chiappero Committed by Herbert Xu
Browse files

crypto: qat - remove unnecessary collision prevention step in PFVF 



The initial version of the PFVF protocol included an initial "carrier
sensing" to get ownership of the channel.

Collisions can happen anyway, the extra wait and test does not prevent
collisions, it instead slows the communication down, so remove it.

Signed-off-by: default avatarMarco Chiappero <marco.chiappero@intel.com>
Reviewed-by: default avatarGiovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 18fcba46

drivers/crypto/qat/qat_common/adf_pf2vf_msg.c

+1 −19
Original line number Diff line number Diff line
@@ -126,28 +126,10 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr) 
		goto out;

	}



	/* Attempt to get ownership of PF2VF CSR */

	msg &= ~local_in_use_mask;

	msg |= local_in_use_pattern;

	ADF_CSR_WR(pmisc_bar_addr, pf2vf_offset, msg);



	/* Wait in case remote func also attempting to get ownership */

	msleep(ADF_IOV_MSG_COLLISION_DETECT_DELAY);



	val = ADF_CSR_RD(pmisc_bar_addr, pf2vf_offset);

	if ((val & local_in_use_mask) != local_in_use_pattern) {

		dev_dbg(&GET_DEV(accel_dev),

			"PF2VF CSR in use by remote - collision detected\n");

		ret = -EBUSY;

		goto out;

	}



	/*

	 * This function now owns the PV2VF CSR.  The IN_USE_BY pattern must

	 * remain in the PF2VF CSR for all writes including ACK from remote

	 * until this local function relinquishes the CSR.  Send the message

	 * by interrupting the remote.

	 */

	/* Attempt to get ownership of the PF2VF CSR */

	ADF_CSR_WR(pmisc_bar_addr, pf2vf_offset, msg | int_bit);



	/* Wait for confirmation from remote func it received the message */