crypto: qat - handle retries due to collisions in adf_iov_putmsg()

Rework __adf_iov_putmsg() to handle retries due to collisions
internally, removing the need for an external retry loop.
The functions __adf_iov_putmsg() and adf_iov_putmsg() have been merged
together maintaining the adf_iov_putmsg() name.

This will allow to use this function only for GEN2 devices, since
collision are peculiar of this generation and therefore should be
confined to the actual implementation of the transport/medium access.

Note that now adf_iov_putmsg() will retry to send a message only in case
of collisions and will now fail if an ACK is not received from the
remote function.

Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
Co-developed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
index 201744825e23a94d7507ec0b5cce1ca624eeabed..d98e3639c9d289313c74a71215e54a11d37506a1 100644 (file)
--- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
+++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
@@ -14,7 +14,7 @@
                                         ADF_PFVF_MSG_ACK_MAX_RETRY + \
                                         ADF_PFVF_MSG_COLLISION_DETECT_DELAY)
 
-static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
+static int adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
 {
        struct adf_accel_pci *pci_info = &accel_dev->accel_pci_dev;
        struct adf_hw_device_data *hw_data = accel_dev->hw_device;
@@ -24,8 +24,9 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
        u32 local_in_use_mask, local_in_use_pattern;
        u32 remote_in_use_mask, remote_in_use_pattern;
        struct mutex *lock;     /* lock preventing concurrent acces of CSR */
+       unsigned int retries = ADF_PFVF_MSG_MAX_RETRIES;
        u32 int_bit;
-       int ret = 0;
+       int ret;
 
        if (accel_dev->is_vf) {
                pf2vf_offset = hw_data->get_pf2vf_offset(0);
@@ -45,20 +46,22 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
                int_bit = ADF_PF2VF_INT;
        }
 
+       msg &= ~local_in_use_mask;
+       msg |= local_in_use_pattern;
+
        mutex_lock(lock);
 
+start:
+       ret = 0;
+
        /* Check if the PFVF CSR is in use by remote function */
        val = ADF_CSR_RD(pmisc_bar_addr, pf2vf_offset);
        if ((val & remote_in_use_mask) == remote_in_use_pattern) {
                dev_dbg(&GET_DEV(accel_dev),
                        "PFVF CSR in use by remote function\n");
-               ret = -EBUSY;
-               goto out;
+               goto retry;
        }
 
-       msg &= ~local_in_use_mask;
-       msg |= local_in_use_pattern;
-
        /* Attempt to get ownership of the PFVF CSR */
        ADF_CSR_WR(pmisc_bar_addr, pf2vf_offset, msg | int_bit);
 
@@ -77,8 +80,7 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
        if (val != msg) {
                dev_dbg(&GET_DEV(accel_dev),
                        "Collision - PFVF CSR overwritten by remote function\n");
-               ret = -EIO;
-               goto out;
+               goto retry;
        }
 
        /* Finished with the PFVF CSR; relinquish it and leave msg in CSR */
@@ -86,31 +88,15 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
 out:
        mutex_unlock(lock);
        return ret;
-}
 
-/**
- * adf_iov_putmsg() - send PFVF message
- * @accel_dev:  Pointer to acceleration device.
- * @msg:       Message to send
- * @vf_nr:     VF number to which the message will be sent if on PF, ignored
- *             otherwise
- *
- * Function sends a message through the PFVF channel
- *
- * Return: 0 on success, error code otherwise.
- */
-static int adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr)
-{
-       u32 count = 0;
-       int ret;
-
-       do {
-               ret = __adf_iov_putmsg(accel_dev, msg, vf_nr);
-               if (ret)
-                       msleep(ADF_PFVF_MSG_RETRY_DELAY);
-       } while (ret && (count++ < ADF_PFVF_MSG_MAX_RETRIES));
-
-       return ret;
+retry:
+       if (--retries) {
+               msleep(ADF_PFVF_MSG_RETRY_DELAY);
+               goto start;
+       } else {
+               ret = -EBUSY;
+               goto out;
+       }
 }
 
 /**