crypto: qat - add rate limiting sysfs interface

Add an interface for the rate limiting feature which allows to add,
remove and modify a QAT SLA (Service Level Agreement).

This adds a new sysfs attribute group, `qat_rl`, which can be accessed
from /sys/bus/pci/devices/<BUS:DEV:FUNCTION> with the following
hierarchy:
    |-+ qat_rl
      |---- id  (RW) # SLA identifier
      |---- cir (RW) # Committed Information Rate
      |---- pir (RW) # Peak Information Rate
      |---- srv (RW) # Service to be rate limited
      |---- rp  (RW) (HEX) # Ring pairs to be rate limited
      |---- cap_rem  (RW)  # Remaining capability for a service
      |---- sla_op   (WO)  # Allows to perform an operation on an SLA

The API works by setting the appropriate RW attributes and then
issuing a command through the `sla_op`. For example, to create an SLA, a
user needs to input the necessary data into the attributes cir, pir, srv
and rp and then write into `sla_op` the command `add` to execute the
operation.
The API also provides `cap_rem` attribute to get information about
the remaining device capability within a certain service which is
required when setting an SLA.

Signed-off-by: Ciunas Bennett <ciunas.bennett@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Damian Muszynski <damian.muszynski@intel.com>
Reviewed-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/crypto/intel/qat/qat_common/adf_rl.c b/drivers/crypto/intel/qat/qat_common/adf_rl.c
index 88a03105b52a..86e3e2152b1b 100644
--- a/drivers/crypto/intel/qat/qat_common/adf_rl.c
+++ b/drivers/crypto/intel/qat/qat_common/adf_rl.c
@@ -16,6 +16,7 @@
 #include "adf_common_drv.h"
 #include "adf_rl_admin.h"
 #include "adf_rl.h"
+#include "adf_sysfs_rl.h"
 
 #define RL_TOKEN_GRANULARITY_PCIEIN_BUCKET	0U
 #define RL_TOKEN_GRANULARITY_PCIEOUT_BUCKET	0U
@@ -1130,8 +1131,16 @@ int adf_rl_start(struct adf_accel_dev *accel_dev)
 		goto ret_sla_rm;
 	}
 
+	ret = adf_sysfs_rl_add(accel_dev);
+	if (ret) {
+		dev_err(&GET_DEV(accel_dev), "failed to add sysfs interface\n");
+		goto ret_sysfs_rm;
+	}
+
 	return 0;
 
+ret_sysfs_rm:
+	adf_sysfs_rl_rm(accel_dev);
 ret_sla_rm:
 	adf_rl_remove_sla_all(accel_dev, true);
 ret_free:
@@ -1146,6 +1155,7 @@ void adf_rl_stop(struct adf_accel_dev *accel_dev)
 	if (!accel_dev->rate_limiting)
 		return;
 
+	adf_sysfs_rl_rm(accel_dev);
 	adf_rl_remove_sla_all(accel_dev, true);
 }