[V3 PATCH 16/16] crypto/nx: Add sysfs interface to export NX capabilities

[Haren Myneni]

Changes to export the following NXGZIP capabilities through sysfs:

/sys/devices/vio/ibm,compression-v1/NxGzCaps:
min_compress_len  /*Recommended minimum compress length in bytes*/
min_decompress_len /*Recommended minimum decompress length in bytes*/
req_max_processed_len /* Maximum number of bytes processed in one
                        request */

Signed-off-by: Haren Myneni <ha...@linux.ibm.com>
---
 drivers/crypto/nx/nx-common-pseries.c | 43 +++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/drivers/crypto/nx/nx-common-pseries.c 
b/drivers/crypto/nx/nx-common-pseries.c
index 49224870d05e..cc258d2c6475 100644
--- a/drivers/crypto/nx/nx-common-pseries.c
+++ b/drivers/crypto/nx/nx-common-pseries.c
@@ -962,6 +962,36 @@ static struct attribute_group nx842_attribute_group = {
        .attrs = nx842_sysfs_entries,
 };
 
+#define        nxct_capab_read(_name)                                          
\
+static ssize_t nxct_##_name##_show(struct device *dev,                 \
+                       struct device_attribute *attr, char *buf)       \
+{                                                                      \
+       return sprintf(buf, "%lld\n", nx_ct_capab._name);               \
+}
+
+#define NXCT_ATTR_RO(_name)                                            \
+       nxct_capab_read(_name);                                         \
+       static struct device_attribute dev_attr_##_name = __ATTR(_name, \
+                                               0444,                   \
+                                               nxct_##_name##_show,    \
+                                               NULL);
+
+NXCT_ATTR_RO(req_max_processed_len);
+NXCT_ATTR_RO(min_compress_len);
+NXCT_ATTR_RO(min_decompress_len);
+
+static struct attribute *nxct_capab_sysfs_entries[] = {
+       &dev_attr_req_max_processed_len.attr,
+       &dev_attr_min_compress_len.attr,
+       &dev_attr_min_decompress_len.attr,
+       NULL,
+};
+
+static struct attribute_group nxct_capab_attr_group = {
+       .name   =       nx_ct_capab.name,
+       .attrs  =       nxct_capab_sysfs_entries,
+};
+
 static struct nx842_driver nx842_pseries_driver = {
        .name =         KBUILD_MODNAME,
        .owner =        THIS_MODULE,
@@ -1051,6 +1081,16 @@ static int nx842_probe(struct vio_dev *viodev,
                goto error;
        }
 
+       if (capab_feat) {
+               if (sysfs_create_group(&viodev->dev.kobj,
+                                       &nxct_capab_attr_group)) {
+                       dev_err(&viodev->dev,
+                               "Could not create sysfs NX capability 
entries\n");
+                       ret = -1;
+                       goto error;
+               }
+       }
+
        return 0;
 
 error_unlock:
@@ -1070,6 +1110,9 @@ static void nx842_remove(struct vio_dev *viodev)
        pr_info("Removing IBM Power 842 compression device\n");
        sysfs_remove_group(&viodev->dev.kobj, &nx842_attribute_group);
 
+       if (capab_feat)
+               sysfs_remove_group(&viodev->dev.kobj, &nxct_capab_attr_group);
+
        crypto_unregister_alg(&nx842_pseries_alg);
 
        spin_lock_irqsave(&devdata_mutex, flags);
-- 
2.18.2