dmaengine: idxd: reformat swerror output to standard Linux bitmap output

SWERROR register is 4 64bit wide registers. Currently the sysfs attribute
just outputs 4 64bit hex integers. Convert to output with %*pb format
specifier.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230303213732.3357494-2-fenghua.yu@intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/idxd.h

@@ -598,6 +598,7 @@ int idxd_register_driver(void);
 void idxd_unregister_driver(void);
 void idxd_wqs_quiesce(struct idxd_device *idxd);
 bool idxd_queue_int_handle_resubmit(struct idxd_desc *desc);
+void multi_u64_to_bmap(unsigned long *bmap, u64 *val, int count);
 
 /* device interrupt control */
 irqreturn_t idxd_misc_thread(int vec, void *data);

drivers/dma/idxd/init.c

@@ -388,7 +388,7 @@ static void idxd_read_table_offsets(struct idxd_device *idxd)
 	dev_dbg(dev, "IDXD Perfmon Offset: %#x\n", idxd->perfmon_offset);
 }
 
-static void multi_u64_to_bmap(unsigned long *bmap, u64 *val, int count)
+void multi_u64_to_bmap(unsigned long *bmap, u64 *val, int count)
 {
 	int i, j, nr;
 

drivers/dma/idxd/sysfs.c

@@ -1452,15 +1452,13 @@ static ssize_t errors_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct idxd_device *idxd = confdev_to_idxd(dev);
-	int i, out = 0;
+	DECLARE_BITMAP(swerr_bmap, 256);
 
+	bitmap_zero(swerr_bmap, 256);
 	spin_lock(&idxd->dev_lock);
-	for (i = 0; i < 4; i++)
-		out += sysfs_emit_at(buf, out, "%#018llx ", idxd->sw_err.bits[i]);
+	multi_u64_to_bmap(swerr_bmap, &idxd->sw_err.bits[0], 4);
 	spin_unlock(&idxd->dev_lock);
-	out--;
-	out += sysfs_emit_at(buf, out, "\n");
-	return out;
+	return sysfs_emit(buf, "%*pb\n", 256, swerr_bmap);
 }
 static DEVICE_ATTR_RO(errors);