dmanegine: idxd: reformat opcap output to match bitmap_parse() input

To make input and output consistent and prepping for the per WQ operation
configuration support, change the output of opcap display to match the
input that is expected by bitmap_parse() helper function. The output will
be a bitmap with field width as the number of bits using the %*pb format
specifier for printk() family.

Signed-off-by: Dave Jiang <[email protected]>
Co-developed-by: Fenghua Yu <[email protected]>
Signed-off-by: Fenghua Yu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: davejiang

drivers/dma/idxd/idxd.h

@@ -310,6 +310,8 @@ struct idxd_device {
 	struct work_struct work;
 
 	struct idxd_pmu *idxd_pmu;
+
+	unsigned long *opcap_bmap;
 };
 
 /* IDXD software descriptor */

drivers/dma/idxd/init.c

@@ -375,6 +375,19 @@ 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)
+{
+	int i, j, nr;
+
+	for (i = 0, nr = 0; i < count; i++) {
+		for (j = 0; j < BITS_PER_LONG_LONG; j++) {
+			if (val[i] & BIT(j))
+				set_bit(nr, bmap);
+			nr++;
+		}
+	}
+}
+
 static void idxd_read_caps(struct idxd_device *idxd)
 {
 	struct device *dev = &idxd->pdev->dev;
@@ -433,6 +446,7 @@ static void idxd_read_caps(struct idxd_device *idxd)
 				IDXD_OPCAP_OFFSET + i * sizeof(u64));
 		dev_dbg(dev, "opcap[%d]: %#llx\n", i, idxd->hw.opcap.bits[i]);
 	}
+	multi_u64_to_bmap(idxd->opcap_bmap, &idxd->hw.opcap.bits[0], 4);
 }
 
 static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_data *data)
@@ -454,6 +468,12 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
 	if (idxd->id < 0)
 		return NULL;
 
+	idxd->opcap_bmap = bitmap_zalloc_node(IDXD_MAX_OPCAP_BITS, GFP_KERNEL, dev_to_node(dev));
+	if (!idxd->opcap_bmap) {
+		ida_free(&idxd_ida, idxd->id);
+		return NULL;
+	}
+
 	device_initialize(conf_dev);
 	conf_dev->parent = dev;
 	conf_dev->bus = &dsa_bus_type;

drivers/dma/idxd/registers.h

@@ -90,6 +90,8 @@ struct opcap {
 	u64 bits[4];
 };
 
+#define IDXD_MAX_OPCAP_BITS		256U
+
 #define IDXD_OPCAP_OFFSET		0x40
 
 #define IDXD_TABLE_OFFSET		0x60

drivers/dma/idxd/sysfs.c

@@ -1180,14 +1180,8 @@ static ssize_t op_cap_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
 	struct idxd_device *idxd = confdev_to_idxd(dev);
-	int i, rc = 0;
-
-	for (i = 0; i < 4; i++)
-		rc += sysfs_emit_at(buf, rc, "%#llx ", idxd->hw.opcap.bits[i]);
 
-	rc--;
-	rc += sysfs_emit_at(buf, rc, "\n");
-	return rc;
+	return sysfs_emit(buf, "%*pb\n", IDXD_MAX_OPCAP_BITS, idxd->opcap_bmap);
 }
 static DEVICE_ATTR_RO(op_cap);
 
@@ -1412,6 +1406,7 @@ static void idxd_conf_device_release(struct device *dev)
 	kfree(idxd->wqs);
 	kfree(idxd->engines);
 	ida_free(&idxd_ida, idxd->id);
+	bitmap_free(idxd->opcap_bmap);
 	kfree(idxd);
 }