[PATCH 2/5] dmanegine: idxd: reformat opcap output to match bitmap_parse() input

[Fenghua Yu]

From: Dave Jiang <dave.jiang@xxxxxxxxx>

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 <dave.jiang@xxxxxxxxx>
Co-developed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 drivers/dma/idxd/idxd.h      |  2 ++
 drivers/dma/idxd/init.c      | 20 ++++++++++++++++++++
 drivers/dma/idxd/registers.h |  2 ++
 drivers/dma/idxd/sysfs.c     |  9 ++-------
 4 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index cda856bfc22a..3ab406d74176 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -308,6 +308,8 @@ struct idxd_device {
 	struct work_struct work;
 
 	struct idxd_pmu *idxd_pmu;
+
+	unsigned long *opcap_bmap;
 };
 
 /* IDXD software descriptor */
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index aa3478257ddb..913a55ccb864 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -369,6 +369,19 @@ 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;
@@ -427,6 +440,7 @@ 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)
@@ -448,6 +462,12 @@ 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;
diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h
index 02449aa9c454..4c96ea85f843 100644
--- a/drivers/dma/idxd/registers.h
+++ b/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
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index be9ff9d4cc4b..9998ab4b28c8 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/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);
 
@@ -1411,6 +1405,7 @@ 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);
 }
 
-- 
2.32.0