NTB: ntb_hw_intel: show BAR size in debugfs info

It will be useful to know the hardware configured BAR size to diagnose
issues with NTB memory windows.

Signed-off-by: Allen Hubbe <[email protected]>
Acked-by: Dave Jiang <[email protected]>
Signed-off-by: Jon Mason <[email protected]>

drivers/ntb/hw/intel/ntb_hw_intel.c

@@ -551,13 +551,15 @@ static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
 				 size_t count, loff_t *offp)
 {
 	struct intel_ntb_dev *ndev;
+	struct pci_dev *pdev;
 	void __iomem *mmio;
 	char *buf;
 	size_t buf_size;
 	ssize_t ret, off;
-	union { u64 v64; u32 v32; u16 v16; } u;
+	union { u64 v64; u32 v32; u16 v16; u8 v8; } u;
 
 	ndev = filp->private_data;
+	pdev = ndev_pdev(ndev);
 	mmio = ndev->self_mmio;
 
 	buf_size = min(count, 0x800ul);
@@ -631,6 +633,41 @@ static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
 	off += scnprintf(buf + off, buf_size - off,
 			 "Doorbell Bell -\t\t%#llx\n", u.v64);
 
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Window Size:\n");
+
+	pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &u.v8);
+	off += scnprintf(buf + off, buf_size - off,
+			 "PBAR23SZ %hhu\n", u.v8);
+	if (!ndev->bar4_split) {
+		pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR45SZ %hhu\n", u.v8);
+	} else {
+		pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR4SZ %hhu\n", u.v8);
+		pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR5SZ %hhu\n", u.v8);
+	}
+
+	pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &u.v8);
+	off += scnprintf(buf + off, buf_size - off,
+			 "SBAR23SZ %hhu\n", u.v8);
+	if (!ndev->bar4_split) {
+		pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR45SZ %hhu\n", u.v8);
+	} else {
+		pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR4SZ %hhu\n", u.v8);
+		pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR5SZ %hhu\n", u.v8);
+	}
+
 	off += scnprintf(buf + off, buf_size - off,
 			 "\nNTB Incoming XLAT:\n");