Merge branch 'pci/doe'

- Fix calculation of DOE length to account for the "0 means 2^18 DWORDs"
  special case (Li Ming)

* pci/doe:
  PCI/DOE: Fix maximum data object length miscalculation

drivers/pci/doe.c

@@ -29,6 +29,9 @@
 #define PCI_DOE_FLAG_CANCEL	0
 #define PCI_DOE_FLAG_DEAD	1
 
+/* Max data object length is 2^18 dwords */
+#define PCI_DOE_MAX_LENGTH	(1 << 18)
+
 /**
  * struct pci_doe_mb - State for a single DOE mailbox
  *
@@ -107,6 +110,7 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
 {
 	struct pci_dev *pdev = doe_mb->pdev;
 	int offset = doe_mb->cap_offset;
+	size_t length;
 	u32 val;
 	int i;
 
@@ -123,15 +127,20 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
 	if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
 		return -EIO;
 
+	/* Length is 2 DW of header + length of payload in DW */
+	length = 2 + task->request_pl_sz / sizeof(u32);
+	if (length > PCI_DOE_MAX_LENGTH)
+		return -EIO;
+	if (length == PCI_DOE_MAX_LENGTH)
+		length = 0;
+
 	/* Write DOE Header */
 	val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) |
 		FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type);
 	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
-	/* Length is 2 DW of header + length of payload in DW */
 	pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
 			       FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH,
-					  2 + task->request_pl_sz /
-						sizeof(u32)));
+					  length));
 	for (i = 0; i < task->request_pl_sz / sizeof(u32); i++)
 		pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
 				       task->request_pl[i]);
@@ -178,7 +187,10 @@ static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *tas
 	pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
 
 	length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val);
-	if (length > SZ_1M || length < 2)
+	/* A value of 0x0 indicates max data object length */
+	if (!length)
+		length = PCI_DOE_MAX_LENGTH;
+	if (length < 2)
 		return -EIO;
 
 	/* First 2 dwords have already been read */