From: Li Ming ming4.li@intel.com
commit a4ff8e7a71601321f7bf7b58ede664dc0d774274 upstream.
Per PCIe r6.0, sec 6.30.1, a data object Length of 0x0 indicates 2^18 DWORDs (256K DW or 1MB) being transferred. Adjust the value of data object length for this case on both sending side and receiving side.
Don't bother checking whether Length is greater than SZ_1M because all values of the 18-bit Length field are valid, and it is impossible to represent anything larger than SZ_1M:
0x00000 256K DW (1M bytes) 0x00001 1 DW (4 bytes) ... 0x3ffff 256K-1 DW (1M - 4 bytes)
[bhelgaas: commit log] Link: https://lore.kernel.org/r/20221116015637.3299664-1-ming4.li@intel.com Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions") Signed-off-by: Li Ming ming4.li@intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Lukas Wunner lukas@wunner.de Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/doe.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)
--- a/drivers/pci/doe.c +++ b/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_d { 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_d 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_ 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 */