On Wed, 16 Nov 2022 09:56:37 +0800
Li Ming <ming4.li@xxxxxxxxx> wrote:
> The value of data object length 0x0 indicates 2^18 dwords being
> transferred. This patch adjusts the value of data object length for the
> above case on both sending side and receiving side.
>
> Besides, it is unnecessary to check whether length is greater than
> SZ_1M while receiving a response data object, because length from LENGTH
> field of data object header, max value is 2^18.
>
> Signed-off-by: Li Ming <ming4.li@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Thanks,
> ---
> v1->v2:
> * Fix the value of PCI_DOE_MAX_LENGTH
> * Moving length checking closer to transferring process
> * Add a missing bracket
> * Adjust patch description
> ---
> drivers/pci/doe.c | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
> index e402f05068a5..66d9ab288646 100644
> --- 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_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 */
