Re: [PATCH v9 4/5] PCI: Add lane equalization register offsets

From: Manivannan Sadhasivam
Date: Wed Apr 02 2025 - 03:58:38 EST


On Fri, Mar 28, 2025 at 03:58:32PM +0530, Krishna Chaitanya Chundru wrote:
> As per PCIe spec 6.0.1, add PCIe lane equalization register offset for
> data rates 8.0 GT/s, 32.0 GT/s and 64.0 GT/s.
>
> Add macro for defining data rate 64.0 GT/s physical layer capability ID.
>
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

- Mani

> ---
> include/uapi/linux/pci_regs.h | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index 3445c4970e4d..0dcd9aba584d 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -749,7 +749,8 @@
> #define PCI_EXT_CAP_ID_NPEM 0x29 /* Native PCIe Enclosure Management */
> #define PCI_EXT_CAP_ID_PL_32GT 0x2A /* Physical Layer 32.0 GT/s */
> #define PCI_EXT_CAP_ID_DOE 0x2E /* Data Object Exchange */
> -#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_DOE
> +#define PCI_EXT_CAP_ID_PL_64GT 0x31 /* Physical Layer 64.0 GT/s */
> +#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_PL_64GT
>
> #define PCI_EXT_CAP_DSN_SIZEOF 12
> #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40
> @@ -1140,12 +1141,21 @@
> #define PCI_DLF_CAP 0x04 /* Capabilities Register */
> #define PCI_DLF_EXCHANGE_ENABLE 0x80000000 /* Data Link Feature Exchange Enable */
>
> +/* Secondary PCIe Capability 8.0 GT/s */
> +#define PCI_SECPCI_LE_CTRL 0x0c /* Lane Equalization Control Register */
> +
> /* Physical Layer 16.0 GT/s */
> #define PCI_PL_16GT_LE_CTRL 0x20 /* Lane Equalization Control Register */
> #define PCI_PL_16GT_LE_CTRL_DSP_TX_PRESET_MASK 0x0000000F
> #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_MASK 0x000000F0
> #define PCI_PL_16GT_LE_CTRL_USP_TX_PRESET_SHIFT 4
>
> +/* Physical Layer 32.0 GT/s */
> +#define PCI_PL_32GT_LE_CTRL 0x20 /* Lane Equalization Control Register */
> +
> +/* Physical Layer 64.0 GT/s */
> +#define PCI_PL_64GT_LE_CTRL 0x20 /* Lane Equalization Control Register */
> +
> /* Native PCIe Enclosure Management */
> #define PCI_NPEM_CAP 0x04 /* NPEM capability register */
> #define PCI_NPEM_CAP_CAPABLE 0x00000001 /* NPEM Capable */
>
> --
> 2.34.1
>

--
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