Re: [PATCH 04/18] PCI: Add PCI_EXP_SLTCAP_*_SHIFT macros

Bjorn Helgaas
2022-05-18T19:23:32Z

On Sun, Feb 20, 2022 at 08:33:32PM +0100, Marek Behún wrote:
> From: Pali Rohár <pali@kernel.org>
>
> These macros allows to easily compose and extract Slot Power Limit and
> Physical Slot Number values from Slot Capability Register.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

We talked about using FIELD_PREP() / FIELD_GET(), which I think would
remove the need for the *_SHIFT macros. But we can always do that
later.

> ---
> include/uapi/linux/pci_regs.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index bee1a9ed6e66..d825e17e448c 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -591,10 +591,13 @@
> #define PCI_EXP_SLTCAP_HPS 0x00000020 /* Hot-Plug Surprise */
> #define PCI_EXP_SLTCAP_HPC 0x00000040 /* Hot-Plug Capable */
> #define PCI_EXP_SLTCAP_SPLV 0x00007f80 /* Slot Power Limit Value */
> +#define PCI_EXP_SLTCAP_SPLV_SHIFT 7 /* Slot Power Limit Value shift */
> #define PCI_EXP_SLTCAP_SPLS 0x00018000 /* Slot Power Limit Scale */
> +#define PCI_EXP_SLTCAP_SPLS_SHIFT 15 /* Slot Power Limit Scale shift */
> #define PCI_EXP_SLTCAP_EIP 0x00020000 /* Electromechanical Interlock Present */
> #define PCI_EXP_SLTCAP_NCCS 0x00040000 /* No Command Completed Support */
> #define PCI_EXP_SLTCAP_PSN 0xfff80000 /* Physical Slot Number */
> +#define PCI_EXP_SLTCAP_PSN_SHIFT 19 /* Physical Slot Number shift */
> #define PCI_EXP_SLTCTL 0x18 /* Slot Control */
> #define PCI_EXP_SLTCTL_ABPE 0x0001 /* Attention Button Pressed Enable */
> #define PCI_EXP_SLTCTL_PFDE 0x0002 /* Power Fault Detected Enable */
> --
> 2.34.1
>