Re: [PATCH 09/10] PCI/VC: Use FIELD_GET()

Ilpo Järvinen
2023-10-11T11:40:10Z

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On Tue, 10 Oct 2023, Bjorn Helgaas wrote:

> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Use FIELD_GET() to remove dependences on the field position, i.e., the
> shift value. No functional change intended.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
> drivers/pci/vc.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/vc.c b/drivers/pci/vc.c
> index 5fc59ac31145..a4ff7f5f66dd 100644
> --- a/drivers/pci/vc.c
> +++ b/drivers/pci/vc.c
> @@ -6,6 +6,7 @@
> * Author: Alex Williamson <alex.williamson@redhat.com>
> */
>
> +#include <linux/bitfield.h>
> #include <linux/device.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> @@ -201,9 +202,9 @@ static int pci_vc_do_save_buffer(struct pci_dev *dev, int pos,
> /* Extended VC Count (not counting VC0) */
> evcc = cap1 & PCI_VC_CAP1_EVCC;
> /* Low Priority Extended VC Count (not counting VC0) */
> - lpevcc = (cap1 & PCI_VC_CAP1_LPEVCC) >> 4;
> + lpevcc = FIELD_GET(PCI_VC_CAP1_LPEVCC, cap1);
> /* Port Arbitration Table Entry Size (bits) */
> - parb_size = 1 << ((cap1 & PCI_VC_CAP1_ARB_SIZE) >> 10);
> + parb_size = 1 << FIELD_GET(PCI_VC_CAP1_ARB_SIZE, cap1);
>
> /*
> * Port VC Control Register contains VC Arbitration Select, which
> @@ -231,7 +232,7 @@ static int pci_vc_do_save_buffer(struct pci_dev *dev, int pos,
> int vcarb_offset;
>
> pci_read_config_dword(dev, pos + PCI_VC_PORT_CAP2, &cap2);
> - vcarb_offset = ((cap2 & PCI_VC_CAP2_ARB_OFF) >> 24) * 16;
> + vcarb_offset = FIELD_GET(PCI_VC_CAP2_ARB_OFF, cap2) * 16;
>
> if (vcarb_offset) {
> int size, vcarb_phases = 0;
> @@ -277,7 +278,7 @@ static int pci_vc_do_save_buffer(struct pci_dev *dev, int pos,
>
> pci_read_config_dword(dev, pos + PCI_VC_RES_CAP +
> (i * PCI_CAP_VC_PER_VC_SIZEOF), &cap);
> - parb_offset = ((cap & PCI_VC_RES_CAP_ARB_OFF) >> 24) * 16;
> + parb_offset = FIELD_GET(PCI_VC_RES_CAP_ARB_OFF, cap) * 16;
> if (parb_offset) {
> int size, parb_phases = 0;

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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