Re: [PATCH 07/10] PCI/PME: Use FIELD_GET()

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

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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/pcie/pme.c        | 4 +++-
>  include/uapi/linux/pci_regs.h | 1 +
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
> index ef8ce436ead9..a2daebd9806c 100644
> --- a/drivers/pci/pcie/pme.c
> +++ b/drivers/pci/pcie/pme.c
> @@ -9,6 +9,7 @@
>  
>  #define dev_fmt(fmt) "PME: " fmt
>  
> +#include <linux/bitfield.h>
>  #include <linux/pci.h>
>  #include <linux/kernel.h>
>  #include <linux/errno.h>
> @@ -235,7 +236,8 @@ static void pcie_pme_work_fn(struct work_struct *work)
>  			pcie_clear_root_pme_status(port);
>  
>  			spin_unlock_irq(&data->lock);
> -			pcie_pme_handle_request(port, rtsta & 0xffff);
> +			pcie_pme_handle_request(port,
> +				    FIELD_GET(PCI_EXP_RTSTA_PME_RQ_ID, rtsta));
>  			spin_lock_irq(&data->lock);
>  
>  			continue;
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index e97a06b50f95..9fb8a69241f4 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -637,6 +637,7 @@
>  #define PCI_EXP_RTCAP		0x1e	/* Root Capabilities */
>  #define  PCI_EXP_RTCAP_CRSVIS	0x0001	/* CRS Software Visibility capability */
>  #define PCI_EXP_RTSTA		0x20	/* Root Status */
> +#define  PCI_EXP_RTSTA_PME_RQ_ID 0x0000ffff /* PME Requester ID */
>  #define  PCI_EXP_RTSTA_PME	0x00010000 /* PME status */
>  #define  PCI_EXP_RTSTA_PENDING	0x00020000 /* PME pending */

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

(I'd have used REQ myself but it seems both forms are commonly used by 
the existing defines.)

-- 
 i.