Re: [PATCH 06/10] PCI/DPC: Use FIELD_GET()

Ilpo Järvinen
2023-10-16T15:14:26Z

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On Mon, 16 Oct 2023, Ilpo Järvinen wrote:

> On Mon, 16 Oct 2023, Ilpo Järvinen wrote:
>
> > On Fri, 13 Oct 2023, Bjorn Helgaas wrote:
> >
> > > On Wed, Oct 11, 2023 at 02:01:13PM +0300, Ilpo Järvinen wrote:
> > > > 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/dpc.c | 9 +++++----
> > > > > drivers/pci/quirks.c | 2 +-
> > > > > include/uapi/linux/pci_regs.h | 1 +
> > > > > 3 files changed, 7 insertions(+), 5 deletions(-)
> > > > >
> > > > > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> > > > > index 3ceed8e3de41..6e551f34ec63 100644
> > > > > --- a/drivers/pci/pcie/dpc.c
> > > > > +++ b/drivers/pci/pcie/dpc.c
> > > > > @@ -8,6 +8,7 @@
> > > > >
> > > > > #define dev_fmt(fmt) "DPC: " fmt
> > > > >
> > > > > +#include <linux/bitfield.h>
> > > > > #include <linux/aer.h>
> > > > > #include <linux/delay.h>
> > > > > #include <linux/interrupt.h>
> > > > > @@ -202,7 +203,7 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
> > > > >
> > > > > /* Get First Error Pointer */
> > > > > pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &dpc_status);
> > > > > - first_error = (dpc_status & 0x1f00) >> 8;
> > > > > + first_error = FIELD_GET(PCI_EXP_DPC_STATUS_FIRST_ERR, dpc_status);
> > > > >
> > > > > for (i = 0; i < ARRAY_SIZE(rp_pio_error_string); i++) {
> > > > > if ((status & ~mask) & (1 << i))
> > > > > @@ -270,8 +271,8 @@ void dpc_process_error(struct pci_dev *pdev)
> > > > > pci_info(pdev, "containment event, status:%#06x source:%#06x\n",
> > > > > status, source);
> > > > >
> > > > > - reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1;
> > > > > - ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5;
> > > > > + reason = FIELD_GET(PCI_EXP_DPC_STATUS_TRIGGER_RSN, status);
> > > > > + ext_reason = FIELD_GET(PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT, status);
> > > > > pci_warn(pdev, "%s detected\n",
> > > > > (reason == 0) ? "unmasked uncorrectable error" :
> > > > > (reason == 1) ? "ERR_NONFATAL" :
> > > >
> > > > BTW, it seems we're doing overlapping work here with many of these
> > > > patches. It takes some time to think these through one by one, I don't
> > > > just autorun through them with coccinelle so I've not posted my changes
> > > > yet.
> > > >
> > > > I went to a different direction here and named all the reasons too with
> > > > defines and used & to get the reason in order to be able to compare with
> > > > the named reasons.
> > > >
> > > > You also missed convering one 0xfff4 to use define (although I suspect it
> > > > never was your goal to go beyond FIELD_GET() here).
> > >
> > > Pure FIELD_GET() and FIELD_PREP() was my goal.
> > >
> > > If you have patches you prefer, I'll drop mine. I did these about a
> > > year ago and it seemed like the time to do something with them since
> > > you did the PCI_EXP_LNKSTA_NLW ones and to try to prevent overlapping
> > > work. Since we've started, I'd like to get as much of it done this
> > > cycle as possible.
> >
> > Okay, I suggest you keep your FIELD_GET/PREP() patch since mine is getting
> > more and more complicated. I can build a nice set of small changes about
> > what remains to do in DPC on top of your patch.
>
> Err, actually, there's still the naming of the define, should _FEP be used
> for First Error Pointer for consistency? You should make that small change
> into your patch if you think _FEP is better because of consistency.

There's also #include order so it seems you should just drop the patch, I
can handle this along my series.

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