[PATCH v2 1/4] pci/msi: Move "no_64bit_msi" flag from powerpc to generic pci_dev

Bjorn Helgaas bhelgaas at google.com
Fri Oct 3 07:46:09 EST 2014


On Thu, Oct 2, 2014 at 3:01 PM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> On Thu, 2014-10-02 at 09:31 -0600, Bjorn Helgaas wrote:
>
>> > So this moves the flag to struct pci_dev instead and adjusts the
>> > corresponding arch/powerpc code to look for it there. At this point,
>> > there is no attempt at making other architectures honor it just yet,
>> > though it appears that x86 doesn't care and always generates 32-bit
>> > MSI addresses.
>>
>> I thought you were going to add something in drivers/pci to make this more
>> generic?
>
> I don't see how. The only thing I can add is the check which I still
> plan to do. But the decision on the address is in the arch.

Yep, the check is what I meant.  That should at least allow the driver
to fail gracefully instead of crashing the machine.

>> Is it feasible to structure this series as follows?
>>
>>   - add generic stuff (struct pci_dev bit, msi.c checks)
>>   - add quirks to drivers to set the pci_dev bit
>>   - change powerpc to check pci_dev bit instead of pdn bit
>>   - remove powerpc-specific quirks since nobody looks as the pdn bit
>>
>> I think it would be easier to follow if the powerpc-specific parts weren't
>> intertwined with the rest.
>
> Well, in that case the first patch just adds one bit to pci_dev and
> maybe one check for address to msi.c. Unfortunately there isn't more
> I can do generically. But ok, I'll do it that way.
>
>> > Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>> > CC: <stable at vger.kernel.org>
>> > ---
>> >
>> > v2: Rename flag to "no_64bit_msi" as suggested by Bjorn
>> >
>> >  arch/powerpc/include/asm/pci-bridge.h     | 2 --
>> >  arch/powerpc/kernel/pci_64.c              | 5 +----
>> >  arch/powerpc/platforms/powernv/pci-ioda.c | 3 +--
>> >  arch/powerpc/platforms/powernv/pci.c      | 3 +--
>> >  arch/powerpc/platforms/pseries/msi.c      | 2 +-
>> >  include/linux/pci.h                       | 1 +
>> >  6 files changed, 5 insertions(+), 11 deletions(-)
>> >
>> > diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
>> > index 4ca90a3..725247b 100644
>> > --- a/arch/powerpc/include/asm/pci-bridge.h
>> > +++ b/arch/powerpc/include/asm/pci-bridge.h
>> > @@ -159,8 +159,6 @@ struct pci_dn {
>> >
>> >     int     pci_ext_config_space;   /* for pci devices */
>> >
>> > -   bool    force_32bit_msi;
>> > -
>> >     struct  pci_dev *pcidev;        /* back-pointer to the pci device */
>> >  #ifdef CONFIG_EEH
>> >     struct eeh_dev *edev;           /* eeh device */
>> > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
>> > index 155013d..d41a831 100644
>> > --- a/arch/powerpc/kernel/pci_64.c
>> > +++ b/arch/powerpc/kernel/pci_64.c
>> > @@ -269,10 +269,7 @@ EXPORT_SYMBOL(pcibus_to_node);
>> >
>> >  static void quirk_radeon_32bit_msi(struct pci_dev *dev)
>> >  {
>> > -   struct pci_dn *pdn = pci_get_pdn(dev);
>> > -
>> > -   if (pdn)
>> > -           pdn->force_32bit_msi = true;
>> > +   dev->no_64bit_msi = true;
>> >  }
>> >  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x68f2, quirk_radeon_32bit_msi);
>> >  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0xaa68, quirk_radeon_32bit_msi);
>> > diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> > index df241b1..a188bb8 100644
>> > --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> > +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> > @@ -1311,7 +1311,6 @@ static int pnv_pci_ioda_msi_setup(struct pnv_phb *phb, struct pci_dev *dev,
>> >                               unsigned int is_64, struct msi_msg *msg)
>> >  {
>> >     struct pnv_ioda_pe *pe = pnv_ioda_get_pe(dev);
>> > -   struct pci_dn *pdn = pci_get_pdn(dev);
>> >     struct irq_data *idata;
>> >     struct irq_chip *ichip;
>> >     unsigned int xive_num = hwirq - phb->msi_base;
>> > @@ -1327,7 +1326,7 @@ static int pnv_pci_ioda_msi_setup(struct pnv_phb *phb, struct pci_dev *dev,
>> >             return -ENXIO;
>> >
>> >     /* Force 32-bit MSI on some broken devices */
>> > -   if (pdn && pdn->force_32bit_msi)
>> > +   if (dev->no_64bit_msi)
>> >             is_64 = 0;
>> >
>> >     /* Assign XIVE to PE */
>> > diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
>> > index b854b57..89c6608 100644
>> > --- a/arch/powerpc/platforms/powernv/pci.c
>> > +++ b/arch/powerpc/platforms/powernv/pci.c
>> > @@ -50,9 +50,8 @@ static int pnv_msi_check_device(struct pci_dev* pdev, int nvec, int type)
>> >  {
>> >     struct pci_controller *hose = pci_bus_to_host(pdev->bus);
>> >     struct pnv_phb *phb = hose->private_data;
>> > -   struct pci_dn *pdn = pci_get_pdn(pdev);
>> >
>> > -   if (pdn && pdn->force_32bit_msi && !phb->msi32_support)
>> > +   if (pdev->no_64bit_msi && !phb->msi32_support)
>> >             return -ENODEV;
>> >
>> >     return (phb && phb->msi_bmp.bitmap) ? 0 : -ENODEV;
>> > diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
>> > index 18ff462..6fd96d8 100644
>> > --- a/arch/powerpc/platforms/pseries/msi.c
>> > +++ b/arch/powerpc/platforms/pseries/msi.c
>> > @@ -429,7 +429,7 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
>> >      */
>> >  again:
>> >     if (type == PCI_CAP_ID_MSI) {
>> > -           if (pdn->force_32bit_msi) {
>> > +           if (pdev->no_64bit_msi) {
>> >                     rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
>> >                     if (rc < 0) {
>> >                             /*
>> > diff --git a/include/linux/pci.h b/include/linux/pci.h
>> > index 96453f9..fc938003 100644
>> > --- a/include/linux/pci.h
>> > +++ b/include/linux/pci.h
>> > @@ -331,6 +331,7 @@ struct pci_dev {
>> >     unsigned int    is_added:1;
>> >     unsigned int    is_busmaster:1; /* device is busmaster */
>> >     unsigned int    no_msi:1;       /* device may not use msi */
>> > +   unsigned int    no_64bit_msi:1; /* Device has broken 64-bit MSIs */
>> >     unsigned int    block_cfg_access:1;     /* config space access is blocked */
>> >     unsigned int    broken_parity_status:1; /* Device generates false positive parity */
>> >     unsigned int    irq_reroute_variant:2;  /* device needs IRQ rerouting variant */
>> >
>> >
>> >
>
>


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