On Wed, Oct 01, 2014 at 12:09:23PM +1000, Benjamin Herrenschmidt wrote:
>
> Some devices have broken 64-bit MSI support which only support some
> address bits (40 to 48 typically). This doesn't work on some platforms
> such as POWER servers, so we need a quirk.
>
> Currently we keep a flag in a powerpc specific data structure which we
> have per PCI device. However this is impractical as we really want the
> driver to set that flag appropriately (and the driver shouldn't touch
> that arch specific data structure).
>
> It's also not unlikely that this limitation will affect other architectures
> in the long run so may as well be prepared for it.
>
> 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 from what I can tell, x86 seems to always use 32-bit addresses
> for MSIs.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> CC: <stable@xxxxxxxxxxxxxxx>
> ---
>
> Note: CC'ing stable as I really want this to hit distros, without that
> (and the three subsequent patches), we crash during boot with a number
> of radeon cards on power machines.
>
> Note2: Alex, we can wait for the response of the HW guys for which revisions
> actually need the quirk in hda_intel but I don't see a big risk or issue in
> just doing it for all AMD/ATI for now and fix that up later
>
> 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..a6ce5fe 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->force_32bit_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..9d98475 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->force_32bit_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..4e43a6f 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->force_32bit_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..b3f2c1a 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->force_32bit_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..740cadd 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 force_32bit_msi:1; /* Device has broken 64-bit MSIs */
I like the idea of handling this more generically, e.g., with a bit like
this in struct pci_dev (I'd probably name it something like "no_64bit_msi"
along the lines of your driver #defines).
What I don't like is that we haven't done anything to help other
architectures, because the only code that *looks* at this bit is in
arch/powerpc. The next arch that tries to use 64-bit MSI addresses for
these devices will trip over the same problem.
Can we check in pci_enable_msi_range() and pci_enable_msix_range() whether
the MSI addresses allocated by the arch are too big, and fail the call if
they are?
Bjorn
> 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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