> -----Original Message-----
> From: Kumar Gala [mailto:ga...@kernel.crashing.org]
> Sent: Friday, March 15, 2013 4:05 AM
> To: Jia Hongtao-B38951
> Cc: linuxppc-dev@lists.ozlabs.org; Wood Scott-B07421;
> mich...@ellerman.id.au; Li Yang-R58472; Jia Hongtao-B38951
> Subject: Re: [PATCH V2] powerpc/85xx: workaround for chips with MSI
> hardware errata
>
>
> On Mar 14, 2013, at 5:35 AM, Jia Hongtao wrote:
>
> > The MPIC version 2.0 has a MSI errata (errata PIC1 of mpc8544), It
> > causes that neither MSI nor MSI-X can work fine. This is a workaround
> > to allow MSI-X to function properly.
> >
> > Signed-off-by: Liu Shuo <soniccat....@gmail.com>
> > Signed-off-by: Li Yang <le...@freescale.com>
> > Signed-off-by: Jia Hongtao <hongtao....@freescale.com>
> > ---
> > Changes for V2:
> > - Address almost all the comments from Michael Ellerman for V1.
> > Here is the link:
> > http://patchwork.ozlabs.org/patch/226833/
> >
> > arch/powerpc/sysdev/fsl_msi.c | 65
> > +++++++++++++++++++++++++++++++++++++++++--
> > arch/powerpc/sysdev/fsl_msi.h | 2 ++
> > 2 files changed, 64 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/powerpc/sysdev/fsl_msi.c
> > b/arch/powerpc/sysdev/fsl_msi.c index 178c994..54cb83e 100644
> > --- a/arch/powerpc/sysdev/fsl_msi.c
> > +++ b/arch/powerpc/sysdev/fsl_msi.c
> > @@ -98,8 +98,18 @@ static int fsl_msi_init_allocator(struct fsl_msi
> > *msi_data)
> >
> > static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int
> > type) {
> > - if (type == PCI_CAP_ID_MSIX)
> > - pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
> > + struct fsl_msi *msi;
> > +
> > + if (type == PCI_CAP_ID_MSI) {
> > + /*
> > + * MPIC version 2.0 has erratum PIC1. For now MSI
> > + * could not work. So check to prevent MSI from
> > + * being used on the board with this erratum.
> > + */
> > + list_for_each_entry(msi, &msi_head, list)
> > + if (msi->feature & MSI_HW_ERRATA_ENDIAN)
> > + return -EINVAL;
> > + }
> >
> > return 0;
> > }
> > @@ -142,7 +152,17 @@ static void fsl_compose_msi_msg(struct pci_dev
> *pdev, int hwirq,
> > msg->address_lo = lower_32_bits(address);
> > msg->address_hi = upper_32_bits(address);
> >
> > - msg->data = hwirq;
> > + /*
> > + * MPIC version 2.0 has erratum PIC1. It causes
> > + * that neither MSI nor MSI-X can work fine.
> > + * This is a workaround to allow MSI-X to function
> > + * properly. It only works for MSI-X, we prevent
> > + * MSI on buggy chips in fsl_msi_check_device().
> > + */
> > + if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
> > + msg->data = __swab32(hwirq);
> > + else
> > + msg->data = hwirq;
> >
> > pr_debug("%s: allocated srs: %d, ibs: %d\n",
> > __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
> @@
> > -361,6 +381,35 @@ static int fsl_msi_setup_hwirq(struct fsl_msi *msi,
> struct platform_device *dev,
> > return 0;
> > }
> >
> > +/* MPIC version 2.0 has erratum PIC1 */ static int
> > +mpic_has_errata(struct platform_device *dev) {
> > + struct device_node *mpic_node;
> > +
> > + mpic_node = of_irq_find_parent(dev->dev.of_node);
> > + if (mpic_node) {
> > + u32 *reg_base, brr1 = 0;
> > + /* Get the PIC reg base */
> > + reg_base = of_iomap(mpic_node, 0);
> > + of_node_put(mpic_node);
> > + if (!reg_base) {
> > + dev_err(&dev->dev, "ioremap problem failed.\n");
> > + return -EIO;
> > + }
> > +
> > + /* Get the mpic version from block revision register 1 */
> > + brr1 = in_be32(reg_base + MPIC_FSL_BRR1);
> > + iounmap(reg_base);
> > + if ((brr1 & MPIC_FSL_BRR1_VER) == 0x0200)
> > + return 1;
> > + } else {
> > + dev_err(&dev->dev, "MSI can't find his parent mpic node.\n");
> > + return -ENODEV;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static const struct of_device_id fsl_of_msi_ids[]; static int
> > fsl_of_msi_probe(struct platform_device *dev) { @@ -423,6 +472,16 @@
> > static int fsl_of_msi_probe(struct platform_device *dev)
> >
> > msi->feature = features->fsl_pic_ip;
> >
> > + if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) == FSL_PIC_IP_MPIC) {
> > + rc = mpic_has_errata(dev);
> > + if (rc > 0) {
> > + msi->feature |= MSI_HW_ERRATA_ENDIAN;
> > + } else if (rc < 0) {
> > + err = rc;
> > + goto error_out;
> > + }
> > + }
> > +
> > /*
> > * Remember the phandle, so that we can match with any PCI nodes
> > * that have an "fsl,msi" property.
> > diff --git a/arch/powerpc/sysdev/fsl_msi.h
> > b/arch/powerpc/sysdev/fsl_msi.h index 8225f86..7389e8e 100644
> > --- a/arch/powerpc/sysdev/fsl_msi.h
> > +++ b/arch/powerpc/sysdev/fsl_msi.h
> > @@ -25,6 +25,8 @@
> > #define FSL_PIC_IP_IPIC 0x00000002
> > #define FSL_PIC_IP_VMPIC 0x00000003
> >
> > +#define MSI_HW_ERRATA_ENDIAN 0x00000010
> > +
>
> Is there any reason to put this in fsl_msi.h rather than just in
> fsl_msi.c itself?
>
> - k
Actually no. This micro is only used by fsl_msi.c.
Will move it to fsl_msi.c.
Thanks.
-Hongtao.
>
> > struct fsl_msi {
> > struct irq_domain *irqhost;
> >
> > --
> > 1.8.0
> >
>
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