Re: [RFC PATCH] Fix Intel IOMMU support for Marvell 88SE91xx SATA controllers.

[Chu Ying]

On 2012-12-19, at 18:58, Andrew Cooks <acooks@xxxxxxxxx> wrote:

> This is my second attempt to make Marvell 88SE91xx SATA controllers work when IOMMU is enabled.[1][2] 
> As suggested, it no longer tries to add support for phantom functions.
> 
> What's missing:
> * No AMD support. I need some help with this.
> * Table of affected chip IDs is incomplete. I think 0x9123, 0x9125, 0x9128 are also affected.

That's not that simple, those devices with 2 functions( one for sata and the other for pata) work well under Intel IOMMU, so I need comfirm what devices should be involved the latest patch.

> Patch is against 3.7.1
> 
> Review and feedback would be appreciated.
> 
> 1. https://bugzilla.redhat.com/show_bug.cgi?id=757166
> 2. https://bugzilla.kernel.org/show_bug.cgi?id=42679
> 
> Signed-off-by: Andrew Cooks <acooks@xxxxxxxxx>
> ---
> drivers/iommu/intel-iommu.c |   36 ++++++++++++++++++++++++++++++++++--
> drivers/pci/quirks.c        |   34 ++++++++++++++++++++++++++++++++++
> include/linux/pci.h         |    1 +
> 3 files changed, 66 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 0badfa4..17e64c0 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -1672,6 +1674,31 @@ static int domain_context_mapping_one(struct dmar_domain *domain, int segment,
>    return 0;
> }
> 
> +/* For buggy devices like Marvell 88SE91xx chips that use unclaimed
> + * functions.
> + */
> +static int map_quirky_dma_fn(struct dmar_domain *domain,
> +        struct pci_dev *pdev,
> +        int translation)
> +{
> +    u8 fn;
> +    int err = 0;
> +
> +    for (fn = 1; fn < 8; fn++) {
> +        if (pci_func_is_dma_source(pdev, fn)) {
> +            err = domain_context_mapping_one(domain,
> +                    pci_domain_nr(pdev->bus),
> +                    pdev->bus->number,
> +                    PCI_DEVFN(PCI_SLOT(pdev->devfn), fn),
> +                    translation);
> +            if (err)
> +                return err;
> +            dev_dbg(&pdev->dev, "func: %d mapped dma quirk", fn);
> +        }
> +    }
> +    return 0;
> +}
> +
> static int
> domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev,
>            int translation)
> @@ -1685,6 +1712,11 @@ domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev,
>    if (ret)
>        return ret;
> 
> +    /* quirk for undeclared pci functions */
> +    ret = map_quirky_dma_fn(domain, pdev, translation);
> +    if (ret)
> +        return ret;
> +
>    /* dependent device mapping */
>    tmp = pci_find_upstream_pcie_bridge(pdev);
>    if (!tmp)
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 7a451ff..8d02bac 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3227,6 +3227,40 @@ static const struct pci_dev_dma_source {
>    { 0 }
> };
> 
> +static const struct pci_dev_dma_source_funcs {
> +    u16 vendor;
> +    u16 device;
> +    u8 func_map;    /* bit map. lsb is fn 0. */
> +} pci_dev_dma_source_funcs[] = {
> +     {0x1b4b, 0x9172, (1<<0)|(1<<1)},
> +     { 0 },    
> +};

Can you confirm function 0 should be marked? Per my PCIe trace, I found no function 0 involved in DMA access?

> +static u8 pci_get_dma_source_map(struct pci_dev *dev)
> +{
> +    const struct pci_dev_dma_source_funcs *i;
> +
> +    for (i = pci_dev_dma_source_funcs; i->func_map; i++) {
> +        if ((i->vendor == dev->vendor ||
> +             i->vendor == (u16)PCI_ANY_ID) &&
> +            (i->device == dev->device ||
> +             i->device == (u16)PCI_ANY_ID)) {
> +            return i->func_map;            
> +        }
> +    }
> +    return 0;
> +}
> +
> +int pci_func_is_dma_source(struct pci_dev *dev, int fn)
> +{
> +    u8 fn_map = pci_get_dma_source_map(dev);
> +
> +    if (fn_map & (1 << fn))
> +        return 1;
> +
> +    return 0;
> +}
> +
> /*
>  * IOMMUs with isolation capabilities need to be programmed with the
>  * correct source ID of a device.  In most cases, the source ID matches
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index ee21795..8f0fa7f 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1546,6 +1546,7 @@ enum pci_fixup_pass {
> #ifdef CONFIG_PCI_QUIRKS
> void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev);
> struct pci_dev *pci_get_dma_source(struct pci_dev *dev);
> +int pci_func_is_dma_source(struct pci_dev *dev, int fn);
> int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
> #else
> static inline void pci_fixup_device(enum pci_fixup_pass pass,
> -- 
> 1.7.1
> 
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