On 10/06/09 13:33, Allen Kay wrote:
> Changes from v3 to v4:
> - enable ACS only if iommu is enabled or if kernel is running as xen dom0
> - changed xen_domain_type from enum to #define to allow it to be used
> in pci/probe.c and to avoid excessive changes to code structure.
>
Why can't it be used as an enum?
> +++ b/drivers/pci/pci.h
> @@ -311,4 +311,14 @@ static inline int pci_resource_alignment(struct pci_dev *dev,
> return resource_alignment(res);
> }
>
> +extern void pci_enable_acs(struct pci_dev *dev);
> +
> +#ifdef CONFIG_DMAR
> +extern int iommu_detected;
> +#endif
> +
> +#ifdef CONFIG_XEN
> +extern int xen_domain_type;
> +#endif
>
That's pretty ugly; duplicate externs are pretty bad idea. Why not just
include the right header? If its because its asm-x86, I'm happy to move
the definitions to somewhere more common.
> +
> #endif /* DRIVERS_PCI_H */
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 8105e32..32703c7 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1014,6 +1014,17 @@ static void pci_init_capabilities(struct pci_dev *dev)
>
> /* Single Root I/O Virtualization */
> pci_iov_init(dev);
> +
> + /* Enable ACS P2P upstream forwarding if HW iommu is detected */
> + if (iommu_detected)
> + pci_enable_acs(dev);
> +
> +#ifdef CONFIG_XEN
> + /* HW iommu is not visible in xen dom0 */
> + if (xen_domain_type)
> + pci_enable_acs(dev);
> +#endif
>
The idea is that you're supposed to use xen_domain() to test for
Xenness; it expands to a constant 0 if Xen isn't configured, so there's
no need to use #ifdefs.
> +
> }
>
> void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> diff --git a/include/linux/dmar.h b/include/linux/dmar.h
> index 69a6fba..d13c21c 100644
> --- a/include/linux/dmar.h
> +++ b/include/linux/dmar.h
> @@ -196,7 +196,7 @@ extern irqreturn_t dmar_fault(int irq, void *dev_id);
> extern int arch_setup_dmar_msi(unsigned int irq);
>
> #ifdef CONFIG_DMAR
> -extern int iommu_detected, no_iommu;
> +extern int no_iommu;
> extern struct list_head dmar_rmrr_units;
> struct dmar_rmrr_unit {
> struct list_head list; /* list of rmrr units */
> diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
> index dd0bed4..d798770 100644
> --- a/include/linux/pci_regs.h
> +++ b/include/linux/pci_regs.h
> @@ -502,6 +502,7 @@
> #define PCI_EXT_CAP_ID_VC 2
> #define PCI_EXT_CAP_ID_DSN 3
> #define PCI_EXT_CAP_ID_PWR 4
> +#define PCI_EXT_CAP_ID_ACS 13
> #define PCI_EXT_CAP_ID_ARI 14
> #define PCI_EXT_CAP_ID_ATS 15
> #define PCI_EXT_CAP_ID_SRIOV 16
> @@ -662,4 +663,16 @@
> #define PCI_SRIOV_VFM_MO 0x2 /* Active.MigrateOut */
> #define PCI_SRIOV_VFM_AV 0x3 /* Active.Available */
>
> +/* Access Control Service */
> +#define PCI_ACS_CAP 0x04 /* ACS Capability Register */
> +#define PCI_ACS_SV 0x01 /* Source Validation */
> +#define PCI_ACS_TB 0x02 /* Translation Blocking */
> +#define PCI_ACS_RR 0x04 /* P2P Request Redirect */
> +#define PCI_ACS_CR 0x08 /* P2P Completion Redirect */
> +#define PCI_ACS_UF 0x10 /* Upstream Forwarding */
> +#define PCI_ACS_EC 0x20 /* P2P Egress Control */
> +#define PCI_ACS_DT 0x40 /* Direct Translated P2P */
> +#define PCI_ACS_CTRL 0x06 /* ACS Control Register */
> +#define PCI_ACS_EGRESS_CTL_V 0x08 /* ACS Egress Control Vector */
> +
> #endif /* LINUX_PCI_REGS_H */
>
NAK
J
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