> 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. The main reason is lack of access of xen header files in driver/pci directory. If we can move xen header files to include/asm-x86, then the ugliness will go away. Specifically, I would like to access header file containing xen_domain_type and associated enum definition from driver/pci directory. -----Original Message----- From: Jeremy Fitzhardinge [mailto:jeremy@xxxxxxxx] Sent: Tuesday, October 06, 2009 2:38 PM To: Kay, Allen M Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; jbarnes@xxxxxxxxxxxxxxxx; matthew@xxxxxx; chris@xxxxxxxxxxxx Subject: Re: [PATCH ACS v4 1/1] Enabling PCI ACS P2P upstream forwarding 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 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
