From b5401a96b59475c1c878439caecb8c521bdfd4ad Mon Sep 17 00:00:00 2001 From: Alex Nixon Date: Thu, 18 Mar 2010 16:31:34 -0400 Subject: xen/x86/PCI: Add support for the Xen PCI subsystem The frontend stub lives in arch/x86/pci/xen.c, alongside other sub-arch PCI init code (e.g. olpc.c). It provides a mechanism for Xen PCI frontend to setup/destroy legacy interrupts, MSI/MSI-X, and PCI configuration operations. [ Impact: add core of Xen PCI support ] [ v2: Removed the IOMMU code and only focusing on PCI.] [ v3: removed usage of pci_scan_all_fns as that does not exist] [ v4: introduced pci_xen value to fix compile warnings] [ v5: squished fixes+features in one patch, changed Reviewed-by to Ccs] [ v7: added Acked-by] Signed-off-by: Alex Nixon Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Stefano Stabellini Acked-by: Jesse Barnes Cc: "H. Peter Anvin" Cc: Matthew Wilcox Cc: Qing He Cc: Thomas Gleixner Cc: x86@kernel.org --- arch/x86/Kconfig | 5 ++ arch/x86/include/asm/xen/pci.h | 53 +++++++++++++++ arch/x86/pci/Makefile | 1 + arch/x86/pci/xen.c | 147 +++++++++++++++++++++++++++++++++++++++++ arch/x86/xen/enlighten.c | 3 + drivers/xen/events.c | 32 ++++++++- include/xen/events.h | 3 + 7 files changed, 242 insertions(+), 2 deletions(-) create mode 100644 arch/x86/include/asm/xen/pci.h create mode 100644 arch/x86/pci/xen.c diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8cc510874e1b..74ea59d34076 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1898,6 +1898,11 @@ config PCI_OLPC def_bool y depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) +config PCI_XEN + def_bool y + depends on PCI && XEN + select SWIOTLB_XEN + config PCI_DOMAINS def_bool y depends on PCI diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h new file mode 100644 index 000000000000..449c82f71677 --- /dev/null +++ b/arch/x86/include/asm/xen/pci.h @@ -0,0 +1,53 @@ +#ifndef _ASM_X86_XEN_PCI_H +#define _ASM_X86_XEN_PCI_H + +#if defined(CONFIG_PCI_XEN) +extern int __init pci_xen_init(void); +#define pci_xen 1 +#else +#define pci_xen 0 +#define pci_xen_init (0) +#endif + +#if defined(CONFIG_PCI_MSI) +#if defined(CONFIG_PCI_XEN) +/* The drivers/pci/xen-pcifront.c sets this structure to + * its own functions. + */ +struct xen_pci_frontend_ops { + int (*enable_msi)(struct pci_dev *dev, int **vectors); + void (*disable_msi)(struct pci_dev *dev); + int (*enable_msix)(struct pci_dev *dev, int **vectors, int nvec); + void (*disable_msix)(struct pci_dev *dev); +}; + +extern struct xen_pci_frontend_ops *xen_pci_frontend; + +static inline int xen_pci_frontend_enable_msi(struct pci_dev *dev, + int **vectors) +{ + if (xen_pci_frontend && xen_pci_frontend->enable_msi) + return xen_pci_frontend->enable_msi(dev, vectors); + return -ENODEV; +} +static inline void xen_pci_frontend_disable_msi(struct pci_dev *dev) +{ + if (xen_pci_frontend && xen_pci_frontend->disable_msi) + xen_pci_frontend->disable_msi(dev); +} +static inline int xen_pci_frontend_enable_msix(struct pci_dev *dev, + int **vectors, int nvec) +{ + if (xen_pci_frontend && xen_pci_frontend->enable_msix) + return xen_pci_frontend->enable_msix(dev, vectors, nvec); + return -ENODEV; +} +static inline void xen_pci_frontend_disable_msix(struct pci_dev *dev) +{ + if (xen_pci_frontend && xen_pci_frontend->disable_msix) + xen_pci_frontend->disable_msix(dev); +} +#endif /* CONFIG_PCI_XEN */ +#endif /* CONFIG_PCI_MSI */ + +#endif /* _ASM_X86_XEN_PCI_H */ diff --git a/arch/x86/pci/Makefile b/arch/x86/pci/Makefile index a0207a7fdf39..effd96e33f16 100644 --- a/arch/x86/pci/Makefile +++ b/arch/x86/pci/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_PCI_BIOS) += pcbios.o obj-$(CONFIG_PCI_MMCONFIG) += mmconfig_$(BITS).o direct.o mmconfig-shared.o obj-$(CONFIG_PCI_DIRECT) += direct.o obj-$(CONFIG_PCI_OLPC) += olpc.o +obj-$(CONFIG_PCI_XEN) += xen.o obj-y += fixup.o obj-$(CONFIG_ACPI) += acpi.o diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c new file mode 100644 index 000000000000..b19c873d8d0c --- /dev/null +++ b/arch/x86/pci/xen.c @@ -0,0 +1,147 @@ +/* + * Xen PCI Frontend Stub - puts some "dummy" functions in to the Linux + * x86 PCI core to support the Xen PCI Frontend + * + * Author: Ryan Wilson + */ +#include +#include +#include +#include + +#include +#include + +#include + +#include +#include + +#if defined(CONFIG_PCI_MSI) +#include + +struct xen_pci_frontend_ops *xen_pci_frontend; +EXPORT_SYMBOL_GPL(xen_pci_frontend); + +/* + * For MSI interrupts we have to use drivers/xen/event.s functions to + * allocate an irq_desc and setup the right */ + + +static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + int irq, ret, i; + struct msi_desc *msidesc; + int *v; + + v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL); + if (!v) + return -ENOMEM; + + if (!xen_initial_domain()) { + if (type == PCI_CAP_ID_MSIX) + ret = xen_pci_frontend_enable_msix(dev, &v, nvec); + else + ret = xen_pci_frontend_enable_msi(dev, &v); + if (ret) + goto error; + } + i = 0; + list_for_each_entry(msidesc, &dev->msi_list, list) { + irq = xen_allocate_pirq(v[i], 0, /* not sharable */ + (type == PCI_CAP_ID_MSIX) ? + "pcifront-msi-x" : "pcifront-msi"); + if (irq < 0) + return -1; + + ret = set_irq_msi(irq, msidesc); + if (ret) + goto error_while; + i++; + } + kfree(v); + return 0; + +error_while: + unbind_from_irqhandler(irq, NULL); +error: + if (ret == -ENODEV) + dev_err(&dev->dev, "Xen PCI frontend has not registered" \ + " MSI/MSI-X support!\n"); + + kfree(v); + return ret; +} + +static void xen_teardown_msi_irqs(struct pci_dev *dev) +{ + /* Only do this when were are in non-privileged mode.*/ + if (!xen_initial_domain()) { + struct msi_desc *msidesc; + + msidesc = list_entry(dev->msi_list.next, struct msi_desc, list); + if (msidesc->msi_attrib.is_msix) + xen_pci_frontend_disable_msix(dev); + else + xen_pci_frontend_disable_msi(dev); + } + +} + +static void xen_teardown_msi_irq(unsigned int irq) +{ + xen_destroy_irq(irq); +} +#endif + +static int xen_pcifront_enable_irq(struct pci_dev *dev) +{ + int rc; + int share = 1; + + dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq); + + if (dev->irq < 0) + return -EINVAL; + + if (dev->irq < NR_IRQS_LEGACY) + share = 0; + + rc = xen_allocate_pirq(dev->irq, share, "pcifront"); + if (rc < 0) { + dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n", + dev->irq, rc); + return rc; + } + return 0; +} + +int __init pci_xen_init(void) +{ + if (!xen_pv_domain() || xen_initial_domain()) + return -ENODEV; + + printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n"); + + pcibios_set_cache_line_size(); + + pcibios_enable_irq = xen_pcifront_enable_irq; + pcibios_disable_irq = NULL; + +#ifdef CONFIG_ACPI + /* Keep ACPI out of the picture */ + acpi_noirq = 1; +#endif + +#ifdef CONFIG_ISAPNP + /* Stop isapnp from probing */ + isapnp_disable = 1; +#endif + +#ifdef CONFIG_PCI_MSI + x86_msi.setup_msi_irqs = xen_setup_msi_irqs; + x86_msi.teardown_msi_irq = xen_teardown_msi_irq; + x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; +#endif + return 0; +} diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 7d46c8441418..1ccfa1bf0f89 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -1220,6 +1221,8 @@ asmlinkage void __init xen_start_kernel(void) add_preferred_console("xenboot", 0, NULL); add_preferred_console("tty", 0, NULL); add_preferred_console("hvc", 0, NULL); + if (pci_xen) + x86_init.pci.arch_init = pci_xen_init; } else { /* Make sure ACS will be enabled */ pci_request_acs(); diff --git a/drivers/xen/events.c b/drivers/xen/events.c index cd504092299b..7016a734257c 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -582,7 +582,9 @@ int xen_allocate_pirq(unsigned gsi, int shareable, char *name) goto out; /* XXX need refcount? */ } - if (identity_mapped_irq(gsi)) { + /* If we are a PV guest, we don't have GSIs (no ACPI passed). Therefore + * we are using the !xen_initial_domain() to drop in the function.*/ + if (identity_mapped_irq(gsi) || !xen_initial_domain()) { irq = gsi; irq_to_desc_alloc_node(irq, 0); dynamic_irq_init(irq); @@ -593,7 +595,13 @@ int xen_allocate_pirq(unsigned gsi, int shareable, char *name) handle_level_irq, name); irq_op.irq = irq; - if (HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) { + irq_op.vector = 0; + + /* Only the privileged domain can do this. For non-priv, the pcifront + * driver provides a PCI bus that does the call to do exactly + * this in the priv domain. */ + if (xen_initial_domain() && + HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) { dynamic_irq_cleanup(irq); irq = -ENOSPC; goto out; @@ -608,6 +616,26 @@ out: return irq; } +int xen_destroy_irq(int irq) +{ + struct irq_desc *desc; + int rc = -ENOENT; + + spin_lock(&irq_mapping_update_lock); + + desc = irq_to_desc(irq); + if (!desc) + goto out; + + irq_info[irq] = mk_unbound_info(); + + dynamic_irq_cleanup(irq); + +out: + spin_unlock(&irq_mapping_update_lock); + return rc; +} + int xen_vector_from_irq(unsigned irq) { return vector_from_irq(irq); diff --git a/include/xen/events.h b/include/xen/events.h index d7a4ca7d17b5..c1717ca5ac13 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -72,6 +72,9 @@ void xen_hvm_evtchn_do_upcall(void); * usual. */ int xen_allocate_pirq(unsigned gsi, int shareable, char *name); +/* De-allocates the above mentioned physical interrupt. */ +int xen_destroy_irq(int irq); + /* Return vector allocated to pirq */ int xen_vector_from_irq(unsigned pirq); -- cgit v1.2.3-59-g8ed1b