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 <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Qing He <qing.he@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
This commit is contained in:
Alex Nixon 2010-03-18 16:31:34 -04:00 committed by Konrad Rzeszutek Wilk
parent 294ee6f89c
commit b5401a96b5
7 changed files with 242 additions and 2 deletions

View file

@ -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

View file

@ -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 */

View file

@ -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

147
arch/x86/pci/xen.c Normal file
View file

@ -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 <hap9@epoch.ncsc.mil>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <asm/pci_x86.h>
#include <asm/xen/hypervisor.h>
#include <xen/events.h>
#include <asm/xen/pci.h>
#if defined(CONFIG_PCI_MSI)
#include <linux/msi.h>
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;
}

View file

@ -45,6 +45,7 @@
#include <asm/paravirt.h>
#include <asm/apic.h>
#include <asm/page.h>
#include <asm/xen/pci.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <asm/fixmap.h>
@ -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();

View file

@ -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 @@ int xen_allocate_pirq(unsigned gsi, int shareable, char *name)
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);

View file

@ -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);