From: Alex Nixon <alex.nixon@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Cc: Qing He <qing.he@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
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 cea0cd9..11cfde8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1925,6 +1925,11 @@ config PCI_OLPC
def_bool y
depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
+config PCI_XEN
+ def_bool n
+ depends on 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 0000000..449c82f
--- /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 a0207a7..effd96e 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 0000000..b19c873
--- /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 <hap9@xxxxxxxxxxxxxx>
+ */
+#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;
+}
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 7d46c84..1ccfa1b 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -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();
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index e97e11a..4e8002e 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -576,7 +576,9 @@ 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);
@@ -587,7 +589,13 @@ 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;
@@ -602,6 +610,26 @@ 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 d7a4ca7..c1717ca 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);
--
1.7.0.4
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