On 21.08.20 02:24, Thomas Gleixner wrote:
X86 cannot store the irq domain pointer in struct device without breaking
XEN because the irq domain pointer takes precedence over arch_*_msi_irqs()
fallbacks.
XENs MSI teardown relies on default_teardown_msi_irqs() which invokes
arch_teardown_msi_irq(). default_teardown_msi_irqs() is a trivial iterator
over the msi entries associated to a device.
Implement this loop in xen_teardown_msi_irqs() to prepare for removal of
the fallbacks for X86.
This is a preparatory step to wrap XEN MSI alloc/free into a irq domain
which in turn allows to store the irq domain pointer in struct device and
to use the irq domain functions directly.
Signed-off-by: Thomas Gleixner<tglx@xxxxxxxxxxxxx>
---
arch/x86/pci/xen.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -376,20 +376,31 @@ static void xen_initdom_restore_msi_irqs
static void xen_teardown_msi_irqs(struct pci_dev *dev)
{
struct msi_desc *msidesc;
+ int i;
+
+ for_each_pci_msi_entry(msidesc, dev) {
+ if (msidesc->irq) {
+ for (i = 0; i < msidesc->nvec_used; i++)
+ xen_destroy_irq(msidesc->irq + i);
+ }
+ }
+}
+
+static void xen_pv_teardown_msi_irqs(struct pci_dev *dev)
+{
+ struct msi_desc *msidesc = first_pci_msi_entry(dev);
- msidesc = first_pci_msi_entry(dev);
if (msidesc->msi_attrib.is_msix)
xen_pci_frontend_disable_msix(dev);
else
xen_pci_frontend_disable_msi(dev);
- /* Free the IRQ's and the msidesc using the generic code. */
- default_teardown_msi_irqs(dev);
+ xen_teardown_msi_irqs(dev);
}
static void xen_teardown_msi_irq(unsigned int irq)
{
- xen_destroy_irq(irq);
+ WARN_ON_ONCE(1);
}
#endif
@@ -412,7 +423,7 @@ int __init pci_xen_init(void)
#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;
+ x86_msi.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
pci_msi_ignore_mask = 1;
#endif
return 0;
@@ -436,6 +447,7 @@ static void __init xen_hvm_msi_init(void
}
x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
+ x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
}
#endif
@@ -472,6 +484,7 @@ int __init pci_xen_initial_domain(void)
#ifdef CONFIG_PCI_MSI
x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
+ x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
This should be xen_pv_teardown_msi_irqs, as pci_xen_initial_domain() is
called only for the pv initial domain case today.
x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
pci_msi_ignore_mask = 1;
#endif
Juergen
