| Message ID | 20200821002947.575838946@linutronix.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86, PCI, XEN, genirq ...: Prepare for device MSI | expand |
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@linutronix.de> > --- > 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
--- 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; x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs; pci_msi_ignore_mask = 1; #endif
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@linutronix.de> --- arch/x86/pci/xen.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)