Commit 7d4d892d authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/xen: Rework MSI teardown 



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: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20200826112333.326841410@linutronix.de
parent 2905c50b

arch/x86/pci/xen.c

+18 −5
Original line number Diff line number Diff line
@@ -377,20 +377,31 @@ static void xen_initdom_restore_msi_irqs(struct pci_dev *dev) 
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
@@ -413,7 +424,7 @@ 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;
@@ -437,6 +448,7 @@ 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
@@ -473,6 +485,7 @@ 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_pv_msi_irqs;

	x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;

	pci_msi_ignore_mask = 1;

#endif

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