From: David Woodhouse Date: Wed, 18 Jan 2023 12:22:38 +0000 (+0000) Subject: xen: Allow platform PCI interrupt to be shared X-Git-Tag: v6.6.17~5259^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3e8cd711c3da6c3d724076048038cd666bdbb2b5;p=platform%2Fkernel%2Flinux-rpi.git xen: Allow platform PCI interrupt to be shared When we don't use the per-CPU vector callback, we ask Xen to deliver event channel interrupts as INTx on the PCI platform device. As such, it can be shared with INTx on other PCI devices. Set IRQF_SHARED, and make it return IRQ_HANDLED or IRQ_NONE according to whether the evtchn_upcall_pending flag was actually set. Now I can share the interrupt: 11: 82 0 IO-APIC 11-fasteoi xen-platform-pci, ens4 Drop the IRQF_TRIGGER_RISING. It has no effect when the IRQ is shared, and besides, the only effect it was having even beforehand was to trigger a debug message in both I/OAPIC and legacy PIC cases: [ 0.915441] genirq: No set_type function for IRQ 11 (IO-APIC) [ 0.951939] genirq: No set_type function for IRQ 11 (XT-PIC) Signed-off-by: David Woodhouse Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/f9a29a68d05668a3636dd09acd94d970269eaec6.camel@infradead.org Signed-off-by: Juergen Gross --- diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index c443f04..c7715f8 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1710,9 +1710,10 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl) generic_handle_irq(irq); } -static void __xen_evtchn_do_upcall(void) +static int __xen_evtchn_do_upcall(void) { struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); + int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE; int cpu = smp_processor_id(); struct evtchn_loop_ctrl ctrl = { 0 }; @@ -1737,6 +1738,8 @@ static void __xen_evtchn_do_upcall(void) * above. */ __this_cpu_inc(irq_epoch); + + return ret; } void xen_evtchn_do_upcall(struct pt_regs *regs) @@ -1751,9 +1754,9 @@ void xen_evtchn_do_upcall(struct pt_regs *regs) set_irq_regs(old_regs); } -void xen_hvm_evtchn_do_upcall(void) +int xen_hvm_evtchn_do_upcall(void) { - __xen_evtchn_do_upcall(); + return __xen_evtchn_do_upcall(); } EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall); diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c index cd07e3f..fcc8191 100644 --- a/drivers/xen/platform-pci.c +++ b/drivers/xen/platform-pci.c @@ -64,14 +64,13 @@ static uint64_t get_callback_via(struct pci_dev *pdev) static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id) { - xen_hvm_evtchn_do_upcall(); - return IRQ_HANDLED; + return xen_hvm_evtchn_do_upcall(); } static int xen_allocate_irq(struct pci_dev *pdev) { return request_irq(pdev->irq, do_hvm_evtchn_intr, - IRQF_NOBALANCING | IRQF_TRIGGER_RISING, + IRQF_NOBALANCING | IRQF_SHARED, "xen-platform-pci", pdev); } diff --git a/include/xen/events.h b/include/xen/events.h index 344081e..44c2855 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -107,7 +107,7 @@ evtchn_port_t evtchn_from_irq(unsigned irq); int xen_set_callback_via(uint64_t via); void xen_evtchn_do_upcall(struct pt_regs *regs); -void xen_hvm_evtchn_do_upcall(void); +int xen_hvm_evtchn_do_upcall(void); /* Bind a pirq for a physical interrupt to an irq. */ int xen_bind_pirq_gsi_to_irq(unsigned gsi,