From 68f5d3f3b6543266b29e047cfaf9842333019b4c Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 5 Mar 2021 13:19:58 +0100 Subject: um: add PCI over virtio emulation driver To support testing of PCI/PCIe drivers in UML, add a PCI bus support driver. This driver uses virtio, which in UML is really just vhost-user, to talk to devices, and adds the devices to the virtual PCI bus in the system. Since virtio already allows DMA/bus mastering this really isn't all that hard, of course we need the logic_iomem infrastructure that was added by a previous patch. The protocol to talk to the device is has a few fairly simple messages for reading to/writing from config and IO spaces, and messages for the device to send the various interrupts (INT#, MSI/MSI-X and while suspended PME#). Note that currently no offical virtio device ID is assigned for this protocol, as a consequence this patch requires defining it in the Kconfig, with a default that makes the driver refuse to work at all. Finally, in order to add support for MSI/MSI-X interrupts, some small changes are needed in the UML IRQ code, it needs to have more interrupts, changing NR_IRQS from 64 to 128 if this driver is enabled, but not actually use them for anything so that the generic IRQ domain/MSI infrastructure can allocate IRQ numbers. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/kernel/irq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/um/kernel/irq.c') diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c index f3f19da7b876..a8873d9bc28b 100644 --- a/arch/um/kernel/irq.c +++ b/arch/um/kernel/irq.c @@ -56,7 +56,7 @@ struct irq_entry { static DEFINE_SPINLOCK(irq_lock); static LIST_HEAD(active_fds); -static DECLARE_BITMAP(irqs_allocated, NR_IRQS); +static DECLARE_BITMAP(irqs_allocated, UM_LAST_SIGNAL_IRQ); static bool irqs_suspended; static void irq_io_loop(struct irq_reg *irq, struct uml_pt_regs *regs) @@ -419,7 +419,8 @@ unsigned int do_IRQ(int irq, struct uml_pt_regs *regs) void um_free_irq(int irq, void *dev) { - if (WARN(irq < 0 || irq > NR_IRQS, "freeing invalid irq %d", irq)) + if (WARN(irq < 0 || irq > UM_LAST_SIGNAL_IRQ, + "freeing invalid irq %d", irq)) return; free_irq_by_irq_and_dev(irq, dev); @@ -648,7 +649,7 @@ void __init init_IRQ(void) irq_set_chip_and_handler(TIMER_IRQ, &alarm_irq_type, handle_edge_irq); - for (i = 1; i < NR_IRQS; i++) + for (i = 1; i < UM_LAST_SIGNAL_IRQ; i++) irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq); /* Initialize EPOLL Loop */ os_setup_epoll(); -- cgit v1.2.3