diff options
author | Johannes Berg <johannes.berg@intel.com> | 2021-03-05 13:19:58 +0100 |
---|---|---|
committer | Richard Weinberger <richard@nod.at> | 2021-06-17 21:45:43 +0200 |
commit | 68f5d3f3b6543266b29e047cfaf9842333019b4c (patch) | |
tree | 29590aaf2cbe0669962f23576c3a0b106327aba9 /arch/um/include/asm/irq.h | |
parent | a5ab7c8467f1934236e33d5fa1c3c6de831a6648 (diff) |
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 <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/include/asm/irq.h')
-rw-r--r-- | arch/um/include/asm/irq.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/um/include/asm/irq.h b/arch/um/include/asm/irq.h index 3f5d3e8228fc..e187c789369d 100644 --- a/arch/um/include/asm/irq.h +++ b/arch/um/include/asm/irq.h @@ -31,7 +31,13 @@ #endif -#define NR_IRQS 64 +#define UM_LAST_SIGNAL_IRQ 64 +/* If we have (simulated) PCI MSI, allow 64 more interrupt numbers for it */ +#ifdef CONFIG_PCI_MSI +#define NR_IRQS (UM_LAST_SIGNAL_IRQ + 64) +#else +#define NR_IRQS UM_LAST_SIGNAL_IRQ +#endif /* CONFIG_PCI_MSI */ #include <asm-generic/irq.h> #endif |