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>
2021-03-05 13:19:58 +01:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
|
|
|
#ifndef __ASM_UM_PCI_H
|
|
|
|
|
#define __ASM_UM_PCI_H
|
|
|
|
|
#include <linux/types.h>
|
|
|
|
|
#include <asm/io.h>
|
|
|
|
|
|
2022-07-23 06:49:44 +09:00
|
|
|
/* Generic PCI */
|
|
|
|
|
#include <asm-generic/pci.h>
|
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>
2021-03-05 13:19:58 +01:00
|
|
|
|
|
|
|
|
#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
|
|
|
|
|
/*
|
|
|
|
|
* This is a bit of an annoying hack, and it assumes we only have
|
|
|
|
|
* the virt-pci (if anything). Which is true, but still.
|
|
|
|
|
*/
|
|
|
|
|
void *pci_root_bus_fwnode(struct pci_bus *bus);
|
|
|
|
|
#define pci_root_bus_fwnode pci_root_bus_fwnode
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#endif /* __ASM_UM_PCI_H */
|