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hw/pci/cxl: Create a CXL bus type

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The easiest way to differentiate a CXL bus, and a PCIE bus is using a
flag. A CXL bus, in hardware, is backward compatible with PCIE, and
therefore the code tries pretty hard to keep them in sync as much as
possible.

The other way to implement this would be to try to cast the bus to the
correct type. This is less code and useful for debugging via simply
looking at the flags.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220429144110.25167-13-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Ben Widawsky 2022-04-29 15:40:37 +01:00 committed by Michael S. Tsirkin
parent 25a2e524e3
commit 9dccb1216b
2 changed files with 15 additions and 1 deletions
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9
hw/pci-bridge/pci_expander_bridge.c
View File

@ -24,7 +24,7 @@
#include "hw/boards.h"
#include "qom/object.h"
enum BusType { PCI, PCIE };
enum BusType { PCI, PCIE, CXL };
#define TYPE_PXB_BUS "pxb-bus"
typedef struct PXBBus PXBBus;
@ -35,6 +35,10 @@ DECLARE_INSTANCE_CHECKER(PXBBus, PXB_BUS,
DECLARE_INSTANCE_CHECKER(PXBBus, PXB_PCIE_BUS,
TYPE_PXB_PCIE_BUS)
#define TYPE_PXB_CXL_BUS "pxb-cxl-bus"
DECLARE_INSTANCE_CHECKER(PXBBus, PXB_CXL_BUS,
TYPE_PXB_CXL_BUS)
struct PXBBus {
/*< private >*/
PCIBus parent_obj;
@ -251,6 +255,9 @@ static void pxb_dev_realize_common(PCIDevice *dev, enum BusType type,
ds = qdev_new(TYPE_PXB_HOST);
if (type == PCIE) {
bus = pci_root_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_PCIE_BUS);
} else if (type == CXL) {
bus = pci_root_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_CXL_BUS);
bus->flags |= PCI_BUS_CXL;
} else {
bus = pci_root_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
bds = qdev_new("pci-bridge");

7
include/hw/pci/pci_bus.h
View File

@ -24,6 +24,8 @@ enum PCIBusFlags {
PCI_BUS_IS_ROOT = 0x0001,
/* PCIe extended configuration space is accessible on this bus */
PCI_BUS_EXTENDED_CONFIG_SPACE = 0x0002,
/* This is a CXL Type BUS */
PCI_BUS_CXL = 0x0004,
};
struct PCIBus {
@ -53,6 +55,11 @@ struct PCIBus {
Notifier machine_done;
};
static inline bool pci_bus_is_cxl(PCIBus *bus)
{
return !!(bus->flags & PCI_BUS_CXL);
}
static inline bool pci_bus_is_root(PCIBus *bus)
{
return !!(bus->flags & PCI_BUS_IS_ROOT);