On Sun, 30 Jun 2019, Mark Cave-Ayland wrote:
On 28/06/2019 19:59, BALATON Zoltan wrote:
QEMU mac99 emulates two of the three PCI buses found on real PowerMac3,1 but OpenBIOS only handles a single PCI bus and initialises and puts info in the device tree of the second PCI bus only which is where devices are connected and calls it bus 0. However, some clients may not know about this or have hardcoded assumptions and erroneously use the address of the first bus to access PCI config registers for devices on the second bus which silently fails as these requests will go to the other empty bus emulated and return invalid values. Devices mapped via MMIO still appear to work but they may not be correctly initialised and some cards are not detected because of this.
Until support for multiple PCI buses is implemented add an empty node in the device tree for the uninitialised bus to let clients know about it. This fixes detecting PCI devices (such as USB) under MorphOS and may also fix enabling the bus master bit needed with some network cards and allow the workarund for that to be reverted.
Signed-off-by: BALATON Zoltan balaton@eik.bme.hu
arch/ppc/qemu/init.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)
diff --git a/arch/ppc/qemu/init.c b/arch/ppc/qemu/init.c index f72728c..a996404 100644 --- a/arch/ppc/qemu/init.c +++ b/arch/ppc/qemu/init.c @@ -716,6 +716,46 @@ static void kvm_of_init(void) fword("finish-device"); }
+static void empty_pci_bus_init(void) +{
- if (machine_id == ARCH_MAC99) {
activate_device("/");fword("new-device");push_str("pci");fword("device-name");push_str("pci");fword("device-type");PUSH(0xf0000000);fword("encode-int");PUSH(0x02000000);fword("encode-int");fword("encode+");push_str("reg");fword("property");PUSH(3);fword("encode-int");push_str("#address-cells");fword("property");PUSH(2);fword("encode-int");push_str("#size-cells");fword("property");PUSH(1);fword("encode-int");push_str("#interrupt-cells");fword("property");PUSH(0);fword("encode-int");PUSH(0);fword("encode-int");fword("encode+");push_str("bus-range");fword("property");fword("finish-device");device_end();- }
+}
/*
- filll ( addr bytes quad -- )
*/ @@ -859,7 +899,17 @@ arch_of_init(void) feval("['] ppc-dma-sync to (dma-sync)");
#ifdef CONFIG_DRIVER_PCI
- /* Add empty node for first pci bus on MAC99 */
- /* Remove this when pci driver is fixed to handle multiple buses */
- empty_pci_bus_init(); ob_pci_init();
- if (machine_id == ARCH_MAC99) {
phandle_t dev = find_dev("/pci@f2000000");if (dev) {u32 props[2] = {0, 1};set_property(dev, "bus-range", (char *)props, 2 * sizeof(props[0]));}- }
#endif
printk("\n");Patching in the bus-range property after the PCI bus enumeration isn't the right way to do this: as per my previous email, the right solution here is to allow the PCI bus enumeration to start with a non-zero bus id.
Then please implement that as I don't know how to do that. The result would be the same so I don't see why this is not acceptable now. This is only touching the qemu init.c and only for MAC99 whereas your suggestion would need changes all over the place that would have a higher chance of breaking something that I can't even test so I won't attempt doing that. If your priorities are to avoid breaking stuff and have device tree corresponding to the real machine then this patch seems to be the easiest way to reach those goals. What is it that you still don't like about this?
Regards, BALATON Zoltan