Re: [PATCH 02/13] hw/ide/via: Implement ISA IRQ routing

[Bernhard Beschow]

Am 22. April 2023 17:23:56 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Sat, 22 Apr 2023, Bernhard Beschow wrote:
>> The VIA south bridge allows the legacy IDE interrupts to be routed to four
>> different ISA interrupts. This can be configured through the 0x4a register in
>> the PCI configuration space of the ISA function. The default routing matches
>> the legacy ISA IRQs, that is 14 and 15.
>
>On VT8231 0x4a is PCI Master Arbitration Control, IDE interrupt Routing is 
>0x4c and only documents 14/15 as valid values.

In the datasheet titled "VT8231 South Bridge", preliminary revision 0.8, Oct. 
29, 1999, page 60, the "IDE Interrupt Routing" register is located at offset 
0x4a and offers the same four interrupts in the same order as in the code. Are 
we looking at the same datasheet?

>Not sure any guest would actually change this or 0x4a and if that could cause 
>problems but you may need to handle this somehow. (Apart from testing with 
>MorphOS with -kernel you should really be testing with pegasos2.rom with 
>MorphOS and Linux, e.g. Debian 8.11 netinstall iso is known to boot.)

I've tested extensively with an x86 Linux guest on my pc-via branch which 
worked flawlessly.

As mentioned in the commit message the default routing of the chipset matches 
legacy behavior, that is interrupts 14 and 15. This is reflected by assigning 
[0x4a] = 4 in the code and that is how the code behaved before.

Best regards,
Bernhard

>
>Regards,
>BALATON Zoltan
>
>> Implement this missing piece of the VIA south bridge.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>> hw/ide/via.c      |  6 ++++--
>> hw/isa/vt82c686.c | 17 +++++++++++++++++
>> 2 files changed, 21 insertions(+), 2 deletions(-)
>> 
>> diff --git a/hw/ide/via.c b/hw/ide/via.c
>> index 177baea9a7..0caae52276 100644
>> --- a/hw/ide/via.c
>> +++ b/hw/ide/via.c
>> @@ -31,6 +31,7 @@
>> #include "sysemu/dma.h"
>> #include "hw/isa/vt82c686.h"
>> #include "hw/ide/pci.h"
>> +#include "hw/irq.h"
>> #include "trace.h"
>> 
>> static uint64_t bmdma_read(void *opaque, hwaddr addr,
>> @@ -104,7 +105,8 @@ static void bmdma_setup_bar(PCIIDEState *d)
>> 
>> static void via_ide_set_irq(void *opaque, int n, int level)
>> {
>> -    PCIDevice *d = PCI_DEVICE(opaque);
>> +    PCIIDEState *s = opaque;
>> +    PCIDevice *d = PCI_DEVICE(s);
>> 
>>     if (level) {
>>         d->config[0x70 + n * 8] |= 0x80;
>> @@ -112,7 +114,7 @@ static void via_ide_set_irq(void *opaque, int n, int 
>> level)
>>         d->config[0x70 + n * 8] &= ~0x80;
>>     }
>> 
>> -    via_isa_set_irq(pci_get_function_0(d), 14 + n, level);
>> +    qemu_set_irq(s->isa_irq[n], level);
>> }
>> 
>> static void via_ide_reset(DeviceState *dev)
>> diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c
>> index ca89119ce0..c7e29bb46a 100644
>> --- a/hw/isa/vt82c686.c
>> +++ b/hw/isa/vt82c686.c
>> @@ -568,9 +568,19 @@ static const VMStateDescription vmstate_via = {
>>     }
>> };
>> 
>> +static void via_isa_set_ide_irq(void *opaque, int n, int level)
>> +{
>> +    static const uint8_t irqs[] = { 14, 15, 10, 11 };
>> +    ViaISAState *s = opaque;
>> +    uint8_t irq = irqs[(s->dev.config[0x4a] >> (n * 2)) & 0x3];
>> +
>> +    qemu_set_irq(s->isa_irqs_in[irq], level);
>> +}
>> +
>> static void via_isa_init(Object *obj)
>> {
>>     ViaISAState *s = VIA_ISA(obj);
>> +    DeviceState *dev = DEVICE(s);
>> 
>>     object_initialize_child(obj, "rtc", &s->rtc, TYPE_MC146818_RTC);
>>     object_initialize_child(obj, "ide", &s->ide, TYPE_VIA_IDE);
>> @@ -578,6 +588,8 @@ static void via_isa_init(Object *obj)
>>     object_initialize_child(obj, "uhci2", &s->uhci[1], 
>> TYPE_VT82C686B_USB_UHCI);
>>     object_initialize_child(obj, "ac97", &s->ac97, TYPE_VIA_AC97);
>>     object_initialize_child(obj, "mc97", &s->mc97, TYPE_VIA_MC97);
>> +
>> +    qdev_init_gpio_in_named(dev, via_isa_set_ide_irq, "ide", 
>> ARRAY_SIZE(s->ide.isa_irq));
>> }
>> 
>> static const TypeInfo via_isa_info = {
>> @@ -692,6 +704,10 @@ static void via_isa_realize(PCIDevice *d, Error **errp)
>>     if (!qdev_realize(DEVICE(&s->ide), BUS(pci_bus), errp)) {
>>         return;
>>     }
>> +    for (i = 0; i < 2; i++) {
>> +        qdev_connect_gpio_out(DEVICE(&s->ide), i,
>> +                              qdev_get_gpio_in_named(DEVICE(s), "ide", i));
>> +    }
>> 
>>     /* Functions 2-3: USB Ports */
>>     for (i = 0; i < ARRAY_SIZE(s->uhci); i++) {
>> @@ -814,6 +830,7 @@ static void vt8231_isa_reset(DeviceState *dev)
>>                  PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL);
>>     pci_set_word(pci_conf + PCI_STATUS, PCI_STATUS_DEVSEL_MEDIUM);
>> 
>> +    pci_conf[0x4a] = 0x04; /* IDE interrupt Routing */
>>     pci_conf[0x58] = 0x40; /* Miscellaneous Control 0 */
>>     pci_conf[0x67] = 0x08; /* Fast IR Config */
>>     pci_conf[0x6b] = 0x01; /* Fast IR I/O Base */
>>