Re: [PATCH v4 11/11] hw/isa/vt82c686: Implement relocation and toggling of SuperI/O functions

[Bernhard Beschow]

Am 7. Januar 2024 13:59:44 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Sat, 6 Jan 2024, Bernhard Beschow wrote:
>> The VIA south bridges are able to relocate and toggle (enable or disable) 
>> their
>> SuperI/O functions. So far this is hardcoded such that all functions are 
>> always
>> enabled and are located at fixed addresses.
>> 
>> Some PC BIOSes seem to probe for I/O occupancy before activating such a 
>> function
>> and issue an error in case of a conflict. Since the functions are currently
>> enabled on reset, conflicts are always detected. Prevent that by implementing
>> relocation and toggling of the SuperI/O functions.
>> 
>> Note that all SuperI/O functions are now deactivated upon reset (except for
>> VT82C686B's serial ports where Fuloong 2e's rescue-yl seems to expect them 
>> to be
>> enabled by default). Rely on firmware to configure the functions accordingly.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>> hw/isa/vt82c686.c | 66 ++++++++++++++++++++++++++++++++++++++++-------
>> 1 file changed, 56 insertions(+), 10 deletions(-)
>> 
>> diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c
>> index d3e0f6d01f..9f62fb5964 100644
>> --- a/hw/isa/vt82c686.c
>> +++ b/hw/isa/vt82c686.c
>> @@ -15,6 +15,9 @@
>> 
>> #include "qemu/osdep.h"
>> #include "hw/isa/vt82c686.h"
>> +#include "hw/block/fdc.h"
>> +#include "hw/char/parallel-isa.h"
>> +#include "hw/char/serial.h"
>> #include "hw/pci/pci.h"
>> #include "hw/qdev-properties.h"
>> #include "hw/ide/pci.h"
>> @@ -323,6 +326,18 @@ static uint64_t via_superio_cfg_read(void *opaque, 
>> hwaddr addr, unsigned size)
>>     return val;
>> }
>> 
>> +static void via_superio_devices_enable(ViaSuperIOState *s, uint8_t data)
>> +{
>> +    ISASuperIOClass *ic = ISA_SUPERIO_GET_CLASS(s);
>> +    size_t i;
>
>The expected value for i is 0 or 1 (maybe up to 3 sometimes it there are more 
>serial ports in a chip). so why use such big type?

serial.count is of type size_t, that's why I chose it. Let me know if you still 
want an int, otherwise I'd leave it as is.

Best regards,
Bernhard

> This should just be int. Newly it's also allowed to declare it within the for 
> so if you want that you could do so but I have no preference on that and 
> declaring it here is also OK. Otherwise:
>
>Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
>
>> +
>> +    isa_parallel_set_enabled(s->superio.parallel[0], (data & 0x3) != 3);
>> +    for (i = 0; i < ic->serial.count; i++) {
>> +        isa_serial_set_enabled(s->superio.serial[i], data & BIT(i + 2));
>> +    }
>> +    isa_fdc_set_enabled(s->superio.floppy, data & BIT(4));
>> +}
>> +
>> static void via_superio_class_init(ObjectClass *klass, void *data)
>> {
>>     DeviceClass *dc = DEVICE_CLASS(klass);
>> @@ -368,7 +383,25 @@ static void vt82c686b_superio_cfg_write(void *opaque, 
>> hwaddr addr,
>>     case 0xfd ... 0xff:
>>         /* ignore write to read only registers */
>>         return;
>> -    /* case 0xe6 ... 0xe8: Should set base port of parallel and serial */
>> +    case 0xe2:
>> +        data &= 0x1f;
>> +        via_superio_devices_enable(sc, data);
>> +        break;
>> +    case 0xe3:
>> +        data &= 0xfc;
>> +        isa_fdc_set_iobase(sc->superio.floppy, data << 2);
>> +        break;
>> +    case 0xe6:
>> +        isa_parallel_set_iobase(sc->superio.parallel[0], data << 2);
>> +        break;
>> +    case 0xe7:
>> +        data &= 0xfe;
>> +        isa_serial_set_iobase(sc->superio.serial[0], data << 2);
>> +        break;
>> +    case 0xe8:
>> +        data &= 0xfe;
>> +        isa_serial_set_iobase(sc->superio.serial[1], data << 2);
>> +        break;
>>     default:
>>         qemu_log_mask(LOG_UNIMP,
>>                       "via_superio_cfg: unimplemented register 0x%x\n", idx);
>> @@ -395,9 +428,14 @@ static void vt82c686b_superio_reset(DeviceState *dev)
>>     /* Device ID */
>>     vt82c686b_superio_cfg_write(s, 0, 0xe0, 1);
>>     vt82c686b_superio_cfg_write(s, 1, 0x3c, 1);
>> -    /* Function select - all disabled */
>> +    /*
>> +     * Function select - only serial enabled
>> +     * Fuloong 2e's rescue-yl prints to the serial console w/o enabling it. 
>> This
>> +     * suggests that the serial ports are enabled by default, so override 
>> the
>> +     * datasheet.
>> +     */
>>     vt82c686b_superio_cfg_write(s, 0, 0xe2, 1);
>> -    vt82c686b_superio_cfg_write(s, 1, 0x03, 1);
>> +    vt82c686b_superio_cfg_write(s, 1, 0x0f, 1);
>>     /* Floppy ctrl base addr 0x3f0-7 */
>>     vt82c686b_superio_cfg_write(s, 0, 0xe3, 1);
>>     vt82c686b_superio_cfg_write(s, 1, 0xfc, 1);
>> @@ -465,6 +503,21 @@ static void vt8231_superio_cfg_write(void *opaque, 
>> hwaddr addr,
>>     case 0xfd:
>>         /* ignore write to read only registers */
>>         return;
>> +    case 0xf2:
>> +        data &= 0x17;
>> +        via_superio_devices_enable(sc, data);
>> +        break;
>> +    case 0xf4:
>> +        data &= 0xfe;
>> +        isa_serial_set_iobase(sc->superio.serial[0], data << 2);
>> +        break;
>> +    case 0xf6:
>> +        isa_parallel_set_iobase(sc->superio.parallel[0], data << 2);
>> +        break;
>> +    case 0xf7:
>> +        data &= 0xfc;
>> +        isa_fdc_set_iobase(sc->superio.floppy, data << 2);
>> +        break;
>>     default:
>>         qemu_log_mask(LOG_UNIMP,
>>                       "via_superio_cfg: unimplemented register 0x%x\n", idx);
>> @@ -513,12 +566,6 @@ static void vt8231_superio_init(Object *obj)
>>     VIA_SUPERIO(obj)->io_ops = &vt8231_superio_cfg_ops;
>> }
>> 
>> -static uint16_t vt8231_superio_serial_iobase(ISASuperIODevice *sio,
>> -                                             uint8_t index)
>> -{
>> -        return 0x2f8; /* FIXME: This should be settable via registers f2-f4 
>> */
>> -}
>> -
>> static void vt8231_superio_class_init(ObjectClass *klass, void *data)
>> {
>>     DeviceClass *dc = DEVICE_CLASS(klass);
>> @@ -526,7 +573,6 @@ static void vt8231_superio_class_init(ObjectClass 
>> *klass, void *data)
>> 
>>     dc->reset = vt8231_superio_reset;
>>     sc->serial.count = 1;
>> -    sc->serial.get_iobase = vt8231_superio_serial_iobase;
>>     sc->parallel.count = 1;
>>     sc->ide.count = 0; /* emulated by via-ide */
>>     sc->floppy.count = 1;
>>