[PATCH v2 12/12] hw/isa/vt82c686: Implement relocation and toggling of SuperI/O functions

[Bernhard Beschow <shentey@gmail.com>]

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 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 -- or in case of pegasos2 on board code if
no -bios is given -- to configure the functions accordingly.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
---
 hw/isa/vt82c686.c | 121 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 90 insertions(+), 31 deletions(-)

diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c
index 9c2333a277..be202d23cf 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"
@@ -343,6 +346,35 @@ static const TypeInfo via_superio_info = {
 
 #define TYPE_VT82C686B_SUPERIO "vt82c686b-superio"
 
+static void vt82c686b_superio_update(ViaSuperIOState *s)
+{
+    isa_parallel_set_enabled(s->superio.parallel[0],
+                             (s->regs[0xe2] & 0x3) != 3);
+    isa_serial_set_enabled(s->superio.serial[0], s->regs[0xe2] & BIT(2));
+    isa_serial_set_enabled(s->superio.serial[1], s->regs[0xe2] & BIT(3));
+    isa_fdc_set_enabled(s->superio.floppy, s->regs[0xe2] & BIT(4));
+
+    isa_fdc_set_iobase(s->superio.floppy, (s->regs[0xe3] & 0xfc) << 2);
+    isa_parallel_set_iobase(s->superio.parallel[0], s->regs[0xe6] << 2);
+    isa_serial_set_iobase(s->superio.serial[0], (s->regs[0xe7] & 0xfe) << 2);
+    isa_serial_set_iobase(s->superio.serial[1], (s->regs[0xe8] & 0xfe) << 2);
+}
+
+static int vmstate_vt82c686b_superio_post_load(void *opaque, int version_id)
+{
+    ViaSuperIOState *s = opaque;
+
+    vt82c686b_superio_update(s);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_vt82c686b_superio = {
+    .name = "vt82c686b_superio",
+    .version_id = 1,
+    .post_load = vmstate_vt82c686b_superio_post_load,
+};
+
 static void vt82c686b_superio_cfg_write(void *opaque, hwaddr addr,
                                         uint64_t data, unsigned size)
 {
@@ -368,7 +400,11 @@ 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 ... 0xe3:
+    case 0xe6 ... 0xe8:
+        sc->regs[idx] = data;
+        vt82c686b_superio_update(sc);
+        return;
     default:
         qemu_log_mask(LOG_UNIMP,
                       "via_superio_cfg: unimplemented register 0x%x\n", idx);
@@ -393,25 +429,24 @@ static void vt82c686b_superio_reset(DeviceState *dev)
 
     memset(s->regs, 0, sizeof(s->regs));
     /* Device ID */
-    vt82c686b_superio_cfg_write(s, 0, 0xe0, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0x3c, 1);
-    /* Function select - all disabled */
-    vt82c686b_superio_cfg_write(s, 0, 0xe2, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0x03, 1);
+    s->regs[0xe0] = 0x3c;
+    /*
+     * 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.
+     */
+    s->regs[0xe2] = 0x0f;
     /* Floppy ctrl base addr 0x3f0-7 */
-    vt82c686b_superio_cfg_write(s, 0, 0xe3, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0xfc, 1);
+    s->regs[0xe3] = 0xfc;
     /* Parallel port base addr 0x378-f */
-    vt82c686b_superio_cfg_write(s, 0, 0xe6, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0xde, 1);
+    s->regs[0xe6] = 0xde;
     /* Serial port 1 base addr 0x3f8-f */
-    vt82c686b_superio_cfg_write(s, 0, 0xe7, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0xfe, 1);
+    s->regs[0xe7] = 0xfe;
     /* Serial port 2 base addr 0x2f8-f */
-    vt82c686b_superio_cfg_write(s, 0, 0xe8, 1);
-    vt82c686b_superio_cfg_write(s, 1, 0xbe, 1);
+    s->regs[0xe8] = 0xbe;
 
-    vt82c686b_superio_cfg_write(s, 0, 0, 1);
+    vt82c686b_superio_update(s);
 }
 
 static void vt82c686b_superio_init(Object *obj)
@@ -429,6 +464,7 @@ static void vt82c686b_superio_class_init(ObjectClass *klass, void *data)
     sc->parallel.count = 1;
     sc->ide.count = 0; /* emulated by via-ide */
     sc->floppy.count = 1;
+    dc->vmsd = &vmstate_vt82c686b_superio;
 }
 
 static const TypeInfo vt82c686b_superio_info = {
@@ -443,6 +479,33 @@ static const TypeInfo vt82c686b_superio_info = {
 
 #define TYPE_VT8231_SUPERIO "vt8231-superio"
 
+static void vt8231_superio_update(ViaSuperIOState *s)
+{
+    isa_parallel_set_enabled(s->superio.parallel[0],
+                             (s->regs[0xf2] & 0x3) != 3);
+    isa_serial_set_enabled(s->superio.serial[0], s->regs[0xf2] & BIT(2));
+    isa_fdc_set_enabled(s->superio.floppy, s->regs[0xf2] & BIT(4));
+
+    isa_serial_set_iobase(s->superio.serial[0], (s->regs[0xf4] & 0xfe) << 2);
+    isa_parallel_set_iobase(s->superio.parallel[0], s->regs[0xf6] << 2);
+    isa_fdc_set_iobase(s->superio.floppy, (s->regs[0xf7] & 0xfc) << 2);
+}
+
+static int vmstate_vt8231_superio_post_load(void *opaque, int version_id)
+{
+    ViaSuperIOState *s = opaque;
+
+    vt8231_superio_update(s);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_vt8231_superio = {
+    .name = "vt8231_superio",
+    .version_id = 1,
+    .post_load = vmstate_vt8231_superio_post_load,
+};
+
 static void vt8231_superio_cfg_write(void *opaque, hwaddr addr,
                                      uint64_t data, unsigned size)
 {
@@ -465,6 +528,12 @@ static void vt8231_superio_cfg_write(void *opaque, hwaddr addr,
     case 0xfd:
         /* ignore write to read only registers */
         return;
+    case 0xf2:
+    case 0xf4:
+    case 0xf6 ... 0xf7:
+        sc->regs[idx] = data;
+        vt8231_superio_update(sc);
+        return;
     default:
         qemu_log_mask(LOG_UNIMP,
                       "via_superio_cfg: unimplemented register 0x%x\n", idx);
@@ -493,19 +562,15 @@ static void vt8231_superio_reset(DeviceState *dev)
     /* Device revision */
     s->regs[0xf1] = 0x01;
     /* Function select - all disabled */
-    vt8231_superio_cfg_write(s, 0, 0xf2, 1);
-    vt8231_superio_cfg_write(s, 1, 0x03, 1);
+    s->regs[0xf2] = 0x03;
     /* Serial port base addr */
-    vt8231_superio_cfg_write(s, 0, 0xf4, 1);
-    vt8231_superio_cfg_write(s, 1, 0xfe, 1);
+    s->regs[0xf4] = 0xfe;
     /* Parallel port base addr */
-    vt8231_superio_cfg_write(s, 0, 0xf6, 1);
-    vt8231_superio_cfg_write(s, 1, 0xde, 1);
+    s->regs[0xf6] = 0xde;
     /* Floppy ctrl base addr */
-    vt8231_superio_cfg_write(s, 0, 0xf7, 1);
-    vt8231_superio_cfg_write(s, 1, 0xfc, 1);
+    s->regs[0xf7] = 0xfc;
 
-    vt8231_superio_cfg_write(s, 0, 0, 1);
+    vt8231_superio_update(s);
 }
 
 static void vt8231_superio_init(Object *obj)
@@ -513,12 +578,6 @@ 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);
@@ -526,10 +585,10 @@ 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;
+    dc->vmsd = &vmstate_vt8231_superio;
 }
 
 static const TypeInfo vt8231_superio_info = {
-- 
2.43.0