On 9/15/21 12:10 PM, Mark Cave-Ayland wrote:
> Convert nubus_device_realize() to use a bitmap to manage available slots to
> allow
> for future Nubus devices to be plugged into arbitrary slots from the command
> line.
>
> Update mac_nubus_bridge_init() to only allow slots 0x9 to 0xe on a Macintosh
> machines as documented in "Desigining Cards and Drivers for the Macintosh
> Family".
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
> ---
> hw/nubus/mac-nubus-bridge.c | 3 +++
> hw/nubus/nubus-bus.c | 2 +-
> hw/nubus/nubus-device.c | 33 +++++++++++++++++++++++++++------
> include/hw/nubus/nubus.h | 4 ++--
> 4 files changed, 33 insertions(+), 9 deletions(-)
> static void nubus_class_init(ObjectClass *oc, void *data)
> diff --git a/hw/nubus/nubus-device.c b/hw/nubus/nubus-device.c
> index c1832f73da..f9f614cc01 100644
> --- a/hw/nubus/nubus-device.c
> +++ b/hw/nubus/nubus-device.c
> @@ -160,14 +160,35 @@ static void nubus_device_realize(DeviceState *dev,
> Error **errp)
> NubusDevice *nd = NUBUS_DEVICE(dev);
> char *name;
> hwaddr slot_offset;
> -
> - if (nubus->current_slot < NUBUS_FIRST_SLOT ||
> - nubus->current_slot > NUBUS_LAST_SLOT) {
> - error_setg(errp, "Cannot register nubus card, not enough slots");
> - return;
> + uint16_t s;
> +
> + if (nd->slot == -1) {
> + /* No slot specified, find first available free slot */
> + s = ctz32(nubus->slot_available_mask);
> + if (s != 32) {
> + nd->slot = s;
Can't we have s >= NUBUS_LAST_SLOT here?
> + } else {
> + error_setg(errp, "Cannot register nubus card, no free slot "
> + "available");
> + return;
> + }
> + } else {
If so, maybe better to move this code <...
> + /* Slot specified, make sure the slot is available */
> + if (nd->slot < NUBUS_FIRST_SLOT || nd->slot > NUBUS_LAST_SLOT) {
> + error_setg(errp, "Cannot register nubus card, slot must be "
> + "between %d and %d", NUBUS_FIRST_SLOT,
> + NUBUS_LAST_SLOT);
> + return;
> + }
...> ...
> +
> + if (!(nubus->slot_available_mask & (1UL << nd->slot))) {
> + error_setg(errp, "Cannot register nubus card, slot %d is "
> + "unavailable or already occupied", nd->slot);
> + return;
> + }
> }
... here?
>
> - nd->slot = nubus->current_slot++;
> + nubus->slot_available_mask &= ~(1UL << nd->slot);
>
> /* Super */
> slot_offset = (nd->slot - 6) * NUBUS_SUPER_SLOT_SIZE;
> diff --git a/include/hw/nubus/nubus.h b/include/hw/nubus/nubus.h
> index 357f621d15..8ff4736259 100644
> --- a/include/hw/nubus/nubus.h
> +++ b/include/hw/nubus/nubus.h
> @@ -19,7 +19,7 @@
> #define NUBUS_SLOT_SIZE 0x01000000
> #define NUBUS_SLOT_NB 0xF
>
> -#define NUBUS_FIRST_SLOT 0x9
> +#define NUBUS_FIRST_SLOT 0x0
> #define NUBUS_LAST_SLOT 0xF
>
> #define TYPE_NUBUS_DEVICE "nubus-device"
> @@ -36,7 +36,7 @@ struct NubusBus {
> MemoryRegion super_slot_io;
> MemoryRegion slot_io;
>
> - int current_slot;
> + uint32_t slot_available_mask;
> };
>
> struct NubusDevice {
>
