Hi Andre, On 12/10/20 2:29 PM, Andre Przywara wrote: > Using the UART devices at their legacy I/O addresses as set by IBM in > 1981 was a kludge we used for simplicity on ARM platforms as well. > However this imposes problems due to their missing alignment and overlap > with the PCI I/O address space. > > Now that we can switch a device easily between using ioports and MMIO, > let's move the UARTs out of the first 4K of memory on ARM platforms. > > That should be transparent for well behaved guests, since the change is > naturally reflected in the device tree. Even "earlycon" keeps working, > as the stdout-path property is adjusted automatically. > > People providing direct earlycon parameters via the command line need to > adjust it to: "earlycon=uart,mmio,0x1000000". > > Signed-off-by: Andre Przywara <[email protected]> > --- > hw/serial.c | 52 ++++++++++++++++++++++++++++++++++++---------------- > 1 file changed, 36 insertions(+), 16 deletions(-) > > diff --git a/hw/serial.c b/hw/serial.c > index d840eebc..00fb3aa8 100644 > --- a/hw/serial.c > +++ b/hw/serial.c > @@ -13,6 +13,24 @@ > > #include <pthread.h> > > +#if defined(CONFIG_ARM) || defined(CONFIG_ARM64) > +#define serial_iobase(nr) (0x1000000 + (nr) * 0x1000) > +#define serial_irq(nr) (32 + (nr)) > +#define SERIAL8250_BUS_TYPE DEVICE_BUS_MMIO > +#else > +#define serial_iobase_0 0x3f8 > +#define serial_iobase_1 0x2f8 > +#define serial_iobase_2 0x3e8 > +#define serial_iobase_3 0x2e8 > +#define serial_irq_0 4 > +#define serial_irq_1 3 > +#define serial_irq_2 4 > +#define serial_irq_3 3
Nitpick: serial_iobase_* and serial_irq_* could be changed to have two leading underscores, to stress the fact that they are helpers for serial_iobase() and serial_irq() and are not meant to be used by themselves. But that's just personal preference, otherwise the patch looks really nice and clean: Reviewed-by: Alexandru Elisei <[email protected]> Thanks, Alex > +#define serial_iobase(nr) serial_iobase_##nr > +#define serial_irq(nr) serial_irq_##nr > +#define SERIAL8250_BUS_TYPE DEVICE_BUS_IOPORT > +#endif > + > /* > * This fakes a U6_16550A. The fifo len needs to be 64 as the kernel > * expects that for autodetection. > @@ -27,7 +45,7 @@ struct serial8250_device { > struct mutex mutex; > u8 id; > > - u16 iobase; > + u32 iobase; > u8 irq; > u8 irq_state; > int txcnt; > @@ -65,56 +83,56 @@ static struct serial8250_device devices[] = { > /* ttyS0 */ > [0] = { > .dev_hdr = { > - .bus_type = DEVICE_BUS_IOPORT, > + .bus_type = SERIAL8250_BUS_TYPE, > .data = serial8250_generate_fdt_node, > }, > .mutex = MUTEX_INITIALIZER, > > .id = 0, > - .iobase = 0x3f8, > - .irq = 4, > + .iobase = serial_iobase(0), > + .irq = serial_irq(0), > > SERIAL_REGS_SETTING > }, > /* ttyS1 */ > [1] = { > .dev_hdr = { > - .bus_type = DEVICE_BUS_IOPORT, > + .bus_type = SERIAL8250_BUS_TYPE, > .data = serial8250_generate_fdt_node, > }, > .mutex = MUTEX_INITIALIZER, > > .id = 1, > - .iobase = 0x2f8, > - .irq = 3, > + .iobase = serial_iobase(1), > + .irq = serial_irq(1), > > SERIAL_REGS_SETTING > }, > /* ttyS2 */ > [2] = { > .dev_hdr = { > - .bus_type = DEVICE_BUS_IOPORT, > + .bus_type = SERIAL8250_BUS_TYPE, > .data = serial8250_generate_fdt_node, > }, > .mutex = MUTEX_INITIALIZER, > > .id = 2, > - .iobase = 0x3e8, > - .irq = 4, > + .iobase = serial_iobase(2), > + .irq = serial_irq(2), > > SERIAL_REGS_SETTING > }, > /* ttyS3 */ > [3] = { > .dev_hdr = { > - .bus_type = DEVICE_BUS_IOPORT, > + .bus_type = SERIAL8250_BUS_TYPE, > .data = serial8250_generate_fdt_node, > }, > .mutex = MUTEX_INITIALIZER, > > .id = 3, > - .iobase = 0x2e8, > - .irq = 3, > + .iobase = serial_iobase(3), > + .irq = serial_irq(3), > > SERIAL_REGS_SETTING > }, > @@ -444,7 +462,8 @@ static int serial8250__device_init(struct kvm *kvm, > return r; > > ioport__map_irq(&dev->irq); > - r = kvm__register_pio(kvm, dev->iobase, 8, serial8250_mmio, dev); > + r = kvm__register_iotrap(kvm, dev->iobase, 8, serial8250_mmio, dev, > + SERIAL8250_BUS_TYPE); > > return r; > } > @@ -467,7 +486,7 @@ cleanup: > for (j = 0; j <= i; j++) { > struct serial8250_device *dev = &devices[j]; > > - kvm__deregister_pio(kvm, dev->iobase); > + kvm__deregister_iotrap(kvm, dev->iobase, SERIAL8250_BUS_TYPE); > device__unregister(&dev->dev_hdr); > } > > @@ -483,7 +502,8 @@ int serial8250__exit(struct kvm *kvm) > for (i = 0; i < ARRAY_SIZE(devices); i++) { > struct serial8250_device *dev = &devices[i]; > > - r = kvm__deregister_pio(kvm, dev->iobase); > + r = kvm__deregister_iotrap(kvm, dev->iobase, > + SERIAL8250_BUS_TYPE); > if (r < 0) > return r; > device__unregister(&dev->dev_hdr); _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
