On Thu, 18 Feb 2021 12:18:38 +0000 Alexandru Elisei <[email protected]> wrote:
> Hi Andre, > > On 2/17/21 4:48 PM, Alexandru Elisei wrote: > > 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]> > > I gave it more thought and I think I spoke too soon. I think it would be good > to > document in the commit message how you came to the base MMIO address and size > (even if it was just a nice looking number). Also, the CFI flash device has > its > memory range described in the memory layout for the architecture, in > arm/include/arm-common/kvm-arch.h. I think it would be a good idea to put the > serial region there, to prevent regressions in the future. Yes, that's very true, the memory map should be described in one place only. Will try to do that. > > I did the math to make sure there's no overlap with the ioport region (16M >> > 16K) > or the flash region (16M + 0x4000 < 32M). I also tested the changes with a > kernel > with 4K and 64K pages (I can't access any hardware with 16K pages at the > moment), > and everything worked as expected. Thanks! Andre > >> +#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 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
