Hi Andre,
On 3/15/21 3:33 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".
Checked and that's indeed the address of the first UART.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> arm/include/arm-common/kvm-arch.h | 7 ++--
> hw/serial.c | 54 +++++++++++++++++++++----------
> 2 files changed, 42 insertions(+), 19 deletions(-)
>
> diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h
> index a2e32953..bf34d742 100644
> --- a/arm/include/arm-common/kvm-arch.h
> +++ b/arm/include/arm-common/kvm-arch.h
> @@ -13,8 +13,8 @@
> * 0 64K 16M 32M 48M 1GB 2GB
> * +-------+----+-------+-------+--------+-----+---------+---......
> * | PCI |////| plat | | | | |
> - * | I/O |////| MMIO | Flash | virtio | GIC | PCI | DRAM
> - * | space |////| | | MMIO | | (AXI) |
> + * | I/O |////| MMIO: | Flash | virtio | GIC | PCI | DRAM
> + * | space |////| UART | | MMIO | | (AXI) |
> * | |////| | | | | |
> * +-------+----+-------+-------+--------+-----+---------+---......
> */
> @@ -28,6 +28,9 @@
> #define ARM_IOPORT_SIZE (1U << 16)
>
>
> +#define ARM_UART_MMIO_BASE ARM_MMIO_AREA
> +#define ARM_UART_MMIO_SIZE 0x10000
> +
> #define KVM_FLASH_MMIO_BASE (ARM_MMIO_AREA + 0x1000000)
> #define KVM_FLASH_MAX_SIZE 0x1000000
>
> diff --git a/hw/serial.c b/hw/serial.c
> index 16af493b..3d533623 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) (ARM_UART_MMIO_BASE + (nr) * 0x1000)
> +#define serial_irq(nr) (32 + (nr))
> +#define SERIAL8250_BUS_TYPE DEVICE_BUS_MMIO
> +#else
> +#define serial_iobase_0 (KVM_IOPORT_AREA + 0x3f8)
> +#define serial_iobase_1 (KVM_IOPORT_AREA + 0x2f8)
> +#define serial_iobase_2 (KVM_IOPORT_AREA + 0x3e8)
> +#define serial_iobase_3 (KVM_IOPORT_AREA + 0x2e8)
> +#define serial_irq_0 4
> +#define serial_irq_1 3
> +#define serial_irq_2 4
> +#define serial_irq_3 3
> +#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
> },
> @@ -407,7 +425,7 @@ void serial8250_generate_fdt_node(void *fdt, struct device_header *dev_hdr,
> struct serial8250_device,
> dev_hdr);
>
> - u64 addr = KVM_IOPORT_AREA + dev->iobase;
> + u64 addr = dev->iobase;
> u64 reg_prop[] = {
> cpu_to_fdt64(addr),
> cpu_to_fdt64(8),
> @@ -440,7 +458,8 @@ 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;
> }
> @@ -463,7 +482,7 @@ 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);
> }
>
> @@ -479,7 +498,8 @@ 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);
Looks good to me:
Reviewed-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Thanks,
Alex
