Re: [PATCH 4/4] hw/riscv: virt: Map high mmio for PCIe

[Alistair Francis]

On Fri, Jan 22, 2021 at 4:35 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Bin Meng <bin.meng@windriver.com>
>
> Some peripherals require 64-bit PCI address, so let's map the high
> mmio space for PCIe.
>
> For RV32, the address is hardcoded to below 4 GiB from the highest
> accessible physical address. For RV64, the base address depends on
> top of RAM and is aligned to its size which is using 16 GiB for now.
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

>
> ---
>
>  hw/riscv/virt.c | 36 ++++++++++++++++++++++++++++++++++--
>  1 file changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 4f44509360..4ab3b35cc7 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -59,6 +59,15 @@ static const MemMapEntry virt_memmap[] = {
>      [VIRT_DRAM] =        { 0x80000000,           0x0 },
>  };
>
> +/* PCIe high mmio is fixed for RV32 */
> +#define VIRT32_HIGH_PCIE_MMIO_BASE  0x300000000ULL
> +#define VIRT32_HIGH_PCIE_MMIO_SIZE  (4 * GiB)
> +
> +/* PCIe high mmio for RV64, size is fixed but base depends on top of RAM */
> +#define VIRT64_HIGH_PCIE_MMIO_SIZE  (16 * GiB)
> +
> +static MemMapEntry virt_high_pcie_memmap;
> +
>  #define VIRT_FLASH_SECTOR_SIZE (256 * KiB)
>
>  static PFlashCFI01 *virt_flash_create1(RISCVVirtState *s,
> @@ -371,7 +380,11 @@ static void create_fdt(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>          2, memmap[VIRT_PCIE_PIO].base, 2, memmap[VIRT_PCIE_PIO].size,
>          1, FDT_PCI_RANGE_MMIO,
>          2, memmap[VIRT_PCIE_MMIO].base,
> -        2, memmap[VIRT_PCIE_MMIO].base, 2, memmap[VIRT_PCIE_MMIO].size);
> +        2, memmap[VIRT_PCIE_MMIO].base, 2, memmap[VIRT_PCIE_MMIO].size,
> +        1, FDT_PCI_RANGE_MMIO_64BIT,
> +        2, virt_high_pcie_memmap.base,
> +        2, virt_high_pcie_memmap.base, 2, virt_high_pcie_memmap.size);
> +
>      create_pcie_irq_map(fdt, name, plic_pcie_phandle);
>      g_free(name);
>
> @@ -448,12 +461,14 @@ update_bootargs:
>  static inline DeviceState *gpex_pcie_init(MemoryRegion *sys_mem,
>                                            hwaddr ecam_base, hwaddr ecam_size,
>                                            hwaddr mmio_base, hwaddr mmio_size,
> +                                          hwaddr high_mmio_base,
> +                                          hwaddr high_mmio_size,
>                                            hwaddr pio_base,
>                                            DeviceState *plic)
>  {
>      DeviceState *dev;
>      MemoryRegion *ecam_alias, *ecam_reg;
> -    MemoryRegion *mmio_alias, *mmio_reg;
> +    MemoryRegion *mmio_alias, *high_mmio_alias, *mmio_reg;
>      qemu_irq irq;
>      int i;
>
> @@ -473,6 +488,13 @@ static inline DeviceState *gpex_pcie_init(MemoryRegion 
> *sys_mem,
>                               mmio_reg, mmio_base, mmio_size);
>      memory_region_add_subregion(get_system_memory(), mmio_base, mmio_alias);
>
> +    /* Map high MMIO space */
> +    high_mmio_alias = g_new0(MemoryRegion, 1);
> +    memory_region_init_alias(high_mmio_alias, OBJECT(dev), "pcie-mmio-high",
> +                             mmio_reg, high_mmio_base, high_mmio_size);
> +    memory_region_add_subregion(get_system_memory(), high_mmio_base,
> +                                high_mmio_alias);
> +
>      sysbus_mmio_map(SYS_BUS_DEVICE(dev), 2, pio_base);
>
>      for (i = 0; i < GPEX_NUM_IRQS; i++) {
> @@ -601,6 +623,14 @@ static void virt_machine_init(MachineState *machine)
>              machine->ram_size = 10 * GiB;
>              error_report("Limitting RAM size to 10 GiB");
>          }
> +
> +        virt_high_pcie_memmap.base = VIRT32_HIGH_PCIE_MMIO_BASE;
> +        virt_high_pcie_memmap.size = VIRT32_HIGH_PCIE_MMIO_SIZE;
> +    } else {
> +        virt_high_pcie_memmap.size = VIRT64_HIGH_PCIE_MMIO_SIZE;
> +        virt_high_pcie_memmap.base = memmap[VIRT_DRAM].base + 
> machine->ram_size;
> +        virt_high_pcie_memmap.base =
> +            ROUND_UP(virt_high_pcie_memmap.base, virt_high_pcie_memmap.size);
>      }
>
>      /* register system main memory (actual RAM) */
> @@ -686,6 +716,8 @@ static void virt_machine_init(MachineState *machine)
>                     memmap[VIRT_PCIE_ECAM].size,
>                     memmap[VIRT_PCIE_MMIO].base,
>                     memmap[VIRT_PCIE_MMIO].size,
> +                   virt_high_pcie_memmap.base,
> +                   virt_high_pcie_memmap.size,
>                     memmap[VIRT_PCIE_PIO].base,
>                     DEVICE(pcie_plic));
>
> --
> 2.25.1
>
>