Re: [Qemu-devel] [PATCH v2] spapr-pci: Enable huge BARs

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 12/12/2014 08:38 PM, Alexey Kardashevskiy wrote:
> At the moment sPAPR only supports 512MB window for MMIO BARs. However
> modern devices might want bigger 64bit BARs.
> 
> This extends MMIO window from 512MB to 62GB (aligned to
> SPAPR_PCI_WINDOW_SPACING) and advertises it in 2 records in
> the PHB's "ranges" property. 32bit has all the space from
> SPAPR_PCI_MEM_WIN_BUS_OFFSET till the end of 4GB, 64bit has the rest
> of the window.
> 
> Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> Changes:
> v2:
> * do not change existing memory layout
> * do not create another mmio window
> ---
>  hw/ppc/spapr_pci.c          | 8 +++++++-
>  include/hw/pci-host/spapr.h | 7 ++++---
>  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 21b95b3..3641f87 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -862,6 +862,7 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
>      int bus_off, i, j;
>      char nodename[256];
>      uint32_t bus_range[] = { cpu_to_be32(0), cpu_to_be32(0xff) };
> +    const uint32_t win32size = (1ULL << 32) - SPAPR_PCI_MEM_WIN_BUS_OFFSET;
>      struct {
>          uint32_t hi;
>          uint64_t child;
> @@ -876,7 +877,12 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb,
>          {
>              cpu_to_be32(b_ss(2)), cpu_to_be64(SPAPR_PCI_MEM_WIN_BUS_OFFSET),
>              cpu_to_be64(phb->mem_win_addr),
> -            cpu_to_be64(memory_region_size(&phb->memwindow)),
> +            cpu_to_be64(win32size),
> +        },
> +        {
> +            cpu_to_be32(b_ss(3)), cpu_to_be64(1ULL << 32),
> +            cpu_to_be64(phb->mem_win_addr + win32size),
> +            cpu_to_be64(memory_region_size(&phb->memwindow) - win32size)
>          },
>      };
>      uint64_t bus_reg[] = { cpu_to_be64(phb->buid), 0 };
> diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
> index 4ea2a0d..dc0d870 100644
> --- a/include/hw/pci-host/spapr.h
> +++ b/include/hw/pci-host/spapr.h
> @@ -96,17 +96,18 @@ struct sPAPRPHBVFIOState {
>  
>  #define SPAPR_PCI_BASE_BUID          0x800000020000000ULL
>  
> +#define SPAPR_PCI_MEM_WIN_BUS_OFFSET 0x80000000ULL
> +
>  #define SPAPR_PCI_WINDOW_BASE        0x10000000000ULL
>  #define SPAPR_PCI_WINDOW_SPACING     0x1000000000ULL
>  #define SPAPR_PCI_MMIO_WIN_OFF       0xA0000000
> -#define SPAPR_PCI_MMIO_WIN_SIZE      0x20000000
> +#define SPAPR_PCI_MMIO_WIN_SIZE      (0x1000000000ULL - \
> +                                     SPAPR_PCI_MEM_WIN_BUS_OFFSET)

Uff, should have been:

+#define SPAPR_PCI_MMIO_WIN_SIZE      (SPAPR_PCI_WINDOW_SPACING - \
+                                     SPAPR_PCI_MEM_WIN_BUS_OFFSET)


>  #define SPAPR_PCI_IO_WIN_OFF         0x80000000
>  #define SPAPR_PCI_IO_WIN_SIZE        0x10000
>  
>  #define SPAPR_PCI_MSI_WINDOW         0x40000000000ULL
>  
> -#define SPAPR_PCI_MEM_WIN_BUS_OFFSET 0x80000000ULL
> -
>  static inline qemu_irq spapr_phb_lsi_qirq(struct sPAPRPHBState *phb, int pin)
>  {
>      return xics_get_qirq(spapr->icp, phb->lsi_table[pin].irq);
> 


-- 
Alexey