Re: [PATCH v3 5/8] acpi/gpex: Append pxb devs in ascending order

[Igor Mammedov]

On Wed, 23 Dec 2020 17:08:33 +0800
Jiahui Cen <cenjiahui@huawei.com> wrote:

> The overlap check of IO resource window would fail when Linux kernel
> registers an IO resource [b, c) earlier than another resource [a, b).
> Though this incorrect check could be fixed by [1], it would be better to
> append pxb devs into DSDT table in ascending order.
> 
> [1]: https://lore.kernel.org/lkml/20201218062335.5320-1-cenjiahui@huawei.com/

considering there is acceptable fix for kernel I'd rather avoid
workarounds on QEMU side. So I suggest dropping this patch.

it also should reduce noise in [8/8] masking other changes.

> Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
> ---
>  hw/pci-host/gpex-acpi.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/pci-host/gpex-acpi.c b/hw/pci-host/gpex-acpi.c
> index 4bf1e94309..95a7a0f12b 100644
> --- a/hw/pci-host/gpex-acpi.c
> +++ b/hw/pci-host/gpex-acpi.c
> @@ -141,7 +141,7 @@ static void acpi_dsdt_add_pci_osc(Aml *dev)
>  void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig *cfg)
>  {
>      int nr_pcie_buses = cfg->ecam.size / PCIE_MMCFG_SIZE_MIN;
> -    Aml *method, *crs, *dev, *rbuf;
> +    Aml *method, *crs, *dev, *rbuf, *pxb_devs[nr_pcie_buses];
>      PCIBus *bus = cfg->bus;
>      CrsRangeSet crs_range_set;
>      CrsRangeEntry *entry;
> @@ -149,6 +149,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig 
> *cfg)
>  
>      /* start to construct the tables for pxb */
>      crs_range_set_init(&crs_range_set);
> +    memset(pxb_devs, 0, sizeof(pxb_devs));
>      if (bus) {
>          QLIST_FOREACH(bus, &bus->child, sibling) {
>              uint8_t bus_num = pci_bus_num(bus);
> @@ -190,7 +191,7 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig 
> *cfg)
>  
>              acpi_dsdt_add_pci_osc(dev);
>  
> -            aml_append(scope, dev);
> +            pxb_devs[bus_num] = dev;
>          }
>      }
>  
> @@ -278,5 +279,11 @@ void acpi_dsdt_add_gpex(Aml *scope, struct GPEXConfig 
> *cfg)
>      aml_append(dev, dev_res0);
>      aml_append(scope, dev);
>  
> +    for (i = 0; i < ARRAY_SIZE(pxb_devs); i++) {
> +        if (pxb_devs[i]) {
> +            aml_append(scope, pxb_devs[i]);
> +        }
> +    }
> +
>      crs_range_set_free(&crs_range_set);
>  }