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SubjectRe: [Bugfix v5] x86/PCI/ACPI: Fix regression caused by commit 63f1789ec716

* Jiang Liu <jiang.liu@linux.intel.com> wrote:

> Before commit 593669c2ac0f("Use common ACPI resource interfaces to
> simplify implementation"), arch/x86/pci/acpi.c applies following

s/applies following
/applied the following

> rules when parsing ACPI resources for PCI host bridge:
> 1) Ignore IO port resources defined by acpi_resource_io and
> acpi_resource_fixed_io, which should be used to define resource
> for PCI device instead of PCI bridge.
> 2) Accept IOMEM resource defined by acpi_resource_memory24,
> acpi_resource_memory32 and acpi_resource_fixed_memory32.
> These IOMEM resources are accepted to workaround some BIOS issue,

s/workaround
/work around

It's a verb, not a noun.

> though they should be ignored. For example, PC Engines APU.1C

Please put the platform name into quotes to make it more clearly stand
apart from the rest of the text.

> platform defines PCI host bridge IOMEM resources as:
> Memory32Fixed (ReadOnly,
> 0x000A0000, // Address Base
> 0x00020000, // Address Length
> )
> Memory32Fixed (ReadOnly,
> 0x00000000, // Address Base
> 0x00000000, // Address Length
> _Y00)
> 3) Accept all IO port and IOMEM resources defined by
> acpi_resource_address{16,32,64,extended64}, no matter it's marked as
> ACPI_CONSUMER or ACPI_PRODUCER.

s/no matter it's marked
/regardless of whether it's marked

> Commit 593669c2ac0f("Use common ACPI resource interfaces to
> simplify implementation") accept all IO port and IOMEM resources

s/accept
/started accepting

> defined by acpi_resource_io, acpi_resource_fixed_io,
> acpi_resource_memory24, acpi_resource_memory32,
> acpi_resource_fixed_memory32 and
> acpi_resource_address{16,32,64,extended64}, which causes IO port
> resources consumed by host bridge itself are listed in to host bridge
> resource list.

this latter part of the sentence does not parse. Did you want to
write:

acpi_resource_address{16,32,64,extended64}, which causes IO port
resources consumed by the host bridge itself to be listed in the
host bridge resource list.

?

> Then commit 63f1789ec716("Ignore resources consumed by host bridge
> itself") ignores resources consumed by host bridge itself by checking

s/ignores
/started ignoring

s/by host bridge
/by the host bridge

> IORESOURCE_WINDOW flag, which accidently removed the workaround in 2)
> above for BIOS bug .

s/for BIOS bug .
/for the BIOS bug.

> So revert to the behavior before v3.19 to fix the regression.
>
> Sample ACPI table are archived at:
> https://bugzilla.kernel.org/show_bug.cgi?id=94221
>
> Fixes: 63f1789ec716("Ignore resources consumed by host bridge itself")
> Reported-and-Tested-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
> arch/x86/pci/acpi.c | 25 ++++++++++++++++++++++---
> drivers/acpi/resource.c | 6 +++++-
> 2 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index e4695985f9de..fc2da98985c3 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -332,12 +332,32 @@ static void probe_pci_root_info(struct pci_root_info *info,
> {
> int ret;
> struct resource_entry *entry, *tmp;
> + unsigned long res_flags;
>
> sprintf(info->name, "PCI Bus %04x:%02x", domain, busnum);
> info->bridge = device;
> +
> + /*
> + * An IO or MMIO resource assigned to PCI host bridge may be consumed

s/to PCI host bridge
/to a PCI host bridge

> + * by the host bridge itself or available to its child bus/devices.
> + * On x86 and IA64 platforms, all IO and MMIO resources are assumed to
> + * be available to child bus/devices except one special case:
> + * IO port [0xCF8-0xCFF] is consumed by host bridge itself to

s/by host bridge
/by the host bridge

> + * access PCI configuration space.
> + *
> + * Due to lack of specification to define resources consumed by host
> + * bridge itself, all IO port resources defined by acpi_resource_io

s/by host bridge
/by the host bridge

> + * and acpi_resource_fixed_io are ignored to filter out IO
> + * port[0xCF8-0xCFF]. Seems this solution works with all BIOSes, though
> + * it's not perfect.
> + *
> + * Another possible solution is to explicitly filter out IO

s/is to
/would be to

> + * port[0xCF8-0xCFF].
> + */
> + res_flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_IO_FIXED;
> ret = acpi_dev_get_resources(device, list,
> acpi_dev_filter_resource_type_cb,
> - (void *)(IORESOURCE_IO | IORESOURCE_MEM));
> + (void *)res_flags);
> if (ret < 0)
> dev_warn(&device->dev,
> "failed to parse _CRS method, error code %d\n", ret);
> @@ -346,8 +366,7 @@ static void probe_pci_root_info(struct pci_root_info *info,
> "no IO and memory resources present in _CRS\n");
> else
> resource_list_for_each_entry_safe(entry, tmp, list) {
> - if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||
> - (entry->res->flags & IORESOURCE_DISABLED))
> + if (entry->res->flags & IORESOURCE_DISABLED)
> resource_list_destroy_entry(entry);
> else
> entry->res->name = info->name;
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 5589a6e2a023..79b6d3b5ffd2 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -575,6 +575,9 @@ EXPORT_SYMBOL_GPL(acpi_dev_get_resources);
> *
> * This is a hepler function to support acpi_dev_get_resources(), which filters
> * ACPI resource objects according to resource types.
> + *
> + * Flag IORESOURCE_IO_FIXED is used to opt out io and fixed_io resource

s/Flag IORESOURCE_IO_FIXED is used to opt out io and fixed_io resource
The IORESOURCE_IO_FIXED flag is used to opt out IO and FIXED_IO resource

> + * descriptors for ACPI host bridges on x86 and IA64 platforms.
> */
> int acpi_dev_filter_resource_type(struct acpi_resource *ares,
> unsigned long types)
> @@ -589,7 +592,8 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares,
> break;
> case ACPI_RESOURCE_TYPE_IO:
> case ACPI_RESOURCE_TYPE_FIXED_IO:
> - type = IORESOURCE_IO;
> + if ((types & IORESOURCE_IO_FIXED) == 0)
> + type = IORESOURCE_IO;
> break;
> case ACPI_RESOURCE_TYPE_IRQ:
> case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> --
> 1.7.10.4
>

Thanks,

Ingo


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