Re: [PATCH] PCI: ACPI: IA64: fix IO port generic range check

[Hanjun Guo <hanjun.guo@linaro.org>]

On 2016/2/1 18:25, Lorenzo Pieralisi wrote:
> The [0 - 64k] ACPI PCI IO port resource boundary check in:
>
> acpi_dev_ioresource_flags()
>
> is currently applied blindly in the ACPI resource parsing to all
> architectures, but only x86 suffers from that IO space limitation.
> The check in generic ACPI code leaves other arches (ie IA64) IO space
> broken (ie kernel can't claim IO resources since the host bridge
> IO resource is disabled and discarded by ACPI core code, eg log on
> IA64):
>
> pci 0000:00:03.0: [1002:515e] type 00 class 0x030000
>
> pci 0000:00:03.0: reg 0x10: [mem 0x80000000-0x87ffffff pref]
>
> pci 0000:00:03.0: reg 0x14: [io  0x1000-0x10ff]
>
> pci 0000:00:03.0: reg 0x18: [mem 0x88020000-0x8802ffff]
>
> pci 0000:00:03.0: reg 0x30: [mem 0x88000000-0x8801ffff pref]
>
> pci 0000:00:03.0: supports D1 D2
>
> pci 0000:00:03.0: can't claim BAR 1 [io  0x1000-0x10ff]: no compatible
> bridge window
>
> For this reason, the IO port resources boundaries check in generic ACPI
> parsing code should be moved to x86 arch code so that more arches (ie
> ARM64) can benefit from the generic ACPI resources parsing interface
> without incurring in unexpected resource filtering, fixing at the same
> time current breakage on IA64.
>
> This patch moves the IO ports boundary [0 - 64k] check to x86 arch code
> code that validates the PCI host bridge resources.
>
> Fixes: 3772aea7d6f3 ("ia64/PCI/ACPI: Use common ACPI resource parsing
> interface for host bridge")
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Jiang Liu <jiang.liu@linux.intel.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Tomasz Nowicki <tn@semihalf.com>
> Cc: Mark Salter <msalter@redhat.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
>   arch/x86/pci/acpi.c     | 18 +++++++++++++-----
>   drivers/acpi/resource.c |  3 ---
>   2 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
> index 3cd6983..e20dbe5 100644
> --- a/arch/x86/pci/acpi.c
> +++ b/arch/x86/pci/acpi.c
> @@ -275,11 +275,14 @@ static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci)
>    *     to access PCI configuration space.
>    *
>    * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
> + *
> + * Furthermore, IO ports address space is limited to 16k on x86,

Minor typo for '16k', should be '64k'? or we can just specify
the magic number 0x10003?

By the way, I tested this patch both on x86 and ia64 box,
and PCI for both box is working properly after boot,

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>

Thanks
Hanjun