Hi Bjorn,
Thank you very much for putting this series together !
On Thu, Dec 01, 2016 at 02:29:39AM -0600, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> The static MCFG table tells us the base of ECAM space, but it does not
> reserve the space -- the reservation should be done via a device in the
> ACPI namespace whose _CRS includes the ECAM region.
>
> Add pci_ecam_verify_reservation() to check whether the ECAM space is
> reserved by an ACPI namespace device. If it is, emit a message showing
> which device reserves it. If not, emit a "[Firmware Bug]" warning.
I have a question: do we want to carry out a search on a restricted set
of _HIDs here ? I am not sure we should consider an ECAM region matching
with a resource in a device _CRS whose _HID/_CID is not part of
{PNP0c02, PNP0A03, PNP0A08} as a success, actually I think that would be
a FW bug, right ?
Thanks,
Lorenzo
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/ecam.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> index 43ed08d..3805122 100644
> --- a/drivers/pci/ecam.c
> +++ b/drivers/pci/ecam.c
> @@ -14,6 +14,7 @@
> * version 2 (GPLv2) along with this source code.
> */
>
> +#include <linux/acpi.h>
> #include <linux/device.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> @@ -29,6 +30,24 @@
> */
> static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);
>
> +static void pci_ecam_verify_reservation(struct device *dev,
> + struct resource *ecam)
> +{
> +#ifdef CONFIG_ACPI
> + struct acpi_device *adev;
> +
> + adev = acpi_resource_consumer(ecam);
> + if (!adev) {
> + dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
> + ecam);
> + return;
> + }
> +
> + dev_info(dev, "ECAM area %pR reserved by %s\n", ecam,
> + dev_name(&adev->dev));
> +#endif
> +}
> +
> /*
> * Create a PCI config space window
> * - reserve mem region
> @@ -51,6 +70,8 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
> if (!cfg)
> return ERR_PTR(-ENOMEM);
>
> + pci_ecam_verify_reservation(dev, cfgres);
> +
> cfg->parent = dev;
> cfg->ops = ops;
> cfg->busr.start = busr->start;
>
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