Re: [PATCHv2] PCI: QDF2432 32 bit config space accessors

From: Bjorn Helgaas
Date: Mon Oct 31 2016 - 17:50:10 EST


On Wed, Sep 21, 2016 at 06:38:05PM -0400, Christopher Covington wrote:
> The Qualcomm Technologies QDF2432 SoC does not support accesses smaller
> than 32 bits to the PCI configuration space. Register the appropriate
> quirk.
>
> Signed-off-by: Christopher Covington <cov@xxxxxxxxxxxxxx>

Hi Christopher,

Can you rebase this against v4.9-rc1? It no longer applies to my tree.

Note that this hardware is not spec-compliant since it doesn't support
sub-32 bit config writes. I just proposed a patch to warn about that
[1], so if/when we merge that patch and this one, you'll start seeing
those warnings.

[1] http://lkml.kernel.org/r/20161031213902.6340.96123.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

> ---
> drivers/acpi/pci_mcfg.c | 8 ++++++++
> drivers/pci/ecam.c | 10 ++++++++++
> include/linux/pci-ecam.h | 1 +
> 3 files changed, 19 insertions(+)
>
> diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
> index 245b79f..212334f 100644
> --- a/drivers/acpi/pci_mcfg.c
> +++ b/drivers/acpi/pci_mcfg.c
> @@ -96,6 +96,14 @@ static struct mcfg_fixup mcfg_quirks[] = {
> THUNDER_ECAM_MCFG(2, 12),
> THUNDER_ECAM_MCFG(2, 13),
> #endif
> + { "QCOM ", "QDF2432 ", 1, 0, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 1, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 2, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 3, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 4, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 5, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 6, MCFG_BUS_ANY, &pci_32b_ops },
> + { "QCOM ", "QDF2432 ", 1, 7, MCFG_BUS_ANY, &pci_32b_ops },
> };
>
> static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
> diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
> index 43ed08d..c3b3063 100644
> --- a/drivers/pci/ecam.c
> +++ b/drivers/pci/ecam.c
> @@ -162,3 +162,13 @@ struct pci_ecam_ops pci_generic_ecam_ops = {
> .write = pci_generic_config_write,
> }
> };
> +
> +/* ops for 32 bit config space access quirk */
> +struct pci_ecam_ops pci_32b_ops = {
> + .bus_shift = 20,
> + .pci_ops = {
> + .map_bus = pci_ecam_map_bus,
> + .read = pci_generic_config_read32,
> + .write = pci_generic_config_write32,
> + }
> +};
> diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
> index 35f0e81..a6cffb8 100644
> --- a/include/linux/pci-ecam.h
> +++ b/include/linux/pci-ecam.h
> @@ -65,6 +65,7 @@ extern struct pci_ecam_ops pci_thunder_pem_ops;
> #ifdef CONFIG_PCI_HOST_THUNDER_ECAM
> extern struct pci_ecam_ops pci_thunder_ecam_ops;
> #endif
> +extern struct pci_ecam_ops pci_32b_ops;
>
> #ifdef CONFIG_PCI_HOST_GENERIC
> /* for DT-based PCI controllers that support ECAM */
> --
> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
> Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora
> Forum, a Linux Foundation Collaborative Project.
>