On Sat 09 Oct 21:33 CDT 2021, Dmitry Baryshkov wrote:
> After commit 424953cf3c66 ("qcom_scm: hide Kconfig symbol") arm-smmu got
> qcom_smmu_impl_init() call guarded by IS_ENABLED(CONFIG_ARM_SMMU_QCOM).
> However the CONFIG_ARM_SMMU_QCOM Kconfig entry does not exist, so the
> qcom_smmu_impl_init() is never called.
>
> So, let's fix this by always calling qcom_smmu_impl_init(). It does not
> touch the smmu passed unless the device is a non-Qualcomm one. Make
> ARM_SMMU select QCOM_SCM for ARCH_QCOM.
>
Arnd's intention was to not force QCOM_SCM to be built on non-Qualcomm
devices. But as Daniel experienced, attempting to boot most Qualcomm
boards without this results in a instant reboot.
I think it's okay if we tinker with CONFIG_ARM_SMMU_QCOM for v5.16, but
we're getting late in v5.15 so I would prefer if we make sure this works
out of the box.
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Regards,
Bjorn
> Fixes: 424953cf3c66 ("qcom_scm: hide Kconfig symbol")
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Reported-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> drivers/iommu/Kconfig | 1 +
> drivers/iommu/arm/arm-smmu/Makefile | 3 +--
> drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 9 +++++++--
> 3 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index c5c71b7ab7e8..a4593e53fe7d 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -309,6 +309,7 @@ config ARM_SMMU
> tristate "ARM Ltd. System MMU (SMMU) Support"
> depends on ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64)
> select IOMMU_API
> + select QCOM_SCM
> select IOMMU_IO_PGTABLE_LPAE
> select ARM_DMA_USE_IOMMU if ARM
> help
> diff --git a/drivers/iommu/arm/arm-smmu/Makefile b/drivers/iommu/arm/arm-smmu/Makefile
> index b0cc01aa20c9..e240a7bcf310 100644
> --- a/drivers/iommu/arm/arm-smmu/Makefile
> +++ b/drivers/iommu/arm/arm-smmu/Makefile
> @@ -1,5 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o
> obj-$(CONFIG_ARM_SMMU) += arm_smmu.o
> -arm_smmu-objs += arm-smmu.o arm-smmu-impl.o arm-smmu-nvidia.o
> -arm_smmu-$(CONFIG_ARM_SMMU_QCOM) += arm-smmu-qcom.o
> +arm_smmu-objs += arm-smmu.o arm-smmu-impl.o arm-smmu-nvidia.o arm-smmu-qcom.o
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
> index 2c25cce38060..8199185dd262 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c
> @@ -215,8 +215,13 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu)
> of_device_is_compatible(np, "nvidia,tegra186-smmu"))
> return nvidia_smmu_impl_init(smmu);
>
> - if (IS_ENABLED(CONFIG_ARM_SMMU_QCOM))
> - smmu = qcom_smmu_impl_init(smmu);
> + /*
> + * qcom_smmu_impl_init() will not touch smmu if the device is not
> + * a Qualcomm one.
> + */
> + smmu = qcom_smmu_impl_init(smmu);
> + if (IS_ERR(smmu))
> + return smmu;
>
> if (of_device_is_compatible(np, "marvell,ap806-smmu-500"))
> smmu->impl = &mrvl_mmu500_impl;
> --
> 2.30.2
>
