On Wed, Nov 16, 2016 at 03:29:30PM +0000, Lorenzo Pieralisi wrote:
> Current ARM SMMUv3 probe functions intermingle HW and DT probing in the
> initialization functions to detect and programme the ARM SMMU v3 driver
> features. In order to allow probing the ARM SMMUv3 with other firmwares
> than DT, this patch splits the ARM SMMUv3 init functions into DT and HW
> specific portions so that other FW interfaces (ie ACPI) can reuse the HW
> probing functions and skip the DT portion accordingly.
>
> This patch implements no functional change, only code reshuffling.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Acked-by: Will Deacon <will.deacon@xxxxxxx>
> Reviewed-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Tested-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> ---
> drivers/iommu/arm-smmu-v3.c | 46 +++++++++++++++++++++++++++++----------------
> 1 file changed, 30 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index e6e1c87..ed563307 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2381,10 +2381,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
> return 0;
> }
>
> -static int arm_smmu_device_probe(struct arm_smmu_device *smmu)
> +static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
> {
> u32 reg;
> - bool coherent;
> + bool coherent = smmu->features & ARM_SMMU_FEAT_COHERENCY;
>
> /* IDR0 */
> reg = readl_relaxed(smmu->base + ARM_SMMU_IDR0);
> @@ -2436,13 +2436,9 @@ static int arm_smmu_device_probe(struct arm_smmu_device *smmu)
> smmu->features |= ARM_SMMU_FEAT_HYP;
>
> /*
> - * The dma-coherent property is used in preference to the ID
> + * The coherency feature as set by FW is used in preference to the ID
> * register, but warn on mismatch.
> */
> - coherent = of_dma_is_coherent(smmu->dev->of_node);
> - if (coherent)
> - smmu->features |= ARM_SMMU_FEAT_COHERENCY;
> -
> if (!!(reg & IDR0_COHACC) != coherent)
> dev_warn(smmu->dev, "IDR0.COHACC overridden by dma-coherent property (%s)\n",
> coherent ? "true" : "false");
> @@ -2563,21 +2559,37 @@ static int arm_smmu_device_probe(struct arm_smmu_device *smmu)
> return 0;
> }
>
> -static int arm_smmu_device_dt_probe(struct platform_device *pdev)
> +static int arm_smmu_device_dt_probe(struct platform_device *pdev,
> + struct arm_smmu_device *smmu,
> + bool *bypass)
> {
> - int irq, ret;
> - struct resource *res;
> - struct arm_smmu_device *smmu;
> struct device *dev = &pdev->dev;
> - bool bypass = true;
> u32 cells;
>
> + *bypass = true;
> +
> if (of_property_read_u32(dev->of_node, "#iommu-cells", &cells))
> dev_err(dev, "missing #iommu-cells property\n");
> else if (cells != 1)
> dev_err(dev, "invalid #iommu-cells value (%d)\n", cells);
> else
> - bypass = false;
> + *bypass = false;
> +
> + parse_driver_options(smmu);
> +
> + if (of_dma_is_coherent(dev->of_node))
> + smmu->features |= ARM_SMMU_FEAT_COHERENCY;
> +
> + return 0;
I know you're only moving code here, but the *bypass output parameter
now seems to be redundant with the unconditional return 0. Given that
we only set bypass to true if something went wrong, why don't we return
-ENODEV in those cases, kill the bypass parameter and rework the return
value check in the caller so that, rather than fail the probe, we pass
bypass=true to the reset function?
Will
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