On 2019/3/29 10:54, Zhen Lei wrote:
> This allows the default behaviour to be controlled by a kernel config
> option instead of changing the command line for the kernel to include
> "iommu.strict=0" on ARM64 where this is desired.
>
> This is similar to CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
>
> Signed-off-by: Zhen Lei
> ---
> arch/s390/pci/pci_dma.c| 4
> drivers/iommu/Kconfig | 15 +++
> drivers/iommu/amd_iommu_init.c | 6 +-
> drivers/iommu/intel-iommu.c| 4
> drivers/iommu/iommu.c | 5 +
> 5 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
> index 9e52d1527f71495..d05e8c3820793c5 100644
> --- a/arch/s390/pci/pci_dma.c
> +++ b/arch/s390/pci/pci_dma.c
> @@ -17,7 +17,11 @@
>
> static struct kmem_cache *dma_region_table_cache;
> static struct kmem_cache *dma_page_table_cache;
> +#ifdef CONFIG_IOMMU_DMA_DEFAULT_LAZY_MODE
> static int s390_iommu_strict;
> +#else
> +static int s390_iommu_strict = 1;
> +#endif
>
> static int zpci_refresh_global(struct zpci_dev *zdev)
> {
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 6f07f3b21816c64..ed5206a2d316599 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -85,6 +85,21 @@ config IOMMU_DEFAULT_PASSTHROUGH
>
> If unsure, say N here.
>
> +config IOMMU_DMA_DEFAULT_LAZY_MODE
> + bool "IOMMU DMA use lazy mode to flush IOTLB and free IOVA"
> + depends on IOMMU_API
> + default y
Hi Robin：
Should I change to:
+ default y if !(ARM_SMMU || ARM_SMMU_V3)
> + help
> + Support lazy mode, where for every IOMMU DMA unmap operation, the
> + flush operation of IOTLB and the free operation of IOVA are deferred.
> + They are only guaranteed to be done before the related IOVA will be
> + reused. Removing the need to pass in kernel parameters through
> + command line. For example, iommu.strict=0 on ARM64. If this is
> + enabled, you can still disable with kernel parameters, such as
> + iommu.strict=1 depending on the architecture.
> +
> + If unsure, say N here.
> +
> config OF_IOMMU
> def_bool y
> depends on OF && IOMMU_API
> diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
> index f773792d77fd533..a30805c2f77199c 100644
> --- a/drivers/iommu/amd_iommu_init.c
> +++ b/drivers/iommu/amd_iommu_init.c
> @@ -166,7 +166,11 @@ struct ivmd_header {
> to handle */
> LIST_HEAD(amd_iommu_unity_map); /* a list of required unity
> mappings
> we find in ACPI */
> -bool amd_iommu_unmap_flush; /* if true, flush on every unmap */
> +#ifdef CONFIG_IOMMU_DMA_DEFAULT_LAZY_MODE
> +bool amd_iommu_unmap_flush;
> +#else
> +bool amd_iommu_unmap_flush = true; /* flush on every unmap */
> +#endif
>
> LIST_HEAD(amd_iommu_list); /* list of all AMD IOMMUs in the
> system */
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 28cb713d728ceef..560191a9342b2b8 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -362,7 +362,11 @@ static int domain_detach_iommu(struct dmar_domain
> *domain,
>
> static int dmar_map_gfx = 1;
> static int dmar_forcedac;
> +#ifdef CONFIG_IOMMU_DMA_DEFAULT_LAZY_MODE
> static int intel_iommu_strict;
> +#else
> +static int intel_iommu_strict = 1;
> +#endif
> static int intel_iommu_superpage = 1;
> static int intel_iommu_sm;
> static int iommu_identity_mapping;
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 33a982e33716369..5acb98e79b5b32d 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -43,7 +43,12 @@
> #else
> static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
> #endif
> +
> +#ifdef CONFIG_IOMMU_DMA_DEFAULT_LAZY_MODE
> +static bool iommu_dma_strict __read_mostly;
> +#else
> static bool iommu_dma_strict __read_mostly = true;
> +#endif
>
> struct iommu_callback_data {
> const struct iommu_ops *ops;
>
--
Thanks!
BestRegards
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