| Message ID | 1596527558-22566-1-git-send-email-amhetre@nvidia.com |
|---|---|
| State | Deferred |
| Headers | show |
| Series | iommu/dma: Add support for mapping memory as device memory | expand |
From what I can tell, dma_map_resource already does this (see iommu_dma_map_resource). Can you use that? (also, dropping internal MLs) Mikko On 8/4/20 10:52 AM, Ashish Mhetre wrote: > Add DMA_ATTRS_DEVICE_MAP attribute to support mapping memory as device > memory. > > Signed-off-by: Ashish Mhetre <amhetre@nvidia.com> > --- > drivers/iommu/dma-iommu.c | 3 +++ > include/linux/dma-mapping.h | 6 ++++++ > 2 files changed, 9 insertions(+) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 65ac889..0e411ef 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -388,6 +388,9 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent, > if (attrs & DMA_ATTR_PRIVILEGED) > prot |= IOMMU_PRIV; > > + if (attrs & DMA_ATTR_DEVICE_MAP) > + prot |= IOMMU_MMIO; > + > switch (dir) { > case DMA_BIDIRECTIONAL: > return prot | IOMMU_READ | IOMMU_WRITE; > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 330ad58..b0cb1b3 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -68,6 +68,12 @@ > #define DMA_ATTR_PRIVILEGED (1UL << 9) > > /* > + * DMA_ATTR_DEVICE_MAP: This specifies DMA-mapping subsystem to map memory > + * as device memory. > + */ > +#define DMA_ATTR_DEVICE_MAP (1UL << 10) > + > +/* > * A dma_addr_t can hold any valid DMA or bus address for the platform. > * It can be given to a device to use as a DMA source or target. A CPU cannot > * reference a dma_addr_t directly because there may be translation between >
Can you explain why it is necessary? Can you also include a client driver patches that uses this new attribute? Including the patches that uses this attribute would make it easy to upstream. -KR -----Original Message----- From: Ashish Mhetre <amhetre@nvidia.com> Sent: Tuesday, August 4, 2020 12:53 AM To: Krishna Reddy <vdumpa@nvidia.com>; Thierry Reding <treding@nvidia.com>; Jonathan Hunter <jonathanh@nvidia.com>; Stephen Warren <swarren@nvidia.com>; Sachin Nikam <Snikam@nvidia.com> Cc: SW-Mobile-Linux-Upstreaming <SW-Mobile-Linux-Upstreaming@exchange.nvidia.com>; SW-Mobile-Memory-Core <SW-Mobile-Memory-Core@exchange.nvidia.com>; linux-tegra@vger.kernel.org; Ashish Mhetre <amhetre@nvidia.com> Subject: [PATCH] iommu/dma: Add support for mapping memory as device memory Add DMA_ATTRS_DEVICE_MAP attribute to support mapping memory as device memory. Signed-off-by: Ashish Mhetre <amhetre@nvidia.com> --- drivers/iommu/dma-iommu.c | 3 +++ include/linux/dma-mapping.h | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 65ac889..0e411ef 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -388,6 +388,9 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent, if (attrs & DMA_ATTR_PRIVILEGED) prot |= IOMMU_PRIV; + if (attrs & DMA_ATTR_DEVICE_MAP) + prot |= IOMMU_MMIO; + switch (dir) { case DMA_BIDIRECTIONAL: return prot | IOMMU_READ | IOMMU_WRITE; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 330ad58..b0cb1b3 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -68,6 +68,12 @@ #define DMA_ATTR_PRIVILEGED (1UL << 9) /* + * DMA_ATTR_DEVICE_MAP: This specifies DMA-mapping subsystem to map +memory + * as device memory. + */ +#define DMA_ATTR_DEVICE_MAP (1UL << 10) + +/* * A dma_addr_t can hold any valid DMA or bus address for the platform. * It can be given to a device to use as a DMA source or target. A CPU cannot * reference a dma_addr_t directly because there may be translation between -- 2.7.4
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 65ac889..0e411ef 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -388,6 +388,9 @@ static int dma_info_to_prot(enum dma_data_direction dir, bool coherent, if (attrs & DMA_ATTR_PRIVILEGED) prot |= IOMMU_PRIV; + if (attrs & DMA_ATTR_DEVICE_MAP) + prot |= IOMMU_MMIO; + switch (dir) { case DMA_BIDIRECTIONAL: return prot | IOMMU_READ | IOMMU_WRITE; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 330ad58..b0cb1b3 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -68,6 +68,12 @@ #define DMA_ATTR_PRIVILEGED (1UL << 9) /* + * DMA_ATTR_DEVICE_MAP: This specifies DMA-mapping subsystem to map memory + * as device memory. + */ +#define DMA_ATTR_DEVICE_MAP (1UL << 10) + +/* * A dma_addr_t can hold any valid DMA or bus address for the platform. * It can be given to a device to use as a DMA source or target. A CPU cannot * reference a dma_addr_t directly because there may be translation between
Add DMA_ATTRS_DEVICE_MAP attribute to support mapping memory as device memory. Signed-off-by: Ashish Mhetre <amhetre@nvidia.com> --- drivers/iommu/dma-iommu.c | 3 +++ include/linux/dma-mapping.h | 6 ++++++ 2 files changed, 9 insertions(+)