On Thu, Apr 22, 2021 at 4:17 PM Claire Chang <tientzu@xxxxxxxxxxxx> wrote:
>
> If a device is not behind an IOMMU, we look up the device node and set
> up the restricted DMA when the restricted-dma-pool is presented.
>
> Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx>
> ---
> drivers/of/address.c | 25 +++++++++++++++++++++++++
> drivers/of/device.c | 3 +++
> drivers/of/of_private.h | 5 +++++
> 3 files changed, 33 insertions(+)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 54f221dde267..fff3adfe4986 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -8,6 +8,7 @@
> #include <linux/logic_pio.h>
> #include <linux/module.h>
> #include <linux/of_address.h>
> +#include <linux/of_reserved_mem.h>
> #include <linux/pci.h>
> #include <linux/pci_regs.h>
> #include <linux/sizes.h>
> @@ -1109,6 +1110,30 @@ bool of_dma_is_coherent(struct device_node *np)
> }
> EXPORT_SYMBOL_GPL(of_dma_is_coherent);
>
> +int of_dma_set_restricted_buffer(struct device *dev)
> +{
> + struct device_node *node;
> + int count, i;
> +
> + if (!dev->of_node)
> + return 0;
> +
> + count = of_property_count_elems_of_size(dev->of_node, "memory-region",
> + sizeof(phandle));
> + for (i = 0; i < count; i++) {
> + node = of_parse_phandle(dev->of_node, "memory-region", i);
> + /* There might be multiple memory regions, but only one
> + * restriced-dma-pool region is allowed.
> + */
> + if (of_device_is_compatible(node, "restricted-dma-pool") &&
> + of_device_is_available(node))
> + return of_reserved_mem_device_init_by_idx(
> + dev, dev->of_node, i);
> + }
> +
> + return 0;
> +}
> +
> /**
> * of_mmio_is_nonposted - Check if device uses non-posted MMIO
> * @np: device node
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index c5a9473a5fb1..d8d865223e51 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -165,6 +165,9 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
>
> arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
>
> + if (!iommu)
> + return of_dma_set_restricted_buffer(dev);
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(of_dma_configure_id);
> diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
> index d717efbd637d..e9237f5eff48 100644
> --- a/drivers/of/of_private.h
> +++ b/drivers/of/of_private.h
> @@ -163,12 +163,17 @@ struct bus_dma_region;
> #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
> int of_dma_get_range(struct device_node *np,
> const struct bus_dma_region **map);
> +int of_dma_set_restricted_buffer(struct device *dev);
> #else
> static inline int of_dma_get_range(struct device_node *np,
> const struct bus_dma_region **map)
> {
> return -ENODEV;
> }
> +static inline int of_dma_get_restricted_buffer(struct device *dev)
This one should be of_dma_set_restricted_buffer. Sorry for the typo.
> +{
> + return -ENODEV;
> +}
> #endif
>
> #endif /* _LINUX_OF_PRIVATE_H */
> --
> 2.31.1.368.gbe11c130af-goog
>
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