[Intel-gfx] [PATCH v8 15/15] of: Add plumbing for restricted DMA pool
From: Claire Chang <hidden>
Date: 2021-05-27 13:04:35
Also in:
dri-devel, linux-devicetree, linux-iommu, linux-pci, linuxppc-dev, lkml, xen-devel
Subsystem:
open firmware and flattened device tree, the rest · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds
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 <redacted> --- drivers/of/address.c | 33 +++++++++++++++++++++++++++++++++ drivers/of/device.c | 3 +++ drivers/of/of_private.h | 6 ++++++ 3 files changed, 42 insertions(+)
diff --git a/drivers/of/address.c b/drivers/of/address.c
index aca94c348bd4..6cc7eaaf7e11 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>
@@ -1112,6 +1113,38 @@ 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 *np) +{ + struct device_node *node, *of_node = dev->of_node; + int count, i; + + count = of_property_count_elems_of_size(of_node, "memory-region", + sizeof(u32)); + /* + * If dev->of_node doesn't exist or doesn't contain memory-region, try + * the OF node having DMA configuration. + */ + if (count <= 0) { + of_node = np; + count = of_property_count_elems_of_size( + of_node, "memory-region", sizeof(u32)); + } + + for (i = 0; i < count; i++) { + node = of_parse_phandle(of_node, "memory-region", i); + /* + * There might be multiple memory regions, but only one + * restricted-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, 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..2defdca418ec 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, np); + 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..8fde97565d11 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h@@ -163,12 +163,18 @@ 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, struct device_node *np); #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_set_restricted_buffer(struct device *dev, + struct device_node *np) +{ + return -ENODEV; +} #endif #endif /* _LINUX_OF_PRIVATE_H */
--
2.31.1.818.g46aad6cb9e-goog
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx