diff options
| author | Claire Chang <tientzu@chromium.org> | 2021-06-19 11:40:43 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad@kernel.org> | 2021-07-13 20:04:53 -0400 |
| commit | fec9b625095f7308e52a6922619cd4abaa9534a8 (patch) | |
| tree | bc5495ba83cb96359a1b802e33d317127d7bb3b9 /drivers | |
| parent | b12fe999545cf3fd89e1a178ee4e541a9331da82 (diff) | |
of: Add plumbing for restricted DMA pool
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@chromium.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/of/address.c | 33 | ||||
| -rw-r--r-- | drivers/of/device.c | 3 | ||||
| -rw-r--r-- | drivers/of/of_private.h | 6 |
3 files changed, 42 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c index 94f017d808c4..973257434398 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> @@ -995,6 +996,38 @@ out: of_node_put(node); return ret; } + +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; +} #endif /* CONFIG_HAS_DMA */ /** 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 631489f7f8c0..376462798f7e 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 void fdt_init_reserved_mem(void); |