diff options
Diffstat (limited to 'drivers/base/dma-mapping.c')
| -rw-r--r-- | drivers/base/dma-mapping.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index efd71cf4fdea..449b948c7427 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -7,9 +7,11 @@ * This file is released under the GPLv2. */ +#include <linux/acpi.h> #include <linux/dma-mapping.h> #include <linux/export.h> #include <linux/gfp.h> +#include <linux/of_device.h> #include <linux/slab.h> #include <linux/vmalloc.h> @@ -341,3 +343,41 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) vunmap(cpu_addr); } #endif + +/* + * Common configuration to enable DMA API use for a device + */ +#include <linux/pci.h> + +int dma_configure(struct device *dev) +{ + struct device *bridge = NULL, *dma_dev = dev; + enum dev_dma_attr attr; + + if (dev_is_pci(dev)) { + bridge = pci_get_host_bridge_device(to_pci_dev(dev)); + dma_dev = bridge; + if (IS_ENABLED(CONFIG_OF) && dma_dev->parent && + dma_dev->parent->of_node) + dma_dev = dma_dev->parent; + } + + if (dma_dev->of_node) { + of_dma_configure(dev, dma_dev->of_node); + } else if (has_acpi_companion(dma_dev)) { + attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode)); + if (attr != DEV_DMA_NOT_SUPPORTED) + acpi_dma_configure(dev, attr); + } + + if (bridge) + pci_put_host_bridge_device(bridge); + + return 0; +} + +void dma_deconfigure(struct device *dev) +{ + of_dma_deconfigure(dev); + acpi_dma_deconfigure(dev); +} |