From d760a1baf20e067d3a063aa134834ddd3d183e2f Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 21 Nov 2016 10:01:39 +0000 Subject: ACPI: Implement acpi_dma_configure On DT based systems, the of_dma_configure() API implements DMA configuration for a given device. On ACPI systems an API equivalent to of_dma_configure() is missing which implies that it is currently not possible to set-up DMA operations for devices through the ACPI generic kernel layer. This patch fills the gap by introducing acpi_dma_configure/deconfigure() calls that for now are just wrappers around arch_setup_dma_ops() and arch_teardown_dma_ops() and also updates ACPI and PCI core code to use the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions. Since acpi_dma_configure() is used to configure DMA operations, the function initializes the dma/coherent_dma masks to sane default values if the current masks are uninitialized (also to keep the default values consistent with DT systems) to make sure the device has a complete default DMA set-up. The DMA range size passed to arch_setup_dma_ops() is sized according to the device coherent_dma_mask (starting at address 0x0), mirroring the DT probing path behaviour when a dma-ranges property is not provided for the device being probed; this changes the current arch_setup_dma_ops() call parameters in the ACPI probing case, but since arch_setup_dma_ops() is a NOP on all architectures but ARM/ARM64 this patch does not change the current kernel behaviour on them. Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas [pci] Acked-by: Rafael J. Wysocki Reviewed-by: Tomasz Nowicki Tested-by: Hanjun Guo Tested-by: Tomasz Nowicki Cc: Bjorn Helgaas Cc: Robin Murphy Cc: Tomasz Nowicki Cc: Joerg Roedel Cc: "Rafael J. Wysocki" Signed-off-by: Will Deacon --- drivers/acpi/scan.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 3d1856f1f4d0..45b5710a0404 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1370,6 +1370,46 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev) return DEV_DMA_NON_COHERENT; } +/** + * acpi_dma_configure - Set-up DMA configuration for the device. + * @dev: The pointer to the device + * @attr: device dma attributes + */ +void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) +{ + /* + * Set default coherent_dma_mask to 32 bit. Drivers are expected to + * setup the correct supported mask. + */ + if (!dev->coherent_dma_mask) + dev->coherent_dma_mask = DMA_BIT_MASK(32); + + /* + * Set it to coherent_dma_mask by default if the architecture + * code has not set it. + */ + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; + + /* + * Assume dma valid range starts at 0 and covers the whole + * coherent_dma_mask. + */ + arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, NULL, + attr == DEV_DMA_COHERENT); +} +EXPORT_SYMBOL_GPL(acpi_dma_configure); + +/** + * acpi_dma_deconfigure - Tear-down DMA configuration for the device. + * @dev: The pointer to the device + */ +void acpi_dma_deconfigure(struct device *dev) +{ + arch_teardown_dma_ops(dev); +} +EXPORT_SYMBOL_GPL(acpi_dma_deconfigure); + static void acpi_init_coherency(struct acpi_device *adev) { unsigned long long cca = 0; -- cgit