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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-11-07 03:30:10 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-11-07 03:30:10 +0300 |
commit | f2115faaf0df42623638dfbfc5bdaab6ef7375ab (patch) | |
tree | f8bbd5a1ad3fbcb0b60e455d0dcf29a9fc25602c /drivers/acpi/scan.c | |
parent | 0d51ce9ca1116e8f4dc87cb51db8dd250327e9bb (diff) | |
parent | 29dbe1f0af88b4162d2b57e790db7a51ab061f35 (diff) | |
download | linux-f2115faaf0df42623638dfbfc5bdaab6ef7375ab.tar.xz |
Merge branch 'acpi-pci'
* acpi-pci:
PCI: ACPI: Add support for PCI device DMA coherency
PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()
of/pci: Fix pci_get_host_bridge_device leak
device property: ACPI: Remove unused DMA APIs
device property: ACPI: Make use of the new DMA Attribute APIs
device property: Adding DMA Attribute APIs for Generic Devices
ACPI: Adding DMA Attribute APIs for ACPI Device
device property: Introducing enum dev_dma_attr
ACPI: Honor ACPI _CCA attribute setting
Conflicts:
drivers/crypto/ccp/ccp-platform.c
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r-- | drivers/acpi/scan.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index daf9fc8329e6..78d5f02a073b 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1308,6 +1308,48 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp) kfree(pnp->unique_id); } +/** + * acpi_dma_supported - Check DMA support for the specified device. + * @adev: The pointer to acpi device + * + * Return false if DMA is not supported. Otherwise, return true + */ +bool acpi_dma_supported(struct acpi_device *adev) +{ + if (!adev) + return false; + + if (adev->flags.cca_seen) + return true; + + /* + * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent + * DMA on "Intel platforms". Presumably that includes all x86 and + * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y. + */ + if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED)) + return true; + + return false; +} + +/** + * acpi_get_dma_attr - Check the supported DMA attr for the specified device. + * @adev: The pointer to acpi device + * + * Return enum dev_dma_attr. + */ +enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev) +{ + if (!acpi_dma_supported(adev)) + return DEV_DMA_NOT_SUPPORTED; + + if (adev->flags.coherent_dma) + return DEV_DMA_COHERENT; + else + return DEV_DMA_NON_COHERENT; +} + static void acpi_init_coherency(struct acpi_device *adev) { unsigned long long cca = 0; |