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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2016-11-21 10:01:39 +0000
committerWill Deacon <will.deacon@arm.com>2016-11-29 15:57:44 +0000
commitd760a1baf20e067d3a063aa134834ddd3d183e2f (patch)
tree91185921baa9b7a821f11bd303c2a4b97b6eb492 /drivers/acpi/scan.c
parent778de074537582f86637f2240a8e369833372341 (diff)
downloadlinux-d760a1baf20e067d3a063aa134834ddd3d183e2f.tar.bz2
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 <lorenzo.pieralisi@arm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> [pci] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Tomasz Nowicki <tn@semihalf.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Tomasz Nowicki <tn@semihalf.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Tomasz Nowicki <tn@semihalf.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c40
1 files changed, 40 insertions, 0 deletions
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;