| Message ID | fe956f04bfe7f8293f6205ee224b087046e40a91.1544199754.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Refactor dummy DMA ops | expand |
On Fri, Dec 7, 2018 at 5:31 PM Robin Murphy <robin.murphy@arm.com> wrote: > > Rather than checking the DMA attribute at each callsite, just pass it > through for acpi_dma_configure() to handle directly. That can then deal > with the relatively exceptional DEV_DMA_NOT_SUPPORTED case by explicitly > installing dummy DMA ops instead of just skipping setup entirely. This > will then free up the dev->dma_ops == NULL case for some valuable > fastpath optimisations. > > CC: Rafael J. Wysocki <rjw@rjwysocki.net> > CC: Len Brown <lenb@kernel.org> > CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > CC: Bjorn Helgaas <bhelgaas@google.com> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> The changes in this patch are fine by me: Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > drivers/acpi/scan.c | 5 +++++ > drivers/base/platform.c | 3 +-- > drivers/pci/pci-driver.c | 3 +-- > 3 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index bd1c59fb0e17..b75ae34ed188 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -1456,6 +1456,11 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) > const struct iommu_ops *iommu; > u64 dma_addr = 0, size = 0; > > + if (attr == DEV_DMA_NOT_SUPPORTED) { > + set_dma_ops(dev, &dma_dummy_ops); > + return 0; > + } > + > iort_dma_setup(dev, &dma_addr, &size); > > iommu = iort_iommu_configure(dev); > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 41b91af95afb..c6daca875c17 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -1138,8 +1138,7 @@ int platform_dma_configure(struct device *dev) > ret = of_dma_configure(dev, dev->of_node, true); > } else if (has_acpi_companion(dev)) { > attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode)); > - if (attr != DEV_DMA_NOT_SUPPORTED) > - ret = acpi_dma_configure(dev, attr); > + ret = acpi_dma_configure(dev, attr); > } > > return ret; > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index bef17c3fca67..f899a28b90f8 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -1602,8 +1602,7 @@ static int pci_dma_configure(struct device *dev) > struct acpi_device *adev = to_acpi_device_node(bridge->fwnode); > enum dev_dma_attr attr = acpi_get_dma_attr(adev); > > - if (attr != DEV_DMA_NOT_SUPPORTED) > - ret = acpi_dma_configure(dev, attr); > + ret = acpi_dma_configure(dev, attr); > } > > pci_put_host_bridge_device(bridge); > -- > 2.19.1.dirty >
On Fri, Dec 07, 2018 at 04:31:35PM +0000, Robin Murphy wrote: > Rather than checking the DMA attribute at each callsite, just pass it > through for acpi_dma_configure() to handle directly. That can then deal > with the relatively exceptional DEV_DMA_NOT_SUPPORTED case by explicitly > installing dummy DMA ops instead of just skipping setup entirely. This > will then free up the dev->dma_ops == NULL case for some valuable > fastpath optimisations. > > CC: Rafael J. Wysocki <rjw@rjwysocki.net> > CC: Len Brown <lenb@kernel.org> > CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > CC: Bjorn Helgaas <bhelgaas@google.com> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> FWIW, if this hasn't been applied already (I think you targeted a DMA tree): Acked-by: Bjorn Helgaas <bhelgaas@google.com> > --- > drivers/acpi/scan.c | 5 +++++ > drivers/base/platform.c | 3 +-- > drivers/pci/pci-driver.c | 3 +-- > 3 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index bd1c59fb0e17..b75ae34ed188 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -1456,6 +1456,11 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) > const struct iommu_ops *iommu; > u64 dma_addr = 0, size = 0; > > + if (attr == DEV_DMA_NOT_SUPPORTED) { > + set_dma_ops(dev, &dma_dummy_ops); > + return 0; > + } > + > iort_dma_setup(dev, &dma_addr, &size); > > iommu = iort_iommu_configure(dev); > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 41b91af95afb..c6daca875c17 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -1138,8 +1138,7 @@ int platform_dma_configure(struct device *dev) > ret = of_dma_configure(dev, dev->of_node, true); > } else if (has_acpi_companion(dev)) { > attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode)); > - if (attr != DEV_DMA_NOT_SUPPORTED) > - ret = acpi_dma_configure(dev, attr); > + ret = acpi_dma_configure(dev, attr); > } > > return ret; > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index bef17c3fca67..f899a28b90f8 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -1602,8 +1602,7 @@ static int pci_dma_configure(struct device *dev) > struct acpi_device *adev = to_acpi_device_node(bridge->fwnode); > enum dev_dma_attr attr = acpi_get_dma_attr(adev); > > - if (attr != DEV_DMA_NOT_SUPPORTED) > - ret = acpi_dma_configure(dev, attr); > + ret = acpi_dma_configure(dev, attr); > } > > pci_put_host_bridge_device(bridge); > -- > 2.19.1.dirty > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index bd1c59fb0e17..b75ae34ed188 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1456,6 +1456,11 @@ int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) const struct iommu_ops *iommu; u64 dma_addr = 0, size = 0; + if (attr == DEV_DMA_NOT_SUPPORTED) { + set_dma_ops(dev, &dma_dummy_ops); + return 0; + } + iort_dma_setup(dev, &dma_addr, &size); iommu = iort_iommu_configure(dev); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 41b91af95afb..c6daca875c17 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -1138,8 +1138,7 @@ int platform_dma_configure(struct device *dev) ret = of_dma_configure(dev, dev->of_node, true); } else if (has_acpi_companion(dev)) { attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode)); - if (attr != DEV_DMA_NOT_SUPPORTED) - ret = acpi_dma_configure(dev, attr); + ret = acpi_dma_configure(dev, attr); } return ret; diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index bef17c3fca67..f899a28b90f8 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1602,8 +1602,7 @@ static int pci_dma_configure(struct device *dev) struct acpi_device *adev = to_acpi_device_node(bridge->fwnode); enum dev_dma_attr attr = acpi_get_dma_attr(adev); - if (attr != DEV_DMA_NOT_SUPPORTED) - ret = acpi_dma_configure(dev, attr); + ret = acpi_dma_configure(dev, attr); } pci_put_host_bridge_device(bridge);
Rather than checking the DMA attribute at each callsite, just pass it through for acpi_dma_configure() to handle directly. That can then deal with the relatively exceptional DEV_DMA_NOT_SUPPORTED case by explicitly installing dummy DMA ops instead of just skipping setup entirely. This will then free up the dev->dma_ops == NULL case for some valuable fastpath optimisations. CC: Rafael J. Wysocki <rjw@rjwysocki.net> CC: Len Brown <lenb@kernel.org> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/acpi/scan.c | 5 +++++ drivers/base/platform.c | 3 +-- drivers/pci/pci-driver.c | 3 +-- 3 files changed, 7 insertions(+), 4 deletions(-)