[PATCH v3 4/5] ACPI: Make acpi_dma_configure() DMA regions aware
From: Lorenzo Pieralisi <hidden>
Date: 2017-08-03 12:31:19
Also in:
linux-acpi, lkml
Subsystem:
acpi, acpi for arm64 (acpi/arm64), the rest · Maintainers:
"Rafael J. Wysocki", Lorenzo Pieralisi, Hanjun Guo, Sudeep Holla, Catalin Marinas, Will Deacon, Linus Torvalds
Current ACPI DMA configuration set-up device DMA capabilities through kernel defaults that do not take into account platform specific DMA configurations reported by firmware. By leveraging the ACPI acpi_dev_get_dma_resources() API, add code in acpi_dma_configure() to retrieve the DMA regions to correctly set-up PCI devices DMA parameters. Rework the ACPI IORT kernel API to make sure they can accommodate the DMA set-up required by firmware. By making PCI devices DMA set-up ACPI IORT specific, the kernel is shielded from unwanted regressions that could be triggered by parsing DMA resources on arches that were previously ignoring them (ie x86/ia64), leaving kernel behaviour unchanged on those arches. Signed-off-by: Lorenzo Pieralisi <redacted> Cc: Will Deacon <redacted> Cc: Hanjun Guo <redacted> Cc: Robin Murphy <robin.murphy@arm.com> Cc: "Rafael J. Wysocki" <redacted> --- drivers/acpi/arm64/iort.c | 37 +++++++++++++++++++++++++++++++++++-- include/linux/acpi_iort.h | 5 +++-- 2 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index a3215ee..606af87 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c@@ -681,12 +681,17 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, } /** - * iort_set_dma_mask - Set-up dma mask for a device. + * iort_dma_setup() - Set-up device DMA parameters. * * @dev: device to configure + * @dma_addr: device DMA address result pointer + * @size: DMA range size result pointer */ -void iort_set_dma_mask(struct device *dev) +void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size) { + u64 mask, dmaaddr = 0, size = 0, offset = 0; + int ret, msb; + /* * Set default coherent_dma_mask to 32 bit. Drivers are expected to * setup the correct supported mask.
@@ -700,6 +705,34 @@ void iort_set_dma_mask(struct device *dev) */ if (!dev->dma_mask) dev->dma_mask = &dev->coherent_dma_mask; + + size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); + + if (dev_is_pci(dev)) { + ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size); + if (!ret) { + msb = fls64(dmaaddr + size - 1); + /* + * Round-up to the power-of-two mask or set + * the mask to the whole 64-bit address space + * in case the DMA region covers the full + * memory window. + */ + mask = msb == 64 ? U64_MAX : (1ULL << msb) - 1; + /* + * Limit coherent and dma mask based on size + * retrieved from firmware. + */ + dev->coherent_dma_mask = mask; + *dev->dma_mask = mask; + } + } + + *dma_addr = dmaaddr; + *dma_size = size; + + dev->dma_pfn_offset = PFN_DOWN(offset); + dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset); } /**
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 8379d40..8d3f0bf 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h@@ -36,7 +36,7 @@ struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id); void acpi_configure_pmsi_domain(struct device *dev); int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id); /* IOMMU interface */ -void iort_set_dma_mask(struct device *dev); +void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size); const struct iommu_ops *iort_iommu_configure(struct device *dev); #else static inline void acpi_iort_init(void) { }
@@ -47,7 +47,8 @@ static inline struct irq_domain *iort_get_device_domain(struct device *dev, { return NULL; } static inline void acpi_configure_pmsi_domain(struct device *dev) { } /* IOMMU interface */ -static inline void iort_set_dma_mask(struct device *dev) { } +static inline void iort_dma_setup(struct device *dev, u64 *dma_addr, + u64 *size) { } static inline const struct iommu_ops *iort_iommu_configure(struct device *dev) { return NULL; }
--
2.10.0