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 <lorenzo.pieral...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Hanjun Guo <hanjun....@linaro.org>
Cc: Robin Murphy <robin.mur...@arm.com>
Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
---
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
