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Subject[PATCH v3 5/5] ACPI/IORT: Add IORT named component memory address limits
Date
IORT named components provide firmware configuration describing
how many address bits a given device is capable of generating
to address memory.

Add code to the kernel to retrieve memory address limits
configuration for IORT named components and configure DMA masks
accordingly.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Nate Watterson <nwatters@codeaurora.org>
---
drivers/acpi/arm64/iort.c | 54 ++++++++++++++++++++++++++++++++---------------
1 file changed, 37 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 606af87..5b9e8dc2 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -680,6 +680,24 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
return ret ? NULL : ops;
}

+static int nc_dma_get_range(struct device *dev, u64 *size)
+{
+ struct acpi_iort_node *node;
+ struct acpi_iort_named_component *ncomp;
+
+ node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
+ iort_match_node_callback, dev);
+ if (!node)
+ return -ENODEV;
+
+ ncomp = (struct acpi_iort_named_component *)node->node_data;
+
+ *size = ncomp->memory_address_limit >= 64 ? U64_MAX :
+ 1ULL<<ncomp->memory_address_limit;
+
+ return 0;
+}
+
/**
* iort_dma_setup() - Set-up device DMA parameters.
*
@@ -708,24 +726,26 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)

size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);

- if (dev_is_pci(dev)) {
+ 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;
- }
+ else
+ ret = nc_dma_get_range(dev, &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;
--
2.10.0
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