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ACPI/IORT: Add IORT named component memory address limits

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>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Lorenzo Pieralisi Rafael J. Wysocki
Lorenzo Pieralisi authored and Rafael J. Wysocki committed Aug 3, 2017
1 parent 7ad4263 commit 10d8ab2c15b9ef2f46c35e7c36781399d6f2cc82
Showing with 37 additions and 17 deletions.
  1. +37 −17 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;

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