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ACPI/IORT: Support address size limit for root complexes

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IORT revision D allows PCI root complex nodes to specify a memory
address size limit equivalently to named components, to help describe
straightforward integrations which don't really warrant a full-blown
_DMA method. Now that our headers are up-to-date, plumb it in.

If both _DMA and an address size limit are present, we would always
expect the former to be a more specific subset of the latter (since it
makes little sense for a _DMA range to involve bits which IORT says
aren't wired up), thus we can save calculating an explicit intersection
of the two effective masks and simply use short-circuit logic instead.

Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Robin Murphy 2018-07-23 23:16:06 +01:00 committed by Christoph Hellwig
parent a5516219b1
commit 5ac65e8c89
1 changed files with 23 additions and 2 deletions
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25
drivers/acpi/arm64/iort.c
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@ -947,6 +947,24 @@ static int nc_dma_get_range(struct device *dev, u64 *size)
return 0;
}
static int rc_dma_get_range(struct device *dev, u64 *size)
{
struct acpi_iort_node *node;
struct acpi_iort_root_complex *rc;
node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
iort_match_node_callback, dev);
if (!node || node->revision < 1)
return -ENODEV;
rc = (struct acpi_iort_root_complex *)node->node_data;
*size = rc->memory_address_limit >= 64 ? U64_MAX :
1ULL<<rc->memory_address_limit;
return 0;
}
/**
* iort_dma_setup() - Set-up device DMA parameters.
*
@ -975,10 +993,13 @@ 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);
else
if (ret == -ENODEV)
ret = rc_dma_get_range(dev, &size);
} else {
ret = nc_dma_get_range(dev, &size);
}
if (!ret) {
msb = fls64(dmaaddr + size - 1);