Commit 5ac65e8c authored Jul 23, 2018 by Robin Murphy Committed by Christoph Hellwig Jul 27, 2018

ACPI/IORT: Support address size limit for root complexes



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>

parent a5516219

drivers/acpi/arm64/iort.c

+23 −2

Original line number	Diff line number	Diff line
		@@ -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);

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