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SubjectRe: [PATCH v2 5/5] ACPI/IORT: Add IORT named component memory address limits
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Hi Lorenzo,
I ran a quick test and this seems to work for memory_address_limit < 64,
however memory_address_limit == 64 yields a mask of 0x0.

-Nate

On 7/31/2017 11:23 AM, Lorenzo Pieralisi wrote:
> 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 | 40 ++++++++++++++++++++++++++++++----------
> 1 file changed, 30 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 67b85ae..b85d19f 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 ? ~0ULL :
> + 1ULL<<ncomp->memory_address_limit;
> +
> + return 0;
> +}
> +
> /**
> * iort_dma_setup() - Set-up device DMA parameters.
> *
> @@ -708,17 +726,19 @@ 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) {
> - mask = __roundup_pow_of_two(dmaaddr + size) - 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) {
> + mask = __roundup_pow_of_two(dmaaddr + size) - 1;
> + /*
> + * Limit coherent and dma mask based on size
> + * retrieved from firmware.
> + */
> + dev->coherent_dma_mask = mask;
> + *dev->dma_mask = mask;
> }
>
> *dma_addr = dmaaddr;
>

--
Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

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