[PATCH v6 4/7] PCI: keystone: Add support for PVU-based DMA isolation on AM654

Bjorn Helgaas helgaas at kernel.org
Wed Oct 30 13:57:45 PDT 2024


On Mon, Sep 09, 2024 at 07:03:57PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka at siemens.com>
> 
> The AM654 lacks an IOMMU, thus does not support isolating DMA requests
> from untrusted PCI devices to selected memory regions this way. Use
> static PVU-based protection instead. The PVU, when enabled, will only
> accept DMA requests that address previously configured regions.
> 
> Use the availability of a restricted-dma-pool memory region as trigger
> and register it as valid DMA target with the PVU. In addition, enable
> the mapping of requester IDs to VirtIDs in the PCI RC. Use only a single
> VirtID so far, catching all devices. This may be extended later on.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>

Acked-by: Bjorn Helgaas <bhelgaas at google.com>

> +	/* Only process the first restricted dma pool, more are not allowed */

s/dma/DMA/ to match other usage.



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