Re: [RFC PATCH v3 2/6] swiotlb: Add restricted DMA pool
From: Konrad Rzeszutek Wilk <hidden>
Date: 2021-01-06 18:55:23
Also in:
linux-devicetree, linux-iommu, linuxppc-dev, lkml
Hello! In this file:
quoted hunk ↗ jump to hunk
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index e4368159f88a..7fb2ac087d23 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c
..
+static const struct reserved_mem_ops rmem_swiotlb_ops = {
+ .device_init = rmem_swiotlb_device_init,
+ .device_release = rmem_swiotlb_device_release,
+};
+
+static int __init rmem_swiotlb_setup(struct reserved_mem *rmem)
+{
+ unsigned long node = rmem->fdt_node;
+
+ if (of_get_flat_dt_prop(node, "reusable", NULL) ||
+ of_get_flat_dt_prop(node, "linux,cma-default", NULL) ||
+ of_get_flat_dt_prop(node, "linux,dma-default", NULL) ||
+ of_get_flat_dt_prop(node, "no-map", NULL))
+ return -EINVAL;
+
+ rmem->ops = &rmem_swiotlb_ops;
+ pr_info("Reserved memory: created device swiotlb memory pool at %pa, size %ld MiB\n",
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup);The code should be as much as possible arch-agnostic. That is why there are multiple -swiotlb files scattered in arch directories that own the architecture specific code. Would it be possible to move the code there and perhaps have a ARM specific front-end for this DMA restricted pool there? See for example the xen-swiotlb code. Cheers! Konrad