On Sun, Mar 28, 2021 at 09:40:09AM +0200, Sven Peter wrote:
> Apple's new SoCs use iommus for almost all peripherals. These Device
> Address Resolution Tables must be setup before these peripherals can
> act as DMA masters.
>
> Signed-off-by: Sven Peter <s...@svenpeter.dev>
> ---
> MAINTAINERS | 1 +
> drivers/iommu/Kconfig | 14 +
> drivers/iommu/Makefile | 1 +
> drivers/iommu/apple-dart-iommu.c | 858 +++++++++++++++++++++++++++++++
> 4 files changed, 874 insertions(+)
> create mode 100644 drivers/iommu/apple-dart-iommu.c
[...]
> +/* must be called with held domain->lock */
> +static int apple_dart_attach_stream(struct apple_dart_domain *domain,
> + struct apple_dart *dart, u32 sid)
> +{
> + unsigned long flags;
> + struct apple_dart_stream *stream;
> + struct io_pgtable_cfg *pgtbl_cfg;
> + int ret;
> +
> + list_for_each_entry(stream, &domain->streams, stream_head) {
> + if (stream->dart == dart && stream->sid == sid) {
> + stream->num_devices++;
> + return 0;
> + }
> + }
> +
> + spin_lock_irqsave(&dart->lock, flags);
> +
> + if (WARN_ON(dart->used_sids & BIT(sid))) {
> + ret = -EINVAL;
> + goto error;
> + }
> +
> + stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> + if (!stream) {
> + ret = -ENOMEM;
> + goto error;
> + }
Just in case you missed it, a cocci bot noticed that you're using GFP_KERNEL
to allocate while holding a spinlock here:
https://lore.kernel.org/r/alpine.DEB.2.22.394.2104041724340.2958@hadrien
Will
