On Wed, Apr 7, 2021, at 12:42, Will Deacon wrote:
> 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
>
Thanks for the reminder!
I haven't replied yet because that one was found later when the bot picked up
a (slightly earlier) version that Marc was using to bring up pcie I believe.
I'll fix it for the next version.
Sven
