Re: [PATCH v1 0/2] nvme-pci: Fix dma-iommu mapping failures when PAGE_SIZE=64KB

[Nicolin Chen]

On Thu, Feb 15, 2024 at 02:22:09PM +0000, Will Deacon wrote:

> > Though I am building with a v6.6 kernel, I see some warnings:
> >                  from kernel/dma/swiotlb.c:26:
> > kernel/dma/swiotlb.c: In function ‘swiotlb_area_find_slots’:
> > ./include/linux/minmax.h:21:35: warning: comparison of distinct pointer types lacks a cast
> >    21 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
> >       |                                   ^~
> > ./include/linux/minmax.h:27:18: note: in expansion of macro ‘__typecheck’
> >    27 |                 (__typecheck(x, y) && __no_side_effects(x, y))
> >       |                  ^~~~~~~~~~~
> > ./include/linux/minmax.h:37:31: note: in expansion of macro ‘__safe_cmp’
> >    37 |         __builtin_choose_expr(__safe_cmp(x, y), \
> >       |                               ^~~~~~~~~~
> > ./include/linux/minmax.h:75:25: note: in expansion of macro ‘__careful_cmp’
> >    75 | #define max(x, y)       __careful_cmp(x, y, >)
> >       |                         ^~~~~~~~~~~~~
> > kernel/dma/swiotlb.c:1007:26: note: in expansion of macro ‘max’
> >  1007 |                 stride = max(stride, PAGE_SHIFT - IO_TLB_SHIFT + 1);
> >       |                          ^~~
> >
> > Replacing with a max_t() can fix these.
> 
> Weird, I haven't seen that. I can fix it as you suggest, but please can
> you also share your .config so I can look into it further?

I attached it in my previous reply, yet forgot to mention before
hitting the send key that here is my gcc info:

# gcc -dumpmachine
aarch64-linux-gnu
# gcc --version
gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0