On Sun, 2017-03-05 at 10:54 +1100, Anton Blanchard wrote: > From: Anton Blanchard <an...@samba.org> > > I see a panic in early boot when building with a recent gcc > toolchain. > The issue is a divide by zero, which is undefined. Older toolchains > let us get away with it:
Maybe we should panic though ... not having a valid cache block size is going to be fatal in other areas... > int foo(int a) { return a / 0; } > > foo: > li 9,0 > divw 3,3,9 > extsw 3,3 > blr > > But newer ones catch it: > > foo: > trap > > Add a check to avoid the divide by zero. > > Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache > line") > Signed-off-by: Anton Blanchard <an...@samba.org> > --- > arch/powerpc/kernel/setup_64.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/setup_64.c > b/arch/powerpc/kernel/setup_64.c > index adf2084..afd1c26 100644 > --- a/arch/powerpc/kernel/setup_64.c > +++ b/arch/powerpc/kernel/setup_64.c > @@ -408,7 +408,8 @@ static void init_cache_info(struct ppc_cache_info > *info, u32 size, u32 lsize, > info->line_size = lsize; > info->block_size = bsize; > info->log_block_size = __ilog2(bsize); > - info->blocks_per_page = PAGE_SIZE / bsize; > + if (bsize) > + info->blocks_per_page = PAGE_SIZE / bsize; > > if (sets == 0) > info->assoc = 0xffff;