Commit 6ba422c7 authored by Anton Blanchard's avatar Anton Blanchard Committed by Michael Ellerman

powerpc/64: Avoid panic during boot due to divide by zero in init_cache_info()

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:

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: e2827fe5 ("powerpc/64: Clean up ppc64_caches using a struct per cache")
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 014d02cb
...@@ -408,7 +408,10 @@ static void init_cache_info(struct ppc_cache_info *info, u32 size, u32 lsize, ...@@ -408,7 +408,10 @@ static void init_cache_info(struct ppc_cache_info *info, u32 size, u32 lsize,
info->line_size = lsize; info->line_size = lsize;
info->block_size = bsize; info->block_size = bsize;
info->log_block_size = __ilog2(bsize); info->log_block_size = __ilog2(bsize);
if (bsize)
info->blocks_per_page = PAGE_SIZE / bsize; info->blocks_per_page = PAGE_SIZE / bsize;
else
info->blocks_per_page = 0;
if (sets == 0) if (sets == 0)
info->assoc = 0xffff; info->assoc = 0xffff;
......
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