Re: [PATCH] powerpc/powernv: Fix BE PE number to opal_pci_eeh_freeze_clear()

On Mon, Aug 01, 2016 at 08:50:58PM +1000, Michael Ellerman wrote:

Gavin Shan [off-list ref] writes:

quoted

The PE number (@frozen_pe_no), filled by opal_pci_next_error() is
in big-endian format. Frozen PE number in CPU-endian should be passed
to opal_pci_eeh_freeze_clear() when clearing the frozen state if the
PE is invalid one.

This passes CPU-endian PE number to opal_pci_eeh_freeze_clear() and
it should be part of commit <0f36db77643b> ("powerpc/eeh: Fix wrong
printed PE number").

Which commit added the broken usage?

Looks like 2a485ad7c88d ("powerpc/powernv: Drop PHB operation
next_error()") ?

It is commit 71b540adffd9 ("powerpc/powernv: Don't escalate non-existing frozen PE").
As commit 0f36db77643b was merged to 4.3 kernel and the changes included in this
patch should be part of the commit. It's why I marked this with 4.3+

quoted

Cc: stable@vger.kernel.org # v4.3+
Suggested-by: Paul Mackerras <redacted>
Signed-off-by: Gavin Shan <redacted>
---
 arch/powerpc/platforms/powernv/eeh-powernv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 86544ea..75363d9 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -1538,7 +1538,7 @@ static int pnv_eeh_next_error(struct eeh_pe **pe)
 
 				/* Try best to clear it */
 				opal_pci_eeh_freeze_clear(phb->opal_id,
-					frozen_pe_no,
+					be64_to_cpu(frozen_pe_no),

Sparse knew about this:

 arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41: warning: incorrect type in argument 2 (different base types)
 arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41:    expected unsigned long long [unsigned] [usertype] pe_number
 arch/powerpc/platforms/powernv/eeh-powernv.c:1541:41:    got restricted __be64 [addressable] [usertype] frozen_pe_no

Ok, thanks. I never run sparse before and I will learn from you how to run it.

And finds some other problems in that file:

 arch/powerpc/platforms/powernv/eeh-powernv.c:875:23: warning: constant 0x8000000000000000 is so big it is unsigned long
 arch/powerpc/platforms/powernv/eeh-powernv.c:1309:21: warning: restricted __be16 degrades to integer

Ok. I will fix it with separate patches.

Thanks,
Gavin

cheers