[PATCH 4.7 040/184] powerpc/powernv: Fix corrupted PE allocation bitmap on releasing PE

[Greg Kroah-Hartman]

4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>

commit caa58f808834fca9a4443233fd09df5ab639690d upstream.

In pnv_ioda_free_pe(), the PE object (including the associated PE
number) is cleared before resetting the corresponding bit in the
PE allocation bitmap. It means PE#0 is always released to the bitmap
wrongly.

This fixes above issue by caching the PE number before the PE object
is cleared.

Fixes: 1e9167726c41 ("powerpc/powernv: Use PE instead of number during setup and release"
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/powerpc/platforms/powernv/pci-ioda.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -156,11 +156,12 @@ static struct pnv_ioda_pe *pnv_ioda_allo
 static void pnv_ioda_free_pe(struct pnv_ioda_pe *pe)
 {
 	struct pnv_phb *phb = pe->phb;
+	unsigned int pe_num = pe->pe_number;
 
 	WARN_ON(pe->pdev);
 
 	memset(pe, 0, sizeof(struct pnv_ioda_pe));
-	clear_bit(pe->pe_number, phb->ioda.pe_alloc);
+	clear_bit(pe_num, phb->ioda.pe_alloc);
 }
 
 /* The default M64 BAR is shared by all PEs */