[RFC 4/8] powerpc/ptdump/64: Fix kernel_hash_pagetable dump for ISA v3.00 HPTE format

[Ritesh Harjani (IBM)]

HPTE format was changed since Power9 (ISA 3.0) onwards. While dumping
kernel hash page tables, nothing gets printed on powernv P9+. This patch
utilizes the helpers added in the patch tagged as fixes, to convert new
format to old format and dump the hptes. This fix is only needed for
native_find() (powernv), since pseries continues to work fine with the
old format.

Cc: Madhavan Srinivasan <maddy at linux.ibm.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Nicholas Piggin <npiggin at gmail.com>
Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
Cc: Paul Mackerras <paulus at ozlabs.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar at kernel.org>
Cc: Donet Tom <donettom at linux.ibm.com>
Cc: linuxppc-dev at lists.ozlabs.org
Fixes: 6b243fcfb5f1e ("powerpc/64: Simplify adaptation to new ISA v3.00 HPTE format")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list at gmail.com>
---
 arch/powerpc/mm/ptdump/hashpagetable.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/mm/ptdump/hashpagetable.c b/arch/powerpc/mm/ptdump/hashpagetable.c
index a6baa6166d94..671d0dc00c6d 100644
--- a/arch/powerpc/mm/ptdump/hashpagetable.c
+++ b/arch/powerpc/mm/ptdump/hashpagetable.c
@@ -216,6 +216,8 @@ static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64
 	vpn  = hpt_vpn(ea, vsid, ssize);
 	hash = hpt_hash(vpn, shift, ssize);
 	want_v = hpte_encode_avpn(vpn, psize, ssize);
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		want_v = hpte_old_to_new_v(want_v);

 	/* to check in the secondary hash table, we invert the hash */
 	if (!primary)
@@ -229,6 +231,10 @@ static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64
 			/* HPTE matches */
 			*v = be64_to_cpu(hptep->v);
 			*r = be64_to_cpu(hptep->r);
+			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+				*v = hpte_new_to_old_v(*v, *r);
+				*r = hpte_new_to_old_r(*r);
+			}
 			return 0;
 		}
 		++hpte_group;
--
2.50.1