powerpc/mm: dump block address translation on book3s/32

This patch adds a debugfs file to dump block address translation:

~# cat /sys/kernel/debug/powerpc/block_address_translation
---[ Instruction Block Address Translations ]---
0:         -
1:         -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel EXEC coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel EXEC coherent
4:         -
5:         -
6:         -
7:         -

---[ Data Block Address Translations ]---
0:         -
1:         -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel RW coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent
4:         -
5:         -
6:         -
7:         -

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/32/mmu-hash.h

@@ -37,8 +37,12 @@
 #define BAT_PHYS_ADDR(x) ((u32)((x & 0x00000000fffe0000ULL) | \
 				((x & 0x0000000e00000000ULL) >> 24) | \
 				((x & 0x0000000100000000ULL) >> 30)))
+#define PHYS_BAT_ADDR(x) (((u64)(x) & 0x00000000fffe0000ULL) | \
+			  (((u64)(x) << 24) & 0x0000000e00000000ULL) | \
+			  (((u64)(x) << 30) & 0x0000000100000000ULL))
 #else
 #define BAT_PHYS_ADDR(x) (x)
+#define PHYS_BAT_ADDR(x) ((x) & 0xfffe0000)
 #endif
 
 struct ppc_bat {