[PATCH v3 2/4] armv8: mmu: teach the pagetable dumper to show explicit FAULT maps

[Casey Connolly]

When a region is explicitly unmapped (like with
mmu_change_region_attr(.... PTE_TYPE_FAULT)) the address translation
still remains but won't be used since the region is marked invalid.
Print these regions when we dump the pagetable to help with debugging.

Signed-off-by: Casey Connolly <casey.connolly at linaro.org>
---
 arch/arm/cpu/armv8/cache_v8.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index 368c622cd18e..36d337378fcd 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -533,9 +533,9 @@ static void __pagetable_walk(u64 addr, u64 tcr, int level, pte_walker_cb_t cb, v
 
 		if (exit)
 			return;
 
-		if (pte_type(&pte) == PTE_TYPE_FAULT)
+		if (!pte)
 			continue;
 
 		attrs = pte & ALL_ATTRS;
 		/* If we're currently inside a block or set of pages */
@@ -572,9 +572,9 @@ static void __pagetable_walk(u64 addr, u64 tcr, int level, pte_walker_cb_t cb, v
 
 			/* Go down a level */
 			__pagetable_walk(_addr, tcr, level + 1, cb, priv);
 			state[level] = WALKER_STATE_START;
-		} else if (pte_type(&pte) == PTE_TYPE_BLOCK || pte_type(&pte) == PTE_TYPE_PAGE) {
+		} else {
 			/* We foud a block or page, start walking */
 			entry_start = pte;
 			state[level] = WALKER_STATE_REGION;
 		}
@@ -707,8 +707,12 @@ static bool pagetable_print_entry(u64 start_attrs, u64 end, int va_bits, int lev
 {
 	u64 _addr = start_attrs & GENMASK_ULL(va_bits, PAGE_SHIFT);
 	int indent = va_bits < 39 ? level - 1 : level;
 
+	/* Ignore empty blocks */
+	if (!start_attrs)
+		return false;
+
 	printf("%*s", indent * 2, "");
 	if (PTE_IS_TABLE(start_attrs, level))
 		printf("[%#016llx]%19s", _addr, "");
 	else

-- 
2.53.0