[RFC PATCH v1 49/57] arm64: Convert BUILD_BUG_ON to VM_BUG_ON

[Ryan Roberts]

There are some build bug checks that will no longer compile for
boot-time page size because the values they are testing are no longer
compile-time constants. Resolve these by converting them to VM_BUG_ON,
which will perform a runtime check.

Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
---

***NOTE***
Any confused maintainers may want to read the cover note here for context:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@xxxxxxx/

 arch/arm64/mm/init.c | 6 +++---
 arch/arm64/mm/mmu.c  | 4 ++--
 arch/arm64/mm/pgd.c  | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 42eb246949072..4d24034418b39 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -388,15 +388,15 @@ void __init mem_init(void)
 	 * detected at build time already.
 	 */
 #ifdef CONFIG_COMPAT
-	BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64);
+	VM_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64);
 #endif
 
 	/*
 	 * Selected page table levels should match when derived from
 	 * scratch using the virtual address range and page size.
 	 */
-	BUILD_BUG_ON(ARM64_HW_PGTABLE_LEVELS(CONFIG_ARM64_VA_BITS) !=
-		     CONFIG_PGTABLE_LEVELS);
+	VM_BUG_ON(ARM64_HW_PGTABLE_LEVELS(CONFIG_ARM64_VA_BITS) !=
+		  CONFIG_PGTABLE_LEVELS);
 
 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 		extern int sysctl_overcommit_memory;
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index b4cd3b6a73c22..ad7fd3fda705a 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -639,8 +639,8 @@ static void __init map_mem(pgd_t *pgdp)
 	 * entire reduced VA space is covered by a single pgd_t which will have
 	 * been populated without the PXNTable attribute by the time we get here.)
 	 */
-	BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end) &&
-		     pgd_index(_PAGE_OFFSET(VA_BITS_MIN)) != PTRS_PER_PGD - 1);
+	VM_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end) &&
+		  pgd_index(_PAGE_OFFSET(VA_BITS_MIN)) != PTRS_PER_PGD - 1);
 
 	early_kfence_pool = arm64_kfence_alloc_pool();
 
diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c
index 0c501cabc2384..4b106510358b1 100644
--- a/arch/arm64/mm/pgd.c
+++ b/arch/arm64/mm/pgd.c
@@ -56,7 +56,7 @@ void __init pgtable_cache_init(void)
 	 * With 52-bit physical addresses, the architecture requires the
 	 * top-level table to be aligned to at least 64 bytes.
 	 */
-	BUILD_BUG_ON(PGD_SIZE < 64);
+	VM_BUG_ON(PGD_SIZE < 64);
 #endif
 
 	/*
-- 
2.43.0