--- base/allocator/partition_allocator/page_allocator_constants.h.orig	2022-10-05 07:34:01 UTC
+++ base/allocator/partition_allocator/page_allocator_constants.h
@@ -25,7 +25,7 @@
 // elimination.
 #define PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR __attribute__((const))
 
-#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+#elif (BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_BSD)) && defined(ARCH_CPU_ARM64)
 // This should work for all POSIX (if needed), but currently all other
 // supported OS/architecture combinations use either hard-coded values
 // (such as x86) or have means to determine these values without needing
@@ -81,7 +81,7 @@ PageAllocationGranularityShift() {
   return 14;  // 16kB
 #elif BUILDFLAG(IS_APPLE) && defined(ARCH_CPU_64_BITS)
   return static_cast<size_t>(vm_page_shift);
-#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+#elif (BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_BSD)) && defined(ARCH_CPU_ARM64)
   // arm64 supports 4kb (shift = 12), 16kb (shift = 14), and 64kb (shift = 16)
   // page sizes. Retrieve from or initialize cache.
   size_t shift = page_characteristics.shift.load(std::memory_order_relaxed);
@@ -102,7 +102,7 @@ PageAllocationGranularity() {
   // This is literally equivalent to |1 << PageAllocationGranularityShift()|
   // below, but was separated out for IS_APPLE to avoid << on a non-constexpr.
   return vm_page_size;
-#elif BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64)
+#elif (BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_BSD)) && defined(ARCH_CPU_ARM64)
   // arm64 supports 4kb, 16kb, and 64kb page sizes. Retrieve from or
   // initialize cache.
   size_t size = page_characteristics.size.load(std::memory_order_relaxed);
@@ -141,7 +141,7 @@ SystemPageShift() {
 PAGE_ALLOCATOR_CONSTANTS_DECLARE_CONSTEXPR PA_ALWAYS_INLINE size_t
 SystemPageSize() {
 #if (BUILDFLAG(IS_APPLE) && defined(ARCH_CPU_64_BITS)) || \
-    (BUILDFLAG(IS_LINUX) && defined(ARCH_CPU_ARM64))
+    ((BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_BSD)) && defined(ARCH_CPU_ARM64))
   // This is literally equivalent to |1 << SystemPageShift()| below, but was
   // separated out for 64-bit IS_APPLE and arm64 on Linux to avoid << on a
   // non-constexpr.