xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map

KASAN shadow map doesn't need to be accessible through the linear kernel
mapping, allocate its pages with MEMBLOCK_ALLOC_ANYWHERE so that high
memory can be used. This frees up to ~100MB of low memory on xtensa
configurations with KASAN and high memory.

Cc: stable@vger.kernel.org # v5.1+
Fixes: f240ec09 ("memblock: replace memblock_alloc_base(ANYWHERE) with memblock_phys_alloc")
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/mm/kasan_init.c

@@ -60,7 +60,9 @@ static void __init populate(void *start, void *end)
 
 		for (k = 0; k < PTRS_PER_PTE; ++k, ++j) {
 			phys_addr_t phys =
-				memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+				memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE,
+							  0,
+							  MEMBLOCK_ALLOC_ANYWHERE);
 
 			if (!phys)
 				panic("Failed to allocate page table page\n");