[PATCH] xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map

From: Max Filippov
Date: Wed Nov 13 2019 - 20:08:49 EST


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@xxxxxxxxxxxxxxx # v5.1+
Fixes: f240ec09bb8a ("memblock: replace memblock_alloc_base(ANYWHERE)
with memblock_phys_alloc")
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
arch/xtensa/mm/kasan_init.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/xtensa/mm/kasan_init.c b/arch/xtensa/mm/kasan_init.c
index 9c957791bb33..e3baa21ff24c 100644
--- a/arch/xtensa/mm/kasan_init.c
+++ b/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");
--
2.20.1