[PATCH] xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map

From: Max Filippov <jcmvbkbc@gmail.com>
To: linux-xtensa@linux-xtensa.org
Cc: Chris Zankel <chris@zankel.net>,
	Mike Rapoport <rppt@linux.ibm.com>,
	linux-kernel@vger.kernel.org, Max Filippov <jcmvbkbc@gmail.com>,
	stable@vger.kernel.org
Subject: [PATCH] xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map
Date: Wed, 13 Nov 2019 17:08:24 -0800	[thread overview]
Message-ID: <20191114010824.29540-1-jcmvbkbc@gmail.com> (raw)

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: f240ec09bb8a ("memblock: replace memblock_alloc_base(ANYWHERE)
		     with memblock_phys_alloc")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 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

