[PATCH v5 06/10] arm64/mm: Disable section mappings if XPFO is enabled

Tycho Andersen
2017-08-09T20:09:04Z

From: Juerg Haefliger <juerg.haefliger@hpe.com>

XPFO (eXclusive Page Frame Ownership) doesn't support section mappings
yet, so disable it if XPFO is turned on.

Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Tested-by: Tycho Andersen <tycho@docker.com>
---
arch/arm64/mm/mmu.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index f1eb15e0e864..38026b3ccb46 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -176,6 +176,18 @@ static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr,
} while (addr = next, addr != end);
}

+static inline bool use_section_mapping(unsigned long addr, unsigned long next,
+ unsigned long phys)
+{
+ if (IS_ENABLED(CONFIG_XPFO))
+ return false;
+
+ if (((addr | next | phys) & ~SECTION_MASK) != 0)
+ return false;
+
+ return true;
+}
+
static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end,
phys_addr_t phys, pgprot_t prot,
phys_addr_t (*pgtable_alloc)(void), int flags)
@@ -190,7 +202,7 @@ static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end,
next = pmd_addr_end(addr, end);

/* try section mapping first */
- if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
+ if (use_section_mapping(addr, next, phys) &&
(flags & NO_BLOCK_MAPPINGS) == 0) {
pmd_set_huge(pmd, phys, prot);

--
2.11.0