[PATCH v2 13/13] MIPS: mm: Panic if an XPA kernel is run without RIXI

From: Paul Burton
Date: Mon Apr 18 2016 - 05:39:12 EST


XPA kernels hardcode for the presence of RIXI - the PTE format & its
handling presume RI & XI bits. Make this dependence explicit by panicing
if we run on a system that violates it.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>

---

Changes in v2:
- New patch, in response to clarification on patch 5.

arch/mips/mm/tlbex.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 3f1a8a2..9c39c66 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -2395,6 +2395,9 @@ void build_tlb_refill_handler(void)
*/
static int run_once = 0;

+ if (config_enabled(CONFIG_XPA) && !cpu_has_rixi)
+ panic("Kernels supporting XPA currently require CPUs with RIXI\n");
+
output_pgtable_bits_defines();
check_pabits();

--
2.8.0