powerpc/mm: Add addr_limit to mm_context and use it to derive max slice index

In the followup patch, we will increase the slice array size to handle
512TB range, but will limit the max addr to 128TB. Avoid doing
unnecessary computation and avoid doing slice mask related operation
above address limit.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 4697da895133..a79db6b63466 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -920,6 +920,15 @@ void __init setup_arch(char **cmdline_p)
         init_mm.end_code = (unsigned long) _etext;
         init_mm.end_data = (unsigned long) _edata;
         init_mm.brk = klimit;
+
+#ifdef CONFIG_PPC_MM_SLICES
+#ifdef CONFIG_PPC64
+        init_mm.context.addr_limit = TASK_SIZE_USER64;
+#else
+#error  "context.addr_limit not initialized."
+#endif
+#endif
+
 #ifdef CONFIG_PPC_64K_PAGES
         init_mm.context.pte_frag = NULL;
 #endif