ARM: 6942/1: mm: make TTBR1 always point to swapper_pg_dir on ARMv6/7

This patch makes TTBR1 point to swapper_pg_dir so that global, kernel
mappings can be used exclusively on v6 and v7 cores where they are
needed.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 6 insertions, 2 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c9173cfbbc7..8224b1d5f2f 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -113,6 +113,7 @@ ENTRY(stext)
         ldr     r13, =__mmap_switched           @ address to jump to after
                                                 @ mmu has been enabled
         adr     lr, BSYM(1f)                    @ return (PIC) address
+        mov     r8, r4                          @ set TTBR1 to swapper_pg_dir
  ARM(   add     pc, r10, #PROCINFO_INITFUNC     )
  THUMB( add     r12, r10, #PROCINFO_INITFUNC    )
  THUMB( mov     pc, r12                         )
@@ -302,8 +303,10 @@ ENTRY(secondary_startup)
          */
         adr     r4, __secondary_data
         ldmia   r4, {r5, r7, r12}               @ address to jump to after
-        sub     r4, r4, r5                      @ mmu has been enabled
-        ldr     r4, [r7, r4]                    @ get secondary_data.pgdir
+        sub     lr, r4, r5                      @ mmu has been enabled
+        ldr     r4, [r7, lr]                    @ get secondary_data.pgdir
+        add     r7, r7, #4
+        ldr     r8, [r7, lr]                    @ get secondary_data.swapper_pg_dir
         adr     lr, BSYM(__enable_mmu)          @ return address
         mov     r13, r12                        @ __secondary_switched address
  ARM(   add     pc, r10, #PROCINFO_INITFUNC     ) @ initialise processor
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index d439a8f4c07..344e52b16c8 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -105,6 +105,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
          */
         secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
         secondary_data.pgdir = virt_to_phys(pgd);
+        secondary_data.swapper_pg_dir = virt_to_phys(swapper_pg_dir);
         __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data));
         outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1));