From 59849d29a6d4dca434d2589e72e28d0c0ac99fcc Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Sun, 28 Mar 2010 20:08:25 +0000 Subject: [PATCH] sh: Enable the mmu in start_secondary() commit 4bea3418c737891894b9d3d3e9f8bbd67d66fa38 upstream. For the boot, enable_mmu() is called from setup_arch() but we don't call setup_arch() for any of the other cpus. So turn on the non-boot cpu's mmu inside of start_secondary(). I noticed this bug on an SMP board when trying to map I/O memory (smsc911x registers) into the kernel address space. Since the Address Translation bit in MMUCR wasn't set, accessing the virtual address where the smsc911x registers were supposedly mapped actually performed a physical address access. Signed-off-by: Matt Fleming Signed-off-by: Paul Mundt Signed-off-by: Greg Kroah-Hartman --- arch/sh/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 983e0792d5f3..1d19c199c73d 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -69,6 +69,7 @@ asmlinkage void __cpuinit start_secondary(void) unsigned int cpu; struct mm_struct *mm = &init_mm; + enable_mmu(); atomic_inc(&mm->mm_count); atomic_inc(&mm->mm_users); current->active_mm = mm; -- 2.39.5