| From 4bea3418c737891894b9d3d3e9f8bbd67d66fa38 Mon Sep 17 00:00:00 2001 |
| From: Matt Fleming <matt@console-pimps.org> |
| Date: Sun, 28 Mar 2010 20:08:25 +0000 |
| Subject: sh: Enable the mmu in start_secondary() |
| |
| From: Matt Fleming <matt@console-pimps.org> |
| |
| 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 <matt@console-pimps.org> |
| Signed-off-by: Paul Mundt <lethal@linux-sh.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/sh/kernel/smp.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| --- a/arch/sh/kernel/smp.c |
| +++ b/arch/sh/kernel/smp.c |
| @@ -69,6 +69,7 @@ asmlinkage void __cpuinit start_secondar |
| 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; |