github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-09 23:23:53 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

sh: Enable the mmu in start_secondary()

Browse Source 
commit 4bea3418c7 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>
This commit is contained in:
Matt Fleming 2010-03-28 20:08:25 +00:00 committed by Greg Kroah-Hartman
parent 94aa7e9130
commit 69fd993218
1 changed files with 1 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/sh/kernel/smp.c
View File

@ -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;