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| author | Matt Fleming <matt@console-pimps.org> | 2010-03-28 20:08:25 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-26 07:47:47 -0700 |
| commit | 59849d29a6d4dca434d2589e72e28d0c0ac99fcc (patch) | |
| tree | 30ef6b2d7c351a099fa6b07d1f491026e4cd4895 | |
| parent | be366f07087f374dcf5f038c187828697ddc7480 (diff) | |
| download | lwn-59849d29a6d4dca434d2589e72e28d0c0ac99fcc.tar.gz lwn-59849d29a6d4dca434d2589e72e28d0c0ac99fcc.zip | |
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 <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/sh/kernel/smp.c | 1 |
1 files changed, 1 insertions, 0 deletions
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; |