This simplifies __switch_to a bit, and will make it easier to make iopl
optional later.
Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
arch/x86/kernel/process-io.h | 13 +++++++++++++
arch/x86/kernel/process_32.c | 9 +--------
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/process-io.h b/arch/x86/kernel/process-io.h
index ffa65e8..6d4f147 100644
--- a/arch/x86/kernel/process-io.h
+++ b/arch/x86/kernel/process-io.h
@@ -24,4 +24,17 @@ static inline int copy_io_bitmap(struct task_struct *me,
return 0;
}
+static inline void switch_iopl_mask(struct thread_struct *prev,
+ struct thread_struct *next)
+{
+ /*
+ * Restore IOPL if needed. In normal use, the flags restore
+ * in the switch assembly will handle this. But if the kernel
+ * is running virtualized at a non-zero CPL, the popf will
+ * not restore flags, so it must be done in a separate step.
+ */
+ if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
+ set_iopl_mask(next->iopl);
+}
+
#endif /* _X86_KERNEL_PROCESS_IO_H */
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b55f78e..3b82293 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -265,14 +265,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
*/
load_TLS(next, cpu);
- /*
- * Restore IOPL if needed. In normal use, the flags restore
- * in the switch assembly will handle this. But if the kernel
- * is running virtualized at a non-zero CPL, the popf will
- * not restore flags, so it must be done in a separate step.
- */
- if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
- set_iopl_mask(next->iopl);
+ switch_iopl_mask(prev, next);
/*
* If it were not for PREEMPT_ACTIVE we could guarantee that the
--
2.1.1
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