This patch creates a new function called flush_tm_state to flush
the existing transactional memory state from the thread. It also
creates a function called flush_tmregs_to_thread which will then
be used on subsequent patches in this series.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/switch_to.h | 8 ++++++
arch/powerpc/kernel/process.c | 49 +++++++++++++++++++++++++++++-------
2 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/switch_to.h
b/arch/powerpc/include/asm/switch_to.h
index 58abeda..23752a9 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -82,6 +82,14 @@ static inline void flush_spe_to_thread(struct task_struct *t)
}
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+extern void flush_tmregs_to_thread(struct task_struct *);
+#else
+static inline void flush_tmregs_to_thread(struct task_struct *t)
+{
+}
+#endif
+
static inline void clear_task_ebb(struct task_struct *t)
{
#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index aa1df89..c36477b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -745,6 +745,45 @@ void restore_tm_state(struct pt_regs *regs)
#define __switch_to_tm(prev)
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+/*
+ * flush_tm_state
+ *
+ * Flush TM state out so we can copy it. __switch_to_tm() does this
+ * flush but it removes the checkpointed state from the current CPU and
+ * transitions the CPU out of TM mode. Hence we need to call
+ * tm_recheckpoint_new_task() (on the same task) to restore the
+ * checkpointed state back and the TM mode.
+ */
+static void flush_tm_state(struct task_struct *src)
+{
+ __switch_to_tm(src);
+ tm_recheckpoint_new_task(src);
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+void flush_tmregs_to_thread(struct task_struct *tsk)
+{
+ /*
+ * If task is not current, it should have been flushed
+ * already to it's thread_struct during __switch_to().
+ */
+ if (tsk != current)
+ return;
+
+ preempt_disable();
+ if (tsk->thread.regs) {
+ /*
+ * If we are still current, the TM state need to
+ * be flushed to thread_struct as it will be still
+ * present in the current cpu.
+ */
+ if (MSR_TM_ACTIVE(tsk->thread.regs->msr))
+ flush_tm_state(tsk);
+ }
+ preempt_enable();
+}
+#endif
+
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *new)
{
@@ -1079,15 +1118,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct
task_struct *src)
flush_altivec_to_thread(src);
flush_vsx_to_thread(src);
flush_spe_to_thread(src);
- /*
- * Flush TM state out so we can copy it. __switch_to_tm() does this
- * flush but it removes the checkpointed state from the current CPU and
- * transitions the CPU out of TM mode. Hence we need to call
- * tm_recheckpoint_new_task() (on the same task) to restore the
- * checkpointed state back and the TM mode.
- */
- __switch_to_tm(src);
- tm_recheckpoint_new_task(src);
+ flush_tm_state(src);
*dst = *src;
--
1.9.3
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