[PATCH] [v2] powerpc: Clean up tm_abort duplication in hash_utils_64.c

From: Rui Teng
Date: Fri Sep 02 2016 - 02:17:48 EST


The same logic appears twice and should probably be pulled out into a function.

Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Rui Teng <rui.teng@xxxxxxxxxxxxxxxxxx>
---
Changes in V2:
- Change function to static and inline
- Use #else block to define an empty static inline function

---
arch/powerpc/mm/hash_utils_64.c | 55 +++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 0821556..b68f6d0 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1460,6 +1460,29 @@ out_exit:
local_irq_restore(flags);
}

+/*
+ * Transactions are not aborted by tlbiel, only tlbie.
+ * Without, syncing a page back to a block device w/ PIO could pick up
+ * transactional data (bad!) so we force an abort here. Before the
+ * sync the page will be made read-only, which will flush_hash_page.
+ * BIG ISSUE here: if the kernel uses a page from userspace without
+ * unmapping it first, it may see the speculated version.
+ */
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static inline void local_tm_abort(int local)
+{
+ if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
+ MSR_TM_ACTIVE(current->thread.regs->msr)) {
+ tm_enable();
+ tm_abort(TM_CAUSE_TLBI);
+ }
+}
+#else
+static inline void local_tm_abort(int local)
+{
+}
+#endif
+
/* WARNING: This is called from hash_low_64.S, if you change this prototype,
* do not forget to update the assembly call site !
*/
@@ -1486,21 +1509,7 @@ void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
ssize, local);
} pte_iterate_hashed_end();

-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
- /* Transactions are not aborted by tlbiel, only tlbie.
- * Without, syncing a page back to a block device w/ PIO could pick up
- * transactional data (bad!) so we force an abort here. Before the
- * sync the page will be made read-only, which will flush_hash_page.
- * BIG ISSUE here: if the kernel uses a page from userspace without
- * unmapping it first, it may see the speculated version.
- */
- if (local && cpu_has_feature(CPU_FTR_TM) &&
- current->thread.regs &&
- MSR_TM_ACTIVE(current->thread.regs->msr)) {
- tm_enable();
- tm_abort(TM_CAUSE_TLBI);
- }
-#endif
+ local_tm_abort(local);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -1557,21 +1566,7 @@ void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
MMU_PAGE_16M, ssize, local);
}
tm_abort:
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
- /* Transactions are not aborted by tlbiel, only tlbie.
- * Without, syncing a page back to a block device w/ PIO could pick up
- * transactional data (bad!) so we force an abort here. Before the
- * sync the page will be made read-only, which will flush_hash_page.
- * BIG ISSUE here: if the kernel uses a page from userspace without
- * unmapping it first, it may see the speculated version.
- */
- if (local && cpu_has_feature(CPU_FTR_TM) &&
- current->thread.regs &&
- MSR_TM_ACTIVE(current->thread.regs->msr)) {
- tm_enable();
- tm_abort(TM_CAUSE_TLBI);
- }
-#endif
+ local_tm_abort(local);
return;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
--
2.7.4