Blackfin: SMP: kgdb: flush core internal write buffer before flushinv

KGDB single step in SMP kernel may hang forever in flushinv without a
CSYNC ahead.  This is because the core internal write buffers need to
be flushed before invalidating the data cache to make sure the insn
fetch is not out of sync.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/arch/blackfin/mach-bf561/atomic.S b/arch/blackfin/mach-bf561/atomic.S
index f99f174b129f694609710faf9fe653f01f76b503..52d6f73fccedd152fb215702bebf28556ab3487e 100644 (file)
--- a/arch/blackfin/mach-bf561/atomic.S
+++ b/arch/blackfin/mach-bf561/atomic.S
@@ -49,6 +49,7 @@ ENTRY(_get_core_lock)
        jump .Lretry_corelock
 .Ldone_corelock:
        p0 = r1;
+       /* flush core internal write buffer before invalidate dcache */
        CSYNC(r2);
        flushinv[p0];
        SSYNC(r2);
@@ -685,6 +686,8 @@ ENTRY(___raw_atomic_test_asm)
        r1 = -L1_CACHE_BYTES;
        r1 = r0 & r1;
        p0 = r1;
+       /* flush core internal write buffer before invalidate dcache */
+       CSYNC(r2);
        flushinv[p0];
        SSYNC(r2);
        r0 = [p1];
@@ -907,6 +910,8 @@ ENTRY(___raw_uncached_fetch_asm)
        r1 = -L1_CACHE_BYTES;
        r1 = r0 & r1;
        p0 = r1;
+       /* flush core internal write buffer before invalidate dcache */
+       CSYNC(r2);
        flushinv[p0];
        SSYNC(r2);
        r0 = [p1];