Blackfin arch: Fix BUG -- BF533 + 0.5 silicon + MPU + UART PIO -> crash

Apply ANOMALY_05000283 & ANOMALY_05000315
Workaround also to the EXCEPTION path.

Cover evt_ivhw also with ANOMALY_05000315
The Workaround needs to be prior to accesses (either read or write) to
any system MMR.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

2 files changed, 19 insertions, 1 deletions

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 5a219b228de3..76c42d3b5e85 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -484,6 +484,15 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
         [--sp] = ASTAT;
         [--sp] = (R7:6,P5:4);
 
+#if ANOMALY_05000283 || ANOMALY_05000315
+        cc = r7 == r7;
+        p5.h = HI(CHIPID);
+        p5.l = LO(CHIPID);
+        if cc jump 1f;
+        r7.l = W[p5];
+1:
+#endif
+
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
         /*
          * Save these registers, as they are only valid in exception context
@@ -1020,6 +1029,15 @@ ENTRY(_early_trap)
         SAVE_ALL_SYS
         trace_buffer_stop(p0,r0);
 
+#if ANOMALY_05000283 || ANOMALY_05000315
+        cc = r5 == r5;
+        p4.h = HI(CHIPID);
+        p4.l = LO(CHIPID);
+        if cc jump 1f;
+        r5.l = W[p4];
+1:
+#endif
+
         /* Turn caches off, to ensure we don't get double exceptions */
 
         P4.L = LO(IMEM_CONTROL);
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index b27e59d32401..647f0f522910 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -143,7 +143,7 @@ ENTRY(_evt_ivhw)
         fp = 0;
 #endif
 
-#if ANOMALY_05000283
+#if ANOMALY_05000283 || ANOMALY_05000315
         cc = r7 == r7;
         p5.h = HI(CHIPID);
         p5.l = LO(CHIPID);