Blackfin: workaround anomaly 05000283

Make sure our interrupt entry code with exact hardware errors handles
anomaly 05000283 (infinite stall in system MMR kill) so we don't stall
while under load.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 26 insertions, 4 deletions

diff --git a/arch/blackfin/include/asm/entry.h b/arch/blackfin/include/asm/entry.h
index ec58efc130e6..55b808fced71 100644
--- a/arch/blackfin/include/asm/entry.h
+++ b/arch/blackfin/include/asm/entry.h
@@ -36,6 +36,21 @@
 # define LOAD_IPIPE_IPEND
 #endif
 
+/*
+ * Workaround for anomalies 05000283 and 05000315
+ */
+#if ANOMALY_05000283 || ANOMALY_05000315
+# define ANOMALY_283_315_WORKAROUND(preg, dreg)         \
+        cc = dreg == dreg;                              \
+        preg.h = HI(CHIPID);                            \
+        preg.l = LO(CHIPID);                            \
+        if cc jump 1f;                                  \
+        dreg.l = W[preg];                               \
+1:
+#else
+# define ANOMALY_283_315_WORKAROUND(preg, dreg)
+#endif /* ANOMALY_05000283 || ANOMALY_05000315 */
+
 #ifndef CONFIG_EXACT_HWERR
 /* As a debugging aid - we save IPEND when DEBUG_KERNEL is on,
  * otherwise it is a waste of cycles.
@@ -88,17 +103,22 @@
  * As you can see by the code - we actually need to do two SSYNCS - one to
  * make sure the read/writes complete, and another to make sure the hardware
  * error is recognized by the core.
+ *
+ * The extra nop before the SSYNC is to make sure we work around 05000244,
+ * since the 283/315 workaround includes a branch to the end
  */
 #define INTERRUPT_ENTRY(N)                                              \
-    SSYNC;                                                              \
-    SSYNC;                                                              \
     [--sp] = SYSCFG;                                                    \
     [--sp] = P0;        /*orig_p0*/                                     \
     [--sp] = R0;        /*orig_r0*/                                     \
     [--sp] = (R7:0,P5:0);                                               \
     R1 = ASTAT;                                                         \
+    ANOMALY_283_315_WORKAROUND(p0, r0)                                  \
     P0.L = LO(ILAT);                                                    \
     P0.H = HI(ILAT);                                                    \
+    NOP;                                                                \
+    SSYNC;                                                              \
+    SSYNC;                                                              \
     R0 = [P0];                                                          \
     CC = BITTST(R0, EVT_IVHW_P);                                        \
     IF CC JUMP 1f;                                                      \
@@ -118,15 +138,17 @@
     RTI;
 
 #define TIMER_INTERRUPT_ENTRY(N)                                        \
-    SSYNC;                                                              \
-    SSYNC;                                                              \
     [--sp] = SYSCFG;                                                    \
     [--sp] = P0;        /*orig_p0*/                                     \
     [--sp] = R0;        /*orig_r0*/                                     \
     [--sp] = (R7:0,P5:0);                                               \
     R1 = ASTAT;                                                         \
+    ANOMALY_283_315_WORKAROUND(p0, r0)                                  \
     P0.L = LO(ILAT);                                                    \
     P0.H = HI(ILAT);                                                    \
+    NOP;                                                                \
+    SSYNC;                                                              \
+    SSYNC;                                                              \
     R0 = [P0];                                                          \
     CC = BITTST(R0, EVT_IVHW_P);                                        \
     IF CC JUMP 1f;                                                      \