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>

3 files changed, 31 insertions, 36 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;                                                      \
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index a9b15aaf5254..01af24cde362 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -513,14 +513,7 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
         ssync;
 #endif
 
-#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
+        ANOMALY_283_315_WORKAROUND(p5, r7)
 
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
         /*
@@ -1134,14 +1127,7 @@ 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
+        ANOMALY_283_315_WORKAROUND(p4, r5)
 
         /* Turn caches off, to ensure we don't get double exceptions */
 
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index c754ff74bd5d..82d417ef4b5b 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -119,14 +119,8 @@ __common_int_entry:
         fp = 0;
 #endif
 
-#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
+        ANOMALY_283_315_WORKAROUND(p5, r7)
+
         r1 =  sp;
         SP += -12;
 #ifdef CONFIG_IPIPE
@@ -158,14 +152,7 @@ ENTRY(_evt_ivhw)
         fp = 0;
 #endif
 
-#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
+        ANOMALY_283_315_WORKAROUND(p5, r7)
 
         /* Handle all stacked hardware errors
          * To make sure we don't hang forever, only do it 10 times