---

yaml
---
r: 148567
b: refs/heads/master
c: b9a3899
h: refs/heads/master
i:
  148565: af516fd
  148563: 7e771ff
  148559: b0ee20e
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 97b070c8e7e82be30c8a3bf19e69b8c0c71f1fac
+refs/heads/master: b9a3899d59c3f0fc074573f0eba2419b1e4c0bca

trunk/arch/blackfin/Kconfig.debug

@@ -54,6 +54,19 @@ config DEBUG_HWERR
 	  hardware error interrupts and need to know where they are coming
 	  from.
 
+config EXACT_HWERR
+	bool "Try to make Hardware errors exact"
+	depends on DEBUG_HWERR
+	help
+	  By default, the Blackfin hardware errors are not exact - the error
+          be reported multiple cycles after the error happens. This delay
+	  can cause the wrong application, or even the kernel to receive a
+	  signal to be killed. If you are getting HW errors in your system,
+	  try turning this on to ensure they are at least comming from the
+	  proper thread.
+
+	  On production systems, it is safe (and a small optimization) to say N.
+
 config DEBUG_DOUBLEFAULT
 	bool "Debug Double Faults"
 	default n

trunk/arch/blackfin/include/asm/entry.h

@@ -35,21 +35,39 @@
 #else
 # define LOAD_IPIPE_IPEND
 #endif
+
+#ifndef CONFIG_EXACT_HWERR
+/* As a debugging aid - we save IPEND when DEBUG_KERNEL is on,
+ * otherwise it is a waste of cycles.
+ */
+# ifndef CONFIG_DEBUG_KERNEL
+#define INTERRUPT_ENTRY(N)						\
+    [--sp] = SYSCFG;							\
+    [--sp] = P0;	/*orig_p0*/					\
+    [--sp] = R0;	/*orig_r0*/					\
+    [--sp] = (R7:0,P5:0);						\
+    R0 = (N);								\
+    LOAD_IPIPE_IPEND							\
+    jump __common_int_entry;
+# else /* CONFIG_DEBUG_KERNEL */
 #define INTERRUPT_ENTRY(N)						\
     [--sp] = SYSCFG;							\
-									\
     [--sp] = P0;	/*orig_p0*/					\
     [--sp] = R0;	/*orig_r0*/					\
     [--sp] = (R7:0,P5:0);						\
+    p0.l = lo(IPEND);							\
+    p0.h = hi(IPEND);							\
+    r1 = [p0];								\
     R0 = (N);								\
     LOAD_IPIPE_IPEND							\
     jump __common_int_entry;
+# endif /* CONFIG_DEBUG_KERNEL */
 
 /* For timer interrupts, we need to save IPEND, since the user_mode
-	   macro accesses it to determine where to account time.  */
+ *macro accesses it to determine where to account time.
+ */
 #define TIMER_INTERRUPT_ENTRY(N)					\
     [--sp] = SYSCFG;							\
-									\
     [--sp] = P0;	/*orig_p0*/					\
     [--sp] = R0;	/*orig_r0*/					\
     [--sp] = (R7:0,P5:0);						\
@@ -58,6 +76,74 @@
     r1 = [p0];								\
     R0 = (N);								\
     jump __common_int_entry;
+#else /* CONFIG_EXACT_HWERR is defined */
+
+/* if we want hardware error to be exact, we need to do a SSYNC (which forces
+ * read/writes to complete to the memory controllers), and check to see that
+ * caused a pending HW error condition. If so, we assume it was caused by user
+ * space, by setting the same interrupt that we are in (so it goes off again)
+ * and context restore, and a RTI (without servicing anything). This should
+ * cause the pending HWERR to fire, and when that is done, this interrupt will
+ * be re-serviced properly.
+ * 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.
+ */
+#define INTERRUPT_ENTRY(N)						\
+    SSYNC;								\
+    SSYNC;								\
+    [--sp] = SYSCFG;							\
+    [--sp] = P0;	/*orig_p0*/					\
+    [--sp] = R0;	/*orig_r0*/					\
+    [--sp] = (R7:0,P5:0);						\
+    R1 = ASTAT;								\
+    P0.L = LO(ILAT);							\
+    P0.H = HI(ILAT);							\
+    R0 = [P0];								\
+    CC = BITTST(R0, EVT_IVHW_P);					\
+    IF CC JUMP 1f;							\
+    ASTAT = R1;								\
+    p0.l = lo(IPEND);							\
+    p0.h = hi(IPEND);							\
+    r1 = [p0];								\
+    R0 = (N);								\
+    LOAD_IPIPE_IPEND							\
+    jump __common_int_entry;						\
+1:  ASTAT = R1;								\
+    RAISE N;								\
+    (R7:0, P5:0) = [SP++];						\
+    SP += 0x8;								\
+    SYSCFG = [SP++];							\
+    CSYNC;								\
+    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;								\
+    P0.L = LO(ILAT);							\
+    P0.H = HI(ILAT);							\
+    R0 = [P0];								\
+    CC = BITTST(R0, EVT_IVHW_P);					\
+    IF CC JUMP 1f;							\
+    ASTAT = R1;								\
+    p0.l = lo(IPEND);							\
+    p0.h = hi(IPEND);							\
+    r1 = [p0];								\
+    R0 = (N);								\
+    jump __common_int_entry;						\
+1:  ASTAT = R1;								\
+    RAISE N;								\
+    (R7:0, P5:0) = [SP++];						\
+    SP += 0x8;								\
+    SYSCFG = [SP++];							\
+    CSYNC;								\
+    RTI;
+#endif	/* CONFIG_EXACT_HWERR */
 
 /* This one pushes RETI without using CLI.  Interrupts are enabled.  */
 #define SAVE_CONTEXT_SYSCALL	save_context_syscall

trunk/arch/blackfin/mach-common/entry.S

@@ -200,7 +200,18 @@ ENTRY(_ex_single_step)
 	cc = r7 == 0;
 	if !cc jump 1f;
 #endif
-
+#ifdef CONFIG_EXACT_HWERR
+	/* Read the ILAT, and to check to see if the process we are
+	 * single stepping caused a previous hardware error
+	 * If so, do not single step, (which lowers to IRQ5, and makes
+	 * us miss the error).
+	 */
+	p5.l = lo(ILAT);
+	p5.h = hi(ILAT);
+	r7 = [p5];
+	cc = bittst(r7, EVT_IVHW_P);
+	if cc jump 1f;
+#endif
 	/* Single stepping only a single instruction, so clear the trace
 	 * bit here.  */
 	r7 = syscfg;
@@ -262,15 +273,6 @@ ENTRY(_bfin_return_from_exception)
 	r6 = 0x25;
 	CC = R7 == R6;
 	if CC JUMP _double_fault;
-
-	/* Did we cause a HW error? */
-	p5.l = lo(ILAT);
-	p5.h = hi(ILAT);
-	r6 = [p5];
-	r7 = 0x20;		/* Did I just cause anther HW error? */
-	r6 = r7 & r6;
-	CC = R7 == R6;
-	if CC JUMP _double_fault;
 #endif
 
 	(R7:6,P5:4) = [sp++];
@@ -472,6 +474,16 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
 	[--sp] = ASTAT;
 	[--sp] = (R7:6,P5:4);
 
+#ifdef CONFIG_EXACT_HWERR
+	/* Make sure all pending read/writes complete. This will ensure any
+	 * accesses which could cause hardware errors completes, and signal
+	 * the the hardware before we do something silly, like crash the
+	 * kernel. We don't need to work around anomaly 05000312, since
+	 * we are already atomic
+	 */
+	ssync;
+#endif
+
 #if ANOMALY_05000283 || ANOMALY_05000315
 	cc = r7 == r7;
 	p5.h = HI(CHIPID);
@@ -854,7 +866,7 @@ ENTRY(_ret_from_exception)
 	p1.h = _schedule_and_signal;
 	[p0] = p1;
 	csync;
-	raise 15;		/* raise evt14 to do signal or reschedule */
+	raise 15;		/* raise evt15 to do signal or reschedule */
 4:
 	r0 = syscfg;
 	bitclr(r0, 0);
@@ -915,7 +927,7 @@ ENTRY(_return_from_int)
 	p1.h = _schedule_and_signal_from_int;
 	[p0] = p1;
 	csync;
-#if ANOMALY_05000281
+#if ANOMALY_05000281 || ANOMALY_05000461
 	r0.l = lo(SAFE_USER_INSTRUCTION);
 	r0.h = hi(SAFE_USER_INSTRUCTION);
 	reti = r0;
@@ -929,27 +941,37 @@ ENTRY(_return_from_int)
 ENDPROC(_return_from_int)
 
 ENTRY(_lower_to_irq14)
-#if ANOMALY_05000281
+#if ANOMALY_05000281 || ANOMALY_05000461
 	r0.l = lo(SAFE_USER_INSTRUCTION);
 	r0.h = hi(SAFE_USER_INSTRUCTION);
 	reti = r0;
 #endif
-	r0 = 0x401f;
+
+#ifdef CONFIG_DEBUG_HWERR
+	/* enable irq14 & hwerr interrupt, until we transition to _evt14_softirq */
+	r0 = (EVT_IVG14 | EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
+#else
+	/* Only enable irq14 interrupt, until we transition to _evt14_softirq */
+	r0 = (EVT_IVG14 | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
+#endif
 	sti r0;
 	raise 14;
 	rti;
+ENDPROC(_lower_to_irq14)
+
 ENTRY(_evt14_softirq)
 #ifdef CONFIG_DEBUG_HWERR
-	r0 = 0x3f;
+	r0 = (EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
 	sti r0;
 #else
 	cli r0;
 #endif
 	[--sp] = RETI;
 	SP += 4;
 	rts;
+ENDPROC(_evt14_softirq)
 
-_schedule_and_signal_from_int:
+ENTRY(_schedule_and_signal_from_int)
 	/* To end up here, vector 15 was changed - so we have to change it
 	 * back.
 	 */
@@ -982,8 +1004,9 @@ _schedule_and_signal_from_int:
 	call _finish_atomic_sections;
 	sp += 12;
 	jump.s .Lresume_userspace;
+ENDPROC(_schedule_and_signal_from_int)
 
-_schedule_and_signal:
+ENTRY(_schedule_and_signal)
 	SAVE_CONTEXT_SYSCALL
 	/* To end up here, vector 15 was changed - so we have to change it
 	 * back.
@@ -1001,7 +1024,7 @@ _schedule_and_signal:
 1:
 	RESTORE_CONTEXT
 	rti;
-ENDPROC(_lower_to_irq14)
+ENDPROC(_schedule_and_signal)
 
 /* We handle this 100% in exception space - to reduce overhead
  * Only potiential problem is if the software buffer gets swapped out of the

trunk/arch/blackfin/mach-common/interrupt.S

@@ -145,6 +145,14 @@ __common_int_entry:
 
 /* interrupt routine for ivhw - 5 */
 ENTRY(_evt_ivhw)
+	/* In case a single action kicks off multiple memory transactions, (like
+	 * a cache line fetch, - this can cause multiple hardware errors, let's
+	 * catch them all. First - make sure all the actions are complete, and
+	 * the core sees the hardware errors.
+	 */
+	SSYNC;
+	SSYNC;
+
 	SAVE_ALL_SYS
 #ifdef CONFIG_FRAME_POINTER
 	fp = 0;
@@ -159,6 +167,25 @@ ENTRY(_evt_ivhw)
 1:
 #endif
 
+	/* Handle all stacked hardware errors
+	 * To make sure we don't hang forever, only do it 10 times
+	 */
+	R0 = 0;
+	R2 = 10;
+1:
+	P0.L = LO(ILAT);
+	P0.H = HI(ILAT);
+	R1 = [P0];
+	CC = BITTST(R1, EVT_IVHW_P);
+	IF ! CC JUMP 2f;
+	/* OK a hardware error is pending - clear it */
+	R1 = EVT_IVHW_P;
+	[P0] = R1;
+	R0 += 1;
+	CC = R1 == R2;
+	if CC JUMP 2f;
+	JUMP 1b;
+2:
 	# We are going to dump something out, so make sure we print IPEND properly
 	p2.l = lo(IPEND);
 	p2.h = hi(IPEND);