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-rw-r--r--arch/blackfin/Kconfig.debug13
-rw-r--r--arch/blackfin/include/asm/entry.h92
-rw-r--r--arch/blackfin/mach-common/entry.S59
-rw-r--r--arch/blackfin/mach-common/interrupt.S27
4 files changed, 170 insertions, 21 deletions
diff --git a/arch/blackfin/Kconfig.debug b/arch/blackfin/Kconfig.debug
index 79e7e63ab709..1fc4981d486f 100644
--- a/arch/blackfin/Kconfig.debug
+++ b/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
diff --git a/arch/blackfin/include/asm/entry.h b/arch/blackfin/include/asm/entry.h
index b30a2968e274..ec58efc130e6 100644
--- a/arch/blackfin/include/asm/entry.h
+++ b/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
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index f0636fdcb353..da0558ad1b1a 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/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;
@@ -929,18 +941,27 @@ 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;
@@ -948,8 +969,9 @@ ENTRY(_evt14_softirq)
[--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
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index 0069c2dd4625..9c46680186e4 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/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);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.