From 1aafd9091226a02b481298315f959f777294684e Mon Sep 17 00:00:00 2001
From: Mike Frysinger <michael.frysinger@analog.com>
Date: Wed, 25 Jul 2007 11:19:14 +0800
Subject: Blackfin arch: revise anomaly handling by basing things on the
 compiler not the kconfig defines

revise anomaly handling by basing things on the compiler not the kconfig defines,
so the header is stable and usable outside of the kernel. This also allows us to
move some code from preprocessing to compiling (gcc culls dead code)
which should help with code quality (readability, catch minor bugs, etc...).

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/mach-common/entry.S | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 96045880834..207e69786b4 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -69,7 +69,7 @@
  * patch up CPLB misses on the kernel stack.
  */
 ENTRY(_ex_dcplb)
-#if defined(ANOMALY_05000261)
+#if ANOMALY_05000261
 	/*
 	 * Work around an anomaly: if we see a new DCPLB fault, return
 	 * without doing anything.  Then, if we get the same fault again,
@@ -137,7 +137,7 @@ ENTRY(_ex_single_step)
 
 _return_from_exception:
 	DEBUG_START_HWTRACE(p5, r7)
-#ifdef ANOMALY_05000257
+#if ANOMALY_05000257
 	R7=LC0;
 	LC0=R7;
 	R7=LC1;
@@ -634,7 +634,7 @@ ENTRY(_return_from_int)
 	p1.h = _schedule_and_signal_from_int;
 	[p0] = p1;
 	csync;
-#if defined(ANOMALY_05000281)
+#if ANOMALY_05000281
 	r0.l = lo(CONFIG_BOOT_LOAD);
 	r0.h = hi(CONFIG_BOOT_LOAD);
 	reti = r0;
@@ -648,7 +648,7 @@ ENTRY(_return_from_int)
 ENDPROC(_return_from_int)
 
 ENTRY(_lower_to_irq14)
-#if defined(ANOMALY_05000281)
+#if ANOMALY_05000281
 	r0.l = lo(CONFIG_BOOT_LOAD);
 	r0.h = hi(CONFIG_BOOT_LOAD);
 	reti = r0;
@@ -1184,7 +1184,7 @@ _exception_stack:
 	.endr
 _exception_stack_top:
 
-#if defined(ANOMALY_05000261)
+#if ANOMALY_05000261
 /* Used by the assembly entry point to work around an anomaly.  */
 _last_cplb_fault_retx:
 	.long 0;
-- 
cgit v1.2.3-70-g09d2


From 518039bc24cbb9ce34665814fe120eac50bedd9a Mon Sep 17 00:00:00 2001
From: Robin Getz <robin.getz@analog.com>
Date: Wed, 25 Jul 2007 11:03:28 +0800
Subject: Blackfin arch: Add ability to expend the hardware trace buffer

Add ability to expend the hardware trace buffer via a configurable
software buffer - so you can have lots of history when a crash occurs.

The interesting way we do printk in the traps.c confusese the checking
script

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/Kconfig             | 81 +++++++++++++++++++++++++++++++++++++++
 arch/blackfin/kernel/irqchip.c    |  9 +++++
 arch/blackfin/kernel/traps.c      | 53 +++++++++++++++++++++----
 arch/blackfin/mach-bf533/head.S   |  2 +-
 arch/blackfin/mach-bf537/head.S   |  2 +-
 arch/blackfin/mach-bf548/head.S   |  2 +-
 arch/blackfin/mach-bf561/head.S   |  2 +-
 arch/blackfin/mach-common/entry.S | 73 +++++++++++++++++++++++++++++++++++
 include/asm-blackfin/trace.h      | 55 +++++++++++++++++++++-----
 9 files changed, 259 insertions(+), 20 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 9ce675e8026..a7a6e0c5827 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1024,8 +1024,89 @@ config DEBUG_HUNT_FOR_ZERO
 	  Enabling this option will take up an extra entry in CPLB table.
 	  Otherwise, there is no extra overhead.
 
+config DEBUG_BFIN_HWTRACE_ON
+	bool "Turn on Blackfin's Hardware Trace"
+	default y
+	help
+	  All Blackfins include a Trace Unit which stores a history of the last
+	  16 changes in program flow taken by the program sequencer. The history
+	  allows the user to recreate the program sequencer’s recent path. This
+	  can be handy when an application dies - we print out the execution
+	  path of how it got to the offending instruction.
+
+	  By turning this off, you may save a tiny amount of power.
+
+choice
+	prompt "Omit loop Tracing"
+	default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+	depends on DEBUG_BFIN_HWTRACE_ON
+	help
+	  The trace buffer can be configured to omit recording of changes in
+	  program flow that match either the last entry or one of the last
+	  two entries. Omitting one of these entries from the record prevents
+	  the trace buffer from overflowing because of any sort of loop (for, do
+	  while, etc) in the program.
+
+	  Because zero-overhead Hardware loops are not recorded in the trace buffer,
+	  this feature can be used to prevent trace overflow from loops that
+	  are nested four deep.
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+	bool "Trace all Loops"
+	help
+	  The trace buffer records all changes of flow 
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
+	bool "Compress single-level loops"
+	help
+	  The trace buffer does not record single loops - helpful if trace 
+	  is spinning on a while or do loop.
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
+	bool "Compress two-level loops"
+	help
+	  The trace buffer does not record loops two levels deep. Helpful if
+	  the trace is spinning in a nested loop
+
+endchoice
+
+config DEBUG_BFIN_HWTRACE_COMPRESSION
+	int
+	depends on DEBUG_BFIN_HWTRACE_ON
+	default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
+	default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
+	default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
+
+
+config DEBUG_BFIN_HWTRACE_EXPAND
+	bool "Expand Trace Buffer greater than 16 entries"
+	depends on DEBUG_BFIN_HWTRACE_ON
+	default n
+	help
+	  By selecting this option, every time the 16 hardware entries in
+	  the Blackfin's HW Trace buffer are full, the kernel will move them
+	  into a software buffer, for dumping when there is an issue. This 
+	  has a great impact on performance, (an interrupt every 16 change of 
+	  flows) and should normally be turned off, except in those nasty
+	  debugging sessions
+
+config DEBUG_BFIN_HWTRACE_EXPAND_LEN
+	int "Size of Trace buffer (in power of 2k)"
+	range 0 4
+	depends on DEBUG_BFIN_HWTRACE_EXPAND
+	default 1
+	help
+	  This sets the size of the software buffer that the trace information
+	  is kept in.
+	  0 for (2^0)  1k, or 256 entries,
+	  1 for (2^1)  2k, or 512 entries,
+	  2 for (2^2)  4k, or 1024 entries,
+	  3 for (2^3)  8k, or 2048 entries,
+	  4 for (2^4) 16k, or 4096 entries
+
 config DEBUG_BFIN_NO_KERN_HWTRACE
 	bool "Trace user apps (turn off hwtrace in kernel)"
+	depends on DEBUG_BFIN_HWTRACE_ON
 	default n
 	help
 	  Some pieces of the kernel contain a lot of flow changes which can
diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 1fc001c7abd..462ae41144c 100644
--- a/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -34,6 +34,7 @@
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <asm/trace.h>
 
 static unsigned long irq_err_count;
 static spinlock_t irq_controller_lock;
@@ -144,4 +145,12 @@ void __init init_IRQ(void)
 	}
 
 	init_arch_irq();
+
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+	/* Now that evt_ivhw is set up, turn this on */
+	trace_buff_offset = 0;
+	bfin_write_TBUFCTL(BFIN_TRACE_ON);
+	printk(KERN_INFO "Hardware Trace expanded to %ik\n",
+	  1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN);
+#endif
 }
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 792a8416fe1..0ec02fe663e 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -55,6 +55,7 @@ asmlinkage void trap_c(struct pt_regs *fp);
 
 int kstack_depth_to_print = 48;
 
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
 static int printk_address(unsigned long address)
 {
 	struct vm_list_struct *vml;
@@ -131,10 +132,14 @@ static int printk_address(unsigned long address)
 	/* we were unable to find this address anywhere */
 	return printk("[<0x%p>]", (void *)address);
 }
+#endif
 
 asmlinkage void trap_c(struct pt_regs *fp)
 {
-	int j, sig = 0;
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+	int j;
+#endif
+	int sig = 0;
 	siginfo_t info;
 	unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
 
@@ -429,24 +434,56 @@ asmlinkage void trap_c(struct pt_regs *fp)
 
 /* Typical exception handling routines	*/
 
+#define EXPAND_LEN ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 256 - 1)
+
 void dump_bfin_trace_buffer(void)
 {
-	int tflags;
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+	int tflags, i = 0;
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+	int j, index;
+#endif
+
 	trace_buffer_save(tflags);
 
+	printk(KERN_EMERG "Hardware Trace:\n");
+
 	if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
-		int i;
-		printk(KERN_EMERG "Hardware Trace:\n");
-		for (i = 0; bfin_read_TBUFSTAT() & TBUFCNT; i++) {
-			printk(KERN_EMERG "%2i Target : ", i);
+		for (; bfin_read_TBUFSTAT() & TBUFCNT; i++) {
+			printk(KERN_EMERG "%4i Target : ", i);
 			printk_address((unsigned long)bfin_read_TBUF());
-			printk("\n" KERN_EMERG "   Source : ");
+			printk("\n" KERN_EMERG "     Source : ");
 			printk_address((unsigned long)bfin_read_TBUF());
 			printk("\n");
 		}
 	}
 
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+	if (trace_buff_offset)
+		index = trace_buff_offset/4 - 1;
+	else
+		index = EXPAND_LEN;
+
+	j = (1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 128;
+	while (j) {
+		printk(KERN_EMERG "%4i Target : ", i);
+		printk_address(software_trace_buff[index]);
+		index -= 1;
+		if (index < 0 )
+			index = EXPAND_LEN;
+		printk("\n" KERN_EMERG "     Source : ");
+		printk_address(software_trace_buff[index]);
+		index -= 1;
+		if (index < 0)
+			index = EXPAND_LEN;
+		printk("\n");
+		j--;
+		i++;
+	}
+#endif
+
 	trace_buffer_restore(tflags);
+#endif
 }
 EXPORT_SYMBOL(dump_bfin_trace_buffer);
 
@@ -510,7 +547,9 @@ void show_stack(struct task_struct *task, unsigned long *stack)
 void dump_stack(void)
 {
 	unsigned long stack;
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
 	int tflags;
+#endif
 	trace_buffer_save(tflags);
 	dump_bfin_trace_buffer();
 	show_stack(current, &stack);
diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S
index 9c5378bb8a2..1d5b9dbbbaa 100644
--- a/arch/blackfin/mach-bf533/head.S
+++ b/arch/blackfin/mach-bf533/head.S
@@ -98,7 +98,7 @@ ENTRY(__start)
 	M2 = r0;
 	M3 = r0;
 
-	trace_buffer_start(p0,r0);
+	trace_buffer_init(p0,r0);
 	P0 = R1;
 	R0 = R1;
 
diff --git a/arch/blackfin/mach-bf537/head.S b/arch/blackfin/mach-bf537/head.S
index 82ea0470591..6dbcb77c8d3 100644
--- a/arch/blackfin/mach-bf537/head.S
+++ b/arch/blackfin/mach-bf537/head.S
@@ -96,7 +96,7 @@ ENTRY(__start)
 	M2 = r0;
 	M3 = r0;
 
-	trace_buffer_start(p0,r0);
+	trace_buffer_init(p0,r0);
 	P0 = R1;
 	R0 = R1;
 
diff --git a/arch/blackfin/mach-bf548/head.S b/arch/blackfin/mach-bf548/head.S
index 72087c2e6a8..e53d74d4c0a 100644
--- a/arch/blackfin/mach-bf548/head.S
+++ b/arch/blackfin/mach-bf548/head.S
@@ -93,7 +93,7 @@ ENTRY(__stext)
 	M2 = r0;
 	M3 = r0;
 
-	trace_buffer_start(p0,r0);
+	trace_buffer_init(p0,r0);
 	P0 = R1;
 	R0 = R1;
 
diff --git a/arch/blackfin/mach-bf561/head.S b/arch/blackfin/mach-bf561/head.S
index 83cd3f9bbf2..8c9f73b8e57 100644
--- a/arch/blackfin/mach-bf561/head.S
+++ b/arch/blackfin/mach-bf561/head.S
@@ -96,7 +96,7 @@ ENTRY(__start)
 	M2 = r0;
 	M3 = r0;
 
-	trace_buffer_start(p0,r0);
+	trace_buffer_init(p0,r0);
 	P0 = R1;
 	R0 = R1;
 
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 207e69786b4..ab278a72f28 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -731,6 +731,75 @@ ENTRY(_init_exception_buff)
 	rts;
 ENDPROC(_init_exception_buff)
 
+/* We handle this 100% in exception space - to reduce overhead
+ * Only potiential problem is if the software buffer gets swapped out of the
+ * CPLB table - then double fault. - so we don't let this happen in other places
+ */
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+ENTRY(_ex_trace_buff_full)
+	[--sp] = P3;
+	[--sp] = P2;
+	[--sp] = LC0;
+	[--sp] = LT0;
+	[--sp] = LB0;
+	P5.L = _trace_buff_offset;
+	P5.H = _trace_buff_offset;
+	P3 = [P5];              /* trace_buff_offset */
+	P5.L = lo(TBUFSTAT);
+	P5.H = hi(TBUFSTAT);
+	R7 = [P5];
+	R7 <<= 1;               /* double, since we need to read twice */
+	LC0 = R7;
+	R7 <<= 2;               /* need to shift over again,
+				 * to get the number of bytes */
+	P5.L = lo(TBUF);
+	P5.H = hi(TBUF);
+	R6 = ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN)*1024) - 1;
+
+	P2 = R7;
+	P3 = P3 + P2;
+	R7 = P3;
+	R7 = R7 & R6;
+	P3 = R7;
+	P2.L = _trace_buff_offset;
+	P2.H = _trace_buff_offset;
+	[P2] = P3;
+
+	P2.L = _software_trace_buff;
+	P2.H = _software_trace_buff;
+
+	LSETUP (.Lstart, .Lend) LC0;
+.Lstart:
+	R7 = [P5];      /* read TBUF */
+	P4 = P3 + P2;
+	[P4] = R7;
+	P3 += -4;
+	R7 = P3;
+	R7 = R7 & R6;
+.Lend:
+	P3 = R7;
+
+	LB0 = [sp++];
+	LT0 = [sp++];
+	LC0 = [sp++];
+	P2 = [sp++];
+	P3 = [sp++];
+	jump _return_from_exception;
+
+#if CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN == 4
+.data
+#else
+.section .l1.data.B
+#endif
+ENTRY(_trace_buff_offset)
+        .long 0;
+ALIGN
+ENTRY(_software_trace_buff)
+	.rept ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN)*256);
+	.long 0
+	.endr
+#endif
+
 /*
  * Put these in the kernel data section - that should always be covered by
  * a CPLB. This is needed to ensure we don't get double fault conditions
@@ -764,7 +833,11 @@ _extable:
 	.long _ex_trap_c        /* 0x0E - User Defined */
 	.long _ex_trap_c        /* 0x0F - User Defined */
 	.long _ex_single_step   /* 0x10 - HW Single step */
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+	.long _ex_trace_buff_full /* 0x11 - Trace Buffer Full */
+#else
 	.long _ex_trap_c        /* 0x11 - Trace Buffer Full */
+#endif
 	.long _ex_trap_c        /* 0x12 - Reserved */
 	.long _ex_trap_c        /* 0x13 - Reserved */
 	.long _ex_trap_c        /* 0x14 - Reserved */
diff --git a/include/asm-blackfin/trace.h b/include/asm-blackfin/trace.h
index 9c2474c9a58..6313aace9d5 100644
--- a/include/asm-blackfin/trace.h
+++ b/include/asm-blackfin/trace.h
@@ -6,23 +6,46 @@
 #ifndef _BLACKFIN_TRACE_
 #define _BLACKFIN_TRACE_
 
+/* Normally, we use ON, but you can't turn on software expansion until
+ * interrupts subsystem is ready
+ */
+
+#define BFIN_TRACE_INIT ((CONFIG_DEBUG_BFIN_HWTRACE_COMPRESSION << 4) | 0x03)
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
+#define BFIN_TRACE_ON   (BFIN_TRACE_INIT | (CONFIG_DEBUG_BFIN_HWTRACE_EXPAND << 2))
+#else
+#define BFIN_TRACE_ON   (BFIN_TRACE_INIT)
+#endif
+
 #ifndef __ASSEMBLY__
+extern unsigned long trace_buff_offset;
+extern unsigned long software_trace_buff[];
+
 /* Trace Macros for C files */
 
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+
 #define trace_buffer_save(x) \
-        do { \
-                (x) = bfin_read_TBUFCTL(); \
-                bfin_write_TBUFCTL((x) & ~TBUFEN); \
-        } while (0)
+	do { \
+		(x) = bfin_read_TBUFCTL(); \
+		bfin_write_TBUFCTL((x) & ~TBUFEN); \
+	} while (0)
 
 #define trace_buffer_restore(x) \
-        do { \
-                bfin_write_TBUFCTL((x));        \
-        } while (0)
+	do { \
+		bfin_write_TBUFCTL((x));        \
+	} while (0)
+#else /* DEBUG_BFIN_HWTRACE_ON */
+
+#define trace_buffer_save(x)
+#define trace_buffer_restore(x)
+#endif /* CONFIG_DEBUG_BFIN_HWTRACE_ON */
 
 #else
 /* Trace Macros for Assembly files */
 
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+
 #define TRACE_BUFFER_START(preg, dreg) trace_buffer_start(preg, dreg)
 #define TRACE_BUFFER_STOP(preg, dreg)  trace_buffer_stop(preg, dreg)
 
@@ -32,12 +55,26 @@
 	dreg = 0x1;			\
 	[preg] = dreg;
 
-#define trace_buffer_start(preg, dreg) \
+#define trace_buffer_start(preg, dreg)	\
 	preg.L = LO(TBUFCTL);		\
 	preg.H = HI(TBUFCTL);		\
-	dreg = 0x13;			\
+	dreg = BFIN_TRACE_ON;		\
+	[preg] = dreg;
+
+#define trace_buffer_init(preg, dreg) \
+	preg.L = LO(TBUFCTL);         \
+	preg.H = HI(TBUFCTL);         \
+	dreg = BFIN_TRACE_INIT;       \
 	[preg] = dreg;
 
+#else /* CONFIG_DEBUG_BFIN_HWTRACE_ON */
+
+#define trace_buffer_stop(preg, dreg)
+#define trace_buffer_start(preg, dreg)
+#define trace_buffer_init(preg, dreg)
+
+#endif /* CONFIG_DEBUG_BFIN_HWTRACE_ON */
+
 #ifdef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
 # define DEBUG_START_HWTRACE(preg, dreg) trace_buffer_start(preg, dreg)
 # define DEBUG_STOP_HWTRACE(preg, dreg) trace_buffer_stop(preg, dreg)
-- 
cgit v1.2.3-70-g09d2


From f0b5d12f2b3226c85258519d7725e63d9daf5e90 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <michael.frysinger@analog.com>
Date: Sun, 5 Aug 2007 17:03:59 +0800
Subject: Blackfin arch: allow people to select the feature that is unavailable
 to the kernel

 - allow people to select the feature that is unavailable to the kernel: NMI, JTAG, or CYCLES.
 - change default NMI handler to simply dump hardware trace buffer.
 - remove default NMI handler completely as calling into kernel code is not safe
   move example handler to wiki so people dont haphazardly copy and paste this stuff thinking its safe

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/Kconfig                        | 46 ++++++++++++++++++++++++++++
 arch/blackfin/kernel/irqchip.c               |  3 +-
 arch/blackfin/mach-bf533/head.S              | 10 +++---
 arch/blackfin/mach-bf537/head.S              | 10 +++---
 arch/blackfin/mach-bf548/head.S              | 10 ++++--
 arch/blackfin/mach-bf561/head.S              | 10 +++---
 arch/blackfin/mach-common/entry.S            | 18 ++++++++---
 arch/blackfin/mach-common/interrupt.S        | 28 +++++------------
 arch/blackfin/mach-common/ints-priority-dc.c |  6 +++-
 arch/blackfin/mach-common/ints-priority-sc.c |  6 +++-
 include/asm-blackfin/irq_handler.h           |  5 ++-
 11 files changed, 107 insertions(+), 45 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index cdce8cc5b7b..26ebb0e8c43 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -521,6 +521,52 @@ config BFIN_IDLE_LED_NUM
 	help
 	  Select the LED (marked on the board) for you to blink.
 
+choice
+	prompt "Blackfin Exception Scratch Register"
+	default BFIN_SCRATCH_REG_RETN
+	help
+	  Select the resource to reserve for the Exception handler:
+	    - RETN: Non-Maskable Interrupt (NMI)
+	    - RETE: Exception Return (JTAG/ICE)
+	    - CYCLES: Performance counter
+
+	  If you are unsure, please select "RETN".
+
+config BFIN_SCRATCH_REG_RETN
+	bool "RETN"
+	help
+	  Use the RETN register in the Blackfin exception handler
+	  as a stack scratch register.  This means you cannot
+	  safely use NMI on the Blackfin while running Linux, but
+	  you can debug the system with a JTAG ICE and use the
+	  CYCLES performance registers.
+
+	  If you are unsure, please select "RETN".
+
+config BFIN_SCRATCH_REG_RETE
+	bool "RETE"
+	help
+	  Use the RETE register in the Blackfin exception handler
+	  as a stack scratch register.  This means you cannot
+	  safely use a JTAG ICE while debugging a Blackfin board,
+	  but you can safely use the CYCLES performance registers
+	  and the NMI.
+
+	  If you are unsure, please select "RETN".
+
+config BFIN_SCRATCH_REG_CYCLES
+	bool "CYCLES"
+	help
+	  Use the CYCLES register in the Blackfin exception handler
+	  as a stack scratch register.  This means you cannot
+	  safely use the CYCLES performance registers on a Blackfin
+	  board at anytime, but you can debug the system with a JTAG
+	  ICE and use the NMI.
+
+	  If you are unsure, please select "RETN".
+
+endchoice
+
 #
 # Sorry - but you need to put the hex address here -
 #
diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 462ae41144c..73647c15877 100644
--- a/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -98,9 +98,8 @@ int show_interrupts(struct seq_file *p, void *v)
  */
 
 #ifdef CONFIG_DO_IRQ_L1
-asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)__attribute__((l1_text));
+__attribute__((l1_text))
 #endif
-
 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 {
 	struct pt_regs *old_regs;
diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S
index 1d5b9dbbbaa..3be6feefa8a 100644
--- a/arch/blackfin/mach-bf533/head.S
+++ b/arch/blackfin/mach-bf533/head.S
@@ -53,10 +53,12 @@ __INIT
 ENTRY(__start)
 	/* R0: argument of command line string, passed from uboot, save it */
 	R7 = R0;
-	/* Set the SYSCFG register:
-	 * Enable Cycle Counter and Nesting Of Interrupts (3rd Bit)
-	 */
-	R0 = 0x36;
+	/* Enable Cycle Counter and Nesting Of Interrupts */
+#ifdef CONFIG_BFIN_SCRATCH_REG_CYCLES
+	R0 = SYSCFG_SNEN;
+#else
+	R0 = SYSCFG_SNEN | SYSCFG_CCEN;
+#endif
 	SYSCFG = R0;
 	R0 = 0;
 
diff --git a/arch/blackfin/mach-bf537/head.S b/arch/blackfin/mach-bf537/head.S
index 6dbcb77c8d3..0836bfdcc6c 100644
--- a/arch/blackfin/mach-bf537/head.S
+++ b/arch/blackfin/mach-bf537/head.S
@@ -51,10 +51,12 @@ __INIT
 ENTRY(__start)
 	/* R0: argument of command line string, passed from uboot, save it */
 	R7 = R0;
-	/* Set the SYSCFG register:
-	 * Enable Cycle Counter and Nesting Of Interrupts (3rd Bit)
-	 */
-	R0 = 0x36;
+	/* Enable Cycle Counter and Nesting Of Interrupts */
+#ifdef CONFIG_BFIN_SCRATCH_REG_CYCLES
+	R0 = SYSCFG_SNEN;
+#else
+	R0 = SYSCFG_SNEN | SYSCFG_CCEN;
+#endif
 	SYSCFG = R0;
 	R0 = 0;
 
diff --git a/arch/blackfin/mach-bf548/head.S b/arch/blackfin/mach-bf548/head.S
index 4c7d49f4118..937fbef26a5 100644
--- a/arch/blackfin/mach-bf548/head.S
+++ b/arch/blackfin/mach-bf548/head.S
@@ -50,9 +50,13 @@ ENTRY(__start)
 ENTRY(__stext)
 	/* R0: argument of command line string, passed from uboot, save it */
 	R7 = R0;
-	/* Set the SYSCFG register */
-	R0 = 0x36;
-	SYSCFG = R0;   /*Enable Cycle Counter and Nesting Of Interrupts(3rd Bit)*/
+	/* Enable Cycle Counter and Nesting Of Interrupts */
+#ifdef CONFIG_BFIN_SCRATCH_REG_CYCLES
+	R0 = SYSCFG_SNEN;
+#else
+	R0 = SYSCFG_SNEN | SYSCFG_CCEN;
+#endif
+	SYSCFG = R0;
 	R0 = 0;
 
 	/* Clear Out All the data and pointer  Registers*/
diff --git a/arch/blackfin/mach-bf561/head.S b/arch/blackfin/mach-bf561/head.S
index 8c9f73b8e57..139f4cff801 100644
--- a/arch/blackfin/mach-bf561/head.S
+++ b/arch/blackfin/mach-bf561/head.S
@@ -51,10 +51,12 @@ __INIT
 ENTRY(__start)
 	/* R0: argument of command line string, passed from uboot, save it */
 	R7 = R0;
-	/* Set the SYSCFG register:
-	 * Enable Cycle Counter and Nesting Of Interrupts (3rd Bit)
-	 */
-	R0 = 0x36;
+	/* Enable Cycle Counter and Nesting Of Interrupts */
+#ifdef CONFIG_BFIN_SCRATCH_REG_CYCLES
+	R0 = SYSCFG_SNEN;
+#else
+	R0 = SYSCFG_SNEN | SYSCFG_CCEN;
+#endif
 	SYSCFG = R0;
 	R0 = 0;
 
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index ab278a72f28..2188f81c645 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -58,6 +58,14 @@
 
 #include <asm/mach-common/context.S>
 
+#if defined(CONFIG_BFIN_SCRATCH_REG_RETN)
+# define EX_SCRATCH_REG RETN
+#elif defined(CONFIG_BFIN_SCRATCH_REG_RETE)
+# define EX_SCRATCH_REG RETE
+#else
+# define EX_SCRATCH_REG CYCLES
+#endif
+
 #ifdef CONFIG_EXCPT_IRQ_SYSC_L1
 .section .l1.text
 #else
@@ -93,7 +101,7 @@ ENTRY(_ex_icplb)
 	call __cplb_hdr;
 	DEBUG_START_HWTRACE(p5, r7)
 	RESTORE_ALL_SYS
-	SP = RETN;
+	SP = EX_SCRATCH_REG;
 	rtx;
 ENDPROC(_ex_icplb)
 
@@ -102,7 +110,7 @@ ENTRY(_ex_syscall)
 	(R7:6,P5:4) = [sp++];
 	ASTAT = [sp++];
 	raise 15;		/* invoked by TRAP #0, for sys call */
-	sp = retn;
+	sp = EX_SCRATCH_REG;
 	rtx
 ENDPROC(_ex_syscall)
 
@@ -145,7 +153,7 @@ _return_from_exception:
 #endif
 	(R7:6,P5:4) = [sp++];
 	ASTAT = [sp++];
-	sp = retn;
+	sp = EX_SCRATCH_REG;
 	rtx;
 ENDPROC(_ex_soft_bp)
 
@@ -204,7 +212,7 @@ ENTRY(_ex_trap_c)
 	DEBUG_START_HWTRACE(p5, r7)
 	(R7:6,P5:4) = [sp++];
 	ASTAT = [sp++];
-	SP = RETN;
+	SP = EX_SCRATCH_REG;
 	raise 5;
 	rtx;
 ENDPROC(_ex_trap_c)
@@ -279,7 +287,7 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
 	 * covered by a CPLB.  Switch to an exception stack; use RETN as a
 	 * scratch register (for want of a better option).
 	 */
-	retn = sp;
+	EX_SCRATCH_REG = sp;
 	sp.l = _exception_stack_top;
 	sp.h = _exception_stack_top;
 	/* Try to deal with syscalls quickly.  */
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index 1d5ba5e3d91..c6b32fe0f6e 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -177,27 +177,15 @@ ENTRY(_evt_ivhw)
 	jump .Lcommon_restore_context;
 #endif
 
-/* interrupt routine for evt2 - 2.  This is NMI.  */
-ENTRY(_evt_evt2)
-	SAVE_CONTEXT
-#ifdef CONFIG_FRAME_POINTER
-	fp = 0;
-#endif
-#if ANOMALY_05000283
-	cc = r7 == r7;
-	p5.h = 0xffc0;
-	p5.l = 0x0014;
-	if cc jump 1f;
-	r7.l = W[p5];
-1:
-#endif
-	r0 = IRQ_NMI;
-	r1 =  sp;
-	SP += -12;
-	call _asm_do_IRQ;
-	SP += 12;
-	RESTORE_CONTEXT
+/* Interrupt routine for evt2 (NMI).
+ * We don't actually use this, so just return.
+ * For inner circle type details, please see:
+ * http://docs.blackfin.uclinux.org/doku.php?id=linux:nmi
+ */
+ENTRY(_evt_nmi)
+.weak _evt_nmi
 	rtn;
+ENDPROC(_evt_nmi)
 
 /* interrupt routine for core timer - 6 */
 ENTRY(_evt_timer)
diff --git a/arch/blackfin/mach-common/ints-priority-dc.c b/arch/blackfin/mach-common/ints-priority-dc.c
index 684d306ab6b..2db3546fc87 100644
--- a/arch/blackfin/mach-common/ints-priority-dc.c
+++ b/arch/blackfin/mach-common/ints-priority-dc.c
@@ -362,7 +362,11 @@ void __init init_exception_vectors(void)
 {
 	SSYNC();
 
-	bfin_write_EVT2(evt_evt2);
+	/* cannot program in software:
+	 * evt0 - emulation (jtag)
+	 * evt1 - reset
+	 */
+	bfin_write_EVT2(evt_nmi);
 	bfin_write_EVT3(trap);
 	bfin_write_EVT5(evt_ivhw);
 	bfin_write_EVT6(evt_timer);
diff --git a/arch/blackfin/mach-common/ints-priority-sc.c b/arch/blackfin/mach-common/ints-priority-sc.c
index a2016af65eb..d3b7672b2b9 100644
--- a/arch/blackfin/mach-common/ints-priority-sc.c
+++ b/arch/blackfin/mach-common/ints-priority-sc.c
@@ -721,7 +721,11 @@ void __init init_exception_vectors(void)
 {
 	SSYNC();
 
-	bfin_write_EVT2(evt_evt2);
+	/* cannot program in software:
+	 * evt0 - emulation (jtag)
+	 * evt1 - reset
+	 */
+	bfin_write_EVT2(evt_nmi);
 	bfin_write_EVT3(trap);
 	bfin_write_EVT5(evt_ivhw);
 	bfin_write_EVT6(evt_timer);
diff --git a/include/asm-blackfin/irq_handler.h b/include/asm-blackfin/irq_handler.h
index 6a768315bbf..f13cd73b096 100644
--- a/include/asm-blackfin/irq_handler.h
+++ b/include/asm-blackfin/irq_handler.h
@@ -1,12 +1,15 @@
 #ifndef _IRQ_HANDLER_H
 #define _IRQ_HANDLER_H
 
+#include <linux/types.h>
+#include <linux/linkage.h>
+
 /* BASE LEVEL interrupt handler routines */
 asmlinkage void evt_exception(void);
 asmlinkage void trap(void);
 asmlinkage void evt_ivhw(void);
 asmlinkage void evt_timer(void);
-asmlinkage void evt_evt2(void);
+asmlinkage void evt_nmi(void);
 asmlinkage void evt_evt7(void);
 asmlinkage void evt_evt8(void);
 asmlinkage void evt_evt9(void);
-- 
cgit v1.2.3-70-g09d2


From 1ffe6646babf8471714e649849ec2c9662bf410c Mon Sep 17 00:00:00 2001
From: Mike Frysinger <michael.frysinger@analog.com>
Date: Sun, 5 Aug 2007 17:14:04 +0800
Subject: Blackfin arch: add an exception request/free api

add an exception request/free api similar to the interrupt request/fre
api so people can utilize the free software based exceptions for their
own purposes

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/kernel/traps.c       | 38 ++++++++++++++++++++++++++++++++--
 arch/blackfin/mach-common/entry.S  | 42 ++++++++++++++++++++------------------
 include/asm-blackfin/irq_handler.h |  8 ++++++++
 3 files changed, 66 insertions(+), 22 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 0d2052abe41..1a8a5f171bc 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -51,8 +51,6 @@ void __init trap_init(void)
 	CSYNC();
 }
 
-asmlinkage void trap_c(struct pt_regs *fp);
-
 int kstack_depth_to_print = 48;
 
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
@@ -693,6 +691,42 @@ asmlinkage int sys_bfin_spinlock(int *spinlock)
 	return ret;
 }
 
+int bfin_request_exception(unsigned int exception, void (*handler)(void))
+{
+	void (*curr_handler)(void);
+
+	if (exception > 0x3F)
+		return -EINVAL;
+
+	curr_handler = ex_table[exception];
+
+	if (curr_handler != ex_replaceable)
+		return -EBUSY;
+
+	ex_table[exception] = handler;
+
+	return 0;
+}
+EXPORT_SYMBOL(bfin_request_exception);
+
+int bfin_free_exception(unsigned int exception, void (*handler)(void))
+{
+	void (*curr_handler)(void);
+
+	if (exception > 0x3F)
+		return -EINVAL;
+
+	curr_handler = ex_table[exception];
+
+	if (curr_handler != handler)
+		return -EBUSY;
+
+	ex_table[exception] = ex_replaceable;
+
+	return 0;
+}
+EXPORT_SYMBOL(bfin_free_exception);
+
 void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
 {
 	switch (cplb_panic) {
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 2188f81c645..3feca05694f 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -143,7 +143,7 @@ ENTRY(_ex_single_step)
 	cc = r6 == r7;
 	if !cc jump _ex_trap_c;
 
-_return_from_exception:
+ENTRY(_return_from_exception)
 	DEBUG_START_HWTRACE(p5, r7)
 #if ANOMALY_05000257
 	R7=LC0;
@@ -171,6 +171,9 @@ ENTRY(_handle_bad_cplb)
 	[--sp] = ASTAT;
 	[--sp] = (R7:6, P5:4);
 
+ENTRY(_ex_replaceable)
+	nop;
+
 ENTRY(_ex_trap_c)
 	/* Call C code (trap_c) to handle the exception, which most
 	 * likely involves sending a signal to the current process.
@@ -298,8 +301,8 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
 	r6.l = lo(SEQSTAT_EXCAUSE);
 	r6.h = hi(SEQSTAT_EXCAUSE);
 	r7 = r7 & r6;
-	p5.h = _extable;
-	p5.l = _extable;
+	p5.h = _ex_table;
+	p5.l = _ex_table;
 	p4 = r7;
 	p5 = p5 + (p4 << 2);
 	p4 = [p5];
@@ -818,28 +821,27 @@ ENTRY(_software_trace_buff)
 #else
 .data
 #endif
-ALIGN
-_extable:
+ENTRY(_ex_table)
 	/* entry for each EXCAUSE[5:0]
 	 * This table must be in sync with the table in ./kernel/traps.c
 	 * EXCPT instruction can provide 4 bits of EXCAUSE, allowing 16 to be user defined
 	 */
-	.long _ex_syscall;      /* 0x00 - User Defined - Linux Syscall */
+	.long _ex_syscall       /* 0x00 - User Defined - Linux Syscall */
 	.long _ex_soft_bp       /* 0x01 - User Defined - Software breakpoint */
-	.long _ex_trap_c        /* 0x02 - User Defined */
+	.long _ex_replaceable   /* 0x02 - User Defined */
 	.long _ex_trap_c        /* 0x03 - User Defined - userspace stack overflow */
-	.long _ex_trap_c        /* 0x04 - User Defined */
-	.long _ex_trap_c        /* 0x05 - User Defined */
-	.long _ex_trap_c        /* 0x06 - User Defined */
-	.long _ex_trap_c        /* 0x07 - User Defined */
-	.long _ex_trap_c        /* 0x08 - User Defined */
-	.long _ex_trap_c        /* 0x09 - User Defined */
-	.long _ex_trap_c        /* 0x0A - User Defined */
-	.long _ex_trap_c        /* 0x0B - User Defined */
-	.long _ex_trap_c        /* 0x0C - User Defined */
-	.long _ex_trap_c        /* 0x0D - User Defined */
-	.long _ex_trap_c        /* 0x0E - User Defined */
-	.long _ex_trap_c        /* 0x0F - User Defined */
+	.long _ex_replaceable   /* 0x04 - User Defined */
+	.long _ex_replaceable   /* 0x05 - User Defined */
+	.long _ex_replaceable   /* 0x06 - User Defined */
+	.long _ex_replaceable   /* 0x07 - User Defined */
+	.long _ex_replaceable   /* 0x08 - User Defined */
+	.long _ex_replaceable   /* 0x09 - User Defined */
+	.long _ex_replaceable   /* 0x0A - User Defined */
+	.long _ex_replaceable   /* 0x0B - User Defined */
+	.long _ex_replaceable   /* 0x0C - User Defined */
+	.long _ex_replaceable   /* 0x0D - User Defined */
+	.long _ex_replaceable   /* 0x0E - User Defined */
+	.long _ex_replaceable   /* 0x0F - User Defined */
 	.long _ex_single_step   /* 0x10 - HW Single step */
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
 	.long _ex_trace_buff_full /* 0x11 - Trace Buffer Full */
@@ -893,8 +895,8 @@ _extable:
 	.long _ex_trap_c        /* 0x3D - Reserved */
 	.long _ex_trap_c        /* 0x3E - Reserved */
 	.long _ex_trap_c        /* 0x3F - Reserved */
+END(_ex_table)
 
-ALIGN
 ENTRY(_sys_call_table)
 	.long _sys_restart_syscall	/* 0 */
 	.long _sys_exit
diff --git a/include/asm-blackfin/irq_handler.h b/include/asm-blackfin/irq_handler.h
index f13cd73b096..19534c133c9 100644
--- a/include/asm-blackfin/irq_handler.h
+++ b/include/asm-blackfin/irq_handler.h
@@ -20,5 +20,13 @@ asmlinkage void evt_evt13(void);
 asmlinkage void evt_soft_int1(void);
 asmlinkage void evt_system_call(void);
 asmlinkage void init_exception_buff(void);
+asmlinkage void trap_c(struct pt_regs *fp);
+asmlinkage void ex_replaceable(void);
+
+extern void *ex_table[];
+extern void return_from_exception(void);
+
+extern int bfin_request_exception(unsigned int exception, void (*handler)(void));
+extern int bfin_free_exception(unsigned int exception, void (*handler)(void));
 
 #endif
-- 
cgit v1.2.3-70-g09d2


From 2ebcade590dcf822dcdadcc4f8f68efd3ff2e217 Mon Sep 17 00:00:00 2001
From: Robin Getz <robin.getz@analog.com>
Date: Tue, 9 Oct 2007 17:24:30 +0800
Subject: Blackfin arch: fix endless loop bug when a double fault happens

Today when a double fault happens (exception during an exception
handling event), we go into an endless loop, with nothing comming out
the UART. With this patch, we actually see that we have commited a
double fault event

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/kernel/traps.c      |  8 +++++
 arch/blackfin/mach-common/entry.S | 69 ++++++++++++++++++++++++++++++---------
 2 files changed, 62 insertions(+), 15 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 1a8a5f171bc..ba68eb2ec92 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -132,6 +132,14 @@ static int printk_address(unsigned long address)
 }
 #endif
 
+asmlinkage void double_fault_c(struct pt_regs *fp)
+{
+	printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n");
+	dump_bfin_regs(fp, (void *)fp->retx);
+	panic("Double Fault - unrecoverable event\n");
+
+}
+
 asmlinkage void trap_c(struct pt_regs *fp)
 {
 #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 3feca05694f..e2239361cac 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -29,21 +29,7 @@
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-/*
- * 25-Dec-2004 - LG Soft India
- * 	1. Fix in return_from_int, to make sure any pending
- *	system call in ILAT for this process to get
- *	executed, otherwise in case context switch happens,
- *	system call of first process (i.e in ILAT) will be
- *	carried forward to the switched process.
- *	2. Removed Constant references for the following
- *		a.  IPEND
- *		b.  EXCAUSE mask
- *		c.  PAGE Mask
- */
-
-/*
- * NOTE: This code handles signal-recognition, which happens every time
+/* NOTE: This code handles signal-recognition, which happens every time
  * after a timer-interrupt and after each system call.
  */
 
@@ -175,6 +161,13 @@ ENTRY(_ex_replaceable)
 	nop;
 
 ENTRY(_ex_trap_c)
+	/* Make sure we are not in a double fault */
+	p4.l = lo(IPEND);
+	p4.h = hi(IPEND);
+	r7 = [p4];
+	CC = BITTST (r7, 5);
+	if CC jump _double_fault;
+
 	/* Call C code (trap_c) to handle the exception, which most
 	 * likely involves sending a signal to the current process.
 	 * To avoid double faults, lower our priority to IRQ5 first.
@@ -220,6 +213,52 @@ ENTRY(_ex_trap_c)
 	rtx;
 ENDPROC(_ex_trap_c)
 
+/* We just realized we got an exception, while we were processing a different
+ * exception. This is a unrecoverable event, so crash
+ */
+ENTRY(_double_fault)
+        /* Turn caches & protection off, to ensure we don't get any more
+         * double exceptions
+         */
+
+        P4.L = LO(IMEM_CONTROL);
+        P4.H = HI(IMEM_CONTROL);
+
+        R5 = [P4];              /* Control Register*/
+        BITCLR(R5,ENICPLB_P);
+        SSYNC;          /* SSYNC required before writing to IMEM_CONTROL. */
+        .align 8;
+        [P4] = R5;
+        SSYNC;
+
+        P4.L = LO(DMEM_CONTROL);
+        P4.H = HI(DMEM_CONTROL);
+        R5 = [P4];
+        BITCLR(R5,ENDCPLB_P);
+        SSYNC;          /* SSYNC required before writing to DMEM_CONTROL. */
+        .align 8;
+        [P4] = R5;
+        SSYNC;
+
+        /* Fix up the stack */
+        (R7:6,P5:4) = [sp++];
+        ASTAT = [sp++];
+        SP = EX_SCRATCH_REG;
+
+        /* We should be out of the exception stack, and back down into
+         * kernel or user space stack
+         */
+        SAVE_ALL_SYS
+
+        r0 = sp;        /* stack frame pt_regs pointer argument ==> r0 */
+        SP += -12;
+        call _double_fault_c;
+        SP += 12;
+.L_double_fault_panic:
+        JUMP .L_double_fault_panic
+
+ENDPROC(_double_fault)
+
 ENTRY(_exception_to_level5)
 	SAVE_ALL_SYS
 
-- 
cgit v1.2.3-70-g09d2


From 337d390b3a9c1ce92a12bdb77b9ae6ded6273b12 Mon Sep 17 00:00:00 2001
From: Robin Getz <robin.getz@analog.com>
Date: Tue, 9 Oct 2007 17:31:46 +0800
Subject: Blackfin arch: Print out debug info, as early as possible

Print out debug info, as early as possible - even before the
kernel initializes the interrupt vectors. Now we can print out debug
messages almost anytime during the boot process.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/kernel/early_printk.c | 61 ++++++++++++++++++++++++++++++++++---
 arch/blackfin/mach-bf533/head.S     |  6 ++++
 arch/blackfin/mach-bf537/head.S     |  6 ++++
 arch/blackfin/mach-bf548/head.S     |  6 ++++
 arch/blackfin/mach-bf561/head.S     |  6 ++++
 arch/blackfin/mach-common/entry.S   | 43 ++++++++++++++++++++++++--
 include/asm-blackfin/irq_handler.h  |  1 +
 7 files changed, 123 insertions(+), 6 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
index 9bf61706694..6ec518a8111 100644
--- a/arch/blackfin/kernel/early_printk.c
+++ b/arch/blackfin/kernel/early_printk.c
@@ -38,13 +38,13 @@ extern struct console *bfin_earlyserial_init(unsigned int port,
 
 static struct console *early_console;
 
-/* Default console
- * Port n == ttyBFn
- * cflags == UART output modes
- */
+/* Default console */
 #define DEFAULT_PORT 0
 #define DEFAULT_CFLAG CS8|B57600
 
+/* Default console for early crashes */
+#define DEFAULT_EARLY_PORT "serial,uart0,57600"
+
 #ifdef CONFIG_SERIAL_CORE
 /* What should get here is "0,57600" */
 static struct console * __init earlyserial_init(char *buf)
@@ -158,4 +158,57 @@ int __init setup_early_printk(char *buf)
 	return 0;
 }
 
+/*
+ * Set up a temporary Event Vector Table, so if something bad happens before
+ * the kernel is fully started, it doesn't vector off into somewhere we don't
+ * know
+ */
+
+asmlinkage void __init init_early_exception_vectors(void)
+{
+	SSYNC();
+
+	/* cannot program in software:
+	 * evt0 - emulation (jtag)
+	 * evt1 - reset
+	 */
+	bfin_write_EVT2(early_trap);
+	bfin_write_EVT3(early_trap);
+	bfin_write_EVT5(early_trap);
+	bfin_write_EVT6(early_trap);
+	bfin_write_EVT7(early_trap);
+	bfin_write_EVT8(early_trap);
+	bfin_write_EVT9(early_trap);
+	bfin_write_EVT10(early_trap);
+	bfin_write_EVT11(early_trap);
+	bfin_write_EVT12(early_trap);
+	bfin_write_EVT13(early_trap);
+	bfin_write_EVT14(early_trap);
+	bfin_write_EVT15(early_trap);
+	CSYNC();
+
+	/* Set all the return from interupt, exception, NMI to a known place
+	 * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
+	 * Note - don't change RETS - we are in a subroutine, or
+	 * RETE - since it might screw up if emulator is attached
+	 */
+	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
+		: : "p"(early_trap));
+
+}
+
+asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
+{
+	/* This can happen before the uart is initialized, so initialize
+	 * the UART now
+	 */
+	if (likely(early_console == NULL))
+		setup_early_printk(DEFAULT_EARLY_PORT);
+
+	dump_bfin_regs(fp, retaddr);
+	dump_bfin_trace_buffer();
+
+	panic("Died early");
+}
+
 early_param("earlyprintk", setup_early_printk);
diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S
index fa6dc0d8593..1ded945a6fa 100644
--- a/arch/blackfin/mach-bf533/head.S
+++ b/arch/blackfin/mach-bf533/head.S
@@ -181,6 +181,12 @@ ENTRY(__start)
 	fp = sp;
 	usp = sp;
 
+#ifdef CONFIG_EARLY_PRINTK
+	SP += -12;
+	call _init_early_exception_vectors;
+	SP += 12;
+#endif
+
 	/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
 	call _bf53x_relocate_l1_mem;
 #if CONFIG_BFIN_KERNEL_CLOCK
diff --git a/arch/blackfin/mach-bf537/head.S b/arch/blackfin/mach-bf537/head.S
index 2c4ae466d4e..3014fe8dd15 100644
--- a/arch/blackfin/mach-bf537/head.S
+++ b/arch/blackfin/mach-bf537/head.S
@@ -224,6 +224,12 @@ ENTRY(__start)
 	fp = sp;
 	usp = sp;
 
+#ifdef CONFIG_EARLY_PRINTK
+	SP += -12;
+	call _init_early_exception_vectors;
+	SP += 12;
+#endif
+
 	/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
 	call _bf53x_relocate_l1_mem;
 #if CONFIG_BFIN_KERNEL_CLOCK
diff --git a/arch/blackfin/mach-bf548/head.S b/arch/blackfin/mach-bf548/head.S
index 532ed0930b5..3071c243d42 100644
--- a/arch/blackfin/mach-bf548/head.S
+++ b/arch/blackfin/mach-bf548/head.S
@@ -125,6 +125,12 @@ ENTRY(__stext)
 	FP = SP;
 	USP = SP;
 
+#ifdef CONFIG_EARLY_PRINTK
+	SP += -12;
+	call _init_early_exception_vectors;
+	SP += 12;
+#endif
+
 	/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
 	call _bf53x_relocate_l1_mem;
 #if CONFIG_BFIN_KERNEL_CLOCK
diff --git a/arch/blackfin/mach-bf561/head.S b/arch/blackfin/mach-bf561/head.S
index fd39891ae0f..96a3d456fb6 100644
--- a/arch/blackfin/mach-bf561/head.S
+++ b/arch/blackfin/mach-bf561/head.S
@@ -169,6 +169,12 @@ ENTRY(__start)
 	fp = sp;
 	usp = sp;
 
+#ifdef CONFIG_EARLY_PRINTK
+	SP += -12;
+	call _init_early_exception_vectors;
+	SP += 12;
+#endif
+
 	/* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
 	call _bf53x_relocate_l1_mem;
 #if CONFIG_BFIN_KERNEL_CLOCK
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index e2239361cac..a56b231d94c 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -835,12 +835,13 @@ ENTRY(_ex_trace_buff_full)
 	P2 = [sp++];
 	P3 = [sp++];
 	jump _return_from_exception;
+ENDPROC(_ex_trace_buff_full)
 
 #if CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN == 4
 .data
 #else
 .section .l1.data.B
-#endif
+#endif /* CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN */
 ENTRY(_trace_buff_offset)
         .long 0;
 ALIGN
@@ -848,7 +849,45 @@ ENTRY(_software_trace_buff)
 	.rept ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN)*256);
 	.long 0
 	.endr
-#endif
+#endif /* CONFIG_DEBUG_BFIN_HWTRACE_EXPAND */
+
+#if CONFIG_EARLY_PRINTK
+.section .init.text
+ENTRY(_early_trap)
+	SAVE_ALL_SYS
+	trace_buffer_stop(p0,r0);
+
+	/* Turn caches off, to ensure we don't get double exceptions */
+
+	P4.L = LO(IMEM_CONTROL);
+	P4.H = HI(IMEM_CONTROL);
+
+	R5 = [P4];              /* Control Register*/
+	BITCLR(R5,ENICPLB_P);
+	CLI R1;
+	SSYNC;          /* SSYNC required before writing to IMEM_CONTROL. */
+	.align 8;
+	[P4] = R5;
+	SSYNC;
+
+	P4.L = LO(DMEM_CONTROL);
+	P4.H = HI(DMEM_CONTROL);
+	R5 = [P4];
+	BITCLR(R5,ENDCPLB_P);
+	SSYNC;          /* SSYNC required before writing to DMEM_CONTROL. */
+	.align 8;
+	[P4] = R5;
+	SSYNC;
+	STI R1;
+
+	r0 = sp;        /* stack frame pt_regs pointer argument ==> r0 */
+	r1 = RETX;
+
+	SP += -12;
+	call _early_trap_c;
+	SP += 12;
+ENDPROC(_early_trap)
+#endif /* CONFIG_EARLY_PRINTK */
 
 /*
  * Put these in the kernel data section - that should always be covered by
diff --git a/include/asm-blackfin/irq_handler.h b/include/asm-blackfin/irq_handler.h
index 19534c133c9..139b5208f9d 100644
--- a/include/asm-blackfin/irq_handler.h
+++ b/include/asm-blackfin/irq_handler.h
@@ -22,6 +22,7 @@ asmlinkage void evt_system_call(void);
 asmlinkage void init_exception_buff(void);
 asmlinkage void trap_c(struct pt_regs *fp);
 asmlinkage void ex_replaceable(void);
+asmlinkage void early_trap(void);
 
 extern void *ex_table[];
 extern void return_from_exception(void);
-- 
cgit v1.2.3-70-g09d2


From b3f8b9276314f4942ef9033aa5f4dc184901d640 Mon Sep 17 00:00:00 2001
From: Robin Getz <robin.getz@analog.com>
Date: Wed, 10 Oct 2007 17:28:27 +0800
Subject: Blackfin arch: the load address is not safe to point to as a
 workaround for ANOMALY 05000281

Now that we have moved head.S into the init section, the load
address is not safe to point to as a workaround for ANOMALY 05000281

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 arch/blackfin/mach-common/entry.S | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

(limited to 'arch/blackfin/mach-common/entry.S')

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index a56b231d94c..e3ad5802868 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -52,6 +52,15 @@
 # define EX_SCRATCH_REG CYCLES
 #endif
 
+#if ANOMALY_05000281
+ENTRY(_safe_speculative_execution)
+	NOP;
+	NOP;
+	NOP;
+	jump _safe_speculative_execution;
+ENDPROC(_safe_speculative_execution)
+#endif
+
 #ifdef CONFIG_EXCPT_IRQ_SYSC_L1
 .section .l1.text
 #else
@@ -685,8 +694,8 @@ ENTRY(_return_from_int)
 	[p0] = p1;
 	csync;
 #if ANOMALY_05000281
-	r0.l = lo(CONFIG_BOOT_LOAD);
-	r0.h = hi(CONFIG_BOOT_LOAD);
+	r0.l = _safe_speculative_execution;
+	r0.h = _safe_speculative_execution;
 	reti = r0;
 #endif
 	r0 = 0x801f (z);
@@ -699,8 +708,8 @@ ENDPROC(_return_from_int)
 
 ENTRY(_lower_to_irq14)
 #if ANOMALY_05000281
-	r0.l = lo(CONFIG_BOOT_LOAD);
-	r0.h = hi(CONFIG_BOOT_LOAD);
+	r0.l = _safe_speculative_execution;
+	r0.h = _safe_speculative_execution;
 	reti = r0;
 #endif
 	r0 = 0x401f;
-- 
cgit v1.2.3-70-g09d2