---

yaml
---
r: 66007
b: refs/heads/master
c: f0b5d12
h: refs/heads/master
i:
  66005: 252c4c0
  66003: e42f81f
  65999: 5453aed
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 0174dd59bb5f343e8981b5ea7a3dc782fad5b644
+refs/heads/master: f0b5d12f2b3226c85258519d7725e63d9daf5e90

trunk/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 -
 #

trunk/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;

trunk/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;
 

trunk/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;
 

trunk/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*/

trunk/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;
 

trunk/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.  */

trunk/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)

trunk/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);

trunk/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);

trunk/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);