Commit 13fe24f3 authored by Robin Getz's avatar Robin Getz Committed by Bryan Wu
Browse files

[Blackfin] arch: fix bug - trap_tests fails to recover on some tests. 

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3719



When the CPLBs get a miss, we do:
  - find a victim in the HW table
  - remove the victim
  - find the replacement in the software table
  - put it into the HW table.

If we can't find a replacement in the software table, we accidently
leave a duplicate in the HW table. This patch ensures that duplicate
is marked as not valid.

What we should do is find the replacement in the software table, before
we find a victim in the HW table - but its too late in the release cycle
to do that much restructuring of this code.

Rather that duplicate code, connect Hardware Errors (irq5) into trap_c,
so user space processes get killed properly.

The rest of irq_panic() can be moved into traps.c (later)

There is still a small corner case that causes problems when a
pheriperal interrupt goes off a single cycle before a user space
hardware error. This causes a kernel panic, rather than the user
space process being killed.

But, this checkin makes things work in 99.9% of the cases, and is a vast
improvement from what is there today (which fails 100% of the time).

Signed-off-by: default avatarRobin Getz <robin.getz@analog.com>
Signed-off-by: default avatarBryan Wu <bryan.wu@analog.com>
parent f53e8676

arch/blackfin/kernel/traps.c

+46 −8
Original line number Diff line number Diff line
@@ -433,6 +433,36 @@ asmlinkage void trap_c(struct pt_regs *fp) 
	/* 0x3D - Reserved, Caught by default */

	/* 0x3E - Reserved, Caught by default */

	/* 0x3F - Reserved, Caught by default */

	case VEC_HWERR:

		info.si_code = BUS_ADRALN;

		sig = SIGBUS;

		switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {

		/* System MMR Error */

		case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):

			info.si_code = BUS_ADRALN;

			sig = SIGBUS;

			printk(KERN_NOTICE HWC_x2(KERN_NOTICE));

			break;

		/* External Memory Addressing Error */

		case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):

			info.si_code = BUS_ADRERR;

			sig = SIGBUS;

			printk(KERN_NOTICE HWC_x3(KERN_NOTICE));

			break;

		/* Performance Monitor Overflow */

		case (SEQSTAT_HWERRCAUSE_PERF_FLOW):

			printk(KERN_NOTICE HWC_x12(KERN_NOTICE));

			break;

		/* RAISE 5 instruction */

		case (SEQSTAT_HWERRCAUSE_RAISE_5):

			printk(KERN_NOTICE HWC_x18(KERN_NOTICE));

			break;

		default:        /* Reserved */

			printk(KERN_NOTICE HWC_default(KERN_NOTICE));

			break;

		}

		CHK_DEBUGGER_TRAP();

		break;

	default:

		info.si_code = TRAP_ILLTRAP;

		sig = SIGTRAP;
@@ -447,6 +477,10 @@ asmlinkage void trap_c(struct pt_regs *fp) 
	if (sig != SIGTRAP) {

		unsigned long stack;

		dump_bfin_process(fp);

		/* Is it an interrupt, or an exception? */

		if (trapnr == VEC_HWERR)

			dump_bfin_mem((void *)fp->pc);

		else

			dump_bfin_mem((void *)fp->retx);

		show_regs(fp);
@@ -672,12 +706,11 @@ void dump_bfin_mem(void *retaddr) 
			 * context, which should mean an oops is happening

			 */

			if (oops_in_progress && x >= 0x0040 && x <= 0x0047 && i <= 0)

				panic("\n\nWARNING : You should reconfigure"

				printk(KERN_EMERG "\n"

					KERN_EMERG "WARNING : You should reconfigure"

					" the kernel to turn on\n"

					" 'Hardware error interrupt"

					" debugging'\n"

					" The rest of this error"

					" is meanless\n");

					KERN_EMERG " 'Hardware error interrupt debugging'\n"

					KERN_EMERG " The rest of this error is meanless\n");

#endif

			if (i == (unsigned int)retaddr)

				printk("[%04x]", x);
@@ -698,6 +731,10 @@ void show_regs(struct pt_regs *fp) 
	printk(KERN_NOTICE "\n" KERN_NOTICE "SEQUENCER STATUS:\n");

	printk(KERN_NOTICE " SEQSTAT: %08lx  IPEND: %04lx  SYSCFG: %04lx\n",

		(long)fp->seqstat, fp->ipend, fp->syscfg);

	printk(KERN_NOTICE "  HWERRCAUSE: 0x%lx\n",

		(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14);

	printk(KERN_NOTICE "  EXCAUSE   : 0x%lx\n",

		fp->seqstat & SEQSTAT_EXCAUSE);



	decode_address(buf, fp->rete);

	printk(KERN_NOTICE " RETE: %s\n", buf);
@@ -710,7 +747,8 @@ void show_regs(struct pt_regs *fp) 
	decode_address(buf, fp->pc);

	printk(KERN_NOTICE " PC  : %s\n", buf);



	if ((long)fp->seqstat & SEQSTAT_EXCAUSE) {

	if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) &&

	    (((long)fp->seqstat & SEQSTAT_EXCAUSE) != VEC_HWERR)) {

		decode_address(buf, bfin_read_DCPLB_FAULT_ADDR());

		printk(KERN_NOTICE "DCPLB_FAULT_ADDR: %s\n", buf);

		decode_address(buf, bfin_read_ICPLB_FAULT_ADDR());

arch/blackfin/mach-common/cplbmgr.S

+19 −3
Original line number Diff line number Diff line
@@ -190,7 +190,14 @@ ENTRY(_cplb_mgr) 
	[P0 - 4] = R0;

	R0 = [P0 - 0x100];

	[P0-0x104] = R0;

.Lie_move:P0+=4;

.Lie_move:

	P0+=4;



	/* Clear ICPLB_DATA15, in case we don't find a replacement

	 * otherwise, we would have a duplicate entry, and will crash

	 */

	R0 = 0;

	[P0 - 4] = R0;



	/* We've made space in the ICPLB table, so that ICPLB15

	 * is now free to be overwritten. Next, we have to determine
@@ -515,14 +522,23 @@ ENTRY(_cplb_mgr) 
	R0 = [P0++];	/* move data */

	[P0 - 8] = R0;

	R0 = [P0-0x104]	/* move address */

.Lde_move: [P0-0x108] = R0;

.Lde_move:

	 [P0-0x108] = R0;



.Lde_moved:

	NOP;



	/* Clear DCPLB_DATA15, in case we don't find a replacement

	 * otherwise, we would have a duplicate entry, and will crash

	 */

	R0 = 0;

	[P0 - 0x4] = R0;



	/* We've now made space in DCPLB15 for the new CPLB to be

	 * installed. The next stage is to locate a CPLB in the

	 * config table that covers the faulting address.

	 */



.Lde_moved:NOP;

	R0 = I0;		/* Our faulting address */



	P2.L = _dpdt_table;

arch/blackfin/mach-common/interrupt.S

+30 −10
Original line number Diff line number Diff line
@@ -34,9 +34,13 @@ 
#include <asm/entry.h>

#include <asm/asm-offsets.h>

#include <asm/trace.h>

#include <asm/traps.h>

#include <asm/thread_info.h>



#include <asm/mach-common/context.S>



.extern _ret_from_exception



#ifdef CONFIG_I_ENTRY_L1

.section .l1.text

#else
@@ -134,10 +138,11 @@ __common_int_entry: 


/* interrupt routine for ivhw - 5 */

ENTRY(_evt_ivhw)

	SAVE_CONTEXT

	SAVE_ALL_SYS

#ifdef CONFIG_FRAME_POINTER

	fp = 0;

#endif



#if ANOMALY_05000283

	cc = r7 == r7;

	p5.h = 0xffc0;
@@ -147,13 +152,8 @@ ENTRY(_evt_ivhw) 
1:

#endif



	trace_buffer_stop(p0, r0);



	r0 = IRQ_HWERR;

	r1 = sp;



#ifdef CONFIG_HARDWARE_PM

	r7 = SEQSTAT;

	r7 = [sp + PT_SEQSTAT];

	r7 = r7 >>> 0xe;

	r6 = 0x1F;

	r7 = r7 & r6;
@@ -161,11 +161,29 @@ ENTRY(_evt_ivhw) 
	cc = r7 == r5;

	if cc jump .Lcall_do_ovf; /* deal with performance counter overflow */

#endif



	# We are going to dump something out, so make sure we print IPEND properly

	p2.l = lo(IPEND);

	p2.h = hi(IPEND);

	r0 = [p2];

	[sp + PT_IPEND] = r0;



	/* set the EXCAUSE to HWERR for trap_c */

	r0 = [sp + PT_SEQSTAT];

	R1.L = LO(VEC_HWERR);

	R1.H = HI(VEC_HWERR);

	R0 = R0 | R1;

	[sp + PT_SEQSTAT] = R0;



	r0 = sp;        /* stack frame pt_regs pointer argument ==> r0 */

	SP += -12;

	call _irq_panic;

	call _trap_c;

	SP += 12;



	call _ret_from_exception;

.Lcommon_restore_all_sys:

	RESTORE_ALL_SYS

	rti;



#ifdef CONFIG_HARDWARE_PM

.Lcall_do_ovf:
@@ -173,9 +191,11 @@ ENTRY(_evt_ivhw) 
	call _pm_overflow;

	SP += 12;



	jump .Lcommon_restore_context;

	jump .Lcommon_restore_all_sys;

#endif



ENDPROC(_evt_ivhw)



/* Interrupt routine for evt2 (NMI).

 * We don't actually use this, so just return.

 * For inner circle type details, please see:

arch/blackfin/mach-common/irqpanic.c

+0 −50
Original line number Diff line number Diff line
@@ -46,9 +46,6 @@ void irq_panic(int reason, struct pt_regs *regs) __attribute__ ((l1_text)); 
 */

asmlinkage void irq_panic(int reason, struct pt_regs *regs)

{

	int sig = 0;

	siginfo_t info;



#ifdef CONFIG_DEBUG_ICACHE_CHECK

	unsigned int cmd, tag, ca, cache_hi, cache_lo, *pa;

	unsigned short i, j, die;
@@ -136,53 +133,6 @@ asmlinkage void irq_panic(int reason, struct pt_regs *regs) 
	}

#endif



	printk(KERN_EMERG "\n");

	printk(KERN_EMERG "Exception: IRQ 0x%x entered\n", reason);

	printk(KERN_EMERG " code=[0x%08lx],   stack frame=0x%08lx,  "

	    " bad PC=0x%08lx\n",

	    (unsigned long)regs->seqstat,

	    (unsigned long)regs,

	    (unsigned long)regs->pc);

	if (reason == 0x5) {

		printk(KERN_EMERG "----------- HARDWARE ERROR -----------\n");



		/* There is only need to check for Hardware Errors, since other

		 * EXCEPTIONS are handled in TRAPS.c (MH)

		 */

		switch (regs->seqstat & SEQSTAT_HWERRCAUSE) {

		case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):	/* System MMR Error */

			info.si_code = BUS_ADRALN;

			sig = SIGBUS;

			printk(KERN_EMERG HWC_x2(KERN_EMERG));

			break;

		case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):	/* External Memory Addressing Error */

			info.si_code = BUS_ADRERR;

			sig = SIGBUS;

			printk(KERN_EMERG HWC_x3(KERN_EMERG));

			break;

		case (SEQSTAT_HWERRCAUSE_PERF_FLOW):	/* Performance Monitor Overflow */

			printk(KERN_EMERG HWC_x12(KERN_EMERG));

			break;

		case (SEQSTAT_HWERRCAUSE_RAISE_5):	/* RAISE 5 instruction */

			printk(KERN_EMERG HWC_x18(KERN_EMERG));

			break;

		default:	/* Reserved */

			printk(KERN_EMERG HWC_default(KERN_EMERG));

			break;

		}

	}



	regs->ipend = bfin_read_IPEND();

	dump_bfin_process(regs);

	dump_bfin_mem((void *)regs->pc);

	show_regs(regs);

	if (0 == (info.si_signo = sig) || 0 == user_mode(regs))	/* in kernelspace */

		panic("Unhandled IRQ or exceptions!\n");

	else {			/* in userspace */

		info.si_errno = 0;

		info.si_addr = (void *)regs->pc;

		force_sig_info(sig, &info, current);

	}

}



#ifdef CONFIG_HARDWARE_PM

include/asm-blackfin/traps.h

+4 −0
Original line number Diff line number Diff line
@@ -45,6 +45,10 @@ 
#define VEC_CPLB_I_M	(44)

#define VEC_CPLB_I_MHIT	(45)

#define VEC_ILL_RES	(46)	/* including unvalid supervisor mode insn */

/* The hardware reserves (63) for future use - we use it to tell our

 * normal exception handling code we have a hardware error

 */

#define VEC_HWERR	(63)



#ifndef __ASSEMBLY__