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

Browse Source 
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: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
This commit is contained in:
Robin Getz
2008-01-27 15:38:56 +08:00
committed by Bryan Wu
parent f53e86760e
commit 13fe24f37d
5 changed files with 98 additions and 70 deletions
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38
arch/blackfin/mach-common/interrupt.S
View File

@@ -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: