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Diffstat (limited to 'arch/avr32/kernel/entry-avr32b.S')
-rw-r--r--arch/avr32/kernel/entry-avr32b.S140
1 files changed, 99 insertions, 41 deletions
diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S
index 2b398cae110..7301f4806bb 100644
--- a/arch/avr32/kernel/entry-avr32b.S
+++ b/arch/avr32/kernel/entry-avr32b.S
@@ -150,10 +150,10 @@ page_not_present:
tlbmiss_restore
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_page_fault
+ call do_page_fault
rjmp ret_from_exception
.align 2
@@ -250,18 +250,20 @@ syscall_badsys:
.global ret_from_fork
ret_from_fork:
- rcall schedule_tail
+ call schedule_tail
+ mov r12, 0
+ rjmp syscall_return
- /* check for syscall tracing */
- get_thread_info r0
- ld.w r1, r0[TI_flags]
- andl r1, _TIF_ALLWORK_MASK, COH
- brne syscall_exit_work
- rjmp syscall_exit_cont
+ .global ret_from_kernel_thread
+ret_from_kernel_thread:
+ call schedule_tail
+ mov r12, r0
+ mov lr, r2 /* syscall_return */
+ mov pc, r1
syscall_trace_enter:
pushm r8-r12
- rcall syscall_trace
+ call syscall_trace
popm r8-r12
rjmp syscall_trace_cont
@@ -269,25 +271,25 @@ syscall_exit_work:
bld r1, TIF_SYSCALL_TRACE
brcc 1f
unmask_interrupts
- rcall syscall_trace
+ call syscall_trace
mask_interrupts
ld.w r1, r0[TI_flags]
1: bld r1, TIF_NEED_RESCHED
brcc 2f
unmask_interrupts
- rcall schedule
+ call schedule
mask_interrupts
ld.w r1, r0[TI_flags]
rjmp 1b
-2: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
+2: mov r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
tst r1, r2
breq 3f
unmask_interrupts
mov r12, sp
mov r11, r0
- rcall do_notify_resume
+ call do_notify_resume
mask_interrupts
ld.w r1, r0[TI_flags]
rjmp 1b
@@ -334,36 +336,92 @@ save_full_context_ex:
/* Low-level exception handlers */
handle_critical:
+ /*
+ * AT32AP700x errata:
+ *
+ * After a Java stack overflow or underflow trap, any CPU
+ * memory access may cause erratic behavior. This will happen
+ * when the four least significant bits of the JOSP system
+ * register contains any value between 9 and 15 (inclusive).
+ *
+ * Possible workarounds:
+ * - Don't use the Java Extension Module
+ * - Ensure that the stack overflow and underflow trap
+ * handlers do not do any memory access or trigger any
+ * exceptions before the overflow/underflow condition is
+ * cleared (by incrementing or decrementing the JOSP)
+ * - Make sure that JOSP does not contain any problematic
+ * value before doing any exception or interrupt
+ * processing.
+ * - Set up a critical exception handler which writes a
+ * known-to-be-safe value, e.g. 4, to JOSP before doing
+ * any further processing.
+ *
+ * We'll use the last workaround for now since we cannot
+ * guarantee that user space processes don't use Java mode.
+ * Non-well-behaving userland will be terminated with extreme
+ * prejudice.
+ */
+#ifdef CONFIG_CPU_AT32AP700X
+ /*
+ * There's a chance we can't touch memory, so temporarily
+ * borrow PTBR to save the stack pointer while we fix things
+ * up...
+ */
+ mtsr SYSREG_PTBR, sp
+ mov sp, 4
+ mtsr SYSREG_JOSP, sp
+ mfsr sp, SYSREG_PTBR
+ sub pc, -2
+
+ /* Push most of pt_regs on stack. We'll do the rest later */
sub sp, 4
- stmts --sp, r0-lr
- rcall save_full_context_ex
+ pushm r0-r12
+
+ /* PTBR mirrors current_thread_info()->task->active_mm->pgd */
+ get_thread_info r0
+ ld.w r1, r0[TI_task]
+ ld.w r2, r1[TSK_active_mm]
+ ld.w r3, r2[MM_pgd]
+ mtsr SYSREG_PTBR, r3
+#else
+ sub sp, 4
+ pushm r0-r12
+#endif
+ sub r0, sp, -(14 * 4)
+ mov r1, lr
+ mfsr r2, SYSREG_RAR_EX
+ mfsr r3, SYSREG_RSR_EX
+ pushm r0-r3
+
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_critical_exception
+ call do_critical_exception
/* We should never get here... */
bad_return:
sub r12, pc, (. - 1f)
- bral panic
+ lddpc pc, 2f
.align 2
1: .asciz "Return from critical exception!"
+2: .long panic
.align 1
do_bus_error_write:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mov r11, 1
rjmp 1f
do_bus_error_read:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mov r11, 0
1: mfsr r12, SYSREG_BEAR
mov r10, sp
- rcall do_bus_error
+ call do_bus_error
rjmp ret_from_exception
.align 1
@@ -378,7 +436,7 @@ do_nmi_ll:
1: pushm r8, r9 /* PC and SR */
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_nmi
+ call do_nmi
popm r8-r9
mtsr SYSREG_RAR_NMI, r8
tst r0, r0
@@ -402,29 +460,29 @@ do_nmi_ll:
handle_address_fault:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_address_exception
+ call do_address_exception
rjmp ret_from_exception
handle_protection_fault:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_page_fault
+ call do_page_fault
rjmp ret_from_exception
.align 1
do_illegal_opcode_ll:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
mfsr r12, SYSREG_ECR
mov r11, sp
- rcall do_illegal_opcode
+ call do_illegal_opcode
rjmp ret_from_exception
do_dtlb_modified:
@@ -458,11 +516,11 @@ do_dtlb_modified:
do_fpe_ll:
sub sp, 4
stmts --sp, r0-lr
- rcall save_full_context_ex
+ call save_full_context_ex
unmask_interrupts
mov r12, 26
mov r11, sp
- rcall do_fpe
+ call do_fpe
rjmp ret_from_exception
ret_from_exception:
@@ -498,7 +556,7 @@ fault_resume_kernel:
lddsp r4, sp[REG_SR]
bld r4, SYSREG_GM_OFFSET
brcs 1f
- rcall preempt_schedule_irq
+ call preempt_schedule_irq
1:
#endif
@@ -527,18 +585,18 @@ fault_exit_work:
bld r1, TIF_NEED_RESCHED
brcc 1f
unmask_interrupts
- rcall schedule
+ call schedule
mask_interrupts
ld.w r1, r0[TI_flags]
rjmp fault_exit_work
-1: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK
+1: mov r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
tst r1, r2
breq 2f
unmask_interrupts
mov r12, sp
mov r11, r0
- rcall do_notify_resume
+ call do_notify_resume
mask_interrupts
ld.w r1, r0[TI_flags]
rjmp fault_exit_work
@@ -561,10 +619,10 @@ handle_debug:
.Ldebug_fixup_cont:
#ifdef CONFIG_TRACE_IRQFLAGS
- rcall trace_hardirqs_off
+ call trace_hardirqs_off
#endif
mov r12, sp
- rcall do_debug
+ call do_debug
mov sp, r12
lddsp r2, sp[REG_SR]
@@ -588,7 +646,7 @@ handle_debug:
mtsr SYSREG_RSR_DBG, r11
mtsr SYSREG_RAR_DBG, r10
#ifdef CONFIG_TRACE_IRQFLAGS
- rcall trace_hardirqs_on
+ call trace_hardirqs_on
1:
#endif
ldmts sp++, r0-lr
@@ -621,7 +679,7 @@ debug_resume_kernel:
#ifdef CONFIG_TRACE_IRQFLAGS
bld r11, SYSREG_GM_OFFSET
brcc 1f
- rcall trace_hardirqs_on
+ call trace_hardirqs_on
1:
#endif
mfsr r2, SYSREG_SR
@@ -692,7 +750,7 @@ irq_level\level:
mov r11, sp
mov r12, \level
- rcall do_IRQ
+ call do_IRQ
lddsp r4, sp[REG_SR]
bfextu r4, r4, SYSREG_M0_OFFSET, 3
@@ -712,7 +770,7 @@ irq_level\level:
1:
#ifdef CONFIG_TRACE_IRQFLAGS
- rcall trace_hardirqs_on
+ call trace_hardirqs_on
#endif
popm r8-r9
mtsr rar_int\level, r8
@@ -752,7 +810,7 @@ irq_level\level:
lddsp r4, sp[REG_SR]
bld r4, SYSREG_GM_OFFSET
brcs 1b
- rcall preempt_schedule_irq
+ call preempt_schedule_irq
#endif
rjmp 1b
.endm
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-10 14:58:46 +0000