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-rw-r--r--arch/blackfin/mach-common/entry.S191
1 files changed, 100 insertions, 91 deletions
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index fb1795d5be2..01af24cde36 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -301,27 +301,31 @@ ENTRY(_ex_replaceable)
nop;
ENTRY(_ex_trap_c)
+ /* The only thing that has been saved in this context is
+ * (R7:6,P5:4), ASTAT & SP - don't use anything else
+ */
+
+ GET_PDA(p5, r6);
+
/* 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;
+ [p5 + PDA_EXIPEND] = r7;
/* 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.
*/
- P5.h = _exception_to_level5;
- P5.l = _exception_to_level5;
+ r7.h = _exception_to_level5;
+ r7.l = _exception_to_level5;
p4.l = lo(EVT5);
p4.h = hi(EVT5);
- [p4] = p5;
+ [p4] = r7;
csync;
- GET_PDA(p5, r6);
-#ifndef CONFIG_DEBUG_DOUBLEFAULT
-
/*
* Save these registers, as they are only valid in exception context
* (where we are now - as soon as we defer to IRQ5, they can change)
@@ -341,7 +345,10 @@ ENTRY(_ex_trap_c)
r6 = retx;
[p5 + PDA_RETX] = r6;
-#endif
+
+ r6 = SEQSTAT;
+ [p5 + PDA_SEQSTAT] = r6;
+
/* Save the state of single stepping */
r6 = SYSCFG;
[p5 + PDA_SYSCFG] = r6;
@@ -349,8 +356,7 @@ ENTRY(_ex_trap_c)
BITCLR(r6, SYSCFG_SSSTEP_P);
SYSCFG = r6;
- /* Disable all interrupts, but make sure level 5 is enabled so
- * we can switch to that level. Save the old mask. */
+ /* Save the current IMASK, since we change in order to jump to level 5 */
cli r6;
[p5 + PDA_EXIMASK] = r6;
@@ -358,9 +364,21 @@ ENTRY(_ex_trap_c)
p4.h = hi(SAFE_USER_INSTRUCTION);
retx = p4;
+ /* Disable all interrupts, but make sure level 5 is enabled so
+ * we can switch to that level.
+ */
r6 = 0x3f;
sti r6;
+ /* In case interrupts are disabled IPEND[4] (global interrupt disable bit)
+ * clear it (re-enabling interrupts again) by the special sequence of pushing
+ * RETI onto the stack. This way we can lower ourselves to IVG5 even if the
+ * exception was taken after the interrupt handler was called but before it
+ * got a chance to enable global interrupts itself.
+ */
+ [--sp] = reti;
+ sp += 4;
+
raise 5;
jump.s _bfin_return_from_exception;
ENDPROC(_ex_trap_c)
@@ -379,8 +397,7 @@ ENTRY(_double_fault)
R5 = [P4]; /* Control Register*/
BITCLR(R5,ENICPLB_P);
- SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */
- .align 8;
+ CSYNC; /* Disabling of CPLBs should be proceeded by a CSYNC */
[P4] = R5;
SSYNC;
@@ -388,8 +405,7 @@ ENTRY(_double_fault)
P4.H = HI(DMEM_CONTROL);
R5 = [P4];
BITCLR(R5,ENDCPLB_P);
- SSYNC; /* SSYNC required before writing to DMEM_CONTROL. */
- .align 8;
+ CSYNC; /* Disabling of CPLBs should be proceeded by a CSYNC */
[P4] = R5;
SSYNC;
@@ -420,47 +436,55 @@ ENDPROC(_double_fault)
ENTRY(_exception_to_level5)
SAVE_ALL_SYS
- GET_PDA(p4, r7); /* Fetch current PDA */
- r6 = [p4 + PDA_RETX];
+ GET_PDA(p5, r7); /* Fetch current PDA */
+ r6 = [p5 + PDA_RETX];
[sp + PT_PC] = r6;
- r6 = [p4 + PDA_SYSCFG];
+ r6 = [p5 + PDA_SYSCFG];
[sp + PT_SYSCFG] = r6;
- /* Restore interrupt mask. We haven't pushed RETI, so this
- * doesn't enable interrupts until we return from this handler. */
- r6 = [p4 + PDA_EXIMASK];
- sti r6;
+ r6 = [p5 + PDA_SEQSTAT]; /* Read back seqstat */
+ [sp + PT_SEQSTAT] = r6;
/* Restore the hardware error vector. */
- P5.h = _evt_ivhw;
- P5.l = _evt_ivhw;
+ r7.h = _evt_ivhw;
+ r7.l = _evt_ivhw;
p4.l = lo(EVT5);
p4.h = hi(EVT5);
- [p4] = p5;
+ [p4] = r7;
csync;
- p2.l = lo(IPEND);
- p2.h = hi(IPEND);
- csync;
- r0 = [p2]; /* Read current IPEND */
- [sp + PT_IPEND] = r0; /* Store IPEND */
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+ /* Now that we have the hardware error vector programmed properly
+ * we can re-enable interrupts (IPEND[4]), so if the _trap_c causes
+ * another hardware error, we can catch it (self-nesting).
+ */
+ [--sp] = reti;
+ sp += 4;
+#endif
+
+ r7 = [p5 + PDA_EXIPEND] /* Read the IPEND from the Exception state */
+ [sp + PT_IPEND] = r7; /* Store IPEND onto the stack */
r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */
SP += -12;
call _trap_c;
SP += 12;
-#ifdef CONFIG_DEBUG_DOUBLEFAULT
- /* Grab ILAT */
- p2.l = lo(ILAT);
- p2.h = hi(ILAT);
- r0 = [p2];
- r1 = 0x20; /* Did I just cause anther HW error? */
- r0 = r0 & r1;
- CC = R0 == R1;
- if CC JUMP _double_fault;
-#endif
+ /* If interrupts were off during the exception (IPEND[4] = 1), turn them off
+ * before we return.
+ */
+ CC = BITTST(r7, EVT_IRPTEN_P)
+ if !CC jump 1f;
+ /* this will load a random value into the reti register - but that is OK,
+ * since we do restore it to the correct value in the 'RESTORE_ALL_SYS' macro
+ */
+ sp += -4;
+ reti = [sp++];
+1:
+ /* restore the interrupt mask (IMASK) */
+ r6 = [p5 + PDA_EXIMASK];
+ sti r6;
call _ret_from_exception;
RESTORE_ALL_SYS
@@ -474,7 +498,7 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
*/
EX_SCRATCH_REG = sp;
GET_PDA_SAFE(sp);
- sp = [sp + PDA_EXSTACK]
+ sp = [sp + PDA_EXSTACK];
/* Try to deal with syscalls quickly. */
[--sp] = ASTAT;
[--sp] = (R7:6,P5:4);
@@ -489,14 +513,7 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
ssync;
#endif
-#if ANOMALY_05000283 || ANOMALY_05000315
- cc = r7 == r7;
- p5.h = HI(CHIPID);
- p5.l = LO(CHIPID);
- if cc jump 1f;
- r7.l = W[p5];
-1:
-#endif
+ ANOMALY_283_315_WORKAROUND(p5, r7)
#ifdef CONFIG_DEBUG_DOUBLEFAULT
/*
@@ -510,18 +527,18 @@ ENTRY(_trap) /* Exception: 4th entry into system event table(supervisor mode)*/
p4.l = lo(DCPLB_FAULT_ADDR);
p4.h = hi(DCPLB_FAULT_ADDR);
r7 = [p4];
- [p5 + PDA_DCPLB] = r7;
+ [p5 + PDA_DF_DCPLB] = r7;
p4.l = lo(ICPLB_FAULT_ADDR);
p4.h = hi(ICPLB_FAULT_ADDR);
r7 = [p4];
- [p5 + PDA_ICPLB] = r7;
+ [p5 + PDA_DF_ICPLB] = r7;
- r6 = retx;
- [p5 + PDA_RETX] = r6;
+ r7 = retx;
+ [p5 + PDA_DF_RETX] = r7;
r7 = SEQSTAT; /* reason code is in bit 5:0 */
- [p5 + PDA_SEQSTAT] = r7;
+ [p5 + PDA_DF_SEQSTAT] = r7;
#else
r7 = SEQSTAT; /* reason code is in bit 5:0 */
#endif
@@ -686,8 +703,14 @@ ENTRY(_system_call)
#ifdef CONFIG_IPIPE
cc = BITTST(r7, TIF_IRQ_SYNC);
if !cc jump .Lsyscall_no_irqsync;
+ /*
+ * Clear IPEND[4] manually to undo what resume_userspace_1 just did;
+ * we need this so that high priority domain interrupts may still
+ * preempt the current domain while the pipeline log is being played
+ * back.
+ */
[--sp] = reti;
- r0 = [sp++];
+ SP += 4; /* don't merge with next insn to keep the pattern obvious */
SP += -12;
call ___ipipe_sync_root;
SP += 12;
@@ -699,7 +722,7 @@ ENTRY(_system_call)
/* Reenable interrupts. */
[--sp] = reti;
- r0 = [sp++];
+ sp += 4;
SP += -12;
call _schedule;
@@ -715,7 +738,7 @@ ENTRY(_system_call)
.Lsyscall_do_signals:
/* Reenable interrupts. */
[--sp] = reti;
- r0 = [sp++];
+ sp += 4;
r0 = sp;
SP += -12;
@@ -725,10 +748,6 @@ ENTRY(_system_call)
.Lsyscall_really_exit:
r5 = [sp + PT_RESERVED];
rets = r5;
-#ifdef CONFIG_IPIPE
- [--sp] = reti;
- r5 = [sp++];
-#endif /* CONFIG_IPIPE */
rts;
ENDPROC(_system_call)
@@ -816,13 +835,13 @@ ENDPROC(_resume)
ENTRY(_ret_from_exception)
#ifdef CONFIG_IPIPE
- [--sp] = rets;
- SP += -12;
- call ___ipipe_check_root
- SP += 12
- rets = [sp++];
- cc = r0 == 0;
- if cc jump 4f; /* not on behalf of Linux, get out */
+ p2.l = _per_cpu__ipipe_percpu_domain;
+ p2.h = _per_cpu__ipipe_percpu_domain;
+ r0.l = _ipipe_root;
+ r0.h = _ipipe_root;
+ r2 = [p2];
+ cc = r0 == r2;
+ if !cc jump 4f; /* not on behalf of the root domain, get out */
#endif /* CONFIG_IPIPE */
p2.l = lo(IPEND);
p2.h = hi(IPEND);
@@ -882,14 +901,9 @@ ENDPROC(_ret_from_exception)
#ifdef CONFIG_IPIPE
-_sync_root_irqs:
- [--sp] = reti; /* Reenable interrupts */
- r0 = [sp++];
- jump.l ___ipipe_sync_root
-
_resume_kernel_from_int:
- r0.l = _sync_root_irqs
- r0.h = _sync_root_irqs
+ r0.l = ___ipipe_sync_root;
+ r0.h = ___ipipe_sync_root;
[--sp] = rets;
[--sp] = ( r7:4, p5:3 );
SP += -12;
@@ -953,10 +967,10 @@ ENTRY(_lower_to_irq14)
#endif
#ifdef CONFIG_DEBUG_HWERR
- /* enable irq14 & hwerr interrupt, until we transition to _evt14_softirq */
+ /* enable irq14 & hwerr interrupt, until we transition to _evt_evt14 */
r0 = (EVT_IVG14 | EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
#else
- /* Only enable irq14 interrupt, until we transition to _evt14_softirq */
+ /* Only enable irq14 interrupt, until we transition to _evt_evt14 */
r0 = (EVT_IVG14 | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
#endif
sti r0;
@@ -964,7 +978,7 @@ ENTRY(_lower_to_irq14)
rti;
ENDPROC(_lower_to_irq14)
-ENTRY(_evt14_softirq)
+ENTRY(_evt_evt14)
#ifdef CONFIG_DEBUG_HWERR
r0 = (EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
sti r0;
@@ -974,7 +988,7 @@ ENTRY(_evt14_softirq)
[--sp] = RETI;
SP += 4;
rts;
-ENDPROC(_evt14_softirq)
+ENDPROC(_evt_evt14)
ENTRY(_schedule_and_signal_from_int)
/* To end up here, vector 15 was changed - so we have to change it
@@ -1004,6 +1018,12 @@ ENTRY(_schedule_and_signal_from_int)
#endif
sti r0;
+ /* finish the userspace "atomic" functions for it */
+ r1 = FIXED_CODE_END;
+ r2 = [sp + PT_PC];
+ cc = r1 <= r2;
+ if cc jump .Lresume_userspace (bp);
+
r0 = sp;
sp += -12;
call _finish_atomic_sections;
@@ -1107,14 +1127,7 @@ ENTRY(_early_trap)
SAVE_ALL_SYS
trace_buffer_stop(p0,r0);
-#if ANOMALY_05000283 || ANOMALY_05000315
- cc = r5 == r5;
- p4.h = HI(CHIPID);
- p4.l = LO(CHIPID);
- if cc jump 1f;
- r5.l = W[p4];
-1:
-#endif
+ ANOMALY_283_315_WORKAROUND(p4, r5)
/* Turn caches off, to ensure we don't get double exceptions */
@@ -1123,9 +1136,7 @@ ENTRY(_early_trap)
R5 = [P4]; /* Control Register*/
BITCLR(R5,ENICPLB_P);
- CLI R1;
- SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */
- .align 8;
+ CSYNC; /* Disabling of CPLBs should be proceeded by a CSYNC */
[P4] = R5;
SSYNC;
@@ -1133,11 +1144,9 @@ ENTRY(_early_trap)
P4.H = HI(DMEM_CONTROL);
R5 = [P4];
BITCLR(R5,ENDCPLB_P);
- SSYNC; /* SSYNC required before writing to DMEM_CONTROL. */
- .align 8;
+ CSYNC; /* Disabling of CPLBs should be proceeded by a CSYNC */
[P4] = R5;
SSYNC;
- STI R1;
r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */
r1 = RETX;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 09:46:34 +0000