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authorBarry Song <barry.song@analog.com>2010-08-12 07:56:40 +0000
committerMike Frysinger <vapier@gentoo.org>2010-10-22 03:48:55 -0400
commit33ded95b1ca5ebd27a762cabaee63f50eb46dcd6 (patch)
treefe12da8aab11c04b7062be41efbdf75358bee50d /arch/blackfin
parentc0ab9387456d7660dead96ce1b5463741f087db1 (diff)
Blackfin: initial preempt support while returning from interrupt
Signed-off-by: Barry Song <barry.song@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/mach-common/entry.S112
-rw-r--r--arch/blackfin/mach-common/interrupt.S17
2 files changed, 126 insertions, 3 deletions
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index af1bffa21dc..16ea779c3a6 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -889,6 +889,66 @@ ENTRY(_ret_from_exception)
rts;
ENDPROC(_ret_from_exception)
+#if defined(CONFIG_PREEMPT)
+
+ENTRY(_up_to_irq14)
+#if ANOMALY_05000281 || ANOMALY_05000461
+ r0.l = lo(SAFE_USER_INSTRUCTION);
+ r0.h = hi(SAFE_USER_INSTRUCTION);
+ reti = r0;
+#endif
+
+#ifdef CONFIG_DEBUG_HWERR
+ /* 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 _evt_evt14 */
+ r0 = (EVT_IVG14 | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
+#endif
+ sti r0;
+
+ p0.l = lo(EVT14);
+ p0.h = hi(EVT14);
+ p1.l = _evt_up_evt14;
+ p1.h = _evt_up_evt14;
+ [p0] = p1;
+ csync;
+
+ raise 14;
+1:
+ jump 1b;
+ENDPROC(_up_to_irq14)
+
+ENTRY(_evt_up_evt14)
+#ifdef CONFIG_DEBUG_HWERR
+ r0 = (EVT_IVHW | EVT_IRPTEN | EVT_EVX | EVT_NMI | EVT_RST | EVT_EMU);
+ sti r0;
+#else
+ cli r0;
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+ [--sp] = rets;
+ sp += -12;
+ call _trace_hardirqs_off;
+ sp += 12;
+ rets = [sp++];
+#endif
+ [--sp] = RETI;
+ SP += 4;
+
+ /* restore normal evt14 */
+ p0.l = lo(EVT14);
+ p0.h = hi(EVT14);
+ p1.l = _evt_evt14;
+ p1.h = _evt_evt14;
+ [p0] = p1;
+ csync;
+
+ rts;
+ENDPROC(_evt_up_evt14)
+
+#endif
+
#ifdef CONFIG_IPIPE
_resume_kernel_from_int:
@@ -902,8 +962,54 @@ _resume_kernel_from_int:
( r7:4, p5:3 ) = [sp++];
rets = [sp++];
rts
+#elif defined(CONFIG_PREEMPT)
+
+_resume_kernel_from_int:
+ /* check preempt_count */
+ r7 = sp;
+ r4.l = lo(ALIGN_PAGE_MASK);
+ r4.h = hi(ALIGN_PAGE_MASK);
+ r7 = r7 & r4;
+ p5 = r7;
+ r7 = [p5 + TI_PREEMPT];
+ cc = r7 == 0x0;
+ if !cc jump .Lreturn_to_kernel;
+.Lneed_schedule:
+ r7 = [p5 + TI_FLAGS];
+ r4.l = lo(_TIF_WORK_MASK);
+ r4.h = hi(_TIF_WORK_MASK);
+ r7 = r7 & r4;
+ cc = BITTST(r7, TIF_NEED_RESCHED);
+ if !cc jump .Lreturn_to_kernel;
+ /*
+ * let schedule done at level 15, otherwise sheduled process will run
+ * at high level and block low level interrupt
+ */
+ r6 = reti; /* save reti */
+ r5.l = .Lkernel_schedule;
+ r5.h = .Lkernel_schedule;
+ reti = r5;
+ rti;
+.Lkernel_schedule:
+ [--sp] = rets;
+ sp += -12;
+ pseudo_long_call _preempt_schedule_irq, p4;
+ sp += 12;
+ rets = [sp++];
+
+ [--sp] = rets;
+ sp += -12;
+ /* up to irq14 so that reti after restore_all can return to irq15(kernel) */
+ pseudo_long_call _up_to_irq14, p4;
+ sp += 12;
+ rets = [sp++];
+
+ reti = r6; /* restore reti so that origin process can return to interrupted point */
+
+ jump .Lneed_schedule;
#else
-#define _resume_kernel_from_int 2f
+
+#define _resume_kernel_from_int .Lreturn_to_kernel
#endif
ENTRY(_return_from_int)
@@ -913,7 +1019,7 @@ ENTRY(_return_from_int)
p2.h = hi(ILAT);
r0 = [p2];
cc = bittst (r0, EVT_IVG15_P);
- if cc jump 2f;
+ if cc jump .Lreturn_to_kernel;
/* if not return to user mode, get out */
p2.l = lo(IPEND);
@@ -945,7 +1051,7 @@ ENTRY(_return_from_int)
STI r0;
raise 15; /* raise evt15 to do signal or reschedule */
rti;
-2:
+.Lreturn_to_kernel:
rts;
ENDPROC(_return_from_int)
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index cee62cf4acd..2df37db3b49 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -116,7 +116,24 @@ __common_int_entry:
cc = r0 == 0;
if cc jump .Lcommon_restore_context;
#else /* CONFIG_IPIPE */
+
+#ifdef CONFIG_PREEMPT
+ r7 = sp;
+ r4.l = lo(ALIGN_PAGE_MASK);
+ r4.h = hi(ALIGN_PAGE_MASK);
+ r7 = r7 & r4;
+ p5 = r7;
+ r7 = [p5 + TI_PREEMPT]; /* get preempt count */
+ r7 += 1; /* increment it */
+ [p5 + TI_PREEMPT] = r7;
+#endif
pseudo_long_call _do_irq, p2;
+
+#ifdef CONFIG_PREEMPT
+ r7 += -1;
+ [p5 + TI_PREEMPT] = r7; /* restore preempt count */
+#endif
+
SP += 12;
#endif /* CONFIG_IPIPE */
pseudo_long_call _return_from_int, p2;