From 33ded95b1ca5ebd27a762cabaee63f50eb46dcd6 Mon Sep 17 00:00:00 2001 From: Barry Song Date: Thu, 12 Aug 2010 07:56:40 +0000 Subject: [PATCH] Blackfin: initial preempt support while returning from interrupt Signed-off-by: Barry Song Signed-off-by: Mike Frysinger --- arch/blackfin/mach-common/entry.S | 112 +++++++++++++++++++++++++++++++++- arch/blackfin/mach-common/interrupt.S | 17 ++++++ 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; -- 2.11.4.GIT