Some platforms execute their timer handler with the interrupt priority level set below 6. That means the handler could be interrupted by another driver and this could lead to re-entry of the timer core.
Avoid this by use of local_irq_save/restore for timer interrupt dispatch. This provides mutual exclusion around the timer interrupt flag access which is needed later in this series for the clocksource conversion. Reported-by: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/alpine.deb.2.21.1811131407120.2...@nanos.tec.linutronix.de Signed-off-by: Finn Thain <fth...@telegraphics.com.au> --- I've only checked 680x0 MMU platforms for this issue. Changed since v2: - Don't waste an iteration of the for loop in cia_handler(). - Remove q40_timer_routine for better consistency with other platforms. - Minor cleanup. --- arch/m68k/amiga/cia.c | 9 +++++++++ arch/m68k/atari/ataints.c | 4 ++-- arch/m68k/atari/time.c | 15 ++++++++++++++- arch/m68k/bvme6000/config.c | 20 ++++++++++---------- arch/m68k/hp300/time.c | 10 ++++++++-- arch/m68k/mac/via.c | 17 +++++++++++++++++ arch/m68k/mvme147/config.c | 18 ++++++++++-------- arch/m68k/mvme16x/config.c | 21 +++++++++++---------- arch/m68k/q40/q40ints.c | 19 +++++++++++-------- arch/m68k/sun3/sun3ints.c | 3 +++ arch/m68k/sun3x/time.c | 16 ++++++++++------ 11 files changed, 105 insertions(+), 47 deletions(-) diff --git a/arch/m68k/amiga/cia.c b/arch/m68k/amiga/cia.c index 2081b8cd5591..b9aee983e6f4 100644 --- a/arch/m68k/amiga/cia.c +++ b/arch/m68k/amiga/cia.c @@ -88,10 +88,19 @@ static irqreturn_t cia_handler(int irq, void *dev_id) struct ciabase *base = dev_id; int mach_irq; unsigned char ints; + unsigned long flags; + /* Interrupts get disabled while the timer irq flag is cleared and + * the timer interrupt serviced. + */ mach_irq = base->cia_irq; + local_irq_save(flags); ints = cia_set_irq(base, CIA_ICR_ALL); amiga_custom.intreq = base->int_mask; + if (ints & 1) + generic_handle_irq(mach_irq); + local_irq_restore(flags); + mach_irq++, ints >>= 1; for (; ints; mach_irq++, ints >>= 1) { if (ints & 1) generic_handle_irq(mach_irq); diff --git a/arch/m68k/atari/ataints.c b/arch/m68k/atari/ataints.c index 3d2b63bedf05..56f02ea2c248 100644 --- a/arch/m68k/atari/ataints.c +++ b/arch/m68k/atari/ataints.c @@ -142,7 +142,7 @@ struct mfptimerbase { .name = "MFP Timer D" }; -static irqreturn_t mfptimer_handler(int irq, void *dev_id) +static irqreturn_t mfp_timer_d_handler(int irq, void *dev_id) { struct mfptimerbase *base = dev_id; int mach_irq; @@ -344,7 +344,7 @@ void __init atari_init_IRQ(void) st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6; /* request timer D dispatch handler */ - if (request_irq(IRQ_MFP_TIMD, mfptimer_handler, IRQF_SHARED, + if (request_irq(IRQ_MFP_TIMD, mfp_timer_d_handler, IRQF_SHARED, stmfp_base.name, &stmfp_base)) pr_err("Couldn't register %s interrupt\n", stmfp_base.name); diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c index 9cca64286464..fafa20f75ab9 100644 --- a/arch/m68k/atari/time.c +++ b/arch/m68k/atari/time.c @@ -24,6 +24,18 @@ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL_GPL(rtc_lock); +static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id) +{ + irq_handler_t timer_routine = dev_id; + unsigned long flags; + + local_irq_save(flags); + timer_routine(0, NULL); + local_irq_restore(flags); + + return IRQ_HANDLED; +} + void __init atari_sched_init(irq_handler_t timer_routine) { @@ -32,7 +44,8 @@ atari_sched_init(irq_handler_t timer_routine) /* start timer C, div = 1:100 */ st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; /* install interrupt service routine for MFP Timer C */ - if (request_irq(IRQ_MFP_TIMC, timer_routine, 0, "timer", timer_routine)) + if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, 0, "timer", + timer_routine)) pr_err("Couldn't register timer interrupt\n"); } diff --git a/arch/m68k/bvme6000/config.c b/arch/m68k/bvme6000/config.c index 143ee9fa3893..0e5efed4da86 100644 --- a/arch/m68k/bvme6000/config.c +++ b/arch/m68k/bvme6000/config.c @@ -44,11 +44,6 @@ extern int bvme6000_hwclk (int, struct rtc_time *); extern void bvme6000_reset (void); void bvme6000_set_vectors (void); -/* Save tick handler routine pointer, will point to xtime_update() in - * kernel/timer/timekeeping.c, called via bvme6000_process_int() */ - -static irq_handler_t tick_handler; - int __init bvme6000_parse_bootinfo(const struct bi_record *bi) { @@ -157,12 +152,18 @@ irqreturn_t bvme6000_abort_int (int irq, void *dev_id) static irqreturn_t bvme6000_timer_int (int irq, void *dev_id) { + irq_handler_t timer_routine = dev_id; + unsigned long flags; volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE; - unsigned char msr = rtc->msr & 0xc0; + unsigned char msr; + local_irq_save(flags); + msr = rtc->msr & 0xc0; rtc->msr = msr | 0x20; /* Ack the interrupt */ + timer_routine(0, NULL); + local_irq_restore(flags); - return tick_handler(irq, dev_id); + return IRQ_HANDLED; } /* @@ -181,9 +182,8 @@ void bvme6000_sched_init (irq_handler_t timer_routine) rtc->msr = 0; /* Ensure timer registers accessible */ - tick_handler = timer_routine; - if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, 0, - "timer", bvme6000_timer_int)) + if (request_irq(BVME_IRQ_RTC, bvme6000_timer_int, 0, "timer", + timer_routine)) panic ("Couldn't register timer int"); rtc->t1cr_omr = 0x04; /* Mode 2, ext clk */ diff --git a/arch/m68k/hp300/time.c b/arch/m68k/hp300/time.c index 289d928a46cb..d30b03ea93a2 100644 --- a/arch/m68k/hp300/time.c +++ b/arch/m68k/hp300/time.c @@ -38,13 +38,19 @@ static irqreturn_t hp300_tick(int irq, void *dev_id) { + irq_handler_t timer_routine = dev_id; + unsigned long flags; unsigned long tmp; - irq_handler_t vector = dev_id; + + local_irq_save(flags); in_8(CLOCKBASE + CLKSR); asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE)); + timer_routine(0, NULL); + local_irq_restore(flags); + /* Turn off the network and SCSI leds */ blinken_leds(0, 0xe0); - return vector(irq, NULL); + return IRQ_HANDLED; } u32 hp300_gettimeoffset(void) diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c index e4facff0c1f3..f6df83ba2227 100644 --- a/arch/m68k/mac/via.c +++ b/arch/m68k/mac/via.c @@ -436,6 +436,8 @@ void via_nubus_irq_shutdown(int irq) * via6522.c :-), disable/pending masks added. */ +#define VIA_TIMER_1_INT BIT(6) + void via1_irq(struct irq_desc *desc) { int irq_num; @@ -445,6 +447,21 @@ void via1_irq(struct irq_desc *desc) if (!events) return; + irq_num = IRQ_MAC_TIMER_1; + irq_bit = VIA_TIMER_1_INT; + if (events & irq_bit) { + unsigned long flags; + + local_irq_save(flags); + via1[vIFR] = irq_bit; + generic_handle_irq(irq_num); + local_irq_restore(flags); + + events &= ~irq_bit; + if (!events) + return; + } + irq_num = VIA1_SOURCE_BASE; irq_bit = 1; do { diff --git a/arch/m68k/mvme147/config.c b/arch/m68k/mvme147/config.c index adea549d240e..93c68d2b8e0e 100644 --- a/arch/m68k/mvme147/config.c +++ b/arch/m68k/mvme147/config.c @@ -45,11 +45,6 @@ extern void mvme147_reset (void); static int bcd2int (unsigned char b); -/* Save tick handler routine pointer, will point to xtime_update() in - * kernel/time/timekeeping.c, called via mvme147_process_int() */ - -irq_handler_t tick_handler; - int __init mvme147_parse_bootinfo(const struct bi_record *bi) { @@ -104,16 +99,23 @@ void __init config_mvme147(void) static irqreturn_t mvme147_timer_int (int irq, void *dev_id) { + irq_handler_t timer_routine = dev_id; + unsigned long flags; + + local_irq_save(flags); m147_pcc->t1_int_cntrl = PCC_TIMER_INT_CLR; m147_pcc->t1_int_cntrl = PCC_INT_ENAB|PCC_LEVEL_TIMER1; - return tick_handler(irq, dev_id); + timer_routine(0, NULL); + local_irq_restore(flags); + + return IRQ_HANDLED; } void mvme147_sched_init (irq_handler_t timer_routine) { - tick_handler = timer_routine; - if (request_irq(PCC_IRQ_TIMER1, mvme147_timer_int, 0, "timer 1", NULL)) + if (request_irq(PCC_IRQ_TIMER1, mvme147_timer_int, 0, "timer 1", + timer_routine)) pr_err("Couldn't register timer interrupt\n"); /* Init the clock with a value */ diff --git a/arch/m68k/mvme16x/config.c b/arch/m68k/mvme16x/config.c index 6ee36a5b528d..5feb3ab484d0 100644 --- a/arch/m68k/mvme16x/config.c +++ b/arch/m68k/mvme16x/config.c @@ -50,11 +50,6 @@ extern void mvme16x_reset (void); int bcd2int (unsigned char b); -/* Save tick handler routine pointer, will point to xtime_update() in - * kernel/time/timekeeping.c, called via mvme16x_process_int() */ - -static irq_handler_t tick_handler; - unsigned short mvme16x_config; EXPORT_SYMBOL(mvme16x_config); @@ -352,8 +347,15 @@ static irqreturn_t mvme16x_abort_int (int irq, void *dev_id) static irqreturn_t mvme16x_timer_int (int irq, void *dev_id) { - *(volatile unsigned char *)0xfff4201b |= 8; - return tick_handler(irq, dev_id); + irq_handler_t timer_routine = dev_id; + unsigned long flags; + + local_irq_save(flags); + *(volatile unsigned char *)0xfff4201b |= 8; + timer_routine(0, NULL); + local_irq_restore(flags); + + return IRQ_HANDLED; } void mvme16x_sched_init (irq_handler_t timer_routine) @@ -361,14 +363,13 @@ void mvme16x_sched_init (irq_handler_t timer_routine) uint16_t brdno = be16_to_cpu(mvme_bdid.brdno); int irq; - tick_handler = timer_routine; /* Using PCCchip2 or MC2 chip tick timer 1 */ *(volatile unsigned long *)0xfff42008 = 0; *(volatile unsigned long *)0xfff42004 = 10000; /* 10ms */ *(volatile unsigned char *)0xfff42017 |= 3; *(volatile unsigned char *)0xfff4201b = 0x16; - if (request_irq(MVME16x_IRQ_TIMER, mvme16x_timer_int, 0, - "timer", mvme16x_timer_int)) + if (request_irq(MVME16x_IRQ_TIMER, mvme16x_timer_int, 0, "timer", + timer_routine)) panic ("Couldn't register timer int"); if (brdno == 0x0162 || brdno == 0x172) diff --git a/arch/m68k/q40/q40ints.c b/arch/m68k/q40/q40ints.c index 3e7603202977..1c696906c159 100644 --- a/arch/m68k/q40/q40ints.c +++ b/arch/m68k/q40/q40ints.c @@ -127,10 +127,10 @@ void q40_mksound(unsigned int hz, unsigned int ticks) sound_ticks = ticks << 1; } -static irq_handler_t q40_timer_routine; - -static irqreturn_t q40_timer_int (int irq, void * dev) +static irqreturn_t q40_timer_int(int irq, void *dev_id) { + irq_handler_t timer_routine = dev_id; + ql_ticks = ql_ticks ? 0 : 1; if (sound_ticks) { unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL; @@ -139,8 +139,13 @@ static irqreturn_t q40_timer_int (int irq, void * dev) *DAC_RIGHT=sval; } - if (!ql_ticks) - q40_timer_routine(irq, dev); + if (!ql_ticks) { + unsigned long flags; + + local_irq_save(flags); + timer_routine(0, NULL); + local_irq_restore(flags); + } return IRQ_HANDLED; } @@ -148,11 +153,9 @@ void q40_sched_init (irq_handler_t timer_routine) { int timer_irq; - q40_timer_routine = timer_routine; timer_irq = Q40_IRQ_FRAME; - if (request_irq(timer_irq, q40_timer_int, 0, - "timer", q40_timer_int)) + if (request_irq(timer_irq, q40_timer_int, 0, "timer", timer_routine)) panic("Couldn't register timer int"); master_outb(-1, FRAME_CLEAR_REG); diff --git a/arch/m68k/sun3/sun3ints.c b/arch/m68k/sun3/sun3ints.c index 6bbca30c9188..a5824abb4a39 100644 --- a/arch/m68k/sun3/sun3ints.c +++ b/arch/m68k/sun3/sun3ints.c @@ -61,8 +61,10 @@ static irqreturn_t sun3_int7(int irq, void *dev_id) static irqreturn_t sun3_int5(int irq, void *dev_id) { + unsigned long flags; unsigned int cnt; + local_irq_save(flags); #ifdef CONFIG_SUN3 intersil_clear(); #endif @@ -76,6 +78,7 @@ static irqreturn_t sun3_int5(int irq, void *dev_id) cnt = kstat_irqs_cpu(irq, 0); if (!(cnt % 20)) sun3_leds(led_pattern[cnt % 160 / 20]); + local_irq_restore(flags); return IRQ_HANDLED; } diff --git a/arch/m68k/sun3x/time.c b/arch/m68k/sun3x/time.c index 047e2bcee3d7..3c8a86d08508 100644 --- a/arch/m68k/sun3x/time.c +++ b/arch/m68k/sun3x/time.c @@ -80,15 +80,19 @@ u32 sun3x_gettimeoffset(void) } #if 0 -static void sun3x_timer_tick(int irq, void *dev_id, struct pt_regs *regs) +static irqreturn_t sun3x_timer_tick(int irq, void *dev_id) { - void (*vector)(int, void *, struct pt_regs *) = dev_id; + irq_handler_t timer_routine = dev_id; + unsigned long flags; - /* Clear the pending interrupt - pulse the enable line low */ - disable_irq(5); - enable_irq(5); + local_irq_save(flags); + /* Clear the pending interrupt - pulse the enable line low */ + disable_irq(5); + enable_irq(5); + timer_routine(0, NULL); + local_irq_restore(flags); - vector(irq, NULL, regs); + return IRQ_HANDLED; } #endif -- 2.18.1
