sparc64: Do irq_{enter,exit}() around generic_smp_call_function*().

davem330 · gregkh · commit ca9811bf3fc6 · 2014-11-21T09:23:00.000-08:00
[ Upstream commit ab5c780 ] Otherwise rcu_irq_{enter,exit}() do not happen and we get dumps like: ==================== [ 188.275021] =============================== [ 188.309351] [ INFO: suspicious RCU usage. ] [ 188.343737] 3.18.0-rc3-00068-g20f3963-dirty #54 Not tainted [ 188.394786] ------------------------------- [ 188.429170] include/linux/rcupdate.h:883 rcu_read_lock() used illegally while idle! [ 188.505235] other info that might help us debug this: [ 188.554230] RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 [ 188.637587] RCU used illegally from extended quiescent state! [ 188.690684] 3 locks held by swapper/7/0: [ 188.721932] #0: (&x->wait#11){......}, at: [<0000000000495de8>] complete+0x8/0x60 [ 188.797994] #1: (&p->pi_lock){-.-.-.}, at: [<000000000048510c>] try_to_wake_up+0xc/0x400 [ 188.881343] #2: (rcu_read_lock){......}, at: [<000000000048a910>] select_task_rq_fair+0x90/0xb40 [ 188.973043]stack backtrace: [ 188.993879] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 3.18.0-rc3-00068-g20f3963-dirty #54 [ 189.076187] Call Trace: [ 189.089719] [0000000000499360] lockdep_rcu_suspicious+0xe0/0x100 [ 189.147035] [000000000048a99c] select_task_rq_fair+0x11c/0xb40 [ 189.202253] [00000000004852d8] try_to_wake_up+0x1d8/0x400 [ 189.252258] [000000000048554c] default_wake_function+0xc/0x20 [ 189.306435] [0000000000495554] __wake_up_common+0x34/0x80 [ 189.356448] [00000000004955b4] __wake_up_locked+0x14/0x40 [ 189.406456] [0000000000495e08] complete+0x28/0x60 [ 189.448142] [0000000000636e28] blk_end_sync_rq+0x8/0x20 [ 189.496057] [0000000000639898] __blk_mq_end_request+0x18/0x60 [ 189.550249] [00000000006ee014] scsi_end_request+0x94/0x180 [ 189.601286] [00000000006ee334] scsi_io_completion+0x1d4/0x600 [ 189.655463] [00000000006e51c4] scsi_finish_command+0xc4/0xe0 [ 189.708598] [00000000006ed958] scsi_softirq_done+0x118/0x140 [ 189.761735] [00000000006398ec] __blk_mq_complete_request_remote+0xc/0x20 [ 189.827383] [00000000004c75d0] generic_smp_call_function_single_interrupt+0x150/0x1c0 [ 189.906581] [000000000043e514] smp_call_function_single_client+0x14/0x40 ==================== Based almost entirely upon a patch by Paul E. McKenney. Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
@@ -823,13 +823,17 @@ void arch_send_call_function_single_ipi(int cpu)
 void __irq_entry smp_call_function_client(int irq, struct pt_regs *regs)
 {
 	clear_softint(1 << irq);
+	irq_enter();
 	generic_smp_call_function_interrupt();
+	irq_exit();
 }
 
 void __irq_entry smp_call_function_single_client(int irq, struct pt_regs *regs)
 {
 	clear_softint(1 << irq);
+	irq_enter();
 	generic_smp_call_function_single_interrupt();
+	irq_exit();
 }
 
 static void tsb_sync(void *info)

Original file line number	Diff line number	Diff line change
`@@ -823,13 +823,17 @@ void arch_send_call_function_single_ipi(int cpu)`
`823`	`823`	`void __irq_entry smp_call_function_client(int irq, struct pt_regs *regs)`
`824`	`824`	`{`
`825`	`825`	`clear_softint(1 << irq);`
	`826`	`+ irq_enter();`
`826`	`827`	`generic_smp_call_function_interrupt();`
	`828`	`+ irq_exit();`
`827`	`829`	`}`
`828`	`830`
`829`	`831`	`void __irq_entry smp_call_function_single_client(int irq, struct pt_regs *regs)`
`830`	`832`	`{`
`831`	`833`	`clear_softint(1 << irq);`
	`834`	`+ irq_enter();`
`832`	`835`	`generic_smp_call_function_single_interrupt();`
	`836`	`+ irq_exit();`
`833`	`837`	`}`
`834`	`838`
`835`	`839`	`static void tsb_sync(void *info)`