linux-dev/arch/s390/kernel/irq.c, branch linus/master

s390/irq: utilize RCU instead of irq_lock_sparse() in show_msi_interrupt()

2022-04-27T10:53:34Z

As demonstrated by commit 74bdf7815dfb ("genirq: Speedup show_interrupts()"), irq_desc can be accessed safely in RCU read section. Hence here resorting to rcu read lock to get rid of irq_lock_sparse(). Signed-off-by: Pingfan Liu Link: https://lore.kernel.org/r/20220422100212.22666-1-kernelfans@gmail.com Signed-off-by: Heiko Carstens

s390/irq: use assignment instead of cast

2022-03-07T23:33:01Z

Change struct ext_code to contain a union which allows to simply assign the int_code instead of using a cast. In order to keep the patch small the anonymous union is embedded within the existing struct instead of changing the struct ext_code to a union. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/entry: fix duplicate tracking of irq nesting level

2021-12-12T17:52:26Z

In the current code, when exiting from idle, rcu_irq_enter() is called twice during irq entry: irq_entry_enter()-> rcu_irq_enter() irq_enter() -> rcu_irq_enter() This may lead to wrong results from rcu_is_cpu_rrupt_from_idle() because of a wrong dynticks nmi nesting count. Fix this by only calling irq_enter_rcu(). Cc: # 5.12+ Reported-by: Mark Rutland Fixes: 56e62a737028 ("s390: convert to generic entry") Signed-off-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390: add support for BEAR enhancement facility

2021-10-26T13:21:29Z

The Breaking-Event-Address-Register (BEAR) stores the address of the last breaking event instruction. Breaking events are usually instructions that change the program flow - for example branches, and instructions that modify the address in the PSW like lpswe. This is useful for debugging wild branches, because one could easily figure out where the wild branch was originating from. What is problematic is that lpswe is considered a breaking event, and therefore overwrites BEAR on kernel exit. The BEAR enhancement facility adds new instructions that allow to save/restore BEAR and also an lpswey instruction that doesn't cause a breaking event. So we can save BEAR on kernel entry and restore it on exit to user space. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: replace deprecated CPU-hotplug functions

2021-08-05T12:10:53Z

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20210803141621.780504-5-bigeasy@linutronix.de Signed-off-by: Heiko Carstens

s390/irq: use call_on_stack() macro

2021-07-08T20:12:18Z

Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/irq: simplify on_async_stack()

2021-07-08T20:12:17Z

Make on_async_stack() a bit more readable, even though as usual it depends if one considers "!!!" readable or not. At least the new construct to check if the async stack is in use or not is a bit shorter and generates slightly better code. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/irq: inline do_softirq_own_stack()

2021-07-08T20:12:17Z

Move do_softirq_own_stack() to proper header file so it can be inlined; saving a few cycles. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/irq: simplify do_softirq_own_stack()

2021-07-08T20:12:17Z

do_softirq_own_stack() is always called from task context and therefore it is not necessary to check if the async stack is currently used. Remove the check and directly switch to async stack. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: use struct tpi_info in lowcore.h

2021-06-07T15:07:01Z

Signed-off-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik