smp_stop_cpu() should stop the current cpu even for !CONFIG_SMP.
Otherwise machine_halt() will return and and the machine generates a
panic instread of simply stopping the current cpu:
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000
CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 3.14.0-01527-g2b6ef16a6bc5 #10
[...]
Call Trace:
([<0000000000110db0>] show_trace+0xf8/0x158)
[<0000000000110e7a>] show_stack+0x6a/0xe8
[<000000000074dba8>] panic+0xe4/0x268
[<0000000000140570>] do_exit+0xa88/0xb2c
[<000000000016e12c>] SyS_reboot+0x1f0/0x234
[<000000000075da70>] sysc_nr_ok+0x22/0x28
[<000000007d5a09b4>] 0x7d5a09b4
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Just like the RESTART order, the START order also has to report BUSY
while a STOP request is pending, to avoid that the START might be
ignored due to a race condition between the STOP and the START order.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This patch adds the missing SIGP order "conditional emergency
signal" by calling the "emergency signal" SIGP handler if the
required conditions are met.
Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
If sigp sense doesn't have any status bits to report, it should set
cc 0 and leave the register as-is.
Since we know about the external call pending bit, we should report
it if it is set as well.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The smp and the kvm code have different defines for the sigp order codes.
Let's just have a single place where these are defined.
Also move the sigp condition code and sigp cpu status bits to the new
sigp.h header file.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.
The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.
Overall the code is now simpler and there are ~380 lines less code.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The panic function will first print the panic message to the console,
then stop additional cpus with smp_send_stop and finally call the
function on the panic notifier list.
In case of an I/O based console the panic message will cause I/O to
be started and a function on the panic notifier list will wait for the
completion of the I/O. That does not work if an I/O completion interrupt
has already been delivered to a cpu that is then stopped by smp_send_stop.
To break this cyclic dependency add code to smp_send_stop that gives
the additional cpu the opportunity to complete outstanding interrupts.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch introduces a new function that checks the running status
of a cpu in a hypervisor. This status is not virtualized, so the check
is only correct if running in an LPAR. On acquiring a spinlock, if the
cpu holding the lock is scheduled by the hypervisor, we do a busy wait
on the lock. If it is not scheduled, we yield over to that cpu.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Rename signal_processor* functions to sigp*.
Add raw variants of each version, so we can get rid of the hacks played
in smp code which establish temporary cpu logical mappings so they could
call the sigp functions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Finally move it to the place where it belongs to and make get rid of
it for !CONFIG_SMP.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since etr/stp don't need the old smp_call_function semantics anymore
we can convert s390 to the generic IPI infrastructure.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
