linux.git/arch/s390/kernel/setup.c, branch v5.14

Merge tag 's390-5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-07-10T17:46:14+00:00

Pull more s390 updates from Vasily Gorbik:

 - Fix preempt_count initialization.

 - Rework call_on_stack() macro to add proper type handling and avoid
   possible register corruption.

 - More error prone "register asm" removal and fixes.

 - Fix syscall restarting when multiple signals are coming in. This adds
   minimalistic trampolines to vdso so we can return from signal without
   using the stack which requires pgm check handler hacks when NX is
   enabled.

 - Remove HAVE_IRQ_EXIT_ON_IRQ_STACK since this is no longer true after
   switch to generic entry.

 - Fix protected virtualization secure storage access exception
   handling.

 - Make machine check C handler always enter with DAT enabled and move
   register validation to C code.

 - Fix tinyconfig boot problem by avoiding MONITOR CALL without
   CONFIG_BUG.

 - Increase asm symbols alignment to 16 to make it consistent with
   compilers.

 - Enable concurrent access to the CPU Measurement Counter Facility.

 - Add support for dynamic AP bus size limit and rework ap_dqap to deal
   with messages greater than recv buffer.

* tag 's390-5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits)
  s390: preempt: Fix preempt_count initialization
  s390/linkage: increase asm symbols alignment to 16
  s390: rename CALL_ON_STACK_NORETURN() to call_on_stack_noreturn()
  s390: add type checking to CALL_ON_STACK_NORETURN() macro
  s390: remove old CALL_ON_STACK() macro
  s390/softirq: use call_on_stack() macro
  s390/lib: use call_on_stack() macro
  s390/smp: use call_on_stack() macro
  s390/kexec: use call_on_stack() macro
  s390/irq: use call_on_stack() macro
  s390/mm: use call_on_stack() macro
  s390: introduce proper type handling call_on_stack() macro
  s390/irq: simplify on_async_stack()
  s390/irq: inline do_softirq_own_stack()
  s390/irq: simplify do_softirq_own_stack()
  s390/ap: get rid of register asm in ap_dqap()
  s390: rename PIF_SYSCALL_RESTART to PIF_EXECVE_PGSTE_RESTART
  s390: move restart of execve() syscall
  s390/signal: remove sigreturn on stack
  s390/signal: switch to using vdso for sigreturn and syscall restart
  ...

s390: preempt: Fix preempt_count initialization

2021-07-08T20:12:18+00:00

S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the
preempt_count of the requested CPU's idle task: it unconditionally writes
to the current CPU's. This clearly conflicts with idle_threads_init(),
which intends to initialize *all* the idle tasks, including their
preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count).

Unfortunately, it seems the way s390 does things doesn't let us initialize
every possible CPU's preempt_count early on, as the pages where this
resides are only allocated when a CPU is brought up and are freed when it
is brought down.

Let the arch-specific code set a CPU's preempt_count when its lowcore is
allocated, and turn init_idle_preempt_count() into an empty stub.

Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled")
Reported-by: Guenter Roeck 
Signed-off-by: Valentin Schneider 
Tested-by: Guenter Roeck 
Reviewed-by: Heiko Carstens 
Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com
Signed-off-by: Vasily Gorbik

s390: rename CALL_ON_STACK_NORETURN() to call_on_stack_noreturn()

2021-07-08T20:12:18+00:00

Lower case matches the call_on_stack() macro and is easier to read.

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

s390: convert to setup_initial_init_mm()

2021-07-08T18:48:21+00:00

Use setup_initial_init_mm() helper to simplify code.

Link: https://lkml.kernel.org/r/20210608083418.137226-14-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/setup: cleanup reserve/remove_oldmem

2021-06-18T14:41:19+00:00

Since OLDMEM_BASE/OLDMEM_SIZE is already taken into consideration and is
reflected in ident_map_size. reserve/remove_oldmem() is no longer needed
and could be removed.

Reviewed-by: Alexander Gordeev 
Signed-off-by: Vasily Gorbik

s390: setup kernel memory layout early

2021-06-18T14:41:19+00:00

Currently there are two separate places where kernel memory layout has
to be known and adjusted:
1. early kasan setup.
2. paging setup later.

Those 2 places had to be kept in sync and adjusted to reflect peculiar
technical details of one another. With additional factors which influence
kernel memory layout like ultravisor secure storage limit, complexity
of keeping two things in sync grew up even more.

Besides that if we look forward towards creating identity mapping and
enabling DAT before jumping into uncompressed kernel - that would also
require full knowledge of and control over kernel memory layout.

So, de-duplicate and move kernel memory layout setup logic into
the decompressor.

Reviewed-by: Alexander Gordeev 
Signed-off-by: Vasily Gorbik

s390/smp: reallocate IPL CPU lowcore

2021-06-07T15:07:00+00:00

The lowcore for IPL CPU is special. It is allocated early
in the boot process using memblock and never freed since.
The reason is pcpu_alloc_lowcore() and pcpu_free_lowcore()
routines use page allocator which is not available when
the IPL CPU is getting initialized.

Similar problem is already addressed for stacks - once the
virtual memory is available the early boot stacks get re-
allocated. Doing the same for lowcore will allow freeing
the IPL CPU lowcore and make no difference between the
boot and secondary CPUs.

Signed-off-by: Alexander Gordeev 
Reviewed-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik

s390/sclp_vt220: fix console name to match device

2021-06-07T15:06:59+00:00

Console name reported in /proc/consoles:

  ttyS1                -W- (EC p  )    4:65

does not match the char device name:

  crw--w----    1 root     root        4,  65 May 17 12:18 /dev/ttysclp0

so debian-installer inside a QEMU s390x instance gets confused and fails
to start with the following error:

  steal-ctty: No such file or directory

Signed-off-by: Valentin Vidic 
Link: https://lore.kernel.org/r/20210427194010.9330-1-vvidic@valentin-vidic.from.hr
Signed-off-by: Christian Borntraeger 
Signed-off-by: Vasily Gorbik

s390/facilities: move stfl information from lowcore to global data

2021-06-07T15:06:58+00:00

With gcc-11, there are a lot of warnings because the facility functions
are accessing lowcore through a null pointer. Fix this by moving the
facility arrays away from lowcore.

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

s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility

2021-05-04T17:10:56+00:00

The PoP documents:
	134: The vector packed decimal facility is installed in the
	     z/Architecture architectural mode. When bit 134 is
	     one, bit 129 is also one.
	135: The vector enhancements facility 1 is installed in
	     the z/Architecture architectural mode. When bit 135
	     is one, bit 129 is also one.

Looks like we confuse the vector enhancements facility 1 ("EXT") with the
Vector packed decimal facility ("BCD"). Let's fix the facility checks.

Detected while working on QEMU/tcg z14 support and only unlocking
the vector enhancements facility 1, but not the vector packed decimal
facility.

Fixes: 2583b848cad0 ("s390: report new vector facilities")
Cc: Vasily Gorbik 
Signed-off-by: David Hildenbrand 
Reviewed-by: Christian Borntraeger 
Reviewed-by: Cornelia Huck 
Reviewed-by: Janosch Frank 
Link: https://lore.kernel.org/r/20210503121244.25232-1-david@redhat.com
Signed-off-by: Heiko Carstens