Pull exit cleanups from Eric Biederman:
 "While looking at some issues related to the exit path in the kernel I
  found several instances where the code is not using the existing
  abstractions properly.

  This set of changes introduces force_fatal_sig a way of sending a
  signal and not allowing it to be caught, and corrects the misuse of
  the existing abstractions that I found.

  A lot of the misuse of the existing abstractions are silly things such
  as doing something after calling a no return function, rolling BUG by
  hand, doing more work than necessary to terminate a kernel thread, or
  calling do_exit(SIGKILL) instead of calling force_sig(SIGKILL).

  In the review a deficiency in force_fatal_sig and force_sig_seccomp
  where ptrace or sigaction could prevent the delivery of the signal was
  found. I have added a change that adds SA_IMMUTABLE to change that
  makes it impossible to interrupt the delivery of those signals, and
  allows backporting to fix force_sig_seccomp

  And Arnd found an issue where a function passed to kthread_run had the
  wrong prototype, and after my cleanup was failing to build."

* 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
  soc: ti: fix wkup_m3_rproc_boot_thread return type
  signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed
  signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV)
  exit/r8188eu: Replace the macro thread_exit with a simple return 0
  exit/rtl8712: Replace the macro thread_exit with a simple return 0
  exit/rtl8723bs: Replace the macro thread_exit with a simple return 0
  signal/x86: In emulate_vsyscall force a signal instead of calling do_exit
  signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig
  signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails
  exit/syscall_user_dispatch: Send ordinary signals on failure
  signal: Implement force_fatal_sig
  exit/kthread: Have kernel threads return instead of calling do_exit
  signal/s390: Use force_sigsegv in default_trap_handler
  signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.
  signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON
  signal/sparc: In setup_tsb_params convert open coded BUG into BUG
  signal/powerpc: On swapcontext failure force SIGSEGV
  signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL)
  signal/mips: Update (_save|_restore)_fp_context to fail with -EFAULT
  signal/sparc32: Remove unreachable do_exit in do_sparc_fault
  ...

The wkup_m3_rproc_boot_thread() function uses a nonstandard prototype,
which broke after Eric's recent cleanup:

drivers/soc/ti/wkup_m3_ipc.c: In function 'wkup_m3_rproc_boot_thread':
drivers/soc/ti/wkup_m3_ipc.c:429:16: error: 'return' with a value, in function returning void [-Werror=return-type]
  429 |         return 0;
      |                ^
drivers/soc/ti/wkup_m3_ipc.c:416:13: note: declared here
  416 | static void wkup_m3_rproc_boot_thread(struct wkup_m3_ipc *m3_ipc)
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~

Change it to the normal prototype as it should have been from the
start.

Fixes: 111e70490d2a ("exit/kthread: Have kernel threads return instead of calling do_exit")
Fixes: cdd5de500b2c ("soc: ti: Add wkup_m3_ipc driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20211105075119.2327190-1-arnd@kernel.org
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

In 2009 Oleg reworked[1] the kernel threads so that it is not
necessary to call do_exit if you are not using kthread_stop().  Remove
the explicit calls of do_exit and complete_and_exit (with a NULL
completion) that were previously necessary.

[1] 63706172f332 ("kthreads: rework kthread_stop()")
Link: https://lkml.kernel.org/r/20211020174406.17889-12-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Starting with v5.15-rc1, we may now see some am335x beaglebone black
device produce the following error on pruss probe:

Unhandled fault: external abort on non-linefetch (0x1008) at 0xe0326000

This has started with the enabling of pruss for am335x in the dts files.

Turns out the is caused by the PRM reset handling not waiting for the
reset bit to clear. To fix the issue, let's always wait for the reset
bit to clear, even if there is a separate reset status register.

We attempted to fix a similar issue for dra7 iva with a udelay() in
commit effe89e40037 ("soc: ti: omap-prm: Fix occasional abort on reset
deassert for dra7 iva"). There is no longer a need for the udelay()
for dra7 iva reset either with the check added for reset bit clearing.

Cc: Drew Fustini <pdp7pdp7@gmail.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Robert Nelson <robertcnelson@gmail.com>
Cc: Yongqin Liu <yongqin.liu@linaro.org>
Fixes: effe89e40037 ("soc: ti: omap-prm: Fix occasional abort on reset deassert for dra7 iva")
Reported-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

For the smartreflex device, we need to disable smartreflex on SoC idle,
and have been using pm_runtime_irq_safe() to do that. But we want to
remove the irq_safe usage as PM runtime takes a permanent usage count
on the parent device with it.

In order to remove the need for pm_runtime_irq_safe(), let's gate
the clock directly in the driver. This removes the need to call PM runtime
during idle, and allows us to switch to using CPU_PM in the following
patch.

Note that the smartreflex interconnect target module is configured for smart
idle, but the clock does not have autoidle capability, and needs to be gated
manually. If the clock supported autoidle, we would not need to even gate
the clock.

With this change, we can now remove the related quirk flags for ti-sysc
also.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

The K3 AM64x family of SoCs have a similar version of the PRU-ICSS (ICSSG)
processor subsystem present on K3 J721E and K3 AM65x SR2.0 SoCs. These SoCs
contain typically two ICSSG instances named ICSSG0 and ICSSG1. The two
ICSSGs are identical to each other for the most part with minor SoC
integration differences and capabilities. SGMII mode is not supported at
all on these SoCs (unlike specific instances on AM65x, J721E). The ICSSG1
also has limited pins connected on some sub-modules compared to ICSSG0.

There is no change in the Interrupt Controller w.r.t either of AM65x or
J721E SoCs. All other integration aspects are also very similar to the
existing SoCs.

The existing pruss platform driver has been updated to support these
similar ICSSG instances through a new AM64x specific compatible.

Signed-off-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.

Therefore, remove the error printing here to simplify code and reduce the
binary size.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

There is a error message within devm_ioremap_resource
already, so remove the dev_err call to avoid redundant
error message.

Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Qiheng Lin <linqiheng@huawei.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

When moving the l4 interconnect instances to probe with simple-pm-bus and
genpd, we will have l4per and core domains stop idling unless we configure
the domain bits to allow retention when idle.

As the TI SoCs have hardware autoidle capabilities, this is safe to do.
The domains will only enter retention on WFI when none of the devices on
the domain block autoidle in the hardware. This follows what we are
already currently doing.

Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Tero Kristo <kristo@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>