linux-toradex.git/arch/arm64/kernel/psci.c, branch v6.16

arm64: psci: Ignore DENIED CPUs

2024-06-28T17:38:31+00:00

When a CPU is marked as disabled, but online capable in the MADT, PSCI
applies some firmware policy to control when it can be brought online.
PSCI returns DENIED to a CPU_ON request if this is not currently
permitted. The OS can learn the current policy from the _STA enabled bit.

Handle the PSCI DENIED return code gracefully instead of printing an
error.

Note the alternatives to the PSCI cpu_boot() callback do not
return -EPERM so the change in smp.c has no affect.

See https://developer.arm.com/documentation/den0022/f/?lang=en page 58.

Signed-off-by: Jean-Philippe Brucker 
[ morse: Rewrote commit message ]
Signed-off-by: James Morse 
Tested-by: Miguel Luis 
Tested-by: Vishnu Pajjuri 
Tested-by: Jianyong Wu 
Reviewed-by: Gavin Shan 
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Jonathan Cameron 
Reviewed-by: Jonathan Cameron 
Link: https://lore.kernel.org/r/20240529133446.28446-16-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas

treewide: Drop function_nocfi

2022-09-26T17:13:14+00:00

With -fsanitize=kcfi, we no longer need function_nocfi() as
the compiler won't change function references to point to a
jump table. Remove all implementations and uses of the macro.

Signed-off-by: Sami Tolvanen 
Reviewed-by: Kees Cook 
Tested-by: Kees Cook 
Tested-by: Nathan Chancellor 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220908215504.3686827-14-samitolvanen@google.com

arm64: use function_nocfi with __pa_symbol

2021-04-08T23:04:22+00:00

With CONFIG_CFI_CLANG, the compiler replaces function address
references with the address of the function's CFI jump table
entry. This means that __pa_symbol(function) returns the physical
address of the jump table entry, which can lead to address space
confusion as the jump table points to the function's virtual
address. Therefore, use the function_nocfi() macro to ensure we are
always taking the address of the actual function instead.

Signed-off-by: Sami Tolvanen 
Reviewed-by: Kees Cook 
Acked-by: Mark Rutland 
Tested-by: Nathan Chancellor 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20210408182843.1754385-14-samitolvanen@google.com

arm64: psci: Avoid printing in cpu_psci_cpu_die()

2020-11-10T13:11:44+00:00

cpu_psci_cpu_die() is called in the context of the dying CPU, which
will no longer be online or tracked by RCU. It is therefore not generally
safe to call printk() if the PSCI "cpu off" request fails, so remove the
pr_crit() invocation.

Cc: Qian Cai 
Cc: "Paul E. McKenney" 
Cc: Catalin Marinas 
Link: https://lore.kernel.org/r/20201106103602.9849-2-will@kernel.org
Signed-off-by: Will Deacon

arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()

2019-10-25T15:29:11+00:00

In cases like suspend-to-disk and suspend-to-ram, a large number of CPU
cores need to be shut down. At present, the CPU hotplug operation is
serialised, and the CPU cores can only be shut down one by one. In this
process, if PSCI affinity_info() does not return LEVEL_OFF quickly,
cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores
need to be shut down, it will take a long time.

Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So
change the wait interval from 10 ms to max 1 ms and use usleep_range()
instead of msleep() for more accurate timer.

In addition, reducing the time interval will increase the messages
output, so remove the "Retry ..." message, instead, track time and
output to the the sucessful message.

Signed-off-by: Yunfeng Ye 
Reviewed-by: Sudeep Holla 
Signed-off-by: Catalin Marinas

arm64: smp: disable hotplug on trusted OS resident CPU

2019-08-15T10:12:03+00:00

The trusted OS may reject CPU_OFF calls to its resident CPU, so we must
avoid issuing those. We never migrate a Trusted OS and we already take
care to prevent CPU_OFF PSCI call. However, this is not reflected
explicitly to the userspace. Any user can attempt to hotplug trusted OS
resident CPU. The entire motion of going through the various state
transitions in the CPU hotplug state machine gets executed and the
PSCI layer finally refuses to make CPU_OFF call.

This results is unnecessary unwinding of CPU hotplug state machine in
the kernel. Instead we can mark the trusted OS resident CPU as not
available for hotplug, so that the user attempt or request to do the
same will get immediately rejected.

Cc: Mark Rutland 
Cc: Catalin Marinas 
Cc: Will Deacon 
Signed-off-by: Sudeep Holla 
Signed-off-by: Will Deacon

ARM: psci: cpuidle: Enable PSCI CPUidle driver

2019-08-09T16:51:39+00:00

Allow selection of the PSCI CPUidle in the kernel by updating
the respective Kconfig entry.

Remove PSCI callbacks from ARM/ARM64 generic CPU ops
to prevent the PSCI idle driver from clashing with the generic
ARM CPUidle driver initialization, that relies on CPU ops
to initialize and enter idle states.

Signed-off-by: Lorenzo Pieralisi 
Reviewed-by: Ulf Hansson 
Cc: Will Deacon 
Cc: Ulf Hansson 
Cc: Sudeep Holla 
Cc: Daniel Lezcano 
Cc: Catalin Marinas 
Cc: Mark Rutland 
Cc: "Rafael J. Wysocki" 
Signed-off-by: Will Deacon

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

2019-05-30T18:26:41+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Kate Stewart 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman

arm64: remove unused asm/compiler.h header file

2018-10-01T10:57:04+00:00

arm64 does not define CONFIG_HAVE_ARCH_COMPILER_H, nor does it keep
anything useful in its copy of asm/compiler.h, so let's remove it
before anybody starts using it.

Acked-by: Will Deacon 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Catalin Marinas

arm64: Use __pa_symbol for kernel symbols

2017-01-12T15:05:39+00:00

__pa_symbol is technically the marcro that should be used for kernel
symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which
will do bounds checking.

Reviewed-by: Mark Rutland 
Tested-by: Mark Rutland 
Signed-off-by: Laura Abbott 
Signed-off-by: Will Deacon