lwn.git/arch/arm/mach-exynos/platsmp.c, branch v6.2-rc1

ARM: exynos: correct kernel doc in platsmp

2021-04-06T20:30:02+00:00

Correct few kerneldoc issues, including W=1 compile warning: arch/arm/mach-exynos/platsmp.c:89: warning: expecting prototype for exynos_core_power_down(). Prototype was for exynos_cpu_power_down() instead Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20210405181605.52612-1-krzysztof.kozlowski@canonical.com

ARM: exynos: Simplify code in Exynos3250 CPU core restart path

2020-10-28T20:00:32+00:00

exynos_core_restart() is called by secondary CPU boot procedure, used by CPU hotplug and coupled CPU idle. Replace of_machine_is_compatible() call with a simple SoC revision check. of_machine_is_compatible() function performs a dozen of string comparisons during the full device tree walk, while soc_is_exynos3250() is a simple integer check on SoC revision variable. This change also fixes the following warning: ============================= WARNING: suspicious RCU usage 5.10.0-rc1-00001-g6f65599d1f4f-dirty #1800 Not tainted ----------------------------- ./include/trace/events/lock.h:37 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 RCU used illegally from extended quiescent state! no locks held by swapper/0/0. stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-rc1-00001-g6f65599d1f4f-dirty #1800 Hardware name: Samsung Exynos (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xb4/0xd4) [] (dump_stack) from [] (lock_acquire+0x418/0x584) [] (lock_acquire) from [] (_raw_spin_lock_irqsave+0x4c/0x60) [] (_raw_spin_lock_irqsave) from [] (of_device_is_compatible+0x1c/0x4c) [] (of_device_is_compatible) from [] (exynos_core_restart+0x14/0xb0) [] (exynos_core_restart) from [] (exynos_cpu0_enter_aftr+0x1d0/0x1dc) [] (exynos_cpu0_enter_aftr) from [] (exynos_enter_coupled_lowpower+0x44/0x74) [] (exynos_enter_coupled_lowpower) from [] (cpuidle_enter_state+0x178/0x660) [] (cpuidle_enter_state) from [] (cpuidle_enter_state_coupled+0x35c/0x378) [] (cpuidle_enter_state_coupled) from [] (cpuidle_enter+0x50/0x54) [] (cpuidle_enter) from [] (do_idle+0x224/0x2a4) [] (do_idle) from [] (cpu_startup_entry+0x18/0x1c) [] (cpu_startup_entry) from [] (start_kernel+0x640/0x67c) [] (start_kernel) from [<00000000>] (0x0) Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20201027201716.15745-1-m.szyprowski@samsung.com Signed-off-by: Krzysztof Kozlowski

ARM: exynos: use private samsung_cpu_id copy

2020-08-19T19:10:50+00:00

The only part of plat-samsung that is shared with arch-exynos is the CPU identification code. Having a separate exynos_cpu_id variable makes the two completely independent and is actually a bit less code in total. Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20200806182059.2431-14-krzk@kernel.org Signed-off-by: Krzysztof Kozlowski

ARM: exynos: Fix infinite loops on CPU powerup failure

2019-04-09T13:07:33+00:00

Add timeout to infinite loops during the CPU powerup procedures. It is better to report an error instead of busylooping for infinite time in case of failure. Signed-off-by: Marek Szyprowski Signed-off-by: Krzysztof Kozlowski

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2019-03-15T21:37:46+00:00

Pull ARM updates from Russell King: - An improvement from Ard Biesheuvel, who noted that the identity map setup was taking a long time due to flush_cache_louis(). - Update a comment about dma_ops from Wolfram Sang. - Remove use of "-p" with ld, where this flag has been a no-op since 2004. - Remove the printing of the virtual memory layout, which is no longer useful since we hide pointers. - Correct SCU help text. - Remove legacy TWD registration method. - Add pgprot_device() implementation for mapping PCI sysfs resource files. - Initialise PFN limits earlier for kmemleak. - Fix argument count to match macro definition (affects clang builds) - Use unified assembler language almost everywhere for clang, and other clang improvements (from Stefan Agner, Nathan Chancellor). - Support security extension for noMMU and other noMMU cleanups (from Vladimir Murzin). - Remove unnecessary SMP bringup code (which was incorrectly copy'n' pasted from the ARM platform implementations) and remove it from the arch code to discourge further copys of it appearing. - Add Cortex A9 erratum preventing kexec working on some SoCs. - AMBA bus identification updates from Mike Leach. - More use of raw spinlocks to avoid -RT kernel issues (from Yang Shi and Sebastian Andrzej Siewior). - MCPM hyp/svc mode mismatch fixes from Marek Szyprowski. * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits) ARM: 8849/1: NOMMU: Fix encodings for PMSAv8's PRBAR4/PRLAR4 ARM: 8848/1: virt: Align GIC version check with arm64 counterpart ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used ARM: 8845/1: use unified assembler in c files ARM: 8844/1: use unified assembler in assembly files ARM: 8843/1: use unified assembler in headers ARM: 8841/1: use unified assembler in macros ARM: 8840/1: use a raw_spinlock_t in unwind ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_t ARM: 8837/1: coresight: etmv4: Update ID register table to add UCI support ARM: 8836/1: drivers: amba: Update component matching to use the CoreSight UCI values. ARM: 8838/1: drivers: amba: Updates to component identification for driver matching. ARM: 8833/1: Ensure that NEON code always compiles with Clang ARM: avoid Cortex-A9 livelock on tight dmb loops ARM: smp: remove arch-provided "pen_release" ARM: actions: remove boot_lock and pen_release ARM: oxnas: remove CPU hotplug implementation ARM: qcom: remove unnecessary boot_lock ARM: 8832/1: NOMMU: Limit visibility for CONFIG_FLASH_{MEM_BASE,SIZE} ARM: 8831/1: NOMMU: pmsa-v8: remove unneeded semicolon ...

ARM: smp: remove arch-provided "pen_release"

2019-02-01T22:05:23+00:00

Consolidating the "pen_release" stuff amongst the various SoC implementations gives credence to having a CPU holding pen for secondary CPUs. However, this is far from the truth. Many SoC implementations cargo-cult copied various bits of the pen release implementation from the initial Realview/Versatile Express implementation without understanding what it was or why it existed. The reason it existed is because these are _development_ platforms, and some board firmware is unable to individually control the startup of secondary CPUs. Moreover, they do not have a way to power down or reset secondary CPUs for hot-unplug. Hence, the pen_release implementation was designed for ARM Ltd's development platforms to provide a working implementation, even though it is very far from what is required. It was decided a while back to reduce the duplication by consolidating the "pen_release" variable, but this only made the situation worse - we have ended up with several implementations that read this variable but do not write it - again, showing the cargo-cult mentality at work, lack of proper review of new code, and in some cases a lack of testing. While it would be preferable to remove pen_release entirely from the kernel, this is not possible without help from the SoC maintainers, which seems to be lacking. However, I want to remove pen_release from arch code to remove the credence that having it gives. This patch removes pen_release from the arch code entirely, adding private per-SoC definitions for it instead, and explicitly stating that write_pen_release() is cargo-cult copied and should not be copied any further. Rename write_pen_release() in a similar fashion as well. Signed-off-by: Russell King

ARM: exynos: Fix timeout when booting secondary CPUs

2019-02-01T19:07:47+00:00

Without this fix the loop waiting for the timeout exits, but the subsequent test to see if the timeout occurred fails. Signed-off-by: Stuart Menefy Signed-off-by: Krzysztof Kozlowski

ARM: exynos: Remove secondary startup initialization from smp_prepare_cpus

2018-11-18T14:12:50+00:00

We are taking care of setting secondary cpu boot address in exynos_boot_secondary just before sending ipi to secondary CPUs, so we can safely remove this setting from smp_prepare_cpus. Signed-off-by: Pankaj Dubey Reviewed-by: Krzysztof Kozlowski Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Krzysztof Kozlowski

ARM: exynos: Remove static mapping of SCU SFR

2018-05-13T12:06:55+00:00

Lets remove static mapping of SCU SFR mainly used in CORTEX-A9 SoC based boards. Instead use mapping from device tree node of SCU. Signed-off-by: Pankaj Dubey Reviewed-by: Alim Akhtar [mszyprow: rebased, added fallback to scu_a9_get_base() when no SCU DT node is available, removed compatibility break warning, fixed non-SMP build, keep SCU base mapping to avoid issues with calls from CPUidle] Signed-off-by: Marek Szyprowski Signed-off-by: Krzysztof Kozlowski

ARM: EXYNOS: Add SPDX license identifiers

2018-01-03T17:36:22+00:00

Replace GPL license statements with SPDX license identifiers (GPL-2.0 and GPL-2.0+). Signed-off-by: Krzysztof Kozlowski