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2021-12-07arm: ioremap: Remove unused ARM-specific function pci_ioremap_io()Pali Rohár
This function is not used by any driver anymore. So completely remove it. Link: https://lore.kernel.org/r/20211124154116.916-6-pali@kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-12-07locking: Allow to include asm/spinlock_types.h from linux/spinlock_types_raw.hSebastian Andrzej Siewior
The printk header file includes ratelimit_types.h for its __ratelimit() based usage. It is required for the static initializer used in printk_ratelimited(). It uses a raw_spinlock_t and includes the spinlock_types.h. PREEMPT_RT substitutes spinlock_t with a rtmutex based implementation and so its spinlock_t implmentation (provided by spinlock_rt.h) includes rtmutex.h and atomic.h which leads to recursive includes where defines are missing. By including only the raw_spinlock_t defines it avoids the atomic.h related includes at this stage. An example on powerpc: | CALL scripts/atomic/check-atomics.sh |In file included from include/linux/bug.h:5, | from include/linux/page-flags.h:10, | from kernel/bounds.c:10: |arch/powerpc/include/asm/page_32.h: In function ‘clear_page’: |arch/powerpc/include/asm/bug.h:87:4: error: implicit declaration of function â=80=98__WARNâ=80=99 [-Werror=3Dimplicit-function-declaration] | 87 | __WARN(); \ | | ^~~~~~ |arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99 | 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1)); | | ^~~~~~~ |arch/powerpc/include/asm/bug.h:58:17: error: invalid application of ‘sizeofâ€=99 to incomplete type ‘struct bug_entryâ€=99 | 58 | "i" (sizeof(struct bug_entry)), \ | | ^~~~~~ |arch/powerpc/include/asm/bug.h:89:3: note: in expansion of macro ‘BUG_ENTRYâ€=99 | 89 | BUG_ENTRY(PPC_TLNEI " %4, 0", \ | | ^~~~~~~~~ |arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99 | 48 | WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1)); | | ^~~~~~~ |In file included from arch/powerpc/include/asm/ptrace.h:298, | from arch/powerpc/include/asm/hw_irq.h:12, | from arch/powerpc/include/asm/irqflags.h:12, | from include/linux/irqflags.h:16, | from include/asm-generic/cmpxchg-local.h:6, | from arch/powerpc/include/asm/cmpxchg.h:526, | from arch/powerpc/include/asm/atomic.h:11, | from include/linux/atomic.h:7, | from include/linux/rwbase_rt.h:6, | from include/linux/rwlock_types.h:55, | from include/linux/spinlock_types.h:74, | from include/linux/ratelimit_types.h:7, | from include/linux/printk.h:10, | from include/asm-generic/bug.h:22, | from arch/powerpc/include/asm/bug.h:109, | from include/linux/bug.h:5, | from include/linux/page-flags.h:10, | from kernel/bounds.c:10: |include/linux/thread_info.h: In function â=80=98copy_overflowâ=80=99: |include/linux/thread_info.h:210:2: error: implicit declaration of function â=80=98WARNâ=80=99 [-Werror=3Dimplicit-function-declaration] | 210 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); | | ^~~~ The WARN / BUG include pulls in printk.h and then ptrace.h expects WARN (from bug.h) which is not yet complete. Even hw_irq.h has WARN_ON() statements. On POWERPC64 there are missing atomic64 defines while building 32bit VDSO: | VDSO32C arch/powerpc/kernel/vdso32/vgettimeofday.o |In file included from include/linux/atomic.h:80, | from include/linux/rwbase_rt.h:6, | from include/linux/rwlock_types.h:55, | from include/linux/spinlock_types.h:74, | from include/linux/ratelimit_types.h:7, | from include/linux/printk.h:10, | from include/linux/kernel.h:19, | from arch/powerpc/include/asm/page.h:11, | from arch/powerpc/include/asm/vdso/gettimeofday.h:5, | from include/vdso/datapage.h:137, | from lib/vdso/gettimeofday.c:5, | from <command-line>: |include/linux/atomic-arch-fallback.h: In function ‘arch_atomic64_incâ€=99: |include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function ‘arch_atomic64_add’; did you mean ‘arch_atomic_add’? [-Werror=3Dimpl |icit-function-declaration] | 1447 | arch_atomic64_add(1, v); | | ^~~~~~~~~~~~~~~~~ | | arch_atomic_add The generic fallback is not included, atomics itself are not used. If kernel.h does not include printk.h then it comes later from the bug.h include. Allow asm/spinlock_types.h to be included from linux/spinlock_types_raw.h. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20211129174654.668506-12-bigeasy@linutronix.de
2021-12-06ARM: implement THREAD_INFO_IN_TASK for uniprocessor systemsArd Biesheuvel
On UP systems, only a single task can be 'current' at the same time, which means we can use a global variable to track it. This means we can also enable THREAD_INFO_IN_TASK for those systems, as in that case, thread_info is accessed via current rather than the other way around, removing the need to store thread_info at the base of the task stack. This, in turn, permits us to enable IRQ stacks and vmap'ed stacks on UP systems as well. To partially mitigate the performance overhead of this arrangement, use a ADD/ADD/LDR sequence with the appropriate PC-relative group relocations to load the value of current when needed. This means that accessing current will still only require a single load as before, avoiding the need for a literal to carry the address of the global variable in each function. However, accessing thread_info will now require this load as well. Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06ARM: smp: defer TPIDRURO update for SMP v6 configurations tooArd Biesheuvel
Defer TPIDURO updates for user space until exit also for CPU_V6+SMP configurations so that we can decide at runtime whether to use it to carry the current pointer, provided that we are running on a CPU that actually implements this register. This is needed for THREAD_INFO_IN_TASK support for UP systems, which requires that all SMP capable systems use the TPIDRURO based access to 'current' as the only remaining alternative will be a global variable which only works on UP. Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06ARM: percpu: add SMP_ON_UP supportArd Biesheuvel
Permit the use of the TPIDRPRW system register for carrying the per-CPU offset in generic SMP configurations that also target non-SMP capable ARMv6 cores. This uses the SMP_ON_UP code patching framework to turn all TPIDRPRW accesses into reads/writes of entry #0 in the __per_cpu_offset array. While at it, switch over some existing direct TPIDRPRW accesses in asm code to invocations of a new helper that is patched in the same way when necessary. Note that CPU_V6+SMP without SMP_ON_UP results in a kernel that does not boot on v6 CPUs without SMP extensions, so add this dependency to Kconfig as well. Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06ARM: assembler: add optimized ldr/str macros to load variables from memoryArd Biesheuvel
We will be adding variable loads to various hot paths, so it makes sense to add a helper macro that can load variables from asm code without the use of literal pool entries. On v7 or later, we can simply use MOVW/MOVT pairs, but on earlier cores, this requires a bit of hackery to emit a instruction sequence that implements this using a sequence of ADD/LDR instructions. Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06ARM: module: implement support for PC-relative group relocationsArd Biesheuvel
Add support for the R_ARM_ALU_PC_Gn_NC and R_ARM_LDR_PC_G2 group relocations [0] so we can use them in modules. These will be used to load the current task pointer from a global variable without having to rely on a literal pool entry to carry the address of this variable, which may have a significant negative impact on cache utilization for variables that are used often and in many different places, as each occurrence will result in a literal pool entry and therefore a line in the D-cache. [0] 'ELF for the ARM architecture' https://github.com/ARM-software/abi-aa/releases Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06irqchip: nvic: Use GENERIC_IRQ_MULTI_HANDLERVladimir Murzin
Rather then restructuring the ARMv7M entrly logic per TODO, just move NVIC to GENERIC_IRQ_MULTI_HANDLER. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-06ARM: remove old-style irq entryArnd Bergmann
The last user of arch_irq_handler_default is gone now, so the entry-macro-multi.S file and all references to mach/entry-macro.S can be removed, as well as the asm_do_IRQ() entrypoint into the interrupt handling routines implemented in C. Note: The ARMv7-M entry still uses its own top-level IRQ entry, calling nvic_handle_irq() from assembly. This could be changed to go through generic_handle_arch_irq() as well, but it's unclear to me if there are any benefits. Signed-off-by: Arnd Bergmann <arnd@arndb.de> [ardb: keep irq_handler macro as it carries all the IRQ stack handling] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2021-12-06Merge 5.16-rc4 into tty-nextGreg Kroah-Hartman
We need the tty/serial driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-03ARM: riscpc: use GENERIC_IRQ_MULTI_HANDLERArnd Bergmann
This is one of the last platforms using the old entry path. While this code path is spread over a few files, it is fairly straightforward to convert it into an equivalent C version, leaving the existing algorithm and all the priority handling the same. Unlike most irqchip drivers, this means reading the status register(s) in a loop and always handling the highest-priority irq first. The IOMD_IRQREQC and IOMD_IRQREQD registers are not actaully used here, but I left the code in place for the time being, to keep the conversion as direct as possible. It could be removed in a cleanup on top. Signed-off-by: Arnd Bergmann <arnd@arndb.de> [ardb: drop obsolete IOMD_IRQREQC/IOMD_IRQREQD handling] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: riscpc: drop support for IOMD_IRQREQC/IOMD_IRQREQD IRQ groupsArd Biesheuvel
IOMD_IRQREQC nor IOMD_IRQREQD are ever defined, so any conditionally compiled code that depends on them is dead code, and can be removed. Suggested-by: Russell King <linux@armlinux.org.uk> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-12-03ARM: implement support for vmap'ed stacksArd Biesheuvel
Wire up the generic support for managing task stack allocations via vmalloc, and implement the entry code that detects whether we faulted because of a stack overrun (or future stack overrun caused by pushing the pt_regs array) While this adds a fair amount of tricky entry asm code, it should be noted that it only adds a TST + branch to the svc_entry path. The code implementing the non-trivial handling of the overflow stack is emitted out-of-line into the .text section. Since on ARM, we rely on do_translation_fault() to keep PMD level page table entries that cover the vmalloc region up to date, we need to ensure that we don't hit such a stale PMD entry when accessing the stack. So we do a dummy read from the new stack while still running from the old one on the context switch path, and bump the vmalloc_seq counter when PMD level entries in the vmalloc range are modified, so that the MM switch fetches the latest version of the entries. Note that we need to increase the per-mode stack by 1 word, to gain some space to stash a GPR until we know it is safe to touch the stack. However, due to the cacheline alignment of the struct, this does not actually increase the memory footprint of the struct stack array at all. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: implement IRQ stacksArd Biesheuvel
Now that we no longer rely on the stack pointer to access the current task struct or thread info, we can implement support for IRQ stacks cleanly as well. Define a per-CPU IRQ stack and switch to this stack when taking an IRQ, provided that we were not already using that stack in the interrupted context. This is never the case for IRQs taken from user space, but ones taken while running in the kernel could fire while one taken from user space has not completed yet. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: unwind: dump exception stack from calling frameArd Biesheuvel
The existing code that dumps the contents of the pt_regs structure passed to __entry routines does so while unwinding the callee frame, and dereferences the stack pointer as a struct pt_regs*. This will no longer work when we enable support for IRQ or overflow stacks, because the struct pt_regs may live on the task stack, while we are executing from another stack. The unwinder has access to this information, but only while unwinding the calling frame. So let's combine the exception stack dumping code with the handling of the calling frame as well. By printing it before dumping the caller/callee addresses, the output order is preserved. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: export dump_mem() to other objectsArd Biesheuvel
The unwind info based stack unwinder will make its own call to dump_mem() to dump the exception stack, so give it external linkage. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: assembler: introduce bl_r macroArd Biesheuvel
Add a bl_r macro that abstract the difference between the ways indirect calls are performed on older and newer ARM architecture revisions. The main difference is to prefer blx instructions over explicit LR assignments when possible, as these tend to confuse the prediction logic in out-of-order cores when speculating across a function return. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-12-03ARM: remove some dead codeArd Biesheuvel
This code appears to be no longer used so let's get rid of it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Keith Packard <keithpac@amazon.com> Tested-by: Marc Zyngier <maz@kernel.org> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
2021-11-30arm: ioremap: Implement standard PCI function pci_remap_iospace()Pali Rohár
pci_remap_iospace() is standard PCI core function. Architecture code can reimplement default core implementation if needs custom arch specific functionality. ARM needs custom implementation due to pci_ioremap_set_mem_type() hook which allows ARM platforms to change mem type for iospace. Implement this pci_remap_iospace() function for ARM architecture to correctly handle pci_ioremap_set_mem_type() hook, which allows usage of this standard PCI core function also for platforms which needs different mem type (e.g. Marvell Armada 375, 38x and 39x). Link: https://lore.kernel.org/r/20211124154116.916-2-pali@kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-11-25arm: remove zte zx platform left-overLukas Bulwahn
Commit 89d4f98ae90d ("ARM: remove zte zx platform") missed to remove some definitions for this platform's debug and serial, e.g., code dependent on the config DEBUG_ZTE_ZX. Fortunately, ./scripts/checkkconfigsymbols.py detects this and warns: DEBUG_ZTE_ZX Referencing files: arch/arm/include/debug/pl01x.S Further review by Arnd Bergmann identified even more dead code in the amba serial driver. Remove all this left-over from the zte zx platform. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20211102063810.932-1-lukas.bulwahn@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-23arch_topology: Remove unused topology_set_thermal_pressure() and relatedLukasz Luba
There is no need of this function (and related) since code has been converted to use the new arch_update_thermal_pressure() API. The old code can be removed. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-11-23arch_topology: Introduce thermal pressure update functionLukasz Luba
The thermal pressure is a mechanism which is used for providing information about reduced CPU performance to the scheduler. Usually code has to convert the value from frequency units into capacity units, which are understandable by the scheduler. Create a common conversion code which can be just used via a handy API. Internally, the topology_update_thermal_pressure() operates on frequency in MHz and max CPU frequency is taken from 'freq_factor' (per-cpu). Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-11-21ARM: imx: rename DEBUG_IMX21_IMX27_UART to DEBUG_IMX27_UARTLukas Bulwahn
Since commit 4b563a066611 ("ARM: imx: Remove imx21 support"), the config DEBUG_IMX21_IMX27_UART is really only debug support for IMX27. So, rename this option to DEBUG_IMX27_UART and adjust dependencies in Kconfig and rename the definitions to IMX27 as further clean-up. This issue was discovered with ./scripts/checkkconfigsymbols.py, which reported that DEBUG_IMX21_IMX27_UART depends on the non-existing config SOC_IMX21. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2021-11-17Add linux/cacheflush.hMatthew Wilcox (Oracle)
Many architectures do not include asm-generic/cacheflush.h, so turn the includes on their head and add linux/cacheflush.h which includes asm/cacheflush.h. Move the flush_dcache_folio() declaration from asm-generic/cacheflush.h to linux/cacheflush.h and change linux/highmem.h to include linux/cacheflush.h instead of asm/cacheflush.h so that all necessary places will see flush_dcache_folio(). More functions should have their default implementations moved in the future, but those are for follow-on patches. This fixes csky, sparc and sparc64 which were missed in the commit which added flush_dcache_folio(). Fixes: 08b0b0059bf1 ("mm: Add flush_dcache_folio()") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-11-10Merge tag 'asm-generic-5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic cleanup from Arnd Bergmann: "This is a single cleanup from Peter Collingbourne, removing some dead code" * tag 'asm-generic-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: arch: remove unused function syscall_set_arguments()
2021-11-02Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: - Rejig task/thread info to place thread info in task struct - Amba bus cleanups (removing unused functions) - Handle Amba device probe without IRQ domains - Parse linux,usable-memory-range in decompressor - Mark OCRAM as read-only after initialisation - Refactor page fault handling - Fix PXN handling with LPAE kernels - Warning and build fixes from Arnd * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (32 commits) ARM: 9151/1: Thumb2: avoid __builtin_thread_pointer() on Clang ARM: 9150/1: Fix PID_IN_CONTEXTIDR regression when THREAD_INFO_IN_TASK=y ARM: 9147/1: add printf format attribute to early_print() ARM: 9146/1: RiscPC needs older gcc version ARM: 9145/1: patch: fix BE32 compilation ARM: 9144/1: forbid ftrace with clang and thumb2_kernel ARM: 9143/1: add CONFIG_PHYS_OFFSET default values ARM: 9142/1: kasan: work around LPAE build warning ARM: 9140/1: allow compile-testing without machine record ARM: 9137/1: disallow CONFIG_THUMB with ARMv4 ARM: 9136/1: ARMv7-M uses BE-8, not BE-32 ARM: 9135/1: kprobes: address gcc -Wempty-body warning ARM: 9101/1: sa1100/assabet: convert LEDs to gpiod APIs ARM: 9131/1: mm: Fix PXN process with LPAE feature ARM: 9130/1: mm: Provide die_kernel_fault() helper ARM: 9126/1: mm: Kill page table base print in show_pte() ARM: 9127/1: mm: Cleanup access_error() ARM: 9129/1: mm: Kill task_struct argument for __do_page_fault() ARM: 9128/1: mm: Refactor the __do_page_fault() ARM: imx6: mark OCRAM mapping read-only ...
2021-11-02Merge branches 'devel-stable' and 'misc' into for-linusRussell King (Oracle)
2021-11-01Merge tag 'trace-v5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - kprobes: Restructured stack unwinder to show properly on x86 when a stack dump happens from a kretprobe callback. - Fix to bootconfig parsing - Have tracefs allow owner and group permissions by default (only denying others). There's been pressure to allow non root to tracefs in a controlled fashion, and using groups is probably the safest. - Bootconfig memory managament updates. - Bootconfig clean up to have the tools directory be less dependent on changes in the kernel tree. - Allow perf to be traced by function tracer. - Rewrite of function graph tracer to be a callback from the function tracer instead of having its own trampoline (this change will happen on an arch by arch basis, and currently only x86_64 implements it). - Allow multiple direct trampolines (bpf hooks to functions) be batched together in one synchronization. - Allow histogram triggers to add variables that can perform calculations against the event's fields. - Use the linker to determine architecture callbacks from the ftrace trampoline to allow for proper parameter prototypes and prevent warnings from the compiler. - Extend histogram triggers to key off of variables. - Have trace recursion use bit magic to determine preempt context over if branches. - Have trace recursion disable preemption as all use cases do anyway. - Added testing for verification of tracing utilities. - Various small clean ups and fixes. * tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits) tracing/histogram: Fix semicolon.cocci warnings tracing/histogram: Fix documentation inline emphasis warning tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together tracing: Show size of requested perf buffer bootconfig: Initialize ret in xbc_parse_tree() ftrace: do CPU checking after preemption disabled ftrace: disable preemption when recursion locked tracing/histogram: Document expression arithmetic and constants tracing/histogram: Optimize division by a power of 2 tracing/histogram: Covert expr to const if both operands are constants tracing/histogram: Simplify handling of .sym-offset in expressions tracing: Fix operator precedence for hist triggers expression tracing: Add division and multiplication support for hist triggers tracing: Add support for creating hist trigger variables from literal selftests/ftrace: Stop tracing while reading the trace file by default MAINTAINERS: Update KPROBES and TRACING entries test_kprobes: Move it from kernel/ to lib/ docs, kprobes: Remove invalid URL and add new reference samples/kretprobes: Fix return value if register_kretprobe() failed lib/bootconfig: Fix the xbc_get_info kerneldoc ...
2021-11-01Merge tag 'sched-core-2021-11-01' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Thomas Gleixner: - Revert the printk format based wchan() symbol resolution as it can leak the raw value in case that the symbol is not resolvable. - Make wchan() more robust and work with all kind of unwinders by enforcing that the task stays blocked while unwinding is in progress. - Prevent sched_fork() from accessing an invalid sched_task_group - Improve asymmetric packing logic - Extend scheduler statistics to RT and DL scheduling classes and add statistics for bandwith burst to the SCHED_FAIR class. - Properly account SCHED_IDLE entities - Prevent a potential deadlock when initial priority is assigned to a newly created kthread. A recent change to plug a race between cpuset and __sched_setscheduler() introduced a new lock dependency which is now triggered. Break the lock dependency chain by moving the priority assignment to the thread function. - Fix the idle time reporting in /proc/uptime for NOHZ enabled systems. - Improve idle balancing in general and especially for NOHZ enabled systems. - Provide proper interfaces for live patching so it does not have to fiddle with scheduler internals. - Add cluster aware scheduling support. - A small set of tweaks for RT (irqwork, wait_task_inactive(), various scheduler options and delaying mmdrop) - The usual small tweaks and improvements all over the place * tag 'sched-core-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits) sched/fair: Cleanup newidle_balance sched/fair: Remove sysctl_sched_migration_cost condition sched/fair: Wait before decaying max_newidle_lb_cost sched/fair: Skip update_blocked_averages if we are defering load balance sched/fair: Account update_blocked_averages in newidle_balance cost x86: Fix __get_wchan() for !STACKTRACE sched,x86: Fix L2 cache mask sched/core: Remove rq_relock() sched: Improve wake_up_all_idle_cpus() take #2 irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support. sched/rt: Annotate the RT balancing logic irqwork as IRQ_WORK_HARD_IRQ sched: Add cluster scheduler level for x86 sched: Add cluster scheduler level in core and related Kconfig for ARM64 topology: Represent clusters of CPUs within a die sched: Disable -Wunused-but-set-variable sched: Add wrapper for get_wchan() to keep task blocked x86: Fix get_wchan() to support the ORC unwinder proc: Use task_is_running() for wchan in /proc/$pid/stat ...
2021-11-01Merge tag 'timers-core-2021-10-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Time, timers and timekeeping updates: - No core updates - No new clocksource/event driver - A large rework of the ARM architected timer driver to prepare for the support of the upcoming ARMv8.6 support - Fix Kconfig options for Exynos MCT, Samsung PWM and TI DM timers - Address a namespace collison in the ARC sp804 timer driver" * tag 'timers-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/timer-ti-dm: Select TIMER_OF clocksource/drivers/exynosy: Depend on sub-architecture for Exynos MCT and Samsung PWM clocksource/drivers/arch_arm_timer: Move workaround synchronisation around clocksource/drivers/arm_arch_timer: Fix masking for high freq counters clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programming clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL clocksource/drivers/arm_arch_timer: Fix MMIO base address vs callback ordering issue clocksource/drivers/arm_arch_timer: Move drop _tval from erratum function names clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL clocksource/drivers/arm_arch_timer: Extend write side of timer register accessors to u64 clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessors clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses clocksource/drivers/arc_timer: Eliminate redefined macro error
2021-11-01Merge tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds
Pull memory folios from Matthew Wilcox: "Add memory folios, a new type to represent either order-0 pages or the head page of a compound page. This should be enough infrastructure to support filesystems converting from pages to folios. The point of all this churn is to allow filesystems and the page cache to manage memory in larger chunks than PAGE_SIZE. The original plan was to use compound pages like THP does, but I ran into problems with some functions expecting only a head page while others expect the precise page containing a particular byte. The folio type allows a function to declare that it's expecting only a head page. Almost incidentally, this allows us to remove various calls to VM_BUG_ON(PageTail(page)) and compound_head(). This converts just parts of the core MM and the page cache. For 5.17, we intend to convert various filesystems (XFS and AFS are ready; other filesystems may make it) and also convert more of the MM and page cache to folios. For 5.18, multi-page folios should be ready. The multi-page folios offer some improvement to some workloads. The 80% win is real, but appears to be an artificial benchmark (postgres startup, which isn't a serious workload). Real workloads (eg building the kernel, running postgres in a steady state, etc) seem to benefit between 0-10%. I haven't heard of any performance losses as a result of this series. Nobody has done any serious performance tuning; I imagine that tweaking the readahead algorithm could provide some more interesting wins. There are also other places where we could choose to create large folios and currently do not, such as writes that are larger than PAGE_SIZE. I'd like to thank all my reviewers who've offered review/ack tags: Christoph Hellwig, David Howells, Jan Kara, Jeff Layton, Johannes Weiner, Kirill A. Shutemov, Michal Hocko, Mike Rapoport, Vlastimil Babka, William Kucharski, Yu Zhao and Zi Yan. I'd also like to thank those who gave feedback I incorporated but haven't offered up review tags for this part of the series: Nick Piggin, Mel Gorman, Ming Lei, Darrick Wong, Ted Ts'o, John Hubbard, Hugh Dickins, and probably a few others who I forget" * tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache: (90 commits) mm/writeback: Add folio_write_one mm/filemap: Add FGP_STABLE mm/filemap: Add filemap_get_folio mm/filemap: Convert mapping_get_entry to return a folio mm/filemap: Add filemap_add_folio() mm/filemap: Add filemap_alloc_folio mm/page_alloc: Add folio allocation functions mm/lru: Add folio_add_lru() mm/lru: Convert __pagevec_lru_add_fn to take a folio mm: Add folio_evictable() mm/workingset: Convert workingset_refault() to take a folio mm/filemap: Add readahead_folio() mm/filemap: Add folio_mkwrite_check_truncate() mm/filemap: Add i_blocks_per_folio() mm/writeback: Add folio_redirty_for_writepage() mm/writeback: Add folio_account_redirty() mm/writeback: Add folio_clear_dirty_for_io() mm/writeback: Add folio_cancel_dirty() mm/writeback: Add folio_account_cleaned() mm/writeback: Add filemap_dirty_folio() ...
2021-10-30ARM: 9151/1: Thumb2: avoid __builtin_thread_pointer() on ClangArd Biesheuvel
If available, we use the __builtin_thread_pointer() helper to get the value of the TLS register, to help the compiler understand that it doesn't need to reload it every time we access 'current'. Unfortunately, Clang fails to emit the MRC system register read directly when building for Thumb2, and instead, it issues a call to the __aeabi_read_tp helper, which the kernel does not provide, and so this result in link failures at build time. So create a special case for this, and emit the MRC directly using an asm() block, just like we do when the helper is not available to begin with. Link: https://github.com/ClangBuiltLinux/linux/issues/1485 Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-30ARM: 9150/1: Fix PID_IN_CONTEXTIDR regression when THREAD_INFO_IN_TASK=yArd Biesheuvel
The code that implements the rarely used PID_IN_CONTEXTIDR feature dereferences the 'task' field of struct thread_info directly, and this is no longer possible when THREAD_INFO_IN_TASK=y, as the 'task' field is omitted from the struct definition in that case. Instead, we should just cast the thread_info pointer to a task_struct pointer, given that the former is now the first member of the latter. So use a helper that abstracts this, and provide implementations for both cases. Reported by: Arnd Bergmann <arnd@arndb.de> Fixes: 18ed1c01a7dd ("ARM: smp: Enable THREAD_INFO_IN_TASK") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-25ARM: 9147/1: add printf format attribute to early_print()Nicolas Iooss
Adding such an attribute is helpful to detect errors related to printf formats at compile-time. Link: https://lore.kernel.org/r/20160828165815.25647-1-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-25ARM: 9145/1: patch: fix BE32 compilationArnd Bergmann
On BE32 kernels, the __opcode_to_mem_thumb32() interface is intentionally not defined, but it is referenced whenever runtime patching is enabled for the kernel, which may be for ftrace, jump label, kprobes or kgdb: arch/arm/kernel/patch.c: In function '__patch_text_real': arch/arm/kernel/patch.c:94:32: error: implicit declaration of function '__opcode_to_mem_thumb32' [-Werror=implicit-function-declaration] 94 | insn = __opcode_to_mem_thumb32(insn); | ^~~~~~~~~~~~~~~~~~~~~~~ Since BE32 kernels never run Thumb2 code, we never end up using the result of this call, so providing an extern declaration without a definition makes it build correctly. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-22ARM: Recover kretprobe modified return address in stacktraceMasami Hiramatsu
Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, arm unwinder shows it instead of the correct return address. This finds the correct return address from the per-task kretprobe_instances list and verify it is in between the caller fp and callee fp. Note that this supports both GCC and clang if CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=n. For the ARM unwinder, this is still not working correctly. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19ARM: 9132/1: Fix __get_user_check failure with ARM KASAN imagesLexi Shao
ARM: kasan: Fix __get_user_check failure with kasan In macro __get_user_check defined in arch/arm/include/asm/uaccess.h, error code is store in register int __e(r0). When kasan is enabled, assigning value to kernel address might trigger kasan check, which unexpectedly overwrites r0 and causes undefined behavior on arm kasan images. One example is failure in do_futex and results in process soft lockup. Log: watchdog: BUG: soft lockup - CPU#0 stuck for 62946ms! [rs:main Q:Reg:1151] ... (__asan_store4) from (futex_wait_setup+0xf8/0x2b4) (futex_wait_setup) from (futex_wait+0x138/0x394) (futex_wait) from (do_futex+0x164/0xe40) (do_futex) from (sys_futex_time32+0x178/0x230) (sys_futex_time32) from (ret_fast_syscall+0x0/0x50) The soft lockup happens in function futex_wait_setup. The reason is function get_futex_value_locked always return EINVAL, thus pc jump back to retry label and causes looping. This line in function get_futex_value_locked ret = __get_user(*dest, from); is expanded to *dest = (typeof(*(p))) __r2; , in macro __get_user_check. Writing to pointer dest triggers kasan check and overwrites the return value of __get_user_x function. The assembly code of get_futex_value_locked in kernel/futex.c: ... c01f6dc8: eb0b020e bl c04b7608 <__get_user_4> // "x = (typeof(*(p))) __r2;" triggers kasan check and r0 is overwritten c01f6dCc: e1a00007 mov r0, r7 c01f6dd0: e1a05002 mov r5, r2 c01f6dd4: eb04f1e6 bl c0333574 <__asan_store4> c01f6dd8: e5875000 str r5, [r7] // save ret value of __get_user(*dest, from), which is dest address now c01f6ddc: e1a05000 mov r5, r0 ... // checking return value of __get_user failed c01f6e00: e3550000 cmp r5, #0 ... c01f6e0c: 01a00005 moveq r0, r5 // assign return value to EINVAL c01f6e10: 13e0000d mvnne r0, #13 Return value is the destination address of get_user thus certainly non-zero, so get_futex_value_locked always return EINVAL. Fix it by using a tmp vairable to store the error code before the assignment. This fix has no effects to non-kasan images thanks to compiler optimization. It only affects cases that overwrite r0 due to kasan check. This should fix bug discussed in Link: [1] https://lore.kernel.org/linux-arm-kernel/0ef7c2a5-5d8b-c5e0-63fa-31693fd4495c@gmail.com/ Fixes: 421015713b30 ("ARM: 9017/2: Enable KASan for ARM") Signed-off-by: Lexi Shao <shaolexi@huawei.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-19ARM: add __arm_iomem_set_ro() to write-protect ioremapped areaRussell King (Oracle)
__arm_iomem_set_ro() marks an ioremapped area read-only. This is intended for use with __arm_ioremap_exec() to allow the kernel to write some code into e.g. SRAM and then write-protect it so the kernel doesn't complain about W+X mappings. Tested-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-10-18mm: Add flush_dcache_folio()Matthew Wilcox (Oracle)
This is a default implementation which calls flush_dcache_page() on each page in the folio. If architectures can do better, they should implement their own version of it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-10-17clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programmingMarc Zyngier
Switching from TVAL to CVAL has a small drawback: we need an ISB before reading the counter. We cannot get rid of it, but we can instead remove the one that comes just after writing to CVAL. This reduces the number of ISBs from 3 to 2 when programming the timer. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-12-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-17clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVALMarc Zyngier
Similarily to the sysreg-based timer, move the MMIO over to using the CVAL registers instead of TVAL. Note that there is no warranty that the 64bit MMIO access will be atomic, but the timer is always disabled at the point where we program CVAL. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-8-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-17clocksource/drivers/arm_arch_timer: Move system register timer programming ↵Marc Zyngier
over to CVAL In order to cope better with high frequency counters, move the programming of the timers from the countdown timer (TVAL) over to the comparator (CVAL). The programming model is slightly different, as we now need to read the current counter value to have an absolute deadline instead of a relative one. There is a small overhead to this change, which we will address in the following patches. Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-5-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-17clocksource/drivers/arm_arch_timer: Extend write side of timer register ↵Marc Zyngier
accessors to u64 The various accessors for the timer sysreg and MMIO registers are currently hardwired to 32bit. However, we are about to introduce the use of the CVAL registers, which require a 64bit access. Upgrade the write side of the accessors to take a 64bit value (the read side is left untouched as we don't plan to ever read back any of these registers). No functional change expected. Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-4-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-17clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessorsMarc Zyngier
The arch timer driver never reads the various TVAL registers, only writes to them. It is thus pointless to provide accessors for them and to implement errata workarounds. Drop these read-side accessors, and add a couple of BUG() statements for the time being. These statements will be removed further down the line. Reviewed-by: Oliver Upton <oupton@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-3-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-17clocksource/arm_arch_timer: Add build-time guards for unhandled register ↵Marc Zyngier
accesses As we are about to change the registers that are used by the driver, start by adding build-time checks to ensure that we always handle all registers and access modes. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211017124225.3018098-2-maz@kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2021-10-15sched: Add wrapper for get_wchan() to keep task blockedKees Cook
Having a stable wchan means the process must be blocked and for it to stay that way while performing stack unwinding. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm] Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64] Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
2021-09-27ARM: smp: Enable THREAD_INFO_IN_TASKArd Biesheuvel
Now that we no longer rely on thread_info living at the base of the task stack to be able to access the 'current' pointer, we can wire up the generic support for moving thread_info into the task struct itself. Note that this requires us to update the cpu field in thread_info explicitly, now that the core code no longer does so. Ideally, we would switch the percpu code to access the cpu field in task_struct instead, but this unleashes #include circular dependency hell. Co-developed-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
2021-09-27ARM: smp: Store current pointer in TPIDRURO register if availableArd Biesheuvel
Now that the user space TLS register is assigned on every return to user space, we can use it to keep the 'current' pointer while running in the kernel. This removes the need to access it via thread_info, which is located at the base of the stack, but will be moved out of there in a subsequent patch. Use the __builtin_thread_pointer() helper when available - this will help GCC understand that reloading the value within the same function is not necessary, even when using the per-task stack protector (which also generates accesses via the TLS register). For example, the generated code below loads TPIDRURO only once, and uses it to access both the stack canary and the preempt_count fields. <do_one_initcall>: e92d 41f0 stmdb sp!, {r4, r5, r6, r7, r8, lr} ee1d 4f70 mrc 15, 0, r4, cr13, cr0, {3} 4606 mov r6, r0 b094 sub sp, #80 ; 0x50 f8d4 34e8 ldr.w r3, [r4, #1256] ; 0x4e8 <- stack canary 9313 str r3, [sp, #76] ; 0x4c f8d4 8004 ldr.w r8, [r4, #4] <- preempt count Co-developed-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
2021-09-27ARM: smp: Free up the TLS register while running in the kernelArd Biesheuvel
To prepare for a subsequent patch that stores the current task pointer in the user space TLS register while running in the kernel, modify the set_tls and switch_tls routines not to touch the register directly, and update the return to user space code to load the correct value. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
2021-09-27ARM: smp: Pass task to secondary_start_kernelKeith Packard
This avoids needing to compute the task pointer in this function, which will no longer be possible once we move thread_info off the stack. Signed-off-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>