kernel.git/arch/arm64/kernel/suspend.c, branch linux-4.13.y

arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx

2016-11-11T18:25:44Z

When returning from idle, we rely on the fact that thread_info lives at the end of the kernel stack, and restore this by masking the saved stack pointer. Subsequent patches will sever the relationship between the stack and thread_info, and to cater for this we must save/restore sp_el0 explicitly, storing it in cpu_suspend_ctx. As cpu_suspend_ctx must be doubleword aligned, this leaves us with an extra slot in cpu_suspend_ctx. We can use this to save/restore tpidr_el1 in the same way, which simplifies the code, avoiding pointer chasing on the restore path (as we no longer need to load thread_info::cpu followed by the relevant slot in __per_cpu_offset based on this). This patch stashes both registers in cpu_suspend_ctx. Signed-off-by: Mark Rutland Tested-by: Laura Abbott Cc: James Morse Cc: Lorenzo Pieralisi Cc: Will Deacon Signed-off-by: Catalin Marinas

arm64: suspend: Reconfigure PSTATE after resume from idle

2016-10-20T08:50:54Z

The suspend/resume path in kernel/sleep.S, as used by cpu-idle, does not save/restore PSTATE. As a result of this cpufeatures that were detected and have bits in PSTATE get lost when we resume from idle. UAO gets set appropriately on the next context switch. PAN will be re-enabled next time we return from user-space, but on a preemptible kernel we may run work accessing user space before this point. Add code to re-enable theses two features in __cpu_suspend_exit(). We re-use uao_thread_switch() passing current. Signed-off-by: James Morse Cc: Lorenzo Pieralisi Signed-off-by: Will Deacon

arm64: hw_breakpoint: convert CPU hotplug notifier to new infrastructure

2016-09-01T12:45:51Z

The arm64 hw_breakpoint implementation uses a CPU hotplug notifier to reset the {break,watch}point registers when CPUs come online. This patch converts the code to the new hotplug mechanism, whilst moving the invocation earlier to remove the need to disable IRQs explicitly in the driver (which could cause havok if we trip a watchpoint in an IRQ handler whilst restoring the debug register state). Cc: Sebastian Andrzej Siewior Reviewed-by: Lorenzo Pieralisi Signed-off-by: Will Deacon

arm64: Change cpu_resume() to enable mmu early then access sleep_sp by va

2016-04-28T11:05:46Z

By enabling the MMU early in cpu_resume(), the sleep_save_sp and stack can be accessed by VA, which avoids the need to convert-addresses and clean to PoC on the suspend path. MMU setup is shared with the boot path, meaning the swapper_pg_dir is restored directly: ttbr1_el1 is no longer saved/restored. struct sleep_save_sp is removed, replacing it with a single array of pointers. cpu_do_{suspend,resume} could be further reduced to not restore: cpacr_el1, mdscr_el1, tcr_el1, vbar_el1 and sctlr_el1, all of which are set by __cpu_setup(). However these values all contain res0 bits that may be used to enable future features. Signed-off-by: James Morse Reviewed-by: Lorenzo Pieralisi Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon

arm64: kernel: Rework finisher callback out of __cpu_suspend_enter()

2016-04-28T11:05:46Z

Hibernate could make use of the cpu_suspend() code to save/restore cpu state, however it needs to be able to return '0' from the 'finisher'. Rework cpu_suspend() so that the finisher is called from C code, independently from the save/restore of cpu state. Space to save the context in is allocated in the caller's stack frame, and passed into __cpu_suspend_enter(). Hibernate's use of this API will look like a copy of the cpu_suspend() function. Signed-off-by: James Morse Acked-by: Lorenzo Pieralisi Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon

arm64: unify idmap removal

2016-02-16T15:10:44Z

We currently open-code the removal of the idmap and restoration of the current task's MMU state in a few places. Before introducing yet more copies of this sequence, unify these to call a new helper, cpu_uninstall_idmap. Signed-off-by: Mark Rutland Reviewed-by: Catalin Marinas Tested-by: Ard Biesheuvel Reviewed-by: Ard Biesheuvel Tested-by: Jeremy Linton Cc: Laura Abbott Cc: Lorenzo Pieralisi Cc: Will Deacon Signed-off-by: Catalin Marinas

arm64: kernel: pause/unpause function graph tracer in cpu_suspend()

2015-11-17T17:11:45Z

The function graph tracer adds instrumentation that is required to trace both entry and exit of a function. In particular the function graph tracer updates the "return address" of a function in order to insert a trace callback on function exit. Kernel power management functions like cpu_suspend() are called upon power down entry with functions called "finishers" that are in turn called to trigger the power down sequence but they may not return to the kernel through the normal return path. When the core resumes from low-power it returns to the cpu_suspend() function through the cpu_resume path, which leaves the trace stack frame set-up by the function tracer in an incosistent state upon return to the kernel when tracing is enabled. This patch fixes the issue by pausing/resuming the function graph tracer on the thread executing cpu_suspend() (ie the function call that subsequently triggers the "suspend finishers"), so that the function graph tracer state is kept consistent across functions that enter power down states and never return by effectively disabling graph tracer while they are executing. Fixes: 819e50e25d0c ("arm64: Add ftrace support") Signed-off-by: Lorenzo Pieralisi Reported-by: Catalin Marinas Reported-by: AKASHI Takahiro Suggested-by: Steven Rostedt Acked-by: Steven Rostedt Cc: Will Deacon Cc: # 3.16+ Signed-off-by: Catalin Marinas

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2015-11-12T23:33:11Z

Pull arm64 fixes and clean-ups from Catalin Marinas: "Here's a second pull request for this merging window with some fixes/clean-ups: - __cmpxchg_double*() return type fix to avoid truncation of a long to int and subsequent logical "not" in cmpxchg_double() misinterpreting the operation success/failure - BPF fixes for mod and div by zero - Fix compilation with STRICT_MM_TYPECHECKS enabled - VDSO build fix without libgcov - Some static and __maybe_unused annotations - Kconfig clean-up (FRAME_POINTER) - defconfig update for CRYPTO_CRC32_ARM64" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: suspend: make hw_breakpoint_restore static arm64: mmu: make split_pud and fixup_executable static arm64: smp: make of_parse_and_init_cpus static arm64: use linux/types.h in kvm.h arm64: build vdso without libgcov arm64: mark cpus_have_hwcap as __maybe_unused arm64: remove redundant FRAME_POINTER kconfig option and force to select it arm64: fix R/O permissions of FDT mapping arm64: fix STRICT_MM_TYPECHECKS issue in PTE_CONT manipulation arm64: bpf: fix mod-by-zero case arm64: bpf: fix div-by-zero case arm64: Enable CRYPTO_CRC32_ARM64 in defconfig arm64: cmpxchg_dbl: fix return value type

arm64: suspend: make hw_breakpoint_restore static

2015-11-12T15:18:14Z

hw_breakpoint_restore is only used within suspend.c, so it can be declared static. Signed-off-by: Jisheng Zhang Signed-off-by: Catalin Marinas

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2015-11-04T22:47:13Z

Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...