From 8e63d38876691756f9bc6930850f1fb77809be1b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 6 Oct 2015 18:46:23 +0100 Subject: arm64: flush: use local TLB and I-cache invalidation There are a number of places where a single CPU is running with a private page-table and we need to perform maintenance on the TLB and I-cache in order to ensure correctness, but do not require the operation to be broadcast to other CPUs. This patch adds local variants of tlb_flush_all and __flush_icache_all to support these use-cases and updates the callers respectively. __local_flush_icache_all also implies an isb, since it is intended to be used synchronously. Reviewed-by: Catalin Marinas Acked-by: David Daney Acked-by: Ard Biesheuvel Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/suspend.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kernel/suspend.c') diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 8297d502217e..3c5e4e6dcf68 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -90,7 +90,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) else cpu_switch_mm(mm->pgd, mm); - flush_tlb_all(); + local_flush_tlb_all(); /* * Restore per-cpu offset before any kernel -- cgit v1.2.3 From 01b305a234943c25c336a6f2f77932a4eaf125fa Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Thu, 12 Nov 2015 20:04:44 +0800 Subject: arm64: suspend: make hw_breakpoint_restore static 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 --- arch/arm64/kernel/suspend.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kernel/suspend.c') diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 3c5e4e6dcf68..d87403e8ba1d 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -41,7 +41,7 @@ void notrace __cpu_suspend_save(struct cpu_suspend_ctx *ptr, * time the notifier runs debug exceptions might have been enabled already, * with HW breakpoints registers content still in an unknown state. */ -void (*hw_breakpoint_restore)(void *); +static void (*hw_breakpoint_restore)(void *); void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *)) { /* Prevent multiple restore hook initializations */ -- cgit v1.2.3 From de818bd4522c40ea02a81b387d2fa86f989c9623 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Tue, 17 Nov 2015 11:50:51 +0000 Subject: arm64: kernel: pause/unpause function graph tracer in cpu_suspend() 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 --- arch/arm64/kernel/suspend.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm64/kernel/suspend.c') diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index fce95e17cf7f..1095aa483a1c 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -1,3 +1,4 @@ +#include #include #include #include @@ -70,6 +71,13 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) */ local_dbg_save(flags); + /* + * Function graph tracer state gets incosistent when the kernel + * calls functions that never return (aka suspend finishers) hence + * disable graph tracing during their execution. + */ + pause_graph_tracing(); + /* * mm context saved on the stack, it will be restored when * the cpu comes out of reset through the identity mapped @@ -111,6 +119,8 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) hw_breakpoint_restore(NULL); } + unpause_graph_tracing(); + /* * Restore pstate flags. OS lock and mdscr have been already * restored, so from this point onwards, debugging is fully -- cgit v1.2.3