diff options
Diffstat (limited to 'arch/arm64/kernel/suspend.c')
| -rw-r--r-- | arch/arm64/kernel/suspend.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 8297d502217e..1095aa483a1c 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -1,3 +1,4 @@ +#include <linux/ftrace.h> #include <linux/percpu.h> #include <linux/slab.h> #include <asm/cacheflush.h> @@ -41,7 +42,7 @@ 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 */ @@ -71,6 +72,13 @@ 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 * page tables, so that the thread address space is properly @@ -80,17 +88,21 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) if (ret == 0) { /* * We are resuming from reset with TTBR0_EL1 set to the - * idmap to enable the MMU; restore the active_mm mappings in - * TTBR0_EL1 unless the active_mm == &init_mm, in which case - * the thread entered cpu_suspend with TTBR0_EL1 set to - * reserved TTBR0 page tables and should be restored as such. + * idmap to enable the MMU; set the TTBR0 to the reserved + * page tables to prevent speculative TLB allocations, flush + * the local tlb and set the default tcr_el1.t0sz so that + * the TTBR0 address space set-up is properly restored. + * If the current active_mm != &init_mm we entered cpu_suspend + * with mappings in TTBR0 that must be restored, so we switch + * them back to complete the address space configuration + * restoration before returning. */ - if (mm == &init_mm) - cpu_set_reserved_ttbr0(); - else - cpu_switch_mm(mm->pgd, mm); + cpu_set_reserved_ttbr0(); + local_flush_tlb_all(); + cpu_set_default_tcr_t0sz(); - flush_tlb_all(); + if (mm != &init_mm) + cpu_switch_mm(mm->pgd, mm); /* * Restore per-cpu offset before any kernel @@ -107,6 +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 |
