// SPDX-License-Identifier: GPL-2.0 #include <linux/percpu.h> #include <linux/jump_label.h> #include <asm/trace.h> #include <asm/asm-prototypes.h> #ifdef CONFIG_JUMP_LABEL struct static_key opal_tracepoint_key = STATIC_KEY_INIT; int opal_tracepoint_regfunc(void) { static_key_slow_inc(&opal_tracepoint_key); return 0; } void opal_tracepoint_unregfunc(void) { static_key_slow_dec(&opal_tracepoint_key); } #else /* * We optimise OPAL calls by placing opal_tracepoint_refcount * directly in the TOC so we can check if the opal tracepoints are * enabled via a single load. */ /* NB: reg/unreg are called while guarded with the tracepoints_mutex */ extern long opal_tracepoint_refcount; int opal_tracepoint_regfunc(void) { opal_tracepoint_refcount++; return 0; } void opal_tracepoint_unregfunc(void) { opal_tracepoint_refcount--; } #endif /* * Since the tracing code might execute OPAL calls we need to guard against * recursion. */ static DEFINE_PER_CPU(unsigned int, opal_trace_depth); void __trace_opal_entry(unsigned long opcode, unsigned long *args) { unsigned long flags; unsigned int *depth; local_irq_save(flags); depth = this_cpu_ptr(&opal_trace_depth); if (*depth) goto out; (*depth)++; preempt_disable(); trace_opal_entry(opcode, args); (*depth)--; out: local_irq_restore(flags); } void __trace_opal_exit(long opcode, unsigned long retval) { unsigned long flags; unsigned int *depth; local_irq_save(flags); depth = this_cpu_ptr(&opal_trace_depth); if (*depth) goto out; (*depth)++; trace_opal_exit(opcode, retval); preempt_enable(); (*depth)--; out: local_irq_restore(flags); }