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