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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/powernv/opal-tracepoints.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/platforms/powernv/opal-tracepoints.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-tracepoints.c b/arch/powerpc/platforms/powernv/opal-tracepoints.c new file mode 100644 index 000000000..91b36541b --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-tracepoints.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/percpu.h> +#include <linux/jump_label.h> +#include <asm/trace.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); +} |