Skip to content

redhat/configs: enable CONFIG_TRACE_MMIO_ACCESS

Adrien Thierry requested to merge athierry1/centos-stream-9:bz-2196310-enable-register-tracing-config into main-automotive

redhat/configs: enable CONFIG_TRACE_MMIO_ACCESS

Bugzilla: https://bugzilla.redhat.com/2196310

Depends: https://bugzilla.redhat.com/2196244

Upstream Status: RHEL only

Enable register read/write tracing for arm64

How to test

echo 1 > /sys/kernel/tracing/events/rwmmio/enable
cat /sys/kernel/tracing/trace

You should see a trace of register read/write events with a format similar to:

<idle>-0       [004] d...2..   234.967386: rwmmio_post_read: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x150/0x2f4 width=32 val=0x1405fe20 addr=0xffff800008015008
<idle>-0       [004] d...2..   234.967386: rwmmio_read: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x17c/0x2f4 width=32 addr=0xffff80000801500c
<idle>-0       [004] d...2..   234.967386: rwmmio_post_read: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x1ac/0x2f4 width=32 val=0x1 addr=0xffff80000801500c
<idle>-0       [004] d...2..   234.967386: rwmmio_write: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x1f4/0x2f4 width=64 val=0x11408e946 addr=0xffff800008015030
<idle>-0       [004] d...2..   234.967387: rwmmio_post_write: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x228/0x2f4 width=64 val=0x11408e946 addr=0xffff800008015030
<idle>-0       [004] d...2..   234.967387: rwmmio_write: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x258/0x2f4 width=32 val=0x1 addr=0xffff80000801503c
<idle>-0       [004] d...2..   234.967387: rwmmio_post_write: clockevents_program_event+0xa8/0x120 -> arch_timer_set_next_event_virt_mem+0x294/0x2f4 width=32 val=0x1 addr=0xffff80000801503c
<idle>-0       [004] d...3..   234.967389: rwmmio_read: gic_set_affinity+0x88/0x250 -> gic_peek_irq+0x80/0x140 width=32 addr=0xffff800008040104
<idle>-0       [004] d...3..   234.967390: rwmmio_post_read: gic_set_affinity+0x88/0x250 -> gic_peek_irq+0xac/0x140 width=32 val=0x61 addr=0xffff800008040104

Signed-off-by: Adrien Thierry athierry@redhat.com

Edited by Adrien Thierry

Merge request reports