[PATCH v3 0/5] lib: sbi: sse: rework event availability

Clément Léger cleger at rivosinc.com
Thu Dec 12 12:34:16 PST 2024


While reworking the Linux SSE support, it appears that the PMU event
should not be available if the SSCOFPMF extension is not available since
there would be no IRQ. A request to modify the specification has been
send in order to add the possibility to return SBI_ENOTSUPP (see [1]).
This small series modifies the SSE core to detect event support at boot
time using a new callback and return SBI_ENOTSUPP if needed.

Link: https://lists.riscv.org/g/tech-prs/message/1123 [1]

---

Changes in V3:
 - Rework is_supported_cb() to allow per-hart local event availability
 - Remove now useless cached_version of is_supported.
 - Fix eret check + potential empty eret in case event_is_supported()
   returns SBI_SUCCESS.
 - Split commit to set all non software events as non injectable at the
   end of the series.
 - Fix usage of sbi_pmu_irq_bit() in sbi_pmu.c

Changes in v2:
 - Add an sse_event_info struct that stores 'cb_ops' as well as 'supported'
 - Move SSE initialization after all other "drivers" init.
 - Split changes in multiple commits
 - Added an is_supported callback to check for event availability

Clément Léger (5):
  lib: sbi: pmu: fix usage of sbi_pmu_irq_bit()
  lib: sbi: sse: return an error value from sse_event_get()
  lib: sbi: sse: rework event availability
  lib: sbi: pmu: add an sse .is_supported_cb callback implementation
  lib: sbi: sse: set non-software events as unsupported

 include/sbi/riscv_encoding.h                  |   1 -
 include/sbi/sbi_pmu.h                         |   3 +
 include/sbi/sbi_sse.h                         |   5 +
 lib/sbi/sbi_hart.c                            |   2 +-
 lib/sbi/sbi_init.c                            |  21 +-
 lib/sbi/sbi_pmu.c                             |  55 ++--
 lib/sbi/sbi_sse.c                             | 240 +++++++++++++-----
 lib/sbi/sbi_trap.c                            |  17 +-
 .../generic/include/thead/c9xx_encoding.h     |   1 -
 platform/generic/thead/thead_c9xx_pmu.c       |   2 +-
 10 files changed, 240 insertions(+), 107 deletions(-)

-- 
2.45.2




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