Searched hist:b0c5b4f1 (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/arch/powerpc/platforms/powernv/ |
| H A D | idle.c | b0c5b4f1 Tue May 09 22:31:12 CDT 2023 Rohan McLure <rmclure@linux.ibm.com> powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention
The idle_state entry in the PACA on PowerNV features a bit which is
atomically tested and set through ldarx/stdcx. to be used as a spinlock.
This lock then guards access to other bit fields of idle_state. KCSAN
cannot differentiate between any of these bitfield accesses as they all
are implemented by 8-byte store/load instructions, thus cores contending
on the bit-lock appear to data race with modifications to idle_state.
Separate the bit-lock entry from the data guarded by the lock to avoid
the possibility of data races being detected by KCSAN.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-7-rmclure@linux.ibm.com
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| /openbmc/linux/arch/powerpc/include/asm/ |
| H A D | paca.h | b0c5b4f1 Tue May 09 22:31:12 CDT 2023 Rohan McLure <rmclure@linux.ibm.com> powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention
The idle_state entry in the PACA on PowerNV features a bit which is
atomically tested and set through ldarx/stdcx. to be used as a spinlock.
This lock then guards access to other bit fields of idle_state. KCSAN
cannot differentiate between any of these bitfield accesses as they all
are implemented by 8-byte store/load instructions, thus cores contending
on the bit-lock appear to data race with modifications to idle_state.
Separate the bit-lock entry from the data guarded by the lock to avoid
the possibility of data races being detected by KCSAN.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-7-rmclure@linux.ibm.com
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