powerpc/perf: Fix the check for SIAR value
Incase of random sampling, there can be scenarios where Sample Instruction Address Register(SIAR) may not latch to the sampled instruction and could result in the value of 0. In these scenarios it is preferred to return regs->nip. These corner cases are seen in the previous generation (p9) also. Patch adds the check for SIAR value along with regs_use_siar and siar_valid checks so that the function will return regs->nip incase SIAR is zero. Patch drops the code under PPMU_P10_DD1 flag check which handles SIAR 0 case only for Power10 DD1. Fixes: 2ca13a4c ("powerpc/perf: Use regs->nip when SIAR is zero") Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210818171556.36912-3-kjain@linux.ibm.com
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