2 Commits

Author	SHA1	Message	Date
Nicholas Piggin	59dc5bfca0	powerpc/64s: avoid reloading (H)SRR registers if they are still valid ... When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com	2021-06-25 00:06:55 +10:00
Naveen N. Rao	7cd01b08d3	powerpc: Add support for function error injection ... We implement regs_set_return_value() and override_function_with_return() for this purpose. On powerpc, a return from a function (blr) just branches to the location contained in the link register. So, we can just update pt_regs rather than redirecting execution to a dummy function that returns. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>	2018-10-20 13:26:43 +11:00