Thanks Mark, I'll post v5 patch without alternatives. On 12/11/2017 04:45 AM, Mark Rutland wrote: > Hi, > > On Sun, Dec 10, 2017 at 08:03:43PM -0600, Shanker Donthineni wrote: >> +/** >> + * Errata workaround prior to disable MMU. Insert an ISB immediately prior >> + * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0. >> + */ >> + .macro pre_disable_mmu_workaround >> +#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041 >> +alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1041 >> + isb >> +alternative_else_nop_endif >> +#endif >> + .endm > > There's really no need for this to be an alternative. It makes the > kernel larger and more complex due to all the altinstr data and probing > code. > > As Will suggested last time [1], please just use the ifdef, and always > compile-in the extra ISB if CONFIG_QCOM_FALKOR_ERRATUM_E1041 is > selected. Get rid of the alternatives and probing code. > > All you need here is: > > /* > * Some Falkor parts make errant speculative instruction fetches > * when SCTLR_ELx.M is cleared. An ISB before the write to > * SCTLR_ELx prevents this. > */ > .macro pre_disable_mmu_workaround > #ifdef > isb > #endif > .endm > >> + >> + .macro pre_disable_mmu_early_workaround >> +#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041 >> + isb >> +#endif >> + .endm >> + > > ... and we don't need a special early variant. > > Thanks, > Mark. > > [1] https://lkml.kernel.org/r/20171201112457.GE18083@xxxxxxx > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- Shanker Donthineni Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
