On Tue, Oct 16, 2007 at 06:34:14PM +1000, Matthew Chapman wrote: > Where would I find documentation on the Itanium 2 specific flags to > PAL_PROC_SET_FEATURES? "Intel® Itanium® 2 Processors Firmware Guide", though I don't see it on the Intel website. Don't recall if the document is restricted. > Linux arch/ia64/kernel/setup.c seems to enable bit 0x80, but there is no > explanatory comment attached. I assume you are refering to this code. -------------------------------------- #ifdef CONFIG_MCKINLEY { # define FEATURE_SET 16 struct ia64_pal_retval iprv; if (cpu_info->family == 0x1f) { PAL_CALL_PHYS(iprv, PAL_PROC_GET_FEATURES, 0, FEATURE_SET, 0); if ((iprv.status == 0) && (iprv.v0 & 0x80) && (iprv.v2 & 0x80)) PAL_CALL_PHYS(iprv, PAL_PROC_SET_FEATURES, (iprv.v1 | 0x80), FEATURE_SET, 0); } } #endif -------------------------------------- Note that it is setting bit 7 (0x80) in feature set 16 (not feature set 0). > The Itanium 2 microarchitecture manual [1] says that early deferral of > speculative memory ops (bypassing VHPT walker) can be enabled via > PAL_PROC_SET_FEATURES, but as far as I can see does not specify anywhere > which is the appropriate bit... > > Also, is it true that early deferral only happens with psr.ic=0, as > per Table 5-2? What is the motivation for that? > > Matt > > [1] i.e. http://download.intel.com/design/Itanium2/manuals/25111003.pdf > > - > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Russ Anderson RAS group SGI rja@xxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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