Date: Mon, 12 Oct 2009 13:15:41 +0200 From: Rafal Jaworowski <raj@semihalf.com> To: Mark Tinguely <tinguely@casselton.net> Cc: gballet@gmail.com, freebsd-arm@freebsd.org Subject: Re: Adding members to struct cpu_functions Message-ID: <4A95E6D9-7BA5-4D8A-99A1-6BC6A7EABC18@semihalf.com> In-Reply-To: <200910081613.n98GDt7r053539@casselton.net> References: <200910081613.n98GDt7r053539@casselton.net>
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On 2009-10-08, at 18:13, Mark Tinguely wrote: > -- on a tangent about the future -- > Since the ARMv7 is coming to FreeBSD, there are other ARMv4/5 vrs > ARMv6/7 > questions, the most important is should we break the new ARM chips > with > their physical tagged caches to another subbranch or define it into > the > existing code? One example of the existing pmap code that does not > mesh > well with ARMv6/7 is the exisiting flush of the level 2 cache > because the > old archs have VIVT level 2 caches). ARMv6/7 level 2 caches are PIPT, > and would not be flushed until DMA time. A simple solution would be if > an arch needs to flush the level 2 cache when it flushes the level 1 > cache, then it should do so in the level 1 cache flushing routine. I was wondering whether a separate pmap module for ARMv6-7 would not be the best approach. After all v6-7 should be considered an entirely new architecture variation, and we would avoid the very likely #ifdefs hell in case of a single pmap.c. Rafal
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