From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 02 Jun 2005 22:23:33 +0000 Subject: Re: flush_icache_range Message-Id: <17055.34533.385442.252286@napali.hpl.hp.com> List-Id: References: <4236D7B5.8050408@bull.net> In-Reply-To: <4236D7B5.8050408@bull.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Thu, 02 Jun 2005 23:37:36 +0200, "Menyhart, Zoltan" said: Zoltan> I propose to round down "start_address" to be stride size aligned. Sounds reasonable. >> As for setup.c: I'd get rid of LOG_2_I_CACHE_STRIDE_SIZE and just >> initialize log_2_i_cache_stride_size to 5 (there is no point in >> initializing it with a random & useless value). Zoltan> "log_2_i_cache_stride_size" is not initialized to any stride Zoltan> size, it calculates the min. value. Should Zoltan> "pal_cache_config_info" fail, you need something useful to Zoltan> be able to boot up. Zoltan> I 'd rather keep "LOG_2_I_CACHE_STRIDE_SIZE", I like speaking names. Zoltan> Perhaps "LOG_2_DEFAULT_I_CACHE_STRIDE_SIZE" would be even better :-) Sure. The canonical way in Linux to say "log2" is "shift", so perhaps: DEFAULT_I_CACHE_STRIDE_SHIFT ? >> Also, I think you should do take the minimum of _all_ cache-levels, >> not just level 1 (yes, I also have a hard time imagining a system >> where the higher level has a smaller stride, but I don't think there >> is anything that prevents such a system). Zoltan> Well, things are getting complicated :-) I can add it... Zoltan> I've got a concern about the "unique_caches" returned by Zoltan> "pal_cache_summary()". Let's assume that Zoltan> unique_caches - cache_levels = 2 Zoltan> I could not find anything making sure that we've got in this Zoltan> case L1I and L2I, and not L1I and L3I (feeding through the Zoltan> unified L2). Yes, I know there is no such a CPU (at the Zoltan> moment) but the PAL spec. does not exclude it :-) I don't think it matters whether you pick up the stride from an i-cache or a unified cache. As long as you take the minimum stride, it will work correctly. --david