From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dell-paw-3.cambridge.redhat.com ([195.224.55.237] helo=passion.cambridge.redhat.com) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 1573if-0003m8-00 for ; Tue, 05 Jun 2001 00:25:09 +0100 From: David Woodhouse In-Reply-To: <3B1C1872.8D8F1529@mandrakesoft.com> References: <3B1C1872.8D8F1529@mandrakesoft.com> <13942.991696607@redhat.com> To: Jeff Garzik Cc: bjornw@axis.com, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org Subject: Re: Missing cache flush. Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 05 Jun 2001 00:29:22 +0100 Message-ID: <14147.991697362@redhat.com> Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: jgarzik@mandrakesoft.com said: > > I was pointed at Documentation/DMA-mapping.txt but that doesn't seem > > very helpful - it's very PCI-specific, and a quick perusal of > > pci_dma_sync() on i386 shows that it doesn't do what's required anyway. > What should it do on i386? mb()? For it to have any use in the situation I described, it would need to writeback and invalidate the dcache for the affected range. It doesn't seem to do so, so it seems that it isn't what I require. The situation is simple - I have a paged RAM setup and I need it cached. All I want to do is flush and invalidate the cache when I'm about to waggle whatever I/O ports I waggle to change pages. There are other situations in which I need the cache flushed, but the above is one of the simplest. Even flush_page_to_ram() doesn't seem to do what its name implies, on most architectures. -- dwmw2