From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: In-Reply-To: <1177690940.24866.124.camel@luke-laptop> References: <1177626236.24866.99.camel@luke-laptop> , <1177601310.24866.94.camel@luke-laptop> <772e4d4c76807769449cf1bf874d2ce1@bga.com> <1177690940.24866.124.camel@luke-laptop> Mime-Version: 1.0 (Apple Message framework v624) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: From: Milton Miller Subject: Re: [PATCH v4] powerpc: 64K page support for kexec Date: Fri, 27 Apr 2007 11:59:07 -0500 To: Luke Browning Cc: Arnd Bergmann , linuxppc-dev@ozlabs.org, Paul Mackerras , Olof Johansson , cbe-oss-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Apr 27, 2007, at 11:22 AM, Luke Browni+ /* > + * FIXME, the code below works for 16M, 64K, and 4K pages as these > + * fall under the p<=23 rules for calculating the virtual address. > + * In the case of 16M pages, an extra bit is stolen from the AVPN > + * field to achieve the requisite 24 bits. > + * > + * You can use kexec -l to debug new page support! > + */ > + BUG_ON(hpte_v & 0x4000000000000000UL && !panic); /* 1T segment */ > + BUG_ON(size == MMU_PAGE_16G && !panic); > + BUG_ON(size == MMU_PAGE_64K_AP && !panic); > + I see I've achived my nefarious goal of making these bugs never happen. (panic is a function, so you are checking that the staticly linked non-weak function is available. If you want to check on when if its a panic kdump or not, you need to decode the flag and pass it to kexec_sequence, pass it back here, and update all platforms for the new parameter). But I still say the check while clearing the table is too late, it should be a debug scan before clearing any mappings. milton