From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens Date: Tue, 30 Sep 2003 15:49:30 +0000 Subject: Re: 2.6 mca_asm.S VA to PA mappings Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Tue, 30 Sep 2003 08:42:10 -0700, "Luck, Tony" wrote: >> ia64_mca_bspstore (V=0xe000000004d5a6d0) >> DATA_VA_TO_PA (P=0x0000013014d5a6d0) >> DATA_PA_TO_VA (V=0xe000013014d5a6d0) >> >> With the 2.4 alt.dtlb handler that still works, although it is >> confusing to C code which needs to access the RSE data in >> ia64_mca_bspstore. I doubt that DATA_PA_TO_VA will work if the kernel >> is in region 5. > >Same thing, we need LOAD_PHYSICAL there too. Slight confusion. DATA_VA_TO_PA needs to be replaced by LOAD_PHYSICAL, but what replaces DATA_PA_TO_VA in a non-identity mapped kernel? bspstore needs a valid virtual address before calling the C code. If the asm code was told the original virtual address (ia64_mca_bspstore) then DATA_PA_TO_VA could convert ar.bspstore from P to V. Without that hint, I see no way of mapping P to V for an arbitrary address held in a register.