From: Keith Owens <kaos@sgi.com>
To: linux-ia64@vger.kernel.org
Subject: 2.6 mca_asm.S VA to PA mappings
Date: Tue, 30 Sep 2003 06:57:19 +0000 [thread overview]
Message-ID: <marc-linux-ia64-106490506400881@msgid-missing> (raw)
2.6.0-test5-ia64-030908, arch/ia64/kernel/mca_asm.S, ia64_os_mca_done_dump
sets r2 to ia64_mca_bspstore then does DATA_VA_TO_PA(r2) which uses tpa.
This is before MCA has checked for a tlb error. Is it safe to use tpa
before checking that the tlb data is valid or should it be using
LOAD_PHYSICAL?
Before calling the C code, MCA uses VIRTUAL_MODE_ENTER which in turn
calls DATA_PA_TO_VA on ar.bspstore. DATA_PA_TO_VA sets bits 61:63 to
1, which assumes that ar.bspstore is identity mapped. On a
non-identity mapped 2.4 kernel I have seen ar.bspstore go
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.
next reply other threads:[~2003-09-30 6:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-30 6:57 Keith Owens [this message]
2003-09-30 15:42 ` 2.6 mca_asm.S VA to PA mappings Luck, Tony
2003-09-30 15:49 ` Keith Owens
2003-09-30 16:06 ` Luck, Tony
2003-09-30 16:20 ` Keith Owens
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