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| author | Oliver O'Halloran <oohall@gmail.com> | 2019-07-11 01:05:17 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-31 07:28:55 +0200 |
| commit | aef3d0be9a33712ed7551cce5322867a51a6a0c6 (patch) | |
| tree | 36e178de2201db3ef68da703ad3a7b70fdf77afd /arch/powerpc | |
| parent | df41a0872fa09118684c6366c757885bc1e50e7b (diff) | |
powerpc/eeh: Handle hugepages in ioremap space
[ Upstream commit 33439620680be5225c1b8806579a291e0d761ca0 ]
In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap
space") support for using hugepages in the vmalloc and ioremap areas was
enabled for radix. Unfortunately this broke EEH MMIO error checking.
Detection works by inserting a hook which checks the results of the
ioreadXX() set of functions. When a read returns a 0xFFs response we
need to check for an error which we do by mapping the (virtual) MMIO
address back to a physical address, then mapping physical address to a
PCI device via an interval tree.
When translating virt -> phys we currently assume the ioremap space is
only populated by PAGE_SIZE mappings. If a hugepage mapping is found we
emit a WARN_ON(), but otherwise handles the check as though a normal
page was found. In pathalogical cases such as copying a buffer
containing a lot of 0xFFs from BAR memory this can result in the system
not booting because it's too busy printing WARN_ON()s.
There's no real reason to assume huge pages can't be present and we're
prefectly capable of handling them, so do that.
Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 45322b37669a..d2ba7936d0d3 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -361,10 +361,19 @@ static inline unsigned long eeh_token_to_phys(unsigned long token) ptep = find_init_mm_pte(token, &hugepage_shift); if (!ptep) return token; - WARN_ON(hugepage_shift); - pa = pte_pfn(*ptep) << PAGE_SHIFT; - return pa | (token & (PAGE_SIZE-1)); + pa = pte_pfn(*ptep); + + /* On radix we can do hugepage mappings for io, so handle that */ + if (hugepage_shift) { + pa <<= hugepage_shift; + pa |= token & ((1ul << hugepage_shift) - 1); + } else { + pa <<= PAGE_SHIFT; + pa |= token & (PAGE_SIZE - 1); + } + + return pa; } /* |