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| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2018-06-01 11:06:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-04 03:01:45 +0300 |
| commit | 47dd06672f2c87cd542c3bebf7376b75a26a71e7 (patch) | |
| tree | cb328fe262dd2ab68dae7017faef9f5884189620 /arch/powerpc | |
| parent | ad04608260af5216d33ad74ada77bde42239b95d (diff) | |
| download | linux-47dd06672f2c87cd542c3bebf7376b75a26a71e7.tar.xz | |
powerpc/powernv/ioda2: Reduce upper limit for DMA window size
[ Upstream commit d3d4ffaae439981e1e441ebb125aa3588627c5d8 ]
We use PHB in mode1 which uses bit 59 to select a correct DMA window.
However there is mode2 which uses bits 59:55 and allows up to 32 DMA
windows per a PE.
Even though documentation does not clearly specify that, it seems that
the actual hardware does not support bits 59:55 even in mode1, in other
words we can create a window as big as 1<<58 but DMA simply won't work.
This reduces the upper limit from 59 to 55 bits to let the userspace know
about the hardware limits.
Fixes: 7aafac11e3 "powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/platforms/powernv/pci-ioda.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index f52cc6fd4290..8015e40bc7ee 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2623,7 +2623,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset, level_shift = entries_shift + 3; level_shift = max_t(unsigned, level_shift, PAGE_SHIFT); - if ((level_shift - 3) * levels + page_shift >= 60) + if ((level_shift - 3) * levels + page_shift >= 55) return -EINVAL; /* Allocate TCE table */ |