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| author |   Alexey Kardashevskiy <aik@ozlabs.ru> | 2018-06-01 18:06:16 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-07-02 23:54:29 +1000 |
| commit | d3d4ffaae439981e1e441ebb125aa3588627c5d8 (patch) | |
| tree | 246eb16b4fe245bf32384da4e3677b218333dc05 /arch/powerpc/platforms/powernv/pci-ioda.c | |
| parent | powerpc: Document issues with TM on POWER9 (diff) | |
| download | linux-dev-d3d4ffaae439981e1e441ebb125aa3588627c5d8.tar.xz linux-dev-d3d4ffaae439981e1e441ebb125aa3588627c5d8.zip | |
powerpc/powernv/ioda2: Reduce upper limit for DMA window size
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>
Diffstat (limited to '')
| -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 5bd0eb6681bc..ab678177d36e 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2840,7 +2840,7 @@ 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 */ |