diff options
author | Roland Dreier <rdreier@cisco.com> | 2006-12-06 15:15:38 -0800 |
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committer | Paul Mackerras <paulus@samba.org> | 2006-12-08 17:10:18 +1100 |
commit | 1d4454e7ce30239e67b154ae08f6d906b9737334 (patch) | |
tree | 293946b4886a2b9cae9e70479cdd2ab678dd94c4 /include/asm-powerpc/futex.h | |
parent | 885ed0fb484cc2d0a539558edf47a2a7c4fdd664 (diff) |
[POWERPC] Define pci_unmap_addr() et al. when CONFIG_NOT_COHERENT_CACHE=y
The current PowerPC code makes pci_unmap_addr(), pci_unmap_addr_set(),
and friends trivial for all 32-bit kernels. This is reasonable, since
for those kernels it is true that pci_unmap_single() does not need the
DMA address from the original DMA mapping -- in fact, it is a NOP.
However, I recently tried the tg3 driver on a PowerPC 440SPe machine,
which runs a 32-bit kernel and has non-cache-coherent PCI DMA. I
found that the tg3 driver crashed in pci_dma_sync_single_for_cpu(),
since for non-coherent systems, that function must invalidate the
cache for the DMA address range requested, and therefore it does use
the address passed in. tg3 uses a DMA address it stashes away with
pci_unmap_addr_set() and retrieves with pci_unmap_addr(). Of course,
since pci_unmap_addr() is defined to (0) right now, this doesn't work.
It seems to me that the tg3 driver is using pci_unmap_addr() in a
legitimate way -- I wouldn't want to have to teach all drivers that
they should use pci_unmap_addr() if they only need the address for
unmapping functions, but if they want the pci_dma_sync functions, then
they have to store the DMA address without the helper macros.
The right fix therefore seems to be in the definition of the macros in
<asm/pci.h> -- we should use the trivial versions only for 32-bit
kernels for coherent systems, and the real versions for both 64-bit
kernels and non-coherent systems.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc/futex.h')
0 files changed, 0 insertions, 0 deletions