linux_dsm_epyc7002/drivers/net/ethernet/mellanox
Haggai Abramovsky 73898db043 net/mlx4: Avoid wrong virtual mappings
The dma_alloc_coherent() function returns a virtual address which can
be used for coherent access to the underlying memory.  On some
architectures, like arm64, undefined behavior results if this memory is
also accessed via virtual mappings that are not coherent.  Because of
their undefined nature, operations like virt_to_page() return garbage
when passed virtual addresses obtained from dma_alloc_coherent().  Any
subsequent mappings via vmap() of the garbage page values are unusable
and result in bad things like bus errors (synchronous aborts in ARM64
speak).

The mlx4 driver contains code that does the equivalent of:
vmap(virt_to_page(dma_alloc_coherent)), this results in an OOPs when the
device is opened.

Prevent Ethernet driver to run this problematic code by forcing it to
allocate contiguous memory. As for the Infiniband driver, at first we
are trying to allocate contiguous memory, but in case of failure roll
back to work with fragmented memory.

Signed-off-by: Haggai Abramovsky <hagaya@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reported-by: David Daney <david.daney@cavium.com>
Tested-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-05 23:23:05 -04:00
..
mlx4 net/mlx4: Avoid wrong virtual mappings 2016-05-05 23:23:05 -04:00
mlx5/core net/mlx5: E-Switch, Implement trust vf ndo 2016-05-04 14:04:49 -04:00
mlxsw mlxsw: spectrum_buffers: Use MLXSW_SP_PB_UNUSED define for unused pb 2016-04-15 13:02:43 -04:00
Kconfig mlxsw: Introduce Mellanox switch driver core 2015-07-30 00:04:59 -07:00
Makefile mlxsw: Introduce Mellanox switch driver core 2015-07-30 00:04:59 -07:00