Fixes:ee45fd92c739
("sfc: Use TX PIO for sufficiently small packets")
The linux net driver uses memcpy_toio() in order to copy into
the PIO buffers.
Even on a 64bit machine this causes 32bit accesses to a write-
combined memory region.
There are hardware limitations that mean that only 64bit
naturally aligned accesses are safe in all cases.
Due to being write-combined memory region two 32bit accesses
may be coalesced to form a 64bit non 64bit aligned access.
Solution was to open-code the memory copy routines using pointers
and to only enable PIO for x86_64 machines.
Not tested on platforms other than x86_64 because this patch
disables the PIO feature on other platforms.
Compile-tested on x86 to ensure that works.
The WARN_ON_ONCE() code in the previous version of this patch
has been moved into the internal sfc debug driver as the
assertion was unnecessary in the upstream kernel code.
This bug fix applies to v3.13 and v3.14 stable branches.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Try to allocate a segment of PIO buffer to each TX channel. If
allocation fails, log an error but continue.
PIO buffers must be mapped separately from the NIC registers, with
write-combining enabled. Where the host page size is 4K, we could
potentially map each VI's registers and PIO buffer separately.
However, this would add significant complexity, and we also need to
support architectures such as POWER which have a greater page size.
So make a single contiguous write-combining mapping after the
uncacheable mapping, aligned to the host page size, and link PIO
buffers there. Where necessary, allocate additional VIs within
the write-combining mapping purely for access to PIO buffers.
Link all TX buffers to TX queues and the additional VIs in
efx_ef10_dimension_resources() and in efx_ef10_init_nic() after
an MC reboot.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Update the dates for files that have been added to in 2012-2013.
Drop the 'Solarstorm' brand name that's still lingering here.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Also update comments and assertions in io.h:
- EF10 does not have a general BIU collector and does not have the
bug affecting TIMER_COMMAND_REG[0] on Falcon/Siena
- The WPTR field moved within RX_DESC_UPD_REG and TX_DESC_UPD_REG.
Adjust efx_writed_page() accordingly
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
efx_writed_table() uses a step of 16 bytes but efx_readd_table() uses
a step of 4 bytes. Why are they different?
Firstly, register access is asymmetric:
- The EVQ_RPTR table and RX_INDIRECTION_TBL can (or must?) be written
as dwords even though they have a step size of 16 bytes, unlike
most other CSRs.
- In general, a read of any width is valid for registers, so long as
it does not cross register boundaries. There is also no latching
behaviour in the BIU, contrary to rumour.
We write to the EVQ_RPTR table with efx_writed_table() but never read
it back as it's write-only. We write to the RX_INDIRECTION_TBL with
efx_writed_table(), but only read it back for the register dump, where
we use efx_reado_table() as for any other table with step size of 16.
We read MC_TREG_SMEM with efx_readd_table() for the register dump, but
normally read and write it with efx_readd() and efx_writed() using
offsets calculated in bytes.
Since these functions are trivial and have few callers, it's clearer
to open-code them at the call sites. While we're at it, update the
comments on the BIU behaviour again.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Moves the Solarflare drivers into drivers/net/ethernet/sfc/ and
make the necessary Kconfig and Makefile changes.
CC: Steve Hodgson <shodgson@solarflare.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
