nfp: don't depend on compiler constant propagation

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Matthias reports:

  nfp_eth_set_bit_config() is marked as __always_inline to allow gcc to
  identify the 'mask' parameter as known to be constant at compile time,
  which is required to use the FIELD_GET() macro.

  The forced inlining does the trick for gcc, but for kernel builds with
  clang it results in undefined symbols:

  drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.o: In function
    `__nfp_eth_set_aneg':

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c:(.text+0x787):
    undefined reference to `__compiletime_assert_492'

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c:(.text+0x7b1):
    undefined reference to `__compiletime_assert_496'

  These __compiletime_assert_xyx() calls would have been optimized away
if
  the compiler had seen 'mask' as a constant.

Add a macro to extract the mask and shift and pass those to
nfp_eth_set_bit_config() separately.

Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

This commit is contained in:

Jakub Kicinski 2017-11-04 16:48:54 +01:00 • committed by David S. Miller

parent 1f2556916d

commit 4e59532541

1 changed files with 15 additions and 8 deletions

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drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c

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