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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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c
View File

@ -469,10 +469,10 @@ int nfp_eth_set_configured(struct nfp_cpp *cpp, unsigned int idx, bool configed)
return nfp_eth_config_commit_end(nsp);
}
/* Force inline, FIELD_* macroes require masks to be compilation-time known */
static __always_inline int
static int
nfp_eth_set_bit_config(struct nfp_nsp *nsp, unsigned int raw_idx,
const u64 mask, unsigned int val, const u64 ctrl_bit)
const u64 mask, const unsigned int shift,
unsigned int val, const u64 ctrl_bit)
{
union eth_table_entry *entries = nfp_nsp_config_entries(nsp);
unsigned int idx = nfp_nsp_config_idx(nsp);
@ -489,11 +489,11 @@ nfp_eth_set_bit_config(struct nfp_nsp *nsp, unsigned int raw_idx,
/* Check if we are already in requested state */
reg = le64_to_cpu(entries[idx].raw[raw_idx]);
if (val == FIELD_GET(mask, reg))
if (val == (reg & mask) >> shift)
return 0;
reg &= ~mask;
reg |= FIELD_PREP(mask, val);
reg |= (val << shift) & mask;
entries[idx].raw[raw_idx] = cpu_to_le64(reg);
entries[idx].control |= cpu_to_le64(ctrl_bit);
@ -503,6 +503,13 @@ nfp_eth_set_bit_config(struct nfp_nsp *nsp, unsigned int raw_idx,
return 0;
}
#define NFP_ETH_SET_BIT_CONFIG(nsp, raw_idx, mask, val, ctrl_bit) \
({ \
__BF_FIELD_CHECK(mask, 0ULL, val, "NFP_ETH_SET_BIT_CONFIG: "); \
nfp_eth_set_bit_config(nsp, raw_idx, mask, __bf_shf(mask), \
val, ctrl_bit); \
})
/**
* __nfp_eth_set_aneg() - set PHY autonegotiation control bit
* @nsp: NFP NSP handle returned from nfp_eth_config_start()
@ -515,7 +522,7 @@ nfp_eth_set_bit_config(struct nfp_nsp *nsp, unsigned int raw_idx,
*/
int __nfp_eth_set_aneg(struct nfp_nsp *nsp, enum nfp_eth_aneg mode)
{
return nfp_eth_set_bit_config(nsp, NSP_ETH_RAW_STATE,
return NFP_ETH_SET_BIT_CONFIG(nsp, NSP_ETH_RAW_STATE,
NSP_ETH_STATE_ANEG, mode,
NSP_ETH_CTRL_SET_ANEG);
}
@ -544,7 +551,7 @@ int __nfp_eth_set_speed(struct nfp_nsp *nsp, unsigned int speed)
return -EINVAL;
}
return nfp_eth_set_bit_config(nsp, NSP_ETH_RAW_STATE,
return NFP_ETH_SET_BIT_CONFIG(nsp, NSP_ETH_RAW_STATE,
NSP_ETH_STATE_RATE, rate,
NSP_ETH_CTRL_SET_RATE);
}
@ -561,6 +568,6 @@ int __nfp_eth_set_speed(struct nfp_nsp *nsp, unsigned int speed)
*/
int __nfp_eth_set_split(struct nfp_nsp *nsp, unsigned int lanes)
{
return nfp_eth_set_bit_config(nsp, NSP_ETH_RAW_PORT, NSP_ETH_PORT_LANES,
return NFP_ETH_SET_BIT_CONFIG(nsp, NSP_ETH_RAW_PORT, NSP_ETH_PORT_LANES,
lanes, NSP_ETH_CTRL_SET_LANES);
}