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.

Convert nfp_eth_set_bit_config() into a macro, which allows both gcc and
clang to identify 'mask' as a compile time constant.

Signed-off-by: Matthias Kaehlcke <m...@chromium.org>
---
I am aware that a lengthy macro is not a pretty solution, I'm open for
better suggestions.

Note: The patch has been build-tested only since I don't have any NFP
hardware.

 .../ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c   | 67 +++++++++++-----------
 1 file changed, 34 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c 
b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c
index f6f7c085f8e0..e9c635867918 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp_eth.c
@@ -469,39 +469,40 @@ 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
-nfp_eth_set_bit_config(struct nfp_nsp *nsp, unsigned int raw_idx,
-                      const u64 mask, 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);
-       u64 reg;
-
-       /* Note: set features were added in ABI 0.14 but the error
-        *       codes were initially not populated correctly.
-        */
-       if (nfp_nsp_get_abi_ver_minor(nsp) < 17) {
-               nfp_err(nfp_nsp_cpp(nsp),
-                       "set operations not supported, please update flash\n");
-               return -EOPNOTSUPP;
-       }
-
-       /* Check if we are already in requested state */
-       reg = le64_to_cpu(entries[idx].raw[raw_idx]);
-       if (val == FIELD_GET(mask, reg))
-               return 0;
-
-       reg &= ~mask;
-       reg |= FIELD_PREP(mask, val);
-       entries[idx].raw[raw_idx] = cpu_to_le64(reg);
-
-       entries[idx].control |= cpu_to_le64(ctrl_bit);
-
-       nfp_nsp_config_set_modified(nsp, true);
-
-       return 0;
-}
+#define nfp_eth_set_bit_config(nsp, raw_idx, mask, val, ctrl_bit)      \
+({                                                                     \
+       union eth_table_entry *entries = nfp_nsp_config_entries(nsp);   \
+       unsigned int idx = nfp_nsp_config_idx(nsp);                     \
+       u64 reg;                                                        \
+       int rc;                                                         \
+                                                                       \
+       /* Note: set features were added in ABI 0.14 but the error */   \
+       /*       codes were initially not populated correctly.     */   \
+       if (nfp_nsp_get_abi_ver_minor(nsp) < 17) {                      \
+               nfp_err(nfp_nsp_cpp(nsp),                               \
+                       "set operations not supported, please update flash\n"); 
\
+               rc = -EOPNOTSUPP;                                       \
+               goto out;                                               \
+       }                                                               \
+                                                                       \
+       rc = 0;                                                         \
+                                                                       \
+       /* Check if we are already in requested state */                \
+       reg = le64_to_cpu(entries[idx].raw[raw_idx]);                   \
+       if (val == FIELD_GET(mask, reg))                                \
+               goto out;                                               \
+                                                                       \
+       reg &= ~mask;                                                   \
+       reg |= FIELD_PREP(mask, val);                                   \
+       entries[idx].raw[raw_idx] = cpu_to_le64(reg);                   \
+                                                                       \
+       entries[idx].control |= cpu_to_le64(ctrl_bit);                  \
+                                                                       \
+       nfp_nsp_config_set_modified(nsp, true);                         \
+                                                                       \
+out:                                                                   \
+       rc;                                                             \
+})
 
 /**
  * __nfp_eth_set_aneg() - set PHY autonegotiation control bit
-- 
2.14.2.920.gcf0c67979c-goog

Reply via email to