From: Tanmay Patil t-patil@ti.com
[ Upstream commit b685f1a58956fa36cc01123f253351b25bfacfda ]
CPSW ALE has 75 bit ALE entries which are stored within three 32 bit words. The cpsw_ale_get_field() and cpsw_ale_set_field() functions assume that the field will be strictly contained within one word. However, this is not guaranteed to be the case and it is possible for ALE field entries to span across up to two words at the most.
Fix the methods to handle getting/setting fields spanning up to two words.
Fixes: db82173f23c5 ("netdev: driver: ethernet: add cpsw address lookup engine support") Signed-off-by: Tanmay Patil t-patil@ti.com [s-vadapalli@ti.com: rephrased commit message and added Fixes tag] Signed-off-by: Siddharth Vadapalli s-vadapalli@ti.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ti/cpsw_ale.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/ti/cpsw_ale.c b/drivers/net/ethernet/ti/cpsw_ale.c index ddd43e09111e2..d9db5c23a9639 100644 --- a/drivers/net/ethernet/ti/cpsw_ale.c +++ b/drivers/net/ethernet/ti/cpsw_ale.c @@ -67,23 +67,37 @@
static inline int cpsw_ale_get_field(u32 *ale_entry, u32 start, u32 bits) { - int idx; + int idx, idx2; + u32 hi_val = 0;
idx = start / 32; + idx2 = (start + bits - 1) / 32; + /* Check if bits to be fetched exceed a word */ + if (idx != idx2) { + idx2 = 2 - idx2; /* flip */ + hi_val = ale_entry[idx2] << ((idx2 * 32) - start); + } start -= idx * 32; idx = 2 - idx; /* flip */ - return (ale_entry[idx] >> start) & BITMASK(bits); + return (hi_val + (ale_entry[idx] >> start)) & BITMASK(bits); }
static inline void cpsw_ale_set_field(u32 *ale_entry, u32 start, u32 bits, u32 value) { - int idx; + int idx, idx2;
value &= BITMASK(bits); - idx = start / 32; + idx = start / 32; + idx2 = (start + bits - 1) / 32; + /* Check if bits to be set exceed a word */ + if (idx != idx2) { + idx2 = 2 - idx2; /* flip */ + ale_entry[idx2] &= ~(BITMASK(bits + start - (idx2 * 32))); + ale_entry[idx2] |= (value >> ((idx2 * 32) - start)); + } start -= idx * 32; - idx = 2 - idx; /* flip */ + idx = 2 - idx; /* flip */ ale_entry[idx] &= ~(BITMASK(bits) << start); ale_entry[idx] |= (value << start); }