diff options
Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c')
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c index cb28ac03e4cac..c88bf673cb767 100644 --- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c +++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_mutex.c @@ -59,6 +59,11 @@ static u32 nfp_mutex_unlocked(u16 interface) return (u32)interface << 16 | 0x0000; } +static u32 nfp_mutex_owner(u32 val) +{ + return val >> 16; +} + static bool nfp_mutex_is_locked(u32 val) { return (val & 0xffff) == 0x000f; @@ -351,3 +356,43 @@ int nfp_cpp_mutex_trylock(struct nfp_cpp_mutex *mutex) return nfp_mutex_is_locked(tmp) ? -EBUSY : -EINVAL; } + +/** + * nfp_cpp_mutex_reclaim() - Unlock mutex if held by local endpoint + * @cpp: NFP CPP handle + * @target: NFP CPP target ID (ie NFP_CPP_TARGET_CLS or NFP_CPP_TARGET_MU) + * @address: Offset into the address space of the NFP CPP target ID + * + * Release lock if held by local system. Extreme care is advised, call only + * when no local lock users can exist. + * + * Return: 0 if the lock was OK, 1 if locked by us, -errno on invalid mutex + */ +int nfp_cpp_mutex_reclaim(struct nfp_cpp *cpp, int target, + unsigned long long address) +{ + const u32 mur = NFP_CPP_ID(target, 3, 0); /* atomic_read */ + const u32 muw = NFP_CPP_ID(target, 4, 0); /* atomic_write */ + u16 interface = nfp_cpp_interface(cpp); + int err; + u32 tmp; + + err = nfp_cpp_mutex_validate(interface, &target, address); + if (err) + return err; + + /* Check lock */ + err = nfp_cpp_readl(cpp, mur, address, &tmp); + if (err < 0) + return err; + + if (nfp_mutex_is_unlocked(tmp) || nfp_mutex_owner(tmp) != interface) + return 0; + + /* Bust the lock */ + err = nfp_cpp_writel(cpp, muw, address, nfp_mutex_unlocked(interface)); + if (err < 0) + return err; + + return 1; +} |