The swfw_busy flag guarding the AML SW-FW mailbox is a one-bit lock,
so convert it to RTE_ATOMIC(bool) and replace the legacy
test-and-set / clear pair with explicit acquire-release:
rte_atomic32_test_and_set ->
rte_atomic_exchange_explicit(.., true, acquire)
rte_atomic32_clear ->
rte_atomic_store_explicit(.., false, release)
Acquire on the take pairs with release on the drop, so accesses
inside the critical section are synchronized between successive
holders. Default zero-initialization of struct txgbe_hw still
gives swfw_busy = false, so no init site needs updating.
Note: the code for the AML spinlock had a bug because
old rte_atomic32_test_set return value was not what the code
expected. This patch fixes that. A seperate patch for stable
has been sent upstream. (Drop this note from commit message
when rebasing after the fix is merged).
Signed-off-by: Stephen Hemminger <[email protected]>
---
drivers/net/txgbe/base/txgbe_mng.c | 4 ++--
drivers/net/txgbe/base/txgbe_type.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/txgbe/base/txgbe_mng.c
b/drivers/net/txgbe/base/txgbe_mng.c
index a1974820b6..c58e1d6589 100644
--- a/drivers/net/txgbe/base/txgbe_mng.c
+++ b/drivers/net/txgbe/base/txgbe_mng.c
@@ -185,7 +185,7 @@ txgbe_host_interface_command_aml(struct txgbe_hw *hw, u32
*buffer,
}
/* try to get lock */
- while (rte_atomic32_test_and_set(&hw->swfw_busy)) {
+ while (rte_atomic_exchange_explicit(&hw->swfw_busy, true,
rte_memory_order_acquire)) {
timeout--;
if (!timeout)
return TXGBE_ERR_TIMEOUT;
@@ -266,7 +266,7 @@ txgbe_host_interface_command_aml(struct txgbe_hw *hw, u32
*buffer,
/* index++, index replace txgbe_hic_hdr.checksum */
hw->swfw_index = resp->index == TXGBE_HIC_HDR_INDEX_MAX ?
0 : resp->index + 1;
- rte_atomic32_clear(&hw->swfw_busy);
+ rte_atomic_store_explicit(&hw->swfw_busy, false,
rte_memory_order_release);
return err;
}
diff --git a/drivers/net/txgbe/base/txgbe_type.h
b/drivers/net/txgbe/base/txgbe_type.h
index ede780321f..d3c82d51a4 100644
--- a/drivers/net/txgbe/base/txgbe_type.h
+++ b/drivers/net/txgbe/base/txgbe_type.h
@@ -880,7 +880,7 @@ struct txgbe_hw {
rte_spinlock_t phy_lock;
/*amlite: new SW-FW mbox */
u8 swfw_index;
- rte_atomic32_t swfw_busy;
+ RTE_ATOMIC(bool) swfw_busy;
u32 fec_mode;
u32 cur_fec_link;
};
--
2.53.0
