[PATCH 5.10 046/126] iwlwifi: pcie: dont disable interrupts for reg_lock

Greg Kroah-Hartman
2021-04-05T09:10:02Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 874020f8adce535cd318af1768ffe744251b6593 ]

The only thing we do touching the device in hard interrupt context
is, at most, writing an interrupt ACK register, which isn't racing
in with anything protected by the reg_lock.

Thus, avoid disabling interrupts here for potentially long periods
of time, particularly long periods have been observed with dumping
of firmware memory (leading to lockup warnings on some devices.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210210135352.da916ab91298.I064c3e7823b616647293ed97da98edefb9ce9435@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/intel/iwlwifi/pcie/trans.c | 11 +++++-----
.../net/wireless/intel/iwlwifi/pcie/tx-gen2.c | 5 ++---
drivers/net/wireless/intel/iwlwifi/pcie/tx.c | 22 ++++++++-----------
3 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 1a222469b5b4..bb990be7c870 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -2026,7 +2026,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
int ret;
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

- spin_lock_irqsave(&trans_pcie->reg_lock, *flags);
+ spin_lock_bh(&trans_pcie->reg_lock);

if (trans_pcie->cmd_hold_nic_awake)
goto out;
@@ -2111,7 +2111,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans,
}

err:
- spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
+ spin_unlock_bh(&trans_pcie->reg_lock);
return false;
}

@@ -2149,7 +2149,7 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
* scheduled on different CPUs (after we drop reg_lock).
*/
out:
- spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
+ spin_unlock_bh(&trans_pcie->reg_lock);
}

static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr,
@@ -2403,11 +2403,10 @@ static void iwl_trans_pcie_set_bits_mask(struct iwl_trans *trans, u32 reg,
u32 mask, u32 value)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
- unsigned long flags;

- spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+ spin_lock_bh(&trans_pcie->reg_lock);
__iwl_trans_pcie_set_bits_mask(trans, reg, mask, value);
- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+ spin_unlock_bh(&trans_pcie->reg_lock);
}

static const char *get_csr_string(int cmd)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
index baa83a0b8593..8c7138247869 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -78,7 +78,6 @@ static int iwl_pcie_gen2_enqueue_hcmd(struct iwl_trans *trans,
struct iwl_txq *txq = trans->txqs.txq[trans->txqs.cmd.q_id];
struct iwl_device_cmd *out_cmd;
struct iwl_cmd_meta *out_meta;
- unsigned long flags;
void *dup_buf = NULL;
dma_addr_t phys_addr;
int i, cmd_pos, idx;
@@ -291,11 +290,11 @@ static int iwl_pcie_gen2_enqueue_hcmd(struct iwl_trans *trans,
if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)
mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);

- spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+ spin_lock(&trans_pcie->reg_lock);
/* Increment and update queue's write index */
txq->write_ptr = iwl_txq_inc_wrap(trans, txq->write_ptr);
iwl_txq_inc_wr_ptr(trans, txq);
- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+ spin_unlock(&trans_pcie->reg_lock);

out:
spin_unlock_bh(&txq->lock);
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
index ed54d04e4396..50133c09a780 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -321,12 +321,10 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id)
txq->read_ptr = iwl_txq_inc_wrap(trans, txq->read_ptr);

if (txq->read_ptr == txq->write_ptr) {
- unsigned long flags;
-
- spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+ spin_lock(&trans_pcie->reg_lock);
if (txq_id == trans->txqs.cmd.q_id)
iwl_pcie_clear_cmd_in_flight(trans);
- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+ spin_unlock(&trans_pcie->reg_lock);
}
}

@@ -931,7 +929,6 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
struct iwl_txq *txq = trans->txqs.txq[txq_id];
- unsigned long flags;
int nfreed = 0;
u16 r;

@@ -962,9 +959,10 @@ static void iwl_pcie_cmdq_reclaim(struct iwl_trans *trans, int txq_id, int idx)
}

if (txq->read_ptr == txq->write_ptr) {
- spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+ /* BHs are also disabled due to txq->lock */
+ spin_lock(&trans_pcie->reg_lock);
iwl_pcie_clear_cmd_in_flight(trans);
- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
+ spin_unlock(&trans_pcie->reg_lock);
}

iwl_pcie_txq_progress(txq);
@@ -1173,7 +1171,6 @@ static int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
struct iwl_txq *txq = trans->txqs.txq[trans->txqs.cmd.q_id];
struct iwl_device_cmd *out_cmd;
struct iwl_cmd_meta *out_meta;
- unsigned long flags;
void *dup_buf = NULL;
dma_addr_t phys_addr;
int idx;
@@ -1416,20 +1413,19 @@ static int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
if (txq->read_ptr == txq->write_ptr && txq->wd_timeout)
mod_timer(&txq->stuck_timer, jiffies + txq->wd_timeout);

- spin_lock_irqsave(&trans_pcie->reg_lock, flags);
+ spin_lock(&trans_pcie->reg_lock);
ret = iwl_pcie_set_cmd_in_flight(trans, cmd);
if (ret < 0) {
idx = ret;
- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
- goto out;
+ goto unlock_reg;
}

/* Increment and update queue's write index */
txq->write_ptr = iwl_txq_inc_wrap(trans, txq->write_ptr);
iwl_pcie_txq_inc_wr_ptr(trans, txq);

- spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
-
+ unlock_reg:
+ spin_unlock(&trans_pcie->reg_lock);
out:
spin_unlock_bh(&txq->lock);
free_dup_buf:
--
2.30.1