iwlwifi: pcie: don't disable interrupts for reg_lock

[ 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>

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 1a22246..bb990be 100644 (file)
--- 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 baa83a0..8c71382 100644 (file)
--- 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 ed54d04..50133c0 100644 (file)
--- 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: