iwlwifi: move register access lock into transport

Move the reg_lock that protects HW register access
into the transport implementation. Locking is no
longer exposed, but handled internally in grab and
release NIC access. This simplifies the users.

Signed-off-by: Lilach Edelstein <lilach.edelstein@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 31 insertions, 16 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 8692494c1c48..56d4f72500bc 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -806,11 +806,12 @@ static int iwl_trans_pcie_resume(struct iwl_trans *trans)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, bool silent)
+static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, bool silent,
+						unsigned long *flags)
 {
 	int ret;
-
-	lockdep_assert_held(&trans->reg_lock);
+	struct iwl_trans_pcie *pcie_trans = IWL_TRANS_GET_PCIE_TRANS(trans);
+	spin_lock_irqsave(&pcie_trans->reg_lock, *flags);
 
 	/* this bit wakes up the NIC */
 	__iwl_trans_pcie_set_bit(trans, CSR_GP_CNTRL,
@@ -846,16 +847,32 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, bool silent)
 			WARN_ONCE(1,
 				  "Timeout waiting for hardware access (CSR_GP_CNTRL 0x%08x)\n",
 				  val);
+			spin_unlock_irqrestore(&pcie_trans->reg_lock, *flags);
 			return false;
 		}
 	}
 
+	/*
+	 * Fool sparse by faking we release the lock - sparse will
+	 * track nic_access anyway.
+	 */
+	__release(&pcie_trans->reg_lock);
 	return true;
 }
 
-static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans)
+static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
+					      unsigned long *flags)
 {
-	lockdep_assert_held(&trans->reg_lock);
+	struct iwl_trans_pcie *pcie_trans = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	lockdep_assert_held(&pcie_trans->reg_lock);
+
+	/*
+	 * Fool sparse by faking we acquiring the lock - sparse will
+	 * track nic_access anyway.
+	 */
+	__acquire(&pcie_trans->reg_lock);
+
 	__iwl_trans_pcie_clear_bit(trans, CSR_GP_CNTRL,
 				   CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
 	/*
@@ -865,6 +882,7 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans)
 	 * scheduled on different CPUs (after we drop reg_lock).
 	 */
 	mmiowb();
+	spin_unlock_irqrestore(&pcie_trans->reg_lock, *flags);
 }
 
 static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr,
@@ -874,16 +892,14 @@ static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr,
 	int offs, ret = 0;
 	u32 *vals = buf;
 
-	spin_lock_irqsave(&trans->reg_lock, flags);
-	if (iwl_trans_grab_nic_access(trans, false)) {
+	if (iwl_trans_grab_nic_access(trans, false, &flags)) {
 		iwl_write32(trans, HBUS_TARG_MEM_RADDR, addr);
 		for (offs = 0; offs < dwords; offs++)
 			vals[offs] = iwl_read32(trans, HBUS_TARG_MEM_RDAT);
-		iwl_trans_release_nic_access(trans);
+		iwl_trans_release_nic_access(trans, &flags);
 	} else {
 		ret = -EBUSY;
 	}
-	spin_unlock_irqrestore(&trans->reg_lock, flags);
 	return ret;
 }
 
@@ -894,17 +910,15 @@ static int iwl_trans_pcie_write_mem(struct iwl_trans *trans, u32 addr,
 	int offs, ret = 0;
 	u32 *vals = buf;
 
-	spin_lock_irqsave(&trans->reg_lock, flags);
-	if (iwl_trans_grab_nic_access(trans, false)) {
+	if (iwl_trans_grab_nic_access(trans, false, &flags)) {
 		iwl_write32(trans, HBUS_TARG_MEM_WADDR, addr);
 		for (offs = 0; offs < dwords; offs++)
 			iwl_write32(trans, HBUS_TARG_MEM_WDAT,
 				    vals ? vals[offs] : 0);
-		iwl_trans_release_nic_access(trans);
+		iwl_trans_release_nic_access(trans, &flags);
 	} else {
 		ret = -EBUSY;
 	}
-	spin_unlock_irqrestore(&trans->reg_lock, flags);
 	return ret;
 }
 
@@ -982,11 +996,12 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans)
 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->reg_lock, flags);
+	spin_lock_irqsave(&trans_pcie->reg_lock, flags);
 	__iwl_trans_pcie_set_bits_mask(trans, reg, mask, value);
-	spin_unlock_irqrestore(&trans->reg_lock, flags);
+	spin_unlock_irqrestore(&trans_pcie->reg_lock, flags);
 }
 
 static const char *get_fh_string(int cmd)
@@ -1467,6 +1482,7 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 	trans->cfg = cfg;
 	trans_pcie->trans = trans;
 	spin_lock_init(&trans_pcie->irq_lock);
+	spin_lock_init(&trans_pcie->reg_lock);
 	init_waitqueue_head(&trans_pcie->ucode_write_waitq);
 
 	/* W/A - seems to solve weird behavior. We need to remove this if we
@@ -1533,7 +1549,6 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 
 	/* Initialize the wait queue for commands */
 	init_waitqueue_head(&trans_pcie->wait_command_queue);
-	spin_lock_init(&trans->reg_lock);
 
 	snprintf(trans->dev_cmd_pool_name, sizeof(trans->dev_cmd_pool_name),
 		 "iwl_cmd_pool:%s", dev_name(trans->dev));