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>

8 files changed, 75 insertions, 88 deletions

diff --git a/drivers/net/wireless/iwlwifi/dvm/mac80211.c b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
index b55181275fd0..c2f03ecd4bf8 100644
--- a/drivers/net/wireless/iwlwifi/dvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/dvm/mac80211.c
@@ -459,14 +459,12 @@ static int iwlagn_mac_resume(struct ieee80211_hw *hw)
 
         base = priv->device_pointers.error_event_table;
         if (iwlagn_hw_valid_rtc_data_addr(base)) {
-                spin_lock_irqsave(&priv->trans->reg_lock, flags);
-                if (iwl_trans_grab_nic_access(priv->trans, true)) {
+                if (iwl_trans_grab_nic_access(priv->trans, true, &flags)) {
                         iwl_write32(priv->trans, HBUS_TARG_MEM_RADDR, base);
                         status = iwl_read32(priv->trans, HBUS_TARG_MEM_RDAT);
-                        iwl_trans_release_nic_access(priv->trans);
+                        iwl_trans_release_nic_access(priv->trans, &flags);
                         ret = 0;
                 }
-                spin_unlock_irqrestore(&priv->trans->reg_lock, flags);
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
                 if (ret == 0) {
diff --git a/drivers/net/wireless/iwlwifi/dvm/main.c b/drivers/net/wireless/iwlwifi/dvm/main.c
index f5f91644adaa..b9e3517652d6 100644
--- a/drivers/net/wireless/iwlwifi/dvm/main.c
+++ b/drivers/net/wireless/iwlwifi/dvm/main.c
@@ -353,11 +353,8 @@ static void iwl_print_cont_event_trace(struct iwl_priv *priv, u32 base,
                 ptr = base + (4 * sizeof(u32)) + (start_idx * 3 * sizeof(u32));
 
         /* Make sure device is powered up for SRAM reads */
-        spin_lock_irqsave(&priv->trans->reg_lock, reg_flags);
-        if (!iwl_trans_grab_nic_access(priv->trans, false)) {
-                spin_unlock_irqrestore(&priv->trans->reg_lock, reg_flags);
+        if (!iwl_trans_grab_nic_access(priv->trans, false, &reg_flags))
                 return;
-        }
 
         /* Set starting address; reads will auto-increment */
         iwl_write32(priv->trans, HBUS_TARG_MEM_RADDR, ptr);
@@ -388,8 +385,7 @@ static void iwl_print_cont_event_trace(struct iwl_priv *priv, u32 base,
                 }
         }
         /* Allow device to power down */
-        iwl_trans_release_nic_access(priv->trans);
-        spin_unlock_irqrestore(&priv->trans->reg_lock, reg_flags);
+        iwl_trans_release_nic_access(priv->trans, &reg_flags);
 }
 
 static void iwl_continuous_event_trace(struct iwl_priv *priv)
@@ -1717,9 +1713,8 @@ static int iwl_print_event_log(struct iwl_priv *priv, u32 start_idx,
         ptr = base + EVENT_START_OFFSET + (start_idx * event_size);
 
         /* Make sure device is powered up for SRAM reads */
-        spin_lock_irqsave(&trans->reg_lock, reg_flags);
-        if (!iwl_trans_grab_nic_access(trans, false))
-                goto out_unlock;
+        if (!iwl_trans_grab_nic_access(trans, false, &reg_flags))
+                return pos;
 
         /* Set starting address; reads will auto-increment */
         iwl_write32(trans, HBUS_TARG_MEM_RADDR, ptr);
@@ -1757,9 +1752,7 @@ static int iwl_print_event_log(struct iwl_priv *priv, u32 start_idx,
         }
 
         /* Allow device to power down */
-        iwl_trans_release_nic_access(trans);
-out_unlock:
-        spin_unlock_irqrestore(&trans->reg_lock, reg_flags);
+        iwl_trans_release_nic_access(trans, &reg_flags);
         return pos;
 }
 
diff --git a/drivers/net/wireless/iwlwifi/dvm/tt.c b/drivers/net/wireless/iwlwifi/dvm/tt.c
index 617fca3cffe0..67e2e1321b40 100644
--- a/drivers/net/wireless/iwlwifi/dvm/tt.c
+++ b/drivers/net/wireless/iwlwifi/dvm/tt.c
@@ -185,10 +185,8 @@ static void iwl_tt_check_exit_ct_kill(unsigned long data)
                         priv->thermal_throttle.ct_kill_toggle = true;
                 }
                 iwl_read32(priv->trans, CSR_UCODE_DRV_GP1);
-                spin_lock_irqsave(&priv->trans->reg_lock, flags);
-                if (iwl_trans_grab_nic_access(priv->trans, false))
-                        iwl_trans_release_nic_access(priv->trans);
-                spin_unlock_irqrestore(&priv->trans->reg_lock, flags);
+                if (iwl_trans_grab_nic_access(priv->trans, false, &flags))
+                        iwl_trans_release_nic_access(priv->trans, &flags);
 
                 /* Reschedule the ct_kill timer to occur in
                  * CT_KILL_EXIT_DURATION seconds to ensure we get a
diff --git a/drivers/net/wireless/iwlwifi/iwl-io.c b/drivers/net/wireless/iwlwifi/iwl-io.c
index 7ef47389953e..276410d82de4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-io.c
+++ b/drivers/net/wireless/iwlwifi/iwl-io.c
@@ -55,13 +55,10 @@ u32 iwl_read_direct32(struct iwl_trans *trans, u32 reg)
 {
         u32 value = 0x5a5a5a5a;
         unsigned long flags;
-
-        spin_lock_irqsave(&trans->reg_lock, flags);
-        if (iwl_trans_grab_nic_access(trans, false)) {
+        if (iwl_trans_grab_nic_access(trans, false, &flags)) {
                 value = iwl_read32(trans, reg);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 
         return value;
 }
@@ -71,12 +68,10 @@ void iwl_write_direct32(struct iwl_trans *trans, u32 reg, u32 value)
 {
         unsigned long flags;
 
-        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, reg, value);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(iwl_write_direct32);
 
@@ -114,12 +109,10 @@ u32 iwl_read_prph(struct iwl_trans *trans, u32 ofs)
         unsigned long flags;
         u32 val = 0x5a5a5a5a;
 
-        spin_lock_irqsave(&trans->reg_lock, flags);
-        if (iwl_trans_grab_nic_access(trans, false)) {
+        if (iwl_trans_grab_nic_access(trans, false, &flags)) {
                 val = __iwl_read_prph(trans, ofs);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
         return val;
 }
 EXPORT_SYMBOL_GPL(iwl_read_prph);
@@ -128,12 +121,10 @@ void iwl_write_prph(struct iwl_trans *trans, u32 ofs, u32 val)
 {
         unsigned long flags;
 
-        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_write_prph(trans, ofs, val);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(iwl_write_prph);
 
@@ -141,13 +132,11 @@ void iwl_set_bits_prph(struct iwl_trans *trans, u32 ofs, u32 mask)
 {
         unsigned long flags;
 
-        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_write_prph(trans, ofs,
                                  __iwl_read_prph(trans, ofs) | mask);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(iwl_set_bits_prph);
 
@@ -156,13 +145,11 @@ void iwl_set_bits_mask_prph(struct iwl_trans *trans, u32 ofs,
 {
         unsigned long flags;
 
-        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_write_prph(trans, ofs,
                                  (__iwl_read_prph(trans, ofs) & mask) | bits);
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(iwl_set_bits_mask_prph);
 
@@ -171,12 +158,10 @@ void iwl_clear_bits_prph(struct iwl_trans *trans, u32 ofs, u32 mask)
         unsigned long flags;
         u32 val;
 
-        spin_lock_irqsave(&trans->reg_lock, flags);
-        if (iwl_trans_grab_nic_access(trans, false)) {
+        if (iwl_trans_grab_nic_access(trans, false, &flags)) {
                 val = __iwl_read_prph(trans, ofs);
                 __iwl_write_prph(trans, ofs, (val & ~mask));
-                iwl_trans_release_nic_access(trans);
+                iwl_trans_release_nic_access(trans, &flags);
         }
-        spin_unlock_irqrestore(&trans->reg_lock, flags);
 }
 EXPORT_SYMBOL_GPL(iwl_clear_bits_prph);
diff --git a/drivers/net/wireless/iwlwifi/iwl-test.c b/drivers/net/wireless/iwlwifi/iwl-test.c
index d06fc55067df..ce0c67b425ee 100644
--- a/drivers/net/wireless/iwlwifi/iwl-test.c
+++ b/drivers/net/wireless/iwlwifi/iwl-test.c
@@ -466,9 +466,7 @@ static int iwl_test_indirect_read(struct iwl_test *tst, u32 addr, u32 size)
         /* Hard-coded periphery absolute address */
         if (IWL_ABS_PRPH_START <= addr &&
             addr < IWL_ABS_PRPH_START + PRPH_END) {
-                        spin_lock_irqsave(&trans->reg_lock, flags);
-                        if (!iwl_trans_grab_nic_access(trans, false)) {
-                                spin_unlock_irqrestore(&trans->reg_lock, flags);
+                        if (!iwl_trans_grab_nic_access(trans, false, &flags)) {
                                 return -EIO;
                         }
                         iwl_write32(trans, HBUS_TARG_PRPH_RADDR,
@@ -476,8 +474,7 @@ static int iwl_test_indirect_read(struct iwl_test *tst, u32 addr, u32 size)
                         for (i = 0; i < size; i += 4)
                                 *(u32 *)(tst->mem.addr + i) =
                                         iwl_read32(trans, HBUS_TARG_PRPH_RDAT);
-                        iwl_trans_release_nic_access(trans);
-                        spin_unlock_irqrestore(&trans->reg_lock, flags);
+                        iwl_trans_release_nic_access(trans, &flags);
         } else { /* target memory (SRAM) */
                 iwl_trans_read_mem(trans, addr, tst->mem.addr,
                                    tst->mem.size / 4);
@@ -506,19 +503,13 @@ static int iwl_test_indirect_write(struct iwl_test *tst, u32 addr,
                 /* Periphery writes can be 1-3 bytes long, or DWORDs */
                 if (size < 4) {
                         memcpy(&val, buf, size);
-                        spin_lock_irqsave(&trans->reg_lock, flags);
-                        if (!iwl_trans_grab_nic_access(trans, false)) {
-                                spin_unlock_irqrestore(&trans->reg_lock, flags);
+                        if (!iwl_trans_grab_nic_access(trans, false, &flags))
                                         return -EIO;
-                        }
                         iwl_write32(trans, HBUS_TARG_PRPH_WADDR,
                                     (addr & 0x0000FFFF) |
                                     ((size - 1) << 24));
                         iwl_write32(trans, HBUS_TARG_PRPH_WDAT, val);
-                        iwl_trans_release_nic_access(trans);
-                        /* needed after consecutive writes w/o read */
-                        mmiowb();
-                        spin_unlock_irqrestore(&trans->reg_lock, flags);
+                        iwl_trans_release_nic_access(trans, &flags);
                 } else {
                         if (size % 4)
                                 return -EINVAL;
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index c2b7e856a726..0a3d4df5f434 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -416,8 +416,11 @@ struct iwl_trans;
  *      the op_mode. May be called several times before start_fw, can't be
  *      called after that.
  * @set_pmi: set the power pmi state
- * @grab_nic_access: wake the NIC to be able to access non-HBUS regs
- * @release_nic_access: let the NIC go to sleep
+ * @grab_nic_access: wake the NIC to be able to access non-HBUS regs.
+ *      Sleeping is not allowed between grab_nic_access and
+ *      release_nic_access.
+ * @release_nic_access: let the NIC go to sleep. The "flags" parameter
+ *      must be the same one that was sent before to the grab_nic_access.
  * @set_bits_mask - set SRAM register according to value and mask.
  */
 struct iwl_trans_ops {
@@ -461,8 +464,10 @@ struct iwl_trans_ops {
         void (*configure)(struct iwl_trans *trans,
                           const struct iwl_trans_config *trans_cfg);
         void (*set_pmi)(struct iwl_trans *trans, bool state);
-        bool (*grab_nic_access)(struct iwl_trans *trans, bool silent);
-        void (*release_nic_access)(struct iwl_trans *trans);
+        bool (*grab_nic_access)(struct iwl_trans *trans, bool silent,
+                                unsigned long *flags);
+        void (*release_nic_access)(struct iwl_trans *trans,
+                                   unsigned long *flags);
         void (*set_bits_mask)(struct iwl_trans *trans, u32 reg, u32 mask,
                               u32 value);
 };
@@ -484,7 +489,6 @@ enum iwl_trans_state {
  * @ops - pointer to iwl_trans_ops
  * @op_mode - pointer to the op_mode
  * @cfg - pointer to the configuration
- * @reg_lock - protect hw register access
  * @dev - pointer to struct device * that represents the device
  * @hw_id: a u32 with the ID of the device / subdevice.
  *      Set during transport allocation.
@@ -505,7 +509,6 @@ struct iwl_trans {
         struct iwl_op_mode *op_mode;
         const struct iwl_cfg *cfg;
         enum iwl_trans_state state;
-        spinlock_t reg_lock;
 
         struct device *dev;
         u32 hw_rev;
@@ -771,14 +774,14 @@ iwl_trans_set_bits_mask(struct iwl_trans *trans, u32 reg, u32 mask, u32 value)
         trans->ops->set_bits_mask(trans, reg, mask, value);
 }
 
-#define iwl_trans_grab_nic_access(trans, silent)        \
+#define iwl_trans_grab_nic_access(trans, silent, flags) \
         __cond_lock(nic_access,                         \
-                    likely((trans)->ops->grab_nic_access(trans, silent)))
+                    likely((trans)->ops->grab_nic_access(trans, silent, flags)))
 
 static inline void __releases(nic_access)
-iwl_trans_release_nic_access(struct iwl_trans *trans)
+iwl_trans_release_nic_access(struct iwl_trans *trans, unsigned long *flags)
 {
-        trans->ops->release_nic_access(trans);
+        trans->ops->release_nic_access(trans, flags);
         __release(nic_access);
 }
 
diff --git a/drivers/net/wireless/iwlwifi/pcie/internal.h b/drivers/net/wireless/iwlwifi/pcie/internal.h
index 21395fae03c0..5f6bb4e09d42 100644
--- a/drivers/net/wireless/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/iwlwifi/pcie/internal.h
@@ -235,6 +235,7 @@ struct iwl_txq {
  * @bc_table_dword: true if the BC table expects DWORD (as opposed to bytes)
  * @rx_page_order: page order for receive buffer size
  * @wd_timeout: queue watchdog timeout (jiffies)
+ * @reg_lock: protect hw register access
  */
 struct iwl_trans_pcie {
         struct iwl_rxq rxq;
@@ -283,6 +284,9 @@ struct iwl_trans_pcie {
 
         /* queue watchdog */
         unsigned long wd_timeout;
+
+        /*protect hw register */
+        spinlock_t reg_lock;
 };
 
 /**
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));