[PATCH v2 2/7] thunderbolt: Move ICM mailbox functions to icm.c and internalize interrupt work

[Chunfeng Yun <chunfeng.yun@mediatek.com>]

In preparation for modularizing PCIe NHI and ICM support as a separate
driver, clean up internal helper functions so that they do not need to
be exported:

nhi_mailbox_cmd() and nhi_mailbox_mode() are only used by the Intel
firmware Connection Manager (icm.c) to exchange mailbox commands with
firmware running on Intel PCIe NHIs. The Thunderbolt core framework,
software connection manager, and non-PCIe platform controllers do
not use this mailbox interface. Move both functions into icm.c and
mark them static.

nhi_interrupt_work was previously initialized in pci.c within
nhi_pci_init_msi(), requiring it to be visible across files. Move
INIT_WORK(&nhi->interrupt_work, ...) into tb_nhi_probe() so that
the workqueue item is initialized by the NHI core and
nhi_interrupt_work() can be marked static in nhi.c.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
new patch
---
 drivers/thunderbolt/icm.c | 59 ++++++++++++++++++++++++++++++++++++
 drivers/thunderbolt/nhi.c | 64 ++-------------------------------------
 drivers/thunderbolt/nhi.h |  3 --
 drivers/thunderbolt/pci.c |  2 --
 4 files changed, 62 insertions(+), 66 deletions(-)

diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index a295a5e6cc9c..736f551cd567 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -45,6 +45,7 @@
 #define ICM_RETRIES			3
 #define ICM_APPROVE_TIMEOUT		10000	/* ms */
 #define ICM_MAX_LINK			4
+#define ICM_MAILBOX_TIMEOUT		500 /* ms */
 
 static bool start_icm;
 module_param(start_icm, bool, 0444);
@@ -269,6 +270,64 @@ static int pcie2cio_write(struct icm *icm, enum tb_cfg_space cs,
 	return pci2cio_wait_completion(icm, 5000);
 }
 
+/**
+ * nhi_mailbox_cmd() - Send a command through NHI mailbox
+ * @nhi: Pointer to the NHI structure
+ * @cmd: Command to send
+ * @data: Data to be send with the command
+ *
+ * Sends mailbox command to the firmware running on NHI.
+ *
+ * Return: %0 on success, negative errno otherwise.
+ */
+static int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
+{
+	ktime_t timeout;
+	u32 val;
+
+	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
+
+	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
+	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
+	val |= REG_INMAIL_OP_REQUEST | cmd;
+	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
+
+	timeout = ktime_add_ms(ktime_get(), ICM_MAILBOX_TIMEOUT);
+	do {
+		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
+		if (!(val & REG_INMAIL_OP_REQUEST))
+			break;
+		usleep_range(10, 20);
+	} while (ktime_before(ktime_get(), timeout));
+
+	if (val & REG_INMAIL_OP_REQUEST)
+		return -ETIMEDOUT;
+	if (val & REG_INMAIL_ERROR)
+		return -EIO;
+
+	return 0;
+}
+
+/**
+ * nhi_mailbox_mode() - Return current firmware operation mode
+ * @nhi: Pointer to the NHI structure
+ *
+ * The function reads current firmware operation mode using NHI mailbox
+ * registers and returns it to the caller.
+ *
+ * Return: &enum nhi_fw_mode.
+ */
+static enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
+{
+	u32 val;
+
+	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
+	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
+	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
+
+	return (enum nhi_fw_mode)val;
+}
+
 static bool icm_match(const struct tb_cfg_request *req,
 		      const struct ctl_pkg *pkg)
 {
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index c574c336f25b..1e3a58636d3d 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -35,8 +35,6 @@
  */
 #define RING_E2E_RESERVED_HOPID	RING_FIRST_USABLE_HOPID
 
-#define NHI_MAILBOX_TIMEOUT	500 /* ms */
-
 static bool host_reset = true;
 module_param(host_reset, bool, 0444);
 MODULE_PARM_DESC(host_reset, "reset USB4 host router (default: true)");
@@ -964,65 +962,7 @@ int tb_ring_throttling(struct tb_ring *ring, unsigned int interval_nsec)
 }
 EXPORT_SYMBOL_GPL(tb_ring_throttling);
 
-/**
- * nhi_mailbox_cmd() - Send a command through NHI mailbox
- * @nhi: Pointer to the NHI structure
- * @cmd: Command to send
- * @data: Data to be send with the command
- *
- * Sends mailbox command to the firmware running on NHI.
- *
- * Return: %0 on success, negative errno otherwise.
- */
-int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
-{
-	ktime_t timeout;
-	u32 val;
-
-	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
-
-	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
-	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
-	val |= REG_INMAIL_OP_REQUEST | cmd;
-	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
-
-	timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
-	do {
-		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
-		if (!(val & REG_INMAIL_OP_REQUEST))
-			break;
-		usleep_range(10, 20);
-	} while (ktime_before(ktime_get(), timeout));
-
-	if (val & REG_INMAIL_OP_REQUEST)
-		return -ETIMEDOUT;
-	if (val & REG_INMAIL_ERROR)
-		return -EIO;
-
-	return 0;
-}
-
-/**
- * nhi_mailbox_mode() - Return current firmware operation mode
- * @nhi: Pointer to the NHI structure
- *
- * The function reads current firmware operation mode using NHI mailbox
- * registers and returns it to the caller.
- *
- * Return: &enum nhi_fw_mode.
- */
-enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
-{
-	u32 val;
-
-	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
-	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
-	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
-
-	return (enum nhi_fw_mode)val;
-}
-
-void nhi_interrupt_work(struct work_struct *work)
+static void nhi_interrupt_work(struct work_struct *work)
 {
 	struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
 	int value = 0; /* Suppress uninitialized usage warning. */
@@ -1331,6 +1271,8 @@ int tb_nhi_probe(struct tb_nhi *nhi)
 	if (!nhi->tx_rings || !nhi->rx_rings || !nhi->interrupt_mask)
 		return -ENOMEM;
 
+    INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
+
 	nhi_reset(nhi);
 
 	/* In case someone left them on. */
diff --git a/drivers/thunderbolt/nhi.h b/drivers/thunderbolt/nhi.h
index a36c62c49a5c..3dd6ace6150d 100644
--- a/drivers/thunderbolt/nhi.h
+++ b/drivers/thunderbolt/nhi.h
@@ -27,11 +27,8 @@ enum nhi_mailbox_cmd {
 	NHI_MAILBOX_ALLOW_ALL_DEVS = 0x23,
 };
 
-int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data);
-enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi);
 void nhi_enable_int_throttling(struct tb_nhi *nhi);
 void nhi_disable_interrupts(struct tb_nhi *nhi);
-void nhi_interrupt_work(struct work_struct *work);
 irqreturn_t tb_nhi_isr(int irq, void *data);
 irqreturn_t tb_ring_msix(int irq, void *data);
 int tb_nhi_probe(struct tb_nhi *nhi);
diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index 2f0abf4d27a3..275389903090 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -206,8 +206,6 @@ static int nhi_pci_init_msi(struct tb_nhi *nhi)
 		if (nvec < 0)
 			return nvec;
 
-		INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
-
 		irq = pci_irq_vector(pdev, 0);
 		if (irq < 0)
 			return irq;
-- 
2.45.2