thunderbolt: Reduce footprint with CONFIG_PM=n

Add #ifdefs to reduce the Thunderbolt driver's footprint if CONFIG_PM is
disabled.  I've chosen to also exclude dev_pm_ops structs on such
configs as this can be achieved without increasing the LoC count by
using a ternary operator.

I've left some code untouched which is only relevant with CONFIG_PM=y
(e.g. initilization and cancelling of the rescan_work in icm.c) to avoid
negatively impacting readability.  I've also left pointers in structs
which are only relevant with CONFIG_PM=y for the same reason (e.g. the
PM function pointers in struct tb_cm_ops)

A desired side effect is that the driver's dev_pm_ops callbacks may now
access members of struct dev_pm_info which are only available with
CONFIG_PM=y.

Size of thunderbolt.ko on x86_64 with CONFIG_PM=n:
252832 bytes before, 240912 bytes after

Signed-off-by: Lukas Wunner <lukas@wunner.de>

drivers/thunderbolt/domain.c

@@ -515,6 +515,7 @@ int tb_domain_suspend_noirq(struct tb *tb)
 	return ret;
 }
 
+#ifdef CONFIG_PM
 /**
  * tb_domain_resume_noirq() - Resume a domain
  * @tb: Domain to resume
@@ -567,6 +568,7 @@ int tb_domain_runtime_resume(struct tb *tb)
 	}
 	return 0;
 }
+#endif /* CONFIG_PM */
 
 /**
  * tb_domain_approve_switch() - Approve switch

drivers/thunderbolt/icm.c

@@ -297,10 +297,14 @@ static int icm_fr_get_route(struct tb *tb, u8 link, u8 depth, u64 *route)
 	return ret;
 }
 
+#ifdef CONFIG_PM
 static void icm_fr_save_devices(struct tb *tb)
 {
 	nhi_mailbox_cmd(tb->nhi, NHI_MAILBOX_SAVE_DEVS, 0);
 }
+#else
+#define icm_fr_save_devices NULL
+#endif /* CONFIG_PM */
 
 static int
 icm_fr_driver_ready(struct tb *tb, enum tb_security_level *security_level,
@@ -1691,6 +1695,7 @@ static int icm_driver_ready(struct tb *tb)
 	return 0;
 }
 
+#ifdef CONFIG_PM
 static int icm_suspend(struct tb *tb)
 {
 	struct icm *icm = tb_priv(tb);
@@ -1808,6 +1813,13 @@ static int icm_runtime_resume(struct tb *tb)
 	icm_complete(tb);
 	return 0;
 }
+#else
+#define icm_suspend NULL
+#define icm_rescan_work NULL
+#define icm_complete NULL
+#define icm_runtime_suspend NULL
+#define icm_runtime_resume NULL
+#endif /* CONFIG_PM */
 
 static int icm_start(struct tb *tb)
 {

drivers/thunderbolt/nhi.c

@@ -845,14 +845,6 @@ static irqreturn_t nhi_msi(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static int nhi_suspend_noirq(struct device *dev)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct tb *tb = pci_get_drvdata(pdev);
-
-	return tb_domain_suspend_noirq(tb);
-}
-
 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
 {
 	/* Throttling is specified in 256ns increments */
@@ -869,6 +861,15 @@ static void nhi_enable_int_throttling(struct tb_nhi *nhi)
 	}
 }
 
+#ifdef CONFIG_PM
+static int nhi_suspend_noirq(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct tb *tb = pci_get_drvdata(pdev);
+
+	return tb_domain_suspend_noirq(tb);
+}
+
 static int nhi_resume_noirq(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -927,6 +928,7 @@ static int nhi_runtime_resume(struct device *dev)
 	nhi_enable_int_throttling(tb->nhi);
 	return tb_domain_runtime_resume(tb);
 }
+#endif /* CONFIG_PM */
 
 static void nhi_shutdown(struct tb_nhi *nhi)
 {
@@ -1095,6 +1097,7 @@ static void nhi_remove(struct pci_dev *pdev)
 	nhi_shutdown(nhi);
 }
 
+#ifdef CONFIG_PM
 /*
  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
  * the tunnels asap. Device links block the downstream bridges' resume_noirq
@@ -1116,6 +1119,10 @@ static const struct dev_pm_ops nhi_pm_ops = {
 	.runtime_suspend = nhi_runtime_suspend,
 	.runtime_resume = nhi_runtime_resume,
 };
+#define NHI_PM_OPS &nhi_pm_ops
+#else
+#define NHI_PM_OPS NULL
+#endif /* CONFIG_PM */
 
 static struct pci_device_id nhi_ids[] = {
 	/*
@@ -1170,7 +1177,7 @@ static struct pci_driver nhi_driver = {
 	.id_table = nhi_ids,
 	.probe = nhi_probe,
 	.remove = nhi_remove,
-	.driver.pm = &nhi_pm_ops,
+	.driver.pm = NHI_PM_OPS,
 };
 
 static int __init nhi_init(void)

drivers/thunderbolt/switch.c

@@ -632,6 +632,7 @@ static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
 	       sw->__unknown1, sw->__unknown4);
 }
 
+#ifdef CONFIG_PM
 /**
  * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
  *
@@ -655,6 +656,7 @@ int tb_switch_reset(struct tb *tb, u64 route)
 		return -EIO;
 	return res.err;
 }
+#endif /* CONFIG_PM */
 
 struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
 {
@@ -1087,16 +1089,17 @@ static void tb_switch_release(struct device *dev)
 	kfree(sw);
 }
 
+#ifdef CONFIG_PM
 /*
  * Currently only need to provide the callbacks. Everything else is handled
  * in the connection manager.
  */
-static int __maybe_unused tb_switch_runtime_suspend(struct device *dev)
+static int tb_switch_runtime_suspend(struct device *dev)
 {
 	return 0;
 }
 
-static int __maybe_unused tb_switch_runtime_resume(struct device *dev)
+static int tb_switch_runtime_resume(struct device *dev)
 {
 	return 0;
 }
@@ -1105,11 +1108,15 @@ static const struct dev_pm_ops tb_switch_pm_ops = {
 	SET_RUNTIME_PM_OPS(tb_switch_runtime_suspend, tb_switch_runtime_resume,
 			   NULL)
 };
+#define TB_SWITCH_PM_OPS &tb_switch_pm_ops
+#else
+#define TB_SWITCH_PM_OPS NULL
+#endif /* CONFIG_PM */
 
 struct device_type tb_switch_type = {
 	.name = "thunderbolt_device",
 	.release = tb_switch_release,
-	.pm = &tb_switch_pm_ops,
+	.pm = TB_SWITCH_PM_OPS,
 };
 
 static int tb_switch_get_generation(struct tb_switch *sw)
@@ -1537,6 +1544,7 @@ void tb_sw_set_unplugged(struct tb_switch *sw)
 	}
 }
 
+#ifdef CONFIG_PM
 int tb_switch_resume(struct tb_switch *sw)
 {
 	int i, err;
@@ -1604,6 +1612,7 @@ void tb_switch_suspend(struct tb_switch *sw)
 	 * effect?
 	 */
 }
+#endif /* CONFIG_PM */
 
 struct tb_sw_lookup {
 	struct tb *tb;

drivers/thunderbolt/tb.c

@@ -93,6 +93,7 @@ static void tb_free_invalid_tunnels(struct tb *tb)
 	}
 }
 
+#ifdef CONFIG_PM
 /**
  * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
  */
@@ -113,7 +114,7 @@ static void tb_free_unplugged_children(struct tb_switch *sw)
 		}
 	}
 }
-
+#endif /* CONFIG_PM */
 
 /**
  * find_pci_up_port() - return the first PCIe up port on @sw or NULL
@@ -426,6 +427,7 @@ static int tb_start(struct tb *tb)
 	return 0;
 }
 
+#ifdef CONFIG_PM
 static int tb_suspend_noirq(struct tb *tb)
 {
 	struct tb_cm *tcm = tb_priv(tb);
@@ -467,6 +469,10 @@ static int tb_resume_noirq(struct tb *tb)
 
 	return 0;
 }
+#else
+#define tb_suspend_noirq NULL
+#define tb_resume_noirq NULL
+#endif /* CONFIG_PM */
 
 static const struct tb_cm_ops tb_cm_ops = {
 	.start = tb_start,

drivers/thunderbolt/xdomain.c

@@ -1051,13 +1051,14 @@ static void stop_handshake(struct tb_xdomain *xd)
 	cancel_delayed_work_sync(&xd->properties_changed_work);
 }
 
-static int __maybe_unused tb_xdomain_suspend(struct device *dev)
+#ifdef CONFIG_PM
+static int tb_xdomain_suspend(struct device *dev)
 {
 	stop_handshake(tb_to_xdomain(dev));
 	return 0;
 }
 
-static int __maybe_unused tb_xdomain_resume(struct device *dev)
+static int tb_xdomain_resume(struct device *dev)
 {
 	struct tb_xdomain *xd = tb_to_xdomain(dev);
 
@@ -1074,11 +1075,15 @@ static int __maybe_unused tb_xdomain_resume(struct device *dev)
 static const struct dev_pm_ops tb_xdomain_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(tb_xdomain_suspend, tb_xdomain_resume)
 };
+#define TB_XDOMAIN_PM_OPS &tb_xdomain_pm_ops
+#else
+#define TB_XDOMAIN_PM_OPS NULL
+#endif /* CONFIG_PM */
 
 struct device_type tb_xdomain_type = {
 	.name = "thunderbolt_xdomain",
 	.release = tb_xdomain_release,
-	.pm = &tb_xdomain_pm_ops,
+	.pm = TB_XDOMAIN_PM_OPS,
 };
 EXPORT_SYMBOL_GPL(tb_xdomain_type);