From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/drivers/pci/pci.h |   59 ++++++++++++++++++++++++++++-------------------------------
 1 files changed, 28 insertions(+), 31 deletions(-)

diff --git a/kernel/drivers/pci/pci.h b/kernel/drivers/pci/pci.h
index 4e38fdb..43f5082 100644
--- a/kernel/drivers/pci/pci.h
+++ b/kernel/drivers/pci/pci.h
@@ -48,6 +48,19 @@
 #define PCI_PM_D3HOT_WAIT       10	/* msec */
 #define PCI_PM_D3COLD_WAIT      100	/* msec */
 
+/*
+ * Following exit from Conventional Reset, devices must be ready within 1 sec
+ * (PCIe r6.0 sec 6.6.1).  A D3cold to D0 transition implies a Conventional
+ * Reset (PCIe r6.0 sec 5.8).
+ */
+#define PCI_RESET_WAIT		1000	/* msec */
+/*
+ * Devices may extend the 1 sec period through Request Retry Status completions
+ * (PCIe r6.0 sec 2.3.1).  The spec does not provide an upper limit, but 60 sec
+ * ought to be enough for any device to become responsive.
+ */
+#define PCIE_RESET_READY_POLL_MS 60000	/* msec */
+
 /**
  * struct pci_platform_pm_ops - Firmware PM callbacks
  *
@@ -109,7 +122,8 @@
 void pci_free_cap_save_buffers(struct pci_dev *dev);
 bool pci_bridge_d3_possible(struct pci_dev *dev);
 void pci_bridge_d3_update(struct pci_dev *dev);
-void pci_bridge_wait_for_secondary_bus(struct pci_dev *dev);
+int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type,
+				      int timeout);
 
 static inline void pci_wakeup_event(struct pci_dev *dev)
 {
@@ -357,53 +371,36 @@
  * @dev - pci device to set new error_state
  * @new - the state we want dev to be in
  *
- * Must be called with device_lock held.
+ * If the device is experiencing perm_failure, it has to remain in that state.
+ * Any other transition is allowed.
  *
  * Returns true if state has been changed to the requested state.
  */
 static inline bool pci_dev_set_io_state(struct pci_dev *dev,
 					pci_channel_state_t new)
 {
-	bool changed = false;
+	pci_channel_state_t old;
 
-	device_lock_assert(&dev->dev);
 	switch (new) {
 	case pci_channel_io_perm_failure:
-		switch (dev->error_state) {
-		case pci_channel_io_frozen:
-		case pci_channel_io_normal:
-		case pci_channel_io_perm_failure:
-			changed = true;
-			break;
-		}
-		break;
+		xchg(&dev->error_state, pci_channel_io_perm_failure);
+		return true;
 	case pci_channel_io_frozen:
-		switch (dev->error_state) {
-		case pci_channel_io_frozen:
-		case pci_channel_io_normal:
-			changed = true;
-			break;
-		}
-		break;
+		old = cmpxchg(&dev->error_state, pci_channel_io_normal,
+			      pci_channel_io_frozen);
+		return old != pci_channel_io_perm_failure;
 	case pci_channel_io_normal:
-		switch (dev->error_state) {
-		case pci_channel_io_frozen:
-		case pci_channel_io_normal:
-			changed = true;
-			break;
-		}
-		break;
+		old = cmpxchg(&dev->error_state, pci_channel_io_frozen,
+			      pci_channel_io_normal);
+		return old != pci_channel_io_perm_failure;
+	default:
+		return false;
 	}
-	if (changed)
-		dev->error_state = new;
-	return changed;
 }
 
 static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
 {
-	device_lock(&dev->dev);
 	pci_dev_set_io_state(dev, pci_channel_io_perm_failure);
-	device_unlock(&dev->dev);
 
 	return 0;
 }

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