From c1207dc20cfb10830a48d20d77f7a913d7a96029 Mon Sep 17 00:00:00 2001
From: jhb <jhb@FreeBSD.org>
Date: Thu, 27 Jun 2013 20:21:54 +0000
Subject: Make detaching drivers from PCI devices more robust.  While here, fix
 a bug where a PCI device would be powered down if it failed to probe, but not
 when its driver was detached (e.g. via kldunload). - Add a new helper method
 resource_list_release_active() which forcefully   releases any active
 resources of a specified type from a resource list. - Add a
 bus_child_detached method for the PCI bus driver which forces any   active
 resources to be released (and whines to the console if it finds   any) and
 then powers the device down. - Call pci_child_detached() if we fail to probe
 a device when a driver   is kldloaded.  This isn't perfect but can avoid
 leaking resources   from a probe() routine in the kldload case.

Reviewed by:	imp, brooks
MFC after:	1 month
---
 sys/kern/subr_bus.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

(limited to 'sys/kern/subr_bus.c')

diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 1d45f28..f196c8b 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -3316,6 +3316,48 @@ resource_list_release(struct resource_list *rl, device_t bus, device_t child,
 }
 
 /**
+ * @brief Release all active resources of a given type
+ *
+ * Release all active resources of a specified type.  This is intended
+ * to be used to cleanup resources leaked by a driver after detach or
+ * a failed attach.
+ *
+ * @param rl		the resource list which was allocated from
+ * @param bus		the parent device of @p child
+ * @param child		the device whose active resources are being released
+ * @param type		the type of resources to release
+ * 
+ * @retval 0		success
+ * @retval EBUSY	at least one resource was active
+ */
+int
+resource_list_release_active(struct resource_list *rl, device_t bus,
+    device_t child, int type)
+{
+	struct resource_list_entry *rle;
+	int error, retval;
+
+	retval = 0;
+	STAILQ_FOREACH(rle, rl, link) {
+		if (rle->type != type)
+			continue;
+		if (rle->res == NULL)
+			continue;
+		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
+		    RLE_RESERVED)
+			continue;
+		retval = EBUSY;
+		error = resource_list_release(rl, bus, child, type,
+		    rman_get_rid(rle->res), rle->res);
+		if (error != 0)
+			device_printf(bus,
+			    "Failed to release active resource: %d\n", error);
+	}
+	return (retval);
+}
+
+
+/**
  * @brief Fully release a reserved resource
  *
  * Fully releases a resource reserved via resource_list_reserve().
-- 
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