From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 13 Aug 2017 19:44:18 +0000 (-0700)
Subject: Merge tag 'driver-core-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: v4.13-rc5~2
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=c9dc281d91aed57251e94c7cca81a5c8777e3e4a;hp=ce7ba95cf078337c9921b301a7e4b9e82561db38

Merge tag 'driver-core-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are three firmware core fixes for 4.13-rc5.

  All three of these fix reported issues and have been floating around
  for a few weeks. They have been in linux-next with no reported
  problems"

* tag 'driver-core-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  firmware: avoid invalid fallback aborts by using killable wait
  firmware: fix batched requests - send wake up on failure on direct lookups
  firmware: fix batched requests - wake all waiters
---

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index b9f907eedbf7..bfbe1e154128 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -30,7 +30,6 @@
 #include <linux/syscore_ops.h>
 #include <linux/reboot.h>
 #include <linux/security.h>
-#include <linux/swait.h>
 
 #include <generated/utsrelease.h>
 
@@ -112,13 +111,13 @@ static inline long firmware_loading_timeout(void)
  * state of the firmware loading.
  */
 struct fw_state {
-	struct swait_queue_head wq;
+	struct completion completion;
 	enum fw_status status;
 };
 
 static void fw_state_init(struct fw_state *fw_st)
 {
-	init_swait_queue_head(&fw_st->wq);
+	init_completion(&fw_st->completion);
 	fw_st->status = FW_STATUS_UNKNOWN;
 }
 
@@ -131,9 +130,7 @@ static int __fw_state_wait_common(struct fw_state *fw_st, long timeout)
 {
 	long ret;
 
-	ret = swait_event_interruptible_timeout(fw_st->wq,
-				__fw_state_is_done(READ_ONCE(fw_st->status)),
-				timeout);
+	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
 	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 		return -ENOENT;
 	if (!ret)
@@ -148,35 +145,34 @@ static void __fw_state_set(struct fw_state *fw_st,
 	WRITE_ONCE(fw_st->status, status);
 
 	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
-		swake_up(&fw_st->wq);
+		complete_all(&fw_st->completion);
 }
 
 #define fw_state_start(fw_st)					\
 	__fw_state_set(fw_st, FW_STATUS_LOADING)
 #define fw_state_done(fw_st)					\
 	__fw_state_set(fw_st, FW_STATUS_DONE)
+#define fw_state_aborted(fw_st)					\
+	__fw_state_set(fw_st, FW_STATUS_ABORTED)
 #define fw_state_wait(fw_st)					\
 	__fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT)
 
-#ifndef CONFIG_FW_LOADER_USER_HELPER
-
-#define fw_state_is_aborted(fw_st)	false
-
-#else /* CONFIG_FW_LOADER_USER_HELPER */
-
 static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
 {
 	return fw_st->status == status;
 }
 
+#define fw_state_is_aborted(fw_st)				\
+	__fw_state_check(fw_st, FW_STATUS_ABORTED)
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+
 #define fw_state_aborted(fw_st)					\
 	__fw_state_set(fw_st, FW_STATUS_ABORTED)
 #define fw_state_is_done(fw_st)					\
 	__fw_state_check(fw_st, FW_STATUS_DONE)
 #define fw_state_is_loading(fw_st)				\
 	__fw_state_check(fw_st, FW_STATUS_LOADING)
-#define fw_state_is_aborted(fw_st)				\
-	__fw_state_check(fw_st, FW_STATUS_ABORTED)
 #define fw_state_wait_timeout(fw_st, timeout)			\
 	__fw_state_wait_common(fw_st, timeout)
 
@@ -1200,6 +1196,28 @@ _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 	return 1; /* need to load */
 }
 
+/*
+ * Batched requests need only one wake, we need to do this step last due to the
+ * fallback mechanism. The buf is protected with kref_get(), and it won't be
+ * released until the last user calls release_firmware().
+ *
+ * Failed batched requests are possible as well, in such cases we just share
+ * the struct firmware_buf and won't release it until all requests are woken
+ * and have gone through this same path.
+ */
+static void fw_abort_batch_reqs(struct firmware *fw)
+{
+	struct firmware_buf *buf;
+
+	/* Loaded directly? */
+	if (!fw || !fw->priv)
+		return;
+
+	buf = fw->priv;
+	if (!fw_state_is_aborted(&buf->fw_st))
+		fw_state_aborted(&buf->fw_st);
+}
+
 /* called from request_firmware() and request_firmware_work_func() */
 static int
 _request_firmware(const struct firmware **firmware_p, const char *name,
@@ -1243,6 +1261,7 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 
  out:
 	if (ret < 0) {
+		fw_abort_batch_reqs(fw);
 		release_firmware(fw);
 		fw = NULL;
 	}