Subject: linux-next: manual merge of the kvms390 tree with the tip tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 29 Jul 2025 10:56:55 +1000

Hi all,

Today's linux-next merge of the kvms390 tree got a conflict in:

  include/linux/entry-common.h

between commit:

  a70e9f647f50 ("entry: Split generic entry into generic exception and syscall entry")

from the tip tree and commit:

  ee4a2e08c101 ("entry: Add arch_in_rcu_eqs()")

from the kvms390 tree.

I fixed it up (I used the former version of this file and applied the
following merge fix patch) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

From: Stephen Rothwell <[email-masked]>
Date: Tue, 29 Jul 2025 10:49:47 +1000
Subject: [PATCH] fix up for "entry: Add arch_in_rcu_eqs()"

interacting with "entry: Split generic entry into generic exception and
syscall entry" from the tip tree.

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 include/linux/irq-entry-common.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/irq-entry-common.h b/include/linux/irq-entry-common.h
index 0cd828b4a444..d643c7c87822 100644
--- a/include/linux/irq-entry-common.h
+++ b/include/linux/irq-entry-common.h
@@ -49,6 +49,22 @@ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs);
 static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) {}
 #endif
 
+/**
+ * arch_in_rcu_eqs - Architecture specific check for RCU extended quiescent
+ * states.
+ *
+ * Returns: true if the CPU is potentially in an RCU EQS, false otherwise.
+ *
+ * Architectures only need to define this if threads other than the idle thread
+ * may have an interruptible EQS. This does not need to handle idle threads. It
+ * is safe to over-estimate at the cost of redundant RCU management work.
+ *
+ * Invoked from irqentry_enter()
+ */
+#ifndef arch_in_rcu_eqs
+static __always_inline bool arch_in_rcu_eqs(void) { return false; }
+#endif
+
 /**
  * enter_from_user_mode - Establish state when coming from user mode
  *
-- 
2.50.1

-- 
Cheers,
Stephen Rothwell