Merge tag 'xtensa-20220416' of https://github.com/jcmvbkbc/linux-xtensa

Pull xtensa fixes from Max Filippov:

 - fix patching CPU selection in patch_text

 - fix potential deadlock in ISS platform serial driver

 - fix potential register clobbering in coprocessor exception handler

* tag 'xtensa-20220416' of https://github.com/jcmvbkbc/linux-xtensa:
  xtensa: fix a7 clobbering in coprocessor context load/store
  arch: xtensa: platforms: Fix deadlock in rs_close()
  xtensa: patch_text: Fixup last cpu should be master

Author: torvalds

arch/xtensa/kernel/coprocessor.S

@@ -29,7 +29,7 @@
 	.if XTENSA_HAVE_COPROCESSOR(x);					\
 		.align 4;						\
 	.Lsave_cp_regs_cp##x:						\
-		xchal_cp##x##_store a2 a4 a5 a6 a7;			\
+		xchal_cp##x##_store a2 a3 a4 a5 a6;			\
 		jx	a0;						\
 	.endif
 
@@ -46,7 +46,7 @@
 	.if XTENSA_HAVE_COPROCESSOR(x);					\
 		.align 4;						\
 	.Lload_cp_regs_cp##x:						\
-		xchal_cp##x##_load a2 a4 a5 a6 a7;			\
+		xchal_cp##x##_load a2 a3 a4 a5 a6;			\
 		jx	a0;						\
 	.endif
 

arch/xtensa/kernel/jump_label.c

@@ -40,7 +40,7 @@ static int patch_text_stop_machine(void *data)
 {
 	struct patch *patch = data;
 
-	if (atomic_inc_return(&patch->cpu_count) == 1) {
+	if (atomic_inc_return(&patch->cpu_count) == num_online_cpus()) {
 		local_patch_text(patch->addr, patch->data, patch->sz);
 		atomic_inc(&patch->cpu_count);
 	} else {

arch/xtensa/platforms/iss/console.c

@@ -36,24 +36,19 @@ static void rs_poll(struct timer_list *);
 static struct tty_driver *serial_driver;
 static struct tty_port serial_port;
 static DEFINE_TIMER(serial_timer, rs_poll);
-static DEFINE_SPINLOCK(timer_lock);
 
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
-	spin_lock_bh(&timer_lock);
 	if (tty->count == 1)
 		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
-	spin_unlock_bh(&timer_lock);
 
 	return 0;
 }
 
 static void rs_close(struct tty_struct *tty, struct file * filp)
 {
-	spin_lock_bh(&timer_lock);
 	if (tty->count == 1)
 		del_timer_sync(&serial_timer);
-	spin_unlock_bh(&timer_lock);
 }
 
 
@@ -73,8 +68,6 @@ static void rs_poll(struct timer_list *unused)
 	int rd = 1;
 	unsigned char c;
 
-	spin_lock(&timer_lock);
-
 	while (simc_poll(0)) {
 		rd = simc_read(0, &c, 1);
 		if (rd <= 0)
@@ -87,7 +80,6 @@ static void rs_poll(struct timer_list *unused)
 		tty_flip_buffer_push(port);
 	if (rd)
 		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
-	spin_unlock(&timer_lock);
 }