Merge tag 'irqchip-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip/genirq updates from Marc Zyngier:

 * Core code update:

  - Non-SMP IRQ affinity fixes, allowing UP kernel to behave similarly
    to SMP ones for the purpose of interrupt affinity

  - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *

  - Tidy-up the NOMAP irqdomain API variant

  - Teach action_show() to use for_each_action_of_desc()

  - Make irq_chip_request_resources_parent() allow the parent callback
    to be optional

  - Remove dynamic allocations from populate_parent_alloc_arg()

 * New drivers:

  - Merge the long awaited IRQ support for the LoongArch architecture,
    with the provisional ACPICA update (to be reverted once the official
    support lands)

  - New Renesas RZ/G2L IRQC driver, equipped with its companion GPIO
    driver

 * Driver updates

  - Optimise the hot path operations for the SiFive PLIC, trading the
    locking for per-CPU priority masking masking operations which are
    apparently faster

  - Work around broken PLIC implementations that deal pretty badly with
    edge-triggered interrupts. Flag two implementations as affected.

  - Simplify the irq-stm32-exti driver, particularly the table that
    remaps the interrupts from exti to the GIC, reducing the memory usage

  - Convert the ocelot irq_chip to being immutable

  - Check ioremap() return value in the MIPS GIC driver

  - Move MMP driver init function declarations into the common .h

  - The obligatory typo fixes

Link: https://lore.kernel.org/all/20220727192356.1860546-1-maz@kernel.org

1 files changed, 32 insertions, 0 deletions

diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index ef0f9a2044da..caac4de1ea59 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -8,7 +8,9 @@
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/printk.h>
+#include <linux/console.h>
 #include <linux/kprobes.h>
+#include <linux/delay.h>
 
 #include "internal.h"
 
@@ -50,3 +52,33 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	return vprintk_default(fmt, args);
 }
 EXPORT_SYMBOL(vprintk);
+
+/**
+ * try_block_console_kthreads() - Try to block console kthreads and
+ *	make the global console_lock() avaialble
+ *
+ * @timeout_ms:        The maximum time (in ms) to wait.
+ *
+ * Prevent console kthreads from starting processing new messages. Wait
+ * until the global console_lock() become available.
+ *
+ * Context: Can be called in any context.
+ */
+void try_block_console_kthreads(int timeout_ms)
+{
+	block_console_kthreads = true;
+
+	/* Do not wait when the console lock could not be safely taken. */
+	if (this_cpu_read(printk_context) || in_nmi())
+		return;
+
+	while (timeout_ms > 0) {
+		if (console_trylock()) {
+			console_unlock();
+			return;
+		}
+
+		udelay(1000);
+		timeout_ms -= 1;
+	}
+}