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[All] (testing) Bumpe kernel to 6.6.14

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j1nx
2024-02-05 16:41:40 +00:00
parent 4fc5231981
commit fffa51ff5f
231 changed files with 23132 additions and 8386 deletions
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99
buildroot-external/patches/linux/0156-printk-nbcon-Provide-function-to-reacquire-ownership.patch Normal file
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@@ -0,0 +1,99 @@
From f5fb39d46924a5aee5e6c96d5000aa396c7e916e Mon Sep 17 00:00:00 2001
From: John Ogness <john.ogness@linutronix.de>
Date: Fri, 20 Oct 2023 10:01:58 +0000
Subject: [PATCH 156/195] printk: nbcon: Provide function to reacquire
ownership
Contexts may become nbcon owners for various reasons, not just
for printing. Indeed, the port->lock wrapper takes ownership
for anything relating to the hardware.
Since ownership can be lost at any time due to handover or
takeover, a context _should_ be prepared to back out
immediately and carefully. However, there are many scenarios
where the context _must_ reacquire ownership in order to
finalize or revert hardware changes.
One such example is when interrupts are disabled by a context.
No other context will automagically re-enable the interrupts.
For this case, the disabling context _must_ reacquire nbcon
ownership so that it can re-enable the interrupts.
Provide nbcon_reacquire() for exactly this purpose.
Note that for printing contexts, after a successful reacquire
the context will have no output buffer because that has been
lost. nbcon_reacquire() cannot be used to resume printing.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/console.h | 2 ++
kernel/printk/nbcon.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/include/linux/console.h b/include/linux/console.h
index 982c98280ae8..f8a062867888 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -474,12 +474,14 @@ extern void nbcon_cpu_emergency_exit(void);
extern bool nbcon_can_proceed(struct nbcon_write_context *wctxt);
extern bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt);
extern bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt);
+extern void nbcon_reacquire(struct nbcon_write_context *wctxt);
#else
static inline void nbcon_cpu_emergency_enter(void) { }
static inline void nbcon_cpu_emergency_exit(void) { }
static inline bool nbcon_can_proceed(struct nbcon_write_context *wctxt) { return false; }
static inline bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt) { return false; }
static inline bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt) { return false; }
+static inline void nbcon_reacquire(struct nbcon_write_context *wctxt) { }
#endif
extern int console_set_on_cmdline;
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index b866d0138fe0..f843df54ee82 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -830,6 +830,38 @@ bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt)
}
EXPORT_SYMBOL_GPL(nbcon_exit_unsafe);
+/**
+ * nbcon_reacquire - Reacquire a console after losing ownership
+ * @wctxt: The write context that was handed to the write function
+ *
+ * Since ownership can be lost at any time due to handover or takeover, a
+ * printing context _should_ be prepared to back out immediately and
+ * carefully. However, there are many scenarios where the context _must_
+ * reacquire ownership in order to finalize or revert hardware changes.
+ *
+ * This function allows a context to reacquire ownership using the same
+ * priority as its previous ownership.
+ *
+ * Note that for printing contexts, after a successful reacquire the
+ * context will have no output buffer because that has been lost. This
+ * function cannot be used to resume printing.
+ */
+void nbcon_reacquire(struct nbcon_write_context *wctxt)
+{
+ struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+ struct console *con = ctxt->console;
+ struct nbcon_state cur;
+
+ while (!nbcon_context_try_acquire(ctxt))
+ cpu_relax();
+
+ wctxt->outbuf = NULL;
+ wctxt->len = 0;
+ nbcon_state_read(con, &cur);
+ wctxt->unsafe_takeover = cur.unsafe_takeover;
+}
+EXPORT_SYMBOL_GPL(nbcon_reacquire);
+
/**
* nbcon_emit_next_record - Emit a record in the acquired context
* @wctxt: The write context that will be handed to the write function
--
2.43.0