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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:28:00 +0000 |
commit | 3565071f226432336a54d0193d729fa4508a3394 (patch) | |
tree | 4cde13f078f84c0a7785d234fd52edce7c90546a /debian/patches-rt/0110-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch | |
parent | Adding upstream version 6.6.15. (diff) | |
download | linux-3565071f226432336a54d0193d729fa4508a3394.tar.xz linux-3565071f226432336a54d0193d729fa4508a3394.zip |
Adding debian version 6.6.15-2.debian/6.6.15-2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | debian/patches-rt/0110-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/debian/patches-rt/0110-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch b/debian/patches-rt/0110-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch new file mode 100644 index 0000000000..b46ecd7655 --- /dev/null +++ b/debian/patches-rt/0110-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch @@ -0,0 +1,173 @@ +From: John Ogness <john.ogness@linutronix.de> +Date: Tue, 19 Sep 2023 14:33:27 +0000 +Subject: [PATCH 110/134] printk: nbcon: Use nbcon consoles in + console_flush_all() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +Allow nbcon consoles to print messages in the printk() caller +context by integrating them into console_flush_all(). The +write_atomic() callback is used for printing. + +Provide nbcon_console_emit_next_record(), which acts as the +nbcon variant of console_emit_next_record(). Call this variant +within console_flush_all() for nbcon consoles. Since nbcon +consoles use their own @nbcon_seq variable to track the next +record to print, this also must be appropriately handled. + +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + kernel/printk/internal.h | 5 ++++ + kernel/printk/nbcon.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ + kernel/printk/printk.c | 19 +++++++++++++---- + 3 files changed, 69 insertions(+), 5 deletions(-) + +--- a/kernel/printk/internal.h ++++ b/kernel/printk/internal.h +@@ -71,6 +71,8 @@ void defer_console_output(void); + + u16 printk_parse_prefix(const char *text, int *level, + enum printk_info_flags *flags); ++void console_lock_spinning_enable(void); ++int console_lock_spinning_disable_and_check(int cookie); + + u64 nbcon_seq_read(struct console *con); + void nbcon_seq_force(struct console *con, u64 seq); +@@ -78,6 +80,7 @@ bool nbcon_alloc(struct console *con); + void nbcon_init(struct console *con); + void nbcon_free(struct console *con); + void nbcon_atomic_flush_all(void); ++bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie); + + /* + * Check if the given console is currently capable and allowed to print +@@ -133,6 +136,8 @@ static inline bool nbcon_alloc(struct co + static inline void nbcon_init(struct console *con) { } + static inline void nbcon_free(struct console *con) { } + static inline void nbcon_atomic_flush_all(void) { } ++static inline bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, ++ int cookie) { return false; } + + static inline bool console_is_usable(struct console *con, short flags) { return false; } + +--- a/kernel/printk/nbcon.c ++++ b/kernel/printk/nbcon.c +@@ -532,6 +532,7 @@ static struct printk_buffers panic_nbcon + * nbcon_context_try_acquire - Try to acquire nbcon console + * @ctxt: The context of the caller + * ++ * Context: Any context which could not be migrated to another CPU. + * Return: True if the console was acquired. False otherwise. + * + * If the caller allowed an unsafe hostile takeover, on success the +@@ -961,6 +962,55 @@ static bool nbcon_atomic_emit_one(struct + } + + /** ++ * nbcon_atomic_emit_next_record - Print one record for an nbcon console ++ * using the write_atomic() callback ++ * @con: The console to print on ++ * @handover: Will be set to true if a printk waiter has taken over the ++ * console_lock, in which case the caller is no longer holding ++ * both the console_lock and the SRCU read lock. Otherwise it ++ * is set to false. ++ * @cookie: The cookie from the SRCU read lock. ++ * ++ * Context: Any context which could not be migrated to another CPU. ++ * Return: True if a record could be printed, otherwise false. ++ * ++ * This function is meant to be called by console_flush_all() to print records ++ * on nbcon consoles using the write_atomic() callback. Essentially it is the ++ * nbcon version of console_emit_next_record(). ++ */ ++bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie) ++{ ++ struct nbcon_write_context wctxt = { }; ++ struct nbcon_context *ctxt = &ACCESS_PRIVATE(&wctxt, ctxt); ++ unsigned long driver_flags; ++ bool progress = false; ++ unsigned long flags; ++ ++ *handover = false; ++ ++ /* Use the same locking order as console_emit_next_record(). */ ++ printk_safe_enter_irqsave(flags); ++ console_lock_spinning_enable(); ++ stop_critical_timings(); ++ ++ con->driver_enter(con, &driver_flags); ++ cant_migrate(); ++ ++ ctxt->console = con; ++ ctxt->prio = NBCON_PRIO_NORMAL; ++ ++ progress = nbcon_atomic_emit_one(&wctxt); ++ ++ con->driver_exit(con, driver_flags); ++ ++ start_critical_timings(); ++ *handover = console_lock_spinning_disable_and_check(cookie); ++ printk_safe_exit_irqrestore(flags); ++ ++ return progress; ++} ++ ++/** + * __nbcon_atomic_flush_all - Flush all nbcon consoles using their + * write_atomic() callback + * @stop_seq: Flush up until this record +--- a/kernel/printk/printk.c ++++ b/kernel/printk/printk.c +@@ -1872,7 +1872,7 @@ static bool console_waiter; + * there may be a waiter spinning (like a spinlock). Also it must be + * ready to hand over the lock at the end of the section. + */ +-static void console_lock_spinning_enable(void) ++void console_lock_spinning_enable(void) + { + /* + * Do not use spinning in panic(). The panic CPU wants to keep the lock. +@@ -1911,7 +1911,7 @@ static void console_lock_spinning_enable + * + * Return: 1 if the lock rights were passed, 0 otherwise. + */ +-static int console_lock_spinning_disable_and_check(int cookie) ++int console_lock_spinning_disable_and_check(int cookie) + { + int waiter; + +@@ -2949,13 +2949,22 @@ static bool console_flush_all(bool do_co + cookie = console_srcu_read_lock(); + for_each_console_srcu(con) { + short flags = console_srcu_read_flags(con); ++ u64 printk_seq; + bool progress; + + if (!console_is_usable(con, flags)) + continue; + any_usable = true; + +- progress = console_emit_next_record(con, handover, cookie); ++ if (flags & CON_NBCON) { ++ progress = nbcon_atomic_emit_next_record(con, handover, cookie); ++ ++ printk_seq = nbcon_seq_read(con); ++ } else { ++ progress = console_emit_next_record(con, handover, cookie); ++ ++ printk_seq = con->seq; ++ } + + /* + * If a handover has occurred, the SRCU read lock +@@ -2965,8 +2974,8 @@ static bool console_flush_all(bool do_co + return false; + + /* Track the next of the highest seq flushed. */ +- if (con->seq > *next_seq) +- *next_seq = con->seq; ++ if (printk_seq > *next_seq) ++ *next_seq = printk_seq; + + if (!progress) + continue; |