From 8c065e72d7829ba7efeb3c93d98c602f7ba3d158 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 19 Jun 2024 23:00:47 +0200 Subject: Adding debian version 6.9.2-1~exp1. Signed-off-by: Daniel Baumann --- ...n-Use-nbcon-consoles-in-console_flush_all.patch | 209 +++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 debian/patches-rt/0020-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch (limited to 'debian/patches-rt/0020-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch') diff --git a/debian/patches-rt/0020-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch b/debian/patches-rt/0020-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch new file mode 100644 index 0000000000..3507ff2aa2 --- /dev/null +++ b/debian/patches-rt/0020-printk-nbcon-Use-nbcon-consoles-in-console_flush_all.patch @@ -0,0 +1,209 @@ +From: John Ogness +Date: Tue, 19 Sep 2023 14:33:27 +0000 +Subject: [PATCH 20/46] printk: nbcon: Use nbcon consoles in + console_flush_all() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.9/older/patches-6.9-rt5.tar.xz + +Allow nbcon consoles to print messages in the legacy printk() +caller context (printing via unlock) by integrating them into +console_flush_all(). The write_atomic() callback is used for +printing. + +Provide nbcon_legacy_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 in +console_flush_all(). + +Note that the legacy printing logic uses @handover to detect +handovers for printing all consoles. For nbcon consoles, +handovers/takeovers occur on a per-console basis and thus do +not cause the console_flush_all() loop to abort. + +Signed-off-by: John Ogness +Signed-off-by: Sebastian Andrzej Siewior +--- + kernel/printk/internal.h | 6 +++ + kernel/printk/nbcon.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++ + kernel/printk/printk.c | 17 ++++++--- + 3 files changed, 105 insertions(+), 5 deletions(-) + +--- a/kernel/printk/internal.h ++++ b/kernel/printk/internal.h +@@ -78,6 +78,8 @@ 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); +@@ -86,6 +88,8 @@ void nbcon_init(struct console *con, u64 + void nbcon_free(struct console *con); + enum nbcon_prio nbcon_get_default_prio(void); + void nbcon_atomic_flush_pending(void); ++bool nbcon_legacy_emit_next_record(struct console *con, bool *handover, ++ int cookie); + + /* + * Check if the given console is currently capable and allowed to print +@@ -142,6 +146,8 @@ static inline void nbcon_init(struct con + static inline void nbcon_free(struct console *con) { } + static inline enum nbcon_prio nbcon_get_default_prio(void) { return NBCON_PRIO_NONE; } + static inline void nbcon_atomic_flush_pending(void) { } ++static inline bool nbcon_legacy_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 +@@ -953,6 +953,93 @@ enum nbcon_prio nbcon_get_default_prio(v + } + + /* ++ * nbcon_atomic_emit_one - Print one record for an nbcon console using the ++ * write_atomic() callback ++ * @wctxt: An initialized write context struct to use for this context ++ * ++ * Return: True, when a record has been printed and there are still ++ * pending records. The caller might want to continue flushing. ++ * ++ * False, when there is no pending record, or when the console ++ * context cannot be acquired, or the ownership has been lost. ++ * The caller should give up. Either the job is done, cannot be ++ * done, or will be handled by the owning context. ++ * ++ * This is an internal helper to handle the locking of the console before ++ * calling nbcon_emit_next_record(). ++ */ ++static bool nbcon_atomic_emit_one(struct nbcon_write_context *wctxt) ++{ ++ struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt); ++ ++ if (!nbcon_context_try_acquire(ctxt)) ++ return false; ++ ++ /* ++ * nbcon_emit_next_record() returns false when the console was ++ * handed over or taken over. In both cases the context is no ++ * longer valid. ++ * ++ * The higher priority printing context takes over responsibility ++ * to print the pending records. ++ */ ++ if (!nbcon_emit_next_record(wctxt)) ++ return false; ++ ++ nbcon_context_release(ctxt); ++ ++ return ctxt->backlog; ++} ++ ++/** ++ * nbcon_legacy_emit_next_record - Print one record for an nbcon console ++ * in legacy contexts ++ * @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 except NMI. ++ * Return: True, when a record has been printed and there are still ++ * pending records. The caller might want to continue flushing. ++ * ++ * False, when there is no pending record, or when the console ++ * context cannot be acquired, or the ownership has been lost. ++ * The caller should give up. Either the job is done, cannot be ++ * done, or will be handled by the owning context. ++ * ++ * This function is meant to be called by console_flush_all() to print records ++ * on nbcon consoles from legacy context (printing via console unlocking). ++ * Essentially it is the nbcon version of console_emit_next_record(). ++ */ ++bool nbcon_legacy_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 flags; ++ bool progress; ++ ++ /* Use the same procedure as console_emit_next_record(). */ ++ printk_safe_enter_irqsave(flags); ++ console_lock_spinning_enable(); ++ stop_critical_timings(); ++ ++ ctxt->console = con; ++ ctxt->prio = nbcon_get_default_prio(); ++ ++ progress = nbcon_atomic_emit_one(&wctxt); ++ ++ start_critical_timings(); ++ *handover = console_lock_spinning_disable_and_check(cookie); ++ printk_safe_exit_irqrestore(flags); ++ ++ return progress; ++} ++ ++/** + * __nbcon_atomic_flush_pending_con - Flush specified nbcon console using its + * write_atomic() callback + * @con: The nbcon console to flush +--- a/kernel/printk/printk.c ++++ b/kernel/printk/printk.c +@@ -1860,7 +1860,7 @@ 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. +@@ -1899,7 +1899,7 @@ 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; + +@@ -2951,13 +2951,20 @@ 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_legacy_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 +@@ -2967,8 +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; -- cgit v1.2.3