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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-debian/4.19.249-2.tar.xz
linux-debian/4.19.249-2.zip
Adding debian version 4.19.249-2.debian/4.19.249-2debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch')
-rw-r--r--debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch168
1 files changed, 168 insertions, 0 deletions
diff --git a/debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch b/debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch
new file mode 100644
index 000000000..af7fd9bc3
--- /dev/null
+++ b/debian/patches-rt/0242-arm-Add-support-for-lazy-preemption.patch
@@ -0,0 +1,168 @@
+From 3845cb2e5f05561da9e363932c9373f45b5fa6a4 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Wed, 31 Oct 2012 12:04:11 +0100
+Subject: [PATCH 242/347] arm: Add support for lazy preemption
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+Implement the arm pieces for lazy preempt.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+---
+ arch/arm/Kconfig | 1 +
+ arch/arm/include/asm/thread_info.h | 8 ++++++--
+ arch/arm/kernel/asm-offsets.c | 1 +
+ arch/arm/kernel/entry-armv.S | 19 ++++++++++++++++---
+ arch/arm/kernel/entry-common.S | 9 +++++++--
+ arch/arm/kernel/signal.c | 3 ++-
+ 6 files changed, 33 insertions(+), 8 deletions(-)
+
+diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
+index ec99422059e3..2607cae04885 100644
+--- a/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -91,6 +91,7 @@ config ARM
+ select HAVE_PERF_EVENTS
+ select HAVE_PERF_REGS
+ select HAVE_PERF_USER_STACK_DUMP
++ select HAVE_PREEMPT_LAZY
+ select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
+ select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RSEQ
+diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
+index 8f55dc520a3e..4f834bfca470 100644
+--- a/arch/arm/include/asm/thread_info.h
++++ b/arch/arm/include/asm/thread_info.h
+@@ -49,6 +49,7 @@ struct cpu_context_save {
+ struct thread_info {
+ unsigned long flags; /* low level flags */
+ int preempt_count; /* 0 => preemptable, <0 => bug */
++ int preempt_lazy_count; /* 0 => preemptable, <0 => bug */
+ mm_segment_t addr_limit; /* address limit */
+ struct task_struct *task; /* main task structure */
+ __u32 cpu; /* cpu */
+@@ -139,7 +140,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
+ #define TIF_SYSCALL_TRACE 4 /* syscall trace active */
+ #define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
+ #define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
+-#define TIF_SECCOMP 7 /* seccomp syscall filtering active */
++#define TIF_SECCOMP 8 /* seccomp syscall filtering active */
++#define TIF_NEED_RESCHED_LAZY 7
+
+ #define TIF_NOHZ 12 /* in adaptive nohz mode */
+ #define TIF_USING_IWMMXT 17
+@@ -149,6 +151,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
+ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+ #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+ #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
++#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
+ #define _TIF_UPROBE (1 << TIF_UPROBE)
+ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+ #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
+@@ -164,7 +167,8 @@ extern int vfp_restore_user_hwstate(struct user_vfp *,
+ * Change these and you break ASM code in entry-common.S
+ */
+ #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
+- _TIF_NOTIFY_RESUME | _TIF_UPROBE)
++ _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
++ _TIF_NEED_RESCHED_LAZY)
+
+ #endif /* __KERNEL__ */
+ #endif /* __ASM_ARM_THREAD_INFO_H */
+diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
+index 40afe953a0e2..d634d6f36140 100644
+--- a/arch/arm/kernel/asm-offsets.c
++++ b/arch/arm/kernel/asm-offsets.c
+@@ -58,6 +58,7 @@ int main(void)
+ BLANK();
+ DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
+ DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
++ DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
+ DEFINE(TI_ADDR_LIMIT, offsetof(struct thread_info, addr_limit));
+ DEFINE(TI_TASK, offsetof(struct thread_info, task));
+ DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
+diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
+index d779cd1a3b0c..dc7ae3d8e62f 100644
+--- a/arch/arm/kernel/entry-armv.S
++++ b/arch/arm/kernel/entry-armv.S
+@@ -209,11 +209,18 @@ ENDPROC(__dabt_svc)
+
+ #ifdef CONFIG_PREEMPT
+ ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
+- ldr r0, [tsk, #TI_FLAGS] @ get flags
+ teq r8, #0 @ if preempt count != 0
++ bne 1f @ return from exeption
++ ldr r0, [tsk, #TI_FLAGS] @ get flags
++ tst r0, #_TIF_NEED_RESCHED @ if NEED_RESCHED is set
++ blne svc_preempt @ preempt!
++
++ ldr r8, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
++ teq r8, #0 @ if preempt lazy count != 0
+ movne r0, #0 @ force flags to 0
+- tst r0, #_TIF_NEED_RESCHED
++ tst r0, #_TIF_NEED_RESCHED_LAZY
+ blne svc_preempt
++1:
+ #endif
+
+ svc_exit r5, irq = 1 @ return from exception
+@@ -228,8 +235,14 @@ ENDPROC(__irq_svc)
+ 1: bl preempt_schedule_irq @ irq en/disable is done inside
+ ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
+ tst r0, #_TIF_NEED_RESCHED
++ bne 1b
++ tst r0, #_TIF_NEED_RESCHED_LAZY
+ reteq r8 @ go again
+- b 1b
++ ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
++ teq r0, #0 @ if preempt lazy count != 0
++ beq 1b
++ ret r8 @ go again
++
+ #endif
+
+ __und_fault:
+diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
+index e27fc2df5231..bc326519f648 100644
+--- a/arch/arm/kernel/entry-common.S
++++ b/arch/arm/kernel/entry-common.S
+@@ -56,7 +56,9 @@ saved_pc .req lr
+ cmp r2, #TASK_SIZE
+ blne addr_limit_check_failed
+ ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
+- tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
++ tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
++ bne fast_work_pending
++ tst r1, #_TIF_SECCOMP
+ bne fast_work_pending
+
+
+@@ -93,8 +95,11 @@ ENDPROC(ret_fast_syscall)
+ cmp r2, #TASK_SIZE
+ blne addr_limit_check_failed
+ ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
+- tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
++ tst r1, #((_TIF_SYSCALL_WORK | _TIF_WORK_MASK) & ~_TIF_SECCOMP)
++ bne do_slower_path
++ tst r1, #_TIF_SECCOMP
+ beq no_work_pending
++do_slower_path:
+ UNWIND(.fnend )
+ ENDPROC(ret_fast_syscall)
+
+diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
+index 1c01358b9b6d..263b0321dc50 100644
+--- a/arch/arm/kernel/signal.c
++++ b/arch/arm/kernel/signal.c
+@@ -652,7 +652,8 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+ */
+ trace_hardirqs_off();
+ do {
+- if (likely(thread_flags & _TIF_NEED_RESCHED)) {
++ if (likely(thread_flags & (_TIF_NEED_RESCHED |
++ _TIF_NEED_RESCHED_LAZY))) {
+ schedule();
+ } else {
+ if (unlikely(!user_mode(regs)))
+--
+2.36.1
+