diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0243-powerpc-Add-support-for-lazy-preemption.patch | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/debian/patches-rt/0243-powerpc-Add-support-for-lazy-preemption.patch b/debian/patches-rt/0243-powerpc-Add-support-for-lazy-preemption.patch new file mode 100644 index 000000000..7c07610a1 --- /dev/null +++ b/debian/patches-rt/0243-powerpc-Add-support-for-lazy-preemption.patch @@ -0,0 +1,196 @@ +From 0fe19697678375c08da0c1d53231706a9df830d4 Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 1 Nov 2012 10:14:11 +0100 +Subject: [PATCH 243/347] powerpc: 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 powerpc pieces for lazy preempt. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +--- + arch/powerpc/Kconfig | 1 + + arch/powerpc/include/asm/thread_info.h | 9 +++++++-- + arch/powerpc/kernel/asm-offsets.c | 1 + + arch/powerpc/kernel/entry_32.S | 17 ++++++++++++----- + arch/powerpc/kernel/entry_64.S | 16 ++++++++++++---- + 5 files changed, 33 insertions(+), 11 deletions(-) + +diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig +index f4517f4be192..4536d047cdff 100644 +--- a/arch/powerpc/Kconfig ++++ b/arch/powerpc/Kconfig +@@ -217,6 +217,7 @@ config PPC + select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH + select HAVE_PERF_REGS + select HAVE_PERF_USER_STACK_DUMP ++ select HAVE_PREEMPT_LAZY + select HAVE_RCU_TABLE_FREE if SMP + select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_RELIABLE_STACKTRACE if PPC64 && CPU_LITTLE_ENDIAN +diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h +index 3c0002044bc9..ce316076bc52 100644 +--- a/arch/powerpc/include/asm/thread_info.h ++++ b/arch/powerpc/include/asm/thread_info.h +@@ -37,6 +37,8 @@ struct thread_info { + int cpu; /* cpu we're on */ + int preempt_count; /* 0 => preemptable, + <0 => BUG */ ++ int preempt_lazy_count; /* 0 => preemptable, ++ <0 => BUG */ + unsigned long local_flags; /* private flags for thread */ + #ifdef CONFIG_LIVEPATCH + unsigned long *livepatch_sp; +@@ -81,7 +83,7 @@ extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src + #define TIF_SIGPENDING 1 /* signal pending */ + #define TIF_NEED_RESCHED 2 /* rescheduling necessary */ + #define TIF_FSCHECK 3 /* Check FS is USER_DS on return */ +-#define TIF_32BIT 4 /* 32 bit binary */ ++#define TIF_NEED_RESCHED_LAZY 4 /* lazy rescheduling necessary */ + #define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */ + #define TIF_PATCH_PENDING 6 /* pending live patching update */ + #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ +@@ -100,6 +102,7 @@ extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src + #define TIF_ELF2ABI 18 /* function descriptors must die! */ + #endif + #define TIF_POLLING_NRFLAG 19 /* true if poll_idle() is polling TIF_NEED_RESCHED */ ++#define TIF_32BIT 20 /* 32 bit binary */ + + /* as above, but as bit values */ + #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) +@@ -119,6 +122,7 @@ extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src + #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT) + #define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE) + #define _TIF_NOHZ (1<<TIF_NOHZ) ++#define _TIF_NEED_RESCHED_LAZY (1<<TIF_NEED_RESCHED_LAZY) + #define _TIF_FSCHECK (1<<TIF_FSCHECK) + #define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ + _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \ +@@ -127,8 +131,9 @@ extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src + #define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ + _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ + _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \ +- _TIF_FSCHECK) ++ _TIF_FSCHECK | _TIF_NEED_RESCHED_LAZY) + #define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR) ++#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY) + + /* Bits in local_flags */ + /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ +diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c +index 50400f213bbf..1bb82c5dc1d9 100644 +--- a/arch/powerpc/kernel/asm-offsets.c ++++ b/arch/powerpc/kernel/asm-offsets.c +@@ -156,6 +156,7 @@ int main(void) + OFFSET(TI_FLAGS, thread_info, flags); + OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags); + OFFSET(TI_PREEMPT, thread_info, preempt_count); ++ OFFSET(TI_PREEMPT_LAZY, thread_info, preempt_lazy_count); + OFFSET(TI_TASK, thread_info, task); + OFFSET(TI_CPU, thread_info, cpu); + +diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S +index 26b3f853cbf6..3783f3ef17a4 100644 +--- a/arch/powerpc/kernel/entry_32.S ++++ b/arch/powerpc/kernel/entry_32.S +@@ -888,7 +888,14 @@ user_exc_return: /* r10 contains MSR_KERNEL here */ + cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ + bne restore + andi. r8,r8,_TIF_NEED_RESCHED ++ bne+ 1f ++ lwz r0,TI_PREEMPT_LAZY(r9) ++ cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ ++ bne restore ++ lwz r0,TI_FLAGS(r9) ++ andi. r0,r0,_TIF_NEED_RESCHED_LAZY + beq+ restore ++1: + lwz r3,_MSR(r1) + andi. r0,r3,MSR_EE /* interrupts off? */ + beq restore /* don't schedule if so */ +@@ -899,11 +906,11 @@ user_exc_return: /* r10 contains MSR_KERNEL here */ + */ + bl trace_hardirqs_off + #endif +-1: bl preempt_schedule_irq ++2: bl preempt_schedule_irq + CURRENT_THREAD_INFO(r9, r1) + lwz r3,TI_FLAGS(r9) +- andi. r0,r3,_TIF_NEED_RESCHED +- bne- 1b ++ andi. r0,r3,_TIF_NEED_RESCHED_MASK ++ bne- 2b + #ifdef CONFIG_TRACE_IRQFLAGS + /* And now, to properly rebalance the above, we tell lockdep they + * are being turned back on, which will happen when we return +@@ -1232,7 +1239,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) + #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ + + do_work: /* r10 contains MSR_KERNEL here */ +- andi. r0,r9,_TIF_NEED_RESCHED ++ andi. r0,r9,_TIF_NEED_RESCHED_MASK + beq do_user_signal + + do_resched: /* r10 contains MSR_KERNEL here */ +@@ -1253,7 +1260,7 @@ do_resched: /* r10 contains MSR_KERNEL here */ + MTMSRD(r10) /* disable interrupts */ + CURRENT_THREAD_INFO(r9, r1) + lwz r9,TI_FLAGS(r9) +- andi. r0,r9,_TIF_NEED_RESCHED ++ andi. r0,r9,_TIF_NEED_RESCHED_MASK + bne- do_resched + andi. r0,r9,_TIF_USER_WORK_MASK + beq restore_user +diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S +index 58b50967b3e5..ef02e41d5d96 100644 +--- a/arch/powerpc/kernel/entry_64.S ++++ b/arch/powerpc/kernel/entry_64.S +@@ -176,7 +176,7 @@ system_call: /* label this so stack traces look sane */ + * based on caller's run-mode / personality. + */ + ld r11,SYS_CALL_TABLE@toc(2) +- andi. r10,r10,_TIF_32BIT ++ andis. r10,r10,_TIF_32BIT@h + beq 15f + addi r11,r11,8 /* use 32-bit syscall entries */ + clrldi r3,r3,32 +@@ -774,7 +774,7 @@ _GLOBAL(ret_from_except_lite) + bl restore_math + b restore + #endif +-1: andi. r0,r4,_TIF_NEED_RESCHED ++1: andi. r0,r4,_TIF_NEED_RESCHED_MASK + beq 2f + bl restore_interrupts + SCHEDULE_USER +@@ -836,10 +836,18 @@ _GLOBAL(ret_from_except_lite) + + #ifdef CONFIG_PREEMPT + /* Check if we need to preempt */ ++ lwz r8,TI_PREEMPT(r9) ++ cmpwi 0,r8,0 /* if non-zero, just restore regs and return */ ++ bne restore + andi. r0,r4,_TIF_NEED_RESCHED ++ bne+ check_count ++ ++ andi. r0,r4,_TIF_NEED_RESCHED_LAZY + beq+ restore ++ lwz r8,TI_PREEMPT_LAZY(r9) ++ + /* Check that preempt_count() == 0 and interrupts are enabled */ +- lwz r8,TI_PREEMPT(r9) ++check_count: + cmpwi cr0,r8,0 + bne restore + ld r0,SOFTE(r1) +@@ -856,7 +864,7 @@ _GLOBAL(ret_from_except_lite) + /* Re-test flags and eventually loop */ + CURRENT_THREAD_INFO(r9, r1) + ld r4,TI_FLAGS(r9) +- andi. r0,r4,_TIF_NEED_RESCHED ++ andi. r0,r4,_TIF_NEED_RESCHED_MASK + bne 1b + + /* +-- +2.36.1 + |