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From 7e198889f2947f9bfeecdda6955492f55399a621 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 18 Jul 2011 13:59:17 +0200
Subject: [PATCH 120/347] softirq: Disable softirq stacks for RT
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
Disable extra stacks for softirqs. We want to preempt softirqs and
having them on special IRQ-stack does not make this easier.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/powerpc/kernel/irq.c | 2 ++
arch/powerpc/kernel/misc_32.S | 2 ++
arch/powerpc/kernel/misc_64.S | 2 ++
arch/sh/kernel/irq.c | 2 ++
arch/sparc/kernel/irq_64.c | 2 ++
arch/x86/entry/entry_64.S | 2 ++
arch/x86/kernel/irq_32.c | 2 ++
include/linux/interrupt.h | 2 +-
8 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index d37704ebccdb..b45a9849b687 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -766,6 +766,7 @@ void irq_ctx_init(void)
}
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq_own_stack(void)
{
struct thread_info *curtp, *irqtp;
@@ -783,6 +784,7 @@ void do_softirq_own_stack(void)
if (irqtp->flags)
set_bits(irqtp->flags, &curtp->flags);
}
+#endif
irq_hw_number_t virq_to_hw(unsigned int virq)
{
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 695b24a2d954..032ada21b7bd 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -42,6 +42,7 @@
* We store the saved ksp_limit in the unused part
* of the STACK_FRAME_OVERHEAD
*/
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
stw r0,4(r1)
@@ -58,6 +59,7 @@ _GLOBAL(call_do_softirq)
stw r10,THREAD+KSP_LIMIT(r2)
mtlr r0
blr
+#endif
/*
* void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index facc02964ab3..8b1774186c68 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -32,6 +32,7 @@
.text
+#ifndef CONFIG_PREEMPT_RT_FULL
_GLOBAL(call_do_softirq)
mflr r0
std r0,16(r1)
@@ -42,6 +43,7 @@ _GLOBAL(call_do_softirq)
ld r0,16(r1)
mtlr r0
blr
+#endif
_GLOBAL(call_do_irq)
mflr r0
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 5717c7cbdd97..66dd399b2007 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -148,6 +148,7 @@ void irq_ctx_exit(int cpu)
hardirq_ctx[cpu] = NULL;
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq_own_stack(void)
{
struct thread_info *curctx;
@@ -175,6 +176,7 @@ void do_softirq_own_stack(void)
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
}
+#endif
#else
static inline void handle_one_irq(unsigned int irq)
{
diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
index 713670e6d13d..5dfc715343f9 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs)
set_irq_regs(old_regs);
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq_own_stack(void)
{
void *orig_sp, *sp = softirq_stack[smp_processor_id()];
@@ -868,6 +869,7 @@ void do_softirq_own_stack(void)
__asm__ __volatile__("mov %0, %%sp"
: : "r" (orig_sp));
}
+#endif
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index dfe26f3cfffc..f53d995b1370 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1084,6 +1084,7 @@ EXPORT_SYMBOL(native_load_gs_index)
jmp 2b
.previous
+#ifndef CONFIG_PREEMPT_RT_FULL
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(do_softirq_own_stack)
pushq %rbp
@@ -1094,6 +1095,7 @@ ENTRY(do_softirq_own_stack)
leaveq
ret
ENDPROC(do_softirq_own_stack)
+#endif
#ifdef CONFIG_XEN
idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 95600a99ae93..9192d76085ba 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -130,6 +130,7 @@ void irq_ctx_init(int cpu)
cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu));
}
+#ifndef CONFIG_PREEMPT_RT_FULL
void do_softirq_own_stack(void)
{
struct irq_stack *irqstk;
@@ -146,6 +147,7 @@ void do_softirq_own_stack(void)
call_on_stack(__do_softirq, isp);
}
+#endif
bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
{
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 35fa335c475b..eec4bec454b5 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -500,7 +500,7 @@ struct softirq_action
asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
-#ifdef __ARCH_HAS_DO_SOFTIRQ
+#if defined(__ARCH_HAS_DO_SOFTIRQ) && !defined(CONFIG_PREEMPT_RT_FULL)
void do_softirq_own_stack(void);
#else
static inline void do_softirq_own_stack(void)
--
2.36.1
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