rt-patches/0110-softirq-Disable-softirq-stacks-for-RT.patch

   1 From 8967b193c05d8862dec216c6d90f524f2642da70 Mon Sep 17 00:00:00 2001
   2 From: Thomas Gleixner <tglx@linutronix.de>
   3 Date: Mon, 18 Jul 2011 13:59:17 +0200
   4 Subject: [PATCH 110/366] softirq: Disable softirq stacks for RT
   5
   6 Disable extra stacks for softirqs. We want to preempt softirqs and
   7 having them on special IRQ-stack does not make this easier.
   8
   9 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  10 ---
  11  arch/powerpc/kernel/irq.c     | 2 ++
  12  arch/powerpc/kernel/misc_32.S | 2 ++
  13  arch/powerpc/kernel/misc_64.S | 2 ++
  14  arch/sh/kernel/irq.c          | 2 ++
  15  arch/sparc/kernel/irq_64.c    | 2 ++
  16  arch/x86/entry/entry_64.S     | 2 ++
  17  arch/x86/kernel/irq_32.c      | 2 ++
  18  include/linux/interrupt.h     | 2 +-
  19  8 files changed, 15 insertions(+), 1 deletion(-)
  20
  21 diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
  22 index 290559d..070afa6 100644
  23 --- a/arch/powerpc/kernel/irq.c
  24 +++ b/arch/powerpc/kernel/irq.c
  25 @@ -614,6 +614,7 @@ void irq_ctx_init(void)
  26         }
  27  }
  28
  29 +#ifndef CONFIG_PREEMPT_RT_FULL
  30  void do_softirq_own_stack(void)
  31  {
  32         struct thread_info *curtp, *irqtp;
  33 @@ -631,6 +632,7 @@ void do_softirq_own_stack(void)
  34         if (irqtp->flags)
  35                 set_bits(irqtp->flags, &curtp->flags);
  36  }
  37 +#endif
  38
  39  irq_hw_number_t virq_to_hw(unsigned int virq)
  40  {
  41 diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
  42 index ed3ab50..8b26141 100644
  43 --- a/arch/powerpc/kernel/misc_32.S
  44 +++ b/arch/powerpc/kernel/misc_32.S
  45 @@ -40,6 +40,7 @@
  46   * We store the saved ksp_limit in the unused part
  47   * of the STACK_FRAME_OVERHEAD
  48   */
  49 +#ifndef CONFIG_PREEMPT_RT_FULL
  50  _GLOBAL(call_do_softirq)
  51         mflr    r0
  52         stw     r0,4(r1)
  53 @@ -56,6 +57,7 @@ _GLOBAL(call_do_softirq)
  54         stw     r10,THREAD+KSP_LIMIT(r2)
  55         mtlr    r0
  56         blr
  57 +#endif
  58
  59  /*
  60   * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
  61 diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
  62 index db475d4..96b7ef8 100644
  63 --- a/arch/powerpc/kernel/misc_64.S
  64 +++ b/arch/powerpc/kernel/misc_64.S
  65 @@ -30,6 +30,7 @@
  66
  67         .text
  68
  69 +#ifndef CONFIG_PREEMPT_RT_FULL
  70  _GLOBAL(call_do_softirq)
  71         mflr    r0
  72         std     r0,16(r1)
  73 @@ -40,6 +41,7 @@ _GLOBAL(call_do_softirq)
  74         ld      r0,16(r1)
  75         mtlr    r0
  76         blr
  77 +#endif
  78
  79  _GLOBAL(call_do_irq)
  80         mflr    r0
  81 diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
  82 index 6c0378c..abd58b4 100644
  83 --- a/arch/sh/kernel/irq.c
  84 +++ b/arch/sh/kernel/irq.c
  85 @@ -147,6 +147,7 @@ void irq_ctx_exit(int cpu)
  86         hardirq_ctx[cpu] = NULL;
  87  }
  88
  89 +#ifndef CONFIG_PREEMPT_RT_FULL
  90  void do_softirq_own_stack(void)
  91  {
  92         struct thread_info *curctx;
  93 @@ -174,6 +175,7 @@ void do_softirq_own_stack(void)
  94                   "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
  95         );
  96  }
  97 +#endif
  98  #else
  99  static inline void handle_one_irq(unsigned int irq)
 100  {
 101 diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c
 102 index e22416c..d359de7 100644
 103 --- a/arch/sparc/kernel/irq_64.c
 104 +++ b/arch/sparc/kernel/irq_64.c
 105 @@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs)
 106         set_irq_regs(old_regs);
 107  }
 108
 109 +#ifndef CONFIG_PREEMPT_RT_FULL
 110  void do_softirq_own_stack(void)
 111  {
 112         void *orig_sp, *sp = softirq_stack[smp_processor_id()];
 113 @@ -868,6 +869,7 @@ void do_softirq_own_stack(void)
 114         __asm__ __volatile__("mov %0, %%sp"
 115                              : : "r" (orig_sp));
 116  }
 117 +#endif
 118
 119  #ifdef CONFIG_HOTPLUG_CPU
 120  void fixup_irqs(void)
 121 diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
 122 index a55697d..5783f8f 100644
 123 --- a/arch/x86/entry/entry_64.S
 124 +++ b/arch/x86/entry/entry_64.S
 125 @@ -867,6 +867,7 @@ bad_gs:
 126         jmp     2b
 127         .previous
 128
 129 +#ifndef CONFIG_PREEMPT_RT_FULL
 130  /* Call softirq on interrupt stack. Interrupts are off. */
 131  ENTRY(do_softirq_own_stack)
 132         pushq   %rbp
 133 @@ -879,6 +880,7 @@ ENTRY(do_softirq_own_stack)
 134         decl    PER_CPU_VAR(irq_count)
 135         ret
 136  END(do_softirq_own_stack)
 137 +#endif
 138
 139  #ifdef CONFIG_XEN
 140  idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
 141 diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
 142 index 38da8f2..ce71f70 100644
 143 --- a/arch/x86/kernel/irq_32.c
 144 +++ b/arch/x86/kernel/irq_32.c
 145 @@ -128,6 +128,7 @@ void irq_ctx_init(int cpu)
 146                cpu, per_cpu(hardirq_stack, cpu),  per_cpu(softirq_stack, cpu));
 147  }
 148
 149 +#ifndef CONFIG_PREEMPT_RT_FULL
 150  void do_softirq_own_stack(void)
 151  {
 152         struct thread_info *curstk;
 153 @@ -146,6 +147,7 @@ void do_softirq_own_stack(void)
 154
 155         call_on_stack(__do_softirq, isp);
 156  }
 157 +#endif
 158
 159  bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
 160  {
 161 diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
 162 index 8564dba..44f401a 100644
 163 --- a/include/linux/interrupt.h
 164 +++ b/include/linux/interrupt.h
 165 @@ -446,7 +446,7 @@ struct softirq_action
 166  asmlinkage void do_softirq(void);
 167  asmlinkage void __do_softirq(void);
 168
 169 -#ifdef __ARCH_HAS_DO_SOFTIRQ
 170 +#if defined(__ARCH_HAS_DO_SOFTIRQ) && !defined(CONFIG_PREEMPT_RT_FULL)
 171  void do_softirq_own_stack(void);
 172  #else
 173  static inline void do_softirq_own_stack(void)
 174 --
 175 1.9.1
 176