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irq: Consolidate do_softirq() arch overriden implementations

Browse source 
All arch overriden implementations of do_softirq() share the following
common code: disable irqs (to avoid races with the pending check),
check if there are softirqs pending, then execute __do_softirq() on
a specific stack.

Consolidate the common parts such that archs only worry about the
stack switch.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@au1.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Frederic Weisbecker 2013-09-05 15:49:45 +02:00
parent ded7975475
commit 7d65f4a655
11 changed files with 93 additions and 197 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

48
arch/metag/kernel/irq.c
View file

@ -159,44 +159,30 @@ void irq_ctx_exit(int cpu)
extern asmlinkage void __do_softirq(void);
asmlinkage void do_softirq(void)
void do_softirq_own_stack(void)
{
unsigned long flags;
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
if (in_interrupt())
return;
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
local_irq_save(flags);
/* build the stack frame on the softirq stack */
isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info));
if (local_softirq_pending()) {
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
/* build the stack frame on the softirq stack */
isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info));
asm volatile (
"MOV D0.5,%0\n"
"SWAP A0StP,D0.5\n"
"CALLR D1RtP,___do_softirq\n"
"MOV A0StP,D0.5\n"
:
: "r" (isp)
: "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4",
"D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP",
"D0.5"
);
/*
* Shouldn't happen, we returned above if in_interrupt():
*/
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
asm volatile (
"MOV D0.5,%0\n"
"SWAP A0StP,D0.5\n"
"CALLR D1RtP,___do_softirq\n"
"MOV A0StP,D0.5\n"
:
: "r" (isp)
: "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4",
"D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP",
"D0.5"
);
}
#endif

17
arch/parisc/kernel/irq.c
View file

@ -499,22 +499,9 @@ static void execute_on_irq_stack(void *func, unsigned long param1)
*irq_stack_in_use = 1;
}
asmlinkage void do_softirq(void)
void do_softirq_own_stack(void)
{
__u32 pending;
unsigned long flags;
if (in_interrupt())
return;
local_irq_save(flags);
pending = local_softirq_pending();
if (pending)
execute_on_irq_stack(__do_softirq, 0);
local_irq_restore(flags);
execute_on_irq_stack(__do_softirq, 0);
}
#endif /* CONFIG_IRQSTACKS */

17
arch/powerpc/kernel/irq.c
View file

@ -593,7 +593,7 @@ void irq_ctx_init(void)
}
}
static inline void do_softirq_onstack(void)
void do_softirq_own_stack(void)
{
struct thread_info *curtp, *irqtp;
@ -611,21 +611,6 @@ static inline void do_softirq_onstack(void)
set_bits(irqtp->flags, &curtp->flags);
}
void do_softirq(void)
{
unsigned long flags;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending())
do_softirq_onstack();
local_irq_restore(flags);
}
irq_hw_number_t virq_to_hw(unsigned int virq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);

50
arch/s390/kernel/irq.c
View file

@ -157,39 +157,29 @@ int arch_show_interrupts(struct seq_file *p, int prec)
/*
* Switch to the asynchronous interrupt stack for softirq execution.
*/
asmlinkage void do_softirq(void)
void do_softirq_own_stack(void)
{
unsigned long flags, old, new;
unsigned long old, new;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending()) {
/* Get current stack pointer. */
asm volatile("la %0,0(15)" : "=a" (old));
/* Check against async. stack address range. */
new = S390_lowcore.async_stack;
if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
/* Need to switch to the async. stack. */
new -= STACK_FRAME_OVERHEAD;
((struct stack_frame *) new)->back_chain = old;
asm volatile(" la 15,0(%0)\n"
" basr 14,%2\n"
" la 15,0(%1)\n"
: : "a" (new), "a" (old),
"a" (__do_softirq)
: "0", "1", "2", "3", "4", "5", "14",
"cc", "memory" );
} else {
/* We are already on the async stack. */
__do_softirq();
}
/* Get current stack pointer. */
asm volatile("la %0,0(15)" : "=a" (old));
/* Check against async. stack address range. */
new = S390_lowcore.async_stack;
if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
/* Need to switch to the async. stack. */
new -= STACK_FRAME_OVERHEAD;
((struct stack_frame *) new)->back_chain = old;
asm volatile(" la 15,0(%0)\n"
" basr 14,%2\n"
" la 15,0(%1)\n"
: : "a" (new), "a" (old),
"a" (__do_softirq)
: "0", "1", "2", "3", "4", "5", "14",
"cc", "memory" );
} else {
/* We are already on the async stack. */
__do_softirq();
}
local_irq_restore(flags);
}
/*

53
arch/sh/kernel/irq.c
View file

@ -149,47 +149,32 @@ void irq_ctx_exit(int cpu)
hardirq_ctx[cpu] = NULL;
}
asmlinkage void do_softirq(void)
void do_softirq_own_stack(void)
{
unsigned long flags;
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
if (in_interrupt())
return;
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_sp = current_stack_pointer;
local_irq_save(flags);
/* build the stack frame on the softirq stack */
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
if (local_softirq_pending()) {
curctx = current_thread_info();
irqctx = softirq_ctx[smp_processor_id()];
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_sp = current_stack_pointer;
/* build the stack frame on the softirq stack */
isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
__asm__ __volatile__ (
"mov r15, r9 \n"
"jsr @%0 \n"
/* switch to the softirq stack */
" mov %1, r15 \n"
/* restore the thread stack */
"mov r9, r15 \n"
: /* no outputs */
: "r" (__do_softirq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
/*
* Shouldn't happen, we returned above if in_interrupt():
*/
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
__asm__ __volatile__ (
"mov r15, r9 \n"
"jsr @%0 \n"
/* switch to the softirq stack */
" mov %1, r15 \n"
/* restore the thread stack */
"mov r9, r15 \n"
: /* no outputs */
: "r" (__do_softirq), "r" (isp)
: "memory", "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
);
}
#else
static inline void handle_one_irq(unsigned int irq)

31
arch/sparc/kernel/irq_64.c
View file

@ -698,30 +698,19 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs)
set_irq_regs(old_regs);
}
void do_softirq(void)
void do_softirq_own_stack(void)
{
unsigned long flags;
void *orig_sp, *sp = softirq_stack[smp_processor_id()];
if (in_interrupt())
return;
sp += THREAD_SIZE - 192 - STACK_BIAS;
local_irq_save(flags);
if (local_softirq_pending()) {
void *orig_sp, *sp = softirq_stack[smp_processor_id()];
sp += THREAD_SIZE - 192 - STACK_BIAS;
__asm__ __volatile__("mov %%sp, %0\n\t"
"mov %1, %%sp"
: "=&r" (orig_sp)
: "r" (sp));
__do_softirq();
__asm__ __volatile__("mov %0, %%sp"
: : "r" (orig_sp));
}
local_irq_restore(flags);
__asm__ __volatile__("mov %%sp, %0\n\t"
"mov %1, %%sp"
: "=&r" (orig_sp)
: "r" (sp));
__do_softirq();
__asm__ __volatile__("mov %0, %%sp"
: : "r" (orig_sp));
}
#ifdef CONFIG_HOTPLUG_CPU

4
arch/x86/kernel/entry_64.S
View file

@ -1342,7 +1342,7 @@ bad_gs:
.previous
/* Call softirq on interrupt stack. Interrupts are off. */
ENTRY(call_softirq)
ENTRY(do_softirq_own_stack)
CFI_STARTPROC
pushq_cfi %rbp
CFI_REL_OFFSET rbp,0
@ -1359,7 +1359,7 @@ ENTRY(call_softirq)
decl PER_CPU_VAR(irq_count)
ret
CFI_ENDPROC
END(call_softirq)
END(do_softirq_own_stack)
#ifdef CONFIG_XEN
zeroentry xen_hypervisor_callback xen_do_hypervisor_callback

30
arch/x86/kernel/irq_32.c
View file

@ -149,35 +149,21 @@ void irq_ctx_init(int cpu)
cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu));
}
asmlinkage void do_softirq(void)
void do_softirq_own_stack(void)
{
unsigned long flags;
struct thread_info *curctx;
union irq_ctx *irqctx;
u32 *isp;
if (in_interrupt())
return;
curctx = current_thread_info();
irqctx = __this_cpu_read(softirq_ctx);
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_esp = current_stack_pointer;
local_irq_save(flags);
/* build the stack frame on the softirq stack */
isp = (u32 *) ((char *)irqctx + sizeof(*irqctx));
if (local_softirq_pending()) {
curctx = current_thread_info();
irqctx = __this_cpu_read(softirq_ctx);
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_esp = current_stack_pointer;
/* build the stack frame on the softirq stack */
isp = (u32 *) ((char *)irqctx + sizeof(*irqctx));
call_on_stack(__do_softirq, isp);
/*
* Shouldn't happen, we returned above if in_interrupt():
*/
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
call_on_stack(__do_softirq, isp);
}
bool handle_irq(unsigned irq, struct pt_regs *regs)

21
arch/x86/kernel/irq_64.c
View file

@ -87,24 +87,3 @@ bool handle_irq(unsigned irq, struct pt_regs *regs)
generic_handle_irq_desc(irq, desc);
return true;
}
extern void call_softirq(void);
asmlinkage void do_softirq(void)
{
__u32 pending;
unsigned long flags;
if (in_interrupt())
return;
local_irq_save(flags);
pending = local_softirq_pending();
/* Switch to interrupt stack */
if (pending) {
call_softirq();
WARN_ON_ONCE(softirq_count());
}
local_irq_restore(flags);
}

11
include/linux/interrupt.h
View file

@ -19,6 +19,7 @@
#include <linux/atomic.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
/*
* These correspond to the IORESOURCE_IRQ_* defines in
@ -374,6 +375,16 @@ struct softirq_action
asmlinkage void do_softirq(void);
asmlinkage void __do_softirq(void);
#ifdef __ARCH_HAS_DO_SOFTIRQ
void do_softirq_own_stack(void);
#else
static inline void do_softirq_own_stack(void)
{
__do_softirq();
}
#endif
extern void open_softirq(int nr, void (*action)(struct softirq_action *));
extern void softirq_init(void);
extern void __raise_softirq_irqoff(unsigned int nr);

8
kernel/softirq.c
View file

@ -29,7 +29,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
#include <asm/irq.h>
/*
- No shared variables, all the data are CPU local.
- If a softirq needs serialization, let it serialize itself
@ -283,7 +282,7 @@ asmlinkage void __do_softirq(void)
tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}
#ifndef __ARCH_HAS_DO_SOFTIRQ
asmlinkage void do_softirq(void)
{
@ -298,13 +297,12 @@ asmlinkage void do_softirq(void)
pending = local_softirq_pending();
if (pending)
__do_softirq();
do_softirq_own_stack();
WARN_ON_ONCE(softirq_count());
local_irq_restore(flags);
}
#endif
/*
* Enter an interrupt context.
*/