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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 10:02:59 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-12 10:02:59 +0900
commit1006fae359cc810c16354805c0cffbb6ffee602e (patch)
treebd69f7a235f679a8336b237ed9722bb7f64db39a /arch
parent70fdcb83db15c85a0495b07dc55d9347a4c2efd9 (diff)
parent5702941eec32cfd7b8cf9e36a0936e48170011a4 (diff)
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull IRQ changes from Ingo Molnar: "The biggest change this cycle are the softirq/hardirq stack interaction and nesting fixes, cleanups and reorganizations from Frederic. This is the longer followup story to the softirq nesting fix that is already upstream (commit ded797547548: "irq: Force hardirq exit's softirq processing on its own stack")" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro powerpc: Tell about irq stack coverage x86: Tell about irq stack coverage irq: Optimize softirq stack selection in irq exit irq: Justify the various softirq stack choices irq: Improve a bit softirq debugging irq: Optimize call to softirq on hardirq exit irq: Consolidate do_softirq() arch overriden implementations x86/irq: Correct comment about i8259 initialization
Diffstat (limited to 'arch')
-rw-r--r--arch/Kconfig10
-rw-r--r--arch/arm/mach-bcm2835/bcm2835.c5
-rw-r--r--arch/metag/kernel/irq.c52
-rw-r--r--arch/parisc/kernel/irq.c17
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/kernel/irq.c17
-rw-r--r--arch/s390/kernel/irq.c52
-rw-r--r--arch/sh/kernel/irq.c57
-rw-r--r--arch/sparc/kernel/irq_64.c31
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/kernel/entry_64.S4
-rw-r--r--arch/x86/kernel/i8259.c3
-rw-r--r--arch/x86/kernel/irq_32.c30
-rw-r--r--arch/x86/kernel/irq_64.c21
14 files changed, 99 insertions, 202 deletions
diff --git a/arch/Kconfig b/arch/Kconfig
index af2cc6eabcc..ad95133f8fa 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -390,6 +390,16 @@ config HAVE_UNDERSCORE_SYMBOL_PREFIX
Some architectures generate an _ in front of C symbols; things like
module loading and assembly files need to know about this.
+config HAVE_IRQ_EXIT_ON_IRQ_STACK
+ bool
+ help
+ Architecture doesn't only execute the irq handler on the irq stack
+ but also irq_exit(). This way we can process softirqs on this irq
+ stack instead of switching to a new one when we call __do_softirq()
+ in the end of an hardirq.
+ This spares a stack switch and improves cache usage on softirq
+ processing.
+
#
# ABI hall of shame
#
diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c
index d50135be0c2..70f2f3925f0 100644
--- a/arch/arm/mach-bcm2835/bcm2835.c
+++ b/arch/arm/mach-bcm2835/bcm2835.c
@@ -14,7 +14,7 @@
#include <linux/delay.h>
#include <linux/init.h>
-#include <linux/irqchip/bcm2835.h>
+#include <linux/irqchip.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/clk/bcm2835.h>
@@ -130,8 +130,7 @@ static const char * const bcm2835_compat[] = {
DT_MACHINE_START(BCM2835, "BCM2835")
.map_io = bcm2835_map_io,
- .init_irq = bcm2835_init_irq,
- .handle_irq = bcm2835_handle_irq,
+ .init_irq = irqchip_init,
.init_machine = bcm2835_init,
.restart = bcm2835_restart,
.dt_compat = bcm2835_compat
diff --git a/arch/metag/kernel/irq.c b/arch/metag/kernel/irq.c
index 2a2c9d55187..3b4b7f6c095 100644
--- a/arch/metag/kernel/irq.c
+++ b/arch/metag/kernel/irq.c
@@ -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;
-
- local_irq_save(flags);
-
- 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);
+ 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"
+ );
}
#endif
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 501ac8b4dcd..8ceac478560 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -495,22 +495,9 @@ 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 */
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 38f3b7e47ec..b365d5cbb72 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -138,6 +138,7 @@ config PPC
select OLD_SIGSUSPEND
select OLD_SIGACTION if PPC32
select HAVE_DEBUG_STACKOVERFLOW
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK
config EARLY_PRINTK
bool
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index c7cb8c232d2..ba016561521 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -594,7 +594,7 @@ void irq_ctx_init(void)
}
}
-static inline void do_softirq_onstack(void)
+void do_softirq_own_stack(void)
{
struct thread_info *curtp, *irqtp;
@@ -612,21 +612,6 @@ 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);
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 8ac2097f13d..bb27a262c44 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -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;
-
- 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();
- }
+ unsigned long old, new;
+
+ /* 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);
}
/*
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 063af10ff3c..0833736afa3 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -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;
-
- local_irq_save(flags);
-
- 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);
+ 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"
+ );
}
#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 d4840cec2c5..666193f4e8b 100644
--- a/arch/sparc/kernel/irq_64.c
+++ b/arch/sparc/kernel/irq_64.c
@@ -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;
-
- if (in_interrupt())
- return;
-
- local_irq_save(flags);
+ void *orig_sp, *sp = softirq_stack[smp_processor_id()];
- 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));
- }
+ sp += THREAD_SIZE - 192 - STACK_BIAS;
- 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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f67e839f06c..5cd6eea9b7b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -123,6 +123,7 @@ config X86
select COMPAT_OLD_SIGACTION if IA32_EMULATION
select RTC_LIB
select HAVE_DEBUG_STACKOVERFLOW
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
config INSTRUCTION_DECODER
def_bool y
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b077f4cc225..083da7c2f40 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -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
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index 9a5c460404d..2e977b5d61d 100644
--- a/arch/x86/kernel/i8259.c
+++ b/arch/x86/kernel/i8259.c
@@ -312,8 +312,7 @@ static void init_8259A(int auto_eoi)
*/
outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
- /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
- to 0x20-0x27 on i386 */
+ /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
/* 8259A-1 (the master) has a slave on IR2 */
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 4186755f1d7..8a5bb01dbc0 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -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;
-
- local_irq_save(flags);
-
- 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));
+ curctx = current_thread_info();
+ irqctx = __this_cpu_read(softirq_ctx);
+ irqctx->tinfo.task = curctx->task;
+ irqctx->tinfo.previous_esp = current_stack_pointer;
- call_on_stack(__do_softirq, isp);
- /*
- * Shouldn't happen, we returned above if in_interrupt():
- */
- WARN_ON_ONCE(softirq_count());
- }
+ /* build the stack frame on the softirq stack */
+ isp = (u32 *) ((char *)irqctx + sizeof(*irqctx));
- local_irq_restore(flags);
+ call_on_stack(__do_softirq, isp);
}
bool handle_irq(unsigned irq, struct pt_regs *regs)
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index d04d3ecded6..4d1c746892e 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -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);
-}