* [PATCH 0/3] x86/irq: slightly improve handle_irq
@ 2019-08-04 8:18 Heiner Kallweit
2019-08-04 8:19 ` [PATCH 1/3] x86/irq: improve definition of VECTOR_SHUTDOWN et al Heiner Kallweit
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Heiner Kallweit @ 2019-08-04 8:18 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin, x86
Cc: Linux Kernel Mailing List
When checking something else I stumbled across this code.
This patch set simplifies it a little bit.
Heiner Kallweit (3):
x86/irq: improve definition of VECTOR_SHUTDOWN et al
x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific
handle_irq
x86/irq: slightly improve do_IRQ
arch/x86/include/asm/hw_irq.h | 4 ++--
arch/x86/include/asm/irq.h | 2 +-
arch/x86/kernel/irq.c | 7 ++++---
arch/x86/kernel/irq_32.c | 7 +------
arch/x86/kernel/irq_64.c | 6 +-----
5 files changed, 9 insertions(+), 17 deletions(-)
--
2.22.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/3] x86/irq: improve definition of VECTOR_SHUTDOWN et al
2019-08-04 8:18 [PATCH 0/3] x86/irq: slightly improve handle_irq Heiner Kallweit
@ 2019-08-04 8:19 ` Heiner Kallweit
2019-08-04 8:21 ` [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq Heiner Kallweit
2019-08-04 8:22 ` [PATCH 3/3] x86/irq: slightly improve do_IRQ Heiner Kallweit
2 siblings, 0 replies; 5+ messages in thread
From: Heiner Kallweit @ 2019-08-04 8:19 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin, x86
Cc: Linux Kernel Mailing List
These values are used with IS_ERR(), so it's more intuitive to define
them like a standard PTR_ERR() of a negative errno.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
arch/x86/include/asm/hw_irq.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index cbd97e22d..4154bc5f6 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -153,8 +153,8 @@ extern char irq_entries_start[];
extern char spurious_entries_start[];
#define VECTOR_UNUSED NULL
-#define VECTOR_SHUTDOWN ((void *)~0UL)
-#define VECTOR_RETRIGGERED ((void *)~1UL)
+#define VECTOR_SHUTDOWN ((void *)-1L)
+#define VECTOR_RETRIGGERED ((void *)-2L)
typedef struct irq_desc* vector_irq_t[NR_VECTORS];
DECLARE_PER_CPU(vector_irq_t, vector_irq);
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq
2019-08-04 8:18 [PATCH 0/3] x86/irq: slightly improve handle_irq Heiner Kallweit
2019-08-04 8:19 ` [PATCH 1/3] x86/irq: improve definition of VECTOR_SHUTDOWN et al Heiner Kallweit
@ 2019-08-04 8:21 ` Heiner Kallweit
2019-08-19 10:41 ` Thomas Gleixner
2019-08-04 8:22 ` [PATCH 3/3] x86/irq: slightly improve do_IRQ Heiner Kallweit
2 siblings, 1 reply; 5+ messages in thread
From: Heiner Kallweit @ 2019-08-04 8:21 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin, x86
Cc: Linux Kernel Mailing List
The code can be simplified a little by factoring out the IS_ERR_OR_NULL
check from the platform-specific handle_irq implementations.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
arch/x86/include/asm/irq.h | 2 +-
arch/x86/kernel/irq.c | 5 +++--
arch/x86/kernel/irq_32.c | 7 +------
arch/x86/kernel/irq_64.c | 6 +-----
4 files changed, 6 insertions(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 8f95686ec..a176f6165 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -34,7 +34,7 @@ extern __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs);
extern void (*x86_platform_ipi_callback)(void);
extern void native_init_IRQ(void);
-extern bool handle_irq(struct irq_desc *desc, struct pt_regs *regs);
+extern void handle_irq(struct irq_desc *desc, struct pt_regs *regs);
extern __visible unsigned int do_IRQ(struct pt_regs *regs);
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 4215653f8..042f363a8 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -243,8 +243,7 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
desc = __this_cpu_read(vector_irq[vector]);
-
- if (!handle_irq(desc, regs)) {
+ if (IS_ERR_OR_NULL(desc)) {
ack_APIC_irq();
if (desc != VECTOR_RETRIGGERED && desc != VECTOR_SHUTDOWN) {
@@ -254,6 +253,8 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
} else {
__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
}
+ } else {
+ handle_irq(desc, regs);
}
exiting_irq();
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index fc34816c6..a759ca97c 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -148,18 +148,13 @@ void do_softirq_own_stack(void)
call_on_stack(__do_softirq, isp);
}
-bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
+void handle_irq(struct irq_desc *desc, struct pt_regs *regs)
{
int overflow = check_stack_overflow();
- if (IS_ERR_OR_NULL(desc))
- return false;
-
if (user_mode(regs) || !execute_on_irq_stack(overflow, desc)) {
if (unlikely(overflow))
print_stack_overflow();
generic_handle_irq_desc(desc);
}
-
- return true;
}
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 6bf6517a0..cd4595b71 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -26,13 +26,9 @@
DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
DECLARE_INIT_PER_CPU(irq_stack_backing_store);
-bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
+void handle_irq(struct irq_desc *desc, struct pt_regs *regs)
{
- if (IS_ERR_OR_NULL(desc))
- return false;
-
generic_handle_irq_desc(desc);
- return true;
}
#ifdef CONFIG_VMAP_STACK
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 3/3] x86/irq: slightly improve do_IRQ
2019-08-04 8:18 [PATCH 0/3] x86/irq: slightly improve handle_irq Heiner Kallweit
2019-08-04 8:19 ` [PATCH 1/3] x86/irq: improve definition of VECTOR_SHUTDOWN et al Heiner Kallweit
2019-08-04 8:21 ` [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq Heiner Kallweit
@ 2019-08-04 8:22 ` Heiner Kallweit
2 siblings, 0 replies; 5+ messages in thread
From: Heiner Kallweit @ 2019-08-04 8:22 UTC (permalink / raw)
To: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin, x86
Cc: Linux Kernel Mailing List
It's simpler and more intuitive to directly check for VECTOR_UNUSED.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
arch/x86/kernel/irq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 042f363a8..2f1a78c4d 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -246,7 +246,7 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
if (IS_ERR_OR_NULL(desc)) {
ack_APIC_irq();
- if (desc != VECTOR_RETRIGGERED && desc != VECTOR_SHUTDOWN) {
+ if (desc == VECTOR_UNUSED) {
pr_emerg_ratelimited("%s: %d.%d No irq handler for vector\n",
__func__, smp_processor_id(),
vector);
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq
2019-08-04 8:21 ` [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq Heiner Kallweit
@ 2019-08-19 10:41 ` Thomas Gleixner
0 siblings, 0 replies; 5+ messages in thread
From: Thomas Gleixner @ 2019-08-19 10:41 UTC (permalink / raw)
To: Heiner Kallweit
Cc: Ingo Molnar, Borislav Petkov, H. Peter Anvin, x86,
Linux Kernel Mailing List
On Sun, 4 Aug 2019, Heiner Kallweit wrote:
> -
> - if (!handle_irq(desc, regs)) {
> + if (IS_ERR_OR_NULL(desc)) {
This really want's an unlikely or preferrably be written as:
if (likely(!IS_ERR_OR_NULL(desc))) {
handle_irq(desc);
} else {
> ack_APIC_irq();
>
> if (desc != VECTOR_RETRIGGERED && desc != VECTOR_SHUTDOWN) {
> @@ -254,6 +253,8 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
> } else {
> __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
> }
> + } else {
> + handle_irq(desc, regs);
> }
>
> diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
> index 6bf6517a0..cd4595b71 100644
> --- a/arch/x86/kernel/irq_64.c
> +++ b/arch/x86/kernel/irq_64.c
> @@ -26,13 +26,9 @@
> DEFINE_PER_CPU_PAGE_ALIGNED(struct irq_stack, irq_stack_backing_store) __visible;
> DECLARE_INIT_PER_CPU(irq_stack_backing_store);
>
> -bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
> +void handle_irq(struct irq_desc *desc, struct pt_regs *regs)
> {
> - if (IS_ERR_OR_NULL(desc))
> - return false;
> -
> generic_handle_irq_desc(desc);
With that the function call does not make any sense for 64bit. So the
wrapper should be an inline and only for 32bit a function call.
Thanks,
tglx
^ permalink raw reply [flat|nested] 5+ messages in thread
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2019-08-04 8:18 [PATCH 0/3] x86/irq: slightly improve handle_irq Heiner Kallweit
2019-08-04 8:19 ` [PATCH 1/3] x86/irq: improve definition of VECTOR_SHUTDOWN et al Heiner Kallweit
2019-08-04 8:21 ` [PATCH 2/3] x86/irq: factor out IS_ERR_OR_NULL check from platfom-specific handle_irq Heiner Kallweit
2019-08-19 10:41 ` Thomas Gleixner
2019-08-04 8:22 ` [PATCH 3/3] x86/irq: slightly improve do_IRQ Heiner Kallweit
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