From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/apic] x86/ioapic: Cleanup the timer_works() irqflags mess
Date: Thu, 10 Dec 2020 22:04:34 -0000 [thread overview]
Message-ID: <160763787415.3364.14966268731529828798.tip-bot2@tip-bot2> (raw)
In-Reply-To: <87k0tpju47.fsf@nanos.tec.linutronix.de>
The following commit has been merged into the x86/apic branch of tip:
Commit-ID: 058df195c23403f91acc028e39ca2ad599d0af52
Gitweb: https://git.kernel.org/tip/058df195c23403f91acc028e39ca2ad599d0af52
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 10 Dec 2020 21:15:04 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 10 Dec 2020 23:02:31 +01:00
x86/ioapic: Cleanup the timer_works() irqflags mess
Mark tripped over the creative irqflags handling in the IO-APIC timer
delivery check which ends up doing:
local_irq_save(flags);
local_irq_enable();
local_irq_restore(flags);
which triggered a new consistency check he's working on required for
replacing the POPF based restore with a conditional STI.
That code is a historical mess and none of this is needed. Make it
straightforward use local_irq_disable()/enable() as that's all what is
required. It is invoked from interrupt enabled code nowadays.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/87k0tpju47.fsf@nanos.tec.linutronix.de
---
arch/x86/kernel/apic/io_apic.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 089e755..e4ab480 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1620,21 +1620,16 @@ static void __init delay_without_tsc(void)
static int __init timer_irq_works(void)
{
unsigned long t1 = jiffies;
- unsigned long flags;
if (no_timer_check)
return 1;
- local_save_flags(flags);
local_irq_enable();
-
if (boot_cpu_has(X86_FEATURE_TSC))
delay_with_tsc();
else
delay_without_tsc();
- local_irq_restore(flags);
-
/*
* Expect a few ticks at least, to be sure some possible
* glue logic does not lock up after one or two first
@@ -1643,10 +1638,10 @@ static int __init timer_irq_works(void)
* least one tick may be lost due to delays.
*/
- /* jiffies wrap? */
- if (time_after(jiffies, t1 + 4))
- return 1;
- return 0;
+ local_irq_disable();
+
+ /* Did jiffies advance? */
+ return time_after(jiffies, t1 + 4);
}
/*
@@ -2163,13 +2158,12 @@ static inline void __init check_timer(void)
struct irq_cfg *cfg = irqd_cfg(irq_data);
int node = cpu_to_node(0);
int apic1, pin1, apic2, pin2;
- unsigned long flags;
int no_pin1 = 0;
if (!global_clock_event)
return;
- local_irq_save(flags);
+ local_irq_disable();
/*
* get/set the timer IRQ vector:
@@ -2237,7 +2231,6 @@ static inline void __init check_timer(void)
goto out;
}
panic_if_irq_remap("timer doesn't work through Interrupt-remapped IO-APIC");
- local_irq_disable();
clear_IO_APIC_pin(apic1, pin1);
if (!no_pin1)
apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
@@ -2261,7 +2254,6 @@ static inline void __init check_timer(void)
/*
* Cleanup, just in case ...
*/
- local_irq_disable();
legacy_pic->mask(0);
clear_IO_APIC_pin(apic2, pin2);
apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
@@ -2278,7 +2270,6 @@ static inline void __init check_timer(void)
apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
goto out;
}
- local_irq_disable();
legacy_pic->mask(0);
apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
@@ -2297,7 +2288,6 @@ static inline void __init check_timer(void)
apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
goto out;
}
- local_irq_disable();
apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
if (apic_is_x2apic_enabled())
apic_printk(APIC_QUIET, KERN_INFO
@@ -2306,7 +2296,7 @@ static inline void __init check_timer(void)
panic("IO-APIC + timer doesn't work! Boot with apic=debug and send a "
"report. Then try booting with the 'noapic' option.\n");
out:
- local_irq_restore(flags);
+ local_irq_enable();
}
/*
next prev parent reply other threads:[~2020-12-10 23:11 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-20 11:46 [PATCH v2 00/12] x86: major paravirt cleanup Juergen Gross
2020-11-20 11:46 ` [PATCH v2 01/12] x86/xen: use specific Xen pv interrupt entry for MCE Juergen Gross
2020-12-09 21:03 ` Thomas Gleixner
2020-11-20 11:46 ` [PATCH v2 02/12] x86/xen: use specific Xen pv interrupt entry for DF Juergen Gross
2020-12-09 21:03 ` Thomas Gleixner
2020-11-20 11:46 ` [PATCH v2 03/12] x86/pv: switch SWAPGS to ALTERNATIVE Juergen Gross
2020-11-27 11:31 ` Borislav Petkov
2020-12-09 21:07 ` Thomas Gleixner
2020-11-20 11:46 ` [PATCH v2 04/12] x86/xen: drop USERGS_SYSRET64 paravirt call Juergen Gross
2020-12-02 12:32 ` Borislav Petkov
2020-12-02 14:48 ` Jürgen Groß
2020-12-02 17:08 ` Borislav Petkov
2020-11-20 11:46 ` [PATCH v2 05/12] x86: rework arch_local_irq_restore() to not use popf Juergen Gross
2020-11-20 11:59 ` Peter Zijlstra
2020-11-20 12:05 ` Jürgen Groß
2020-11-22 6:55 ` Jürgen Groß
2020-11-22 21:44 ` Andy Lutomirski
2020-11-23 5:21 ` Jürgen Groß
2020-11-23 15:15 ` Andy Lutomirski
2020-12-09 13:27 ` Mark Rutland
2020-12-09 14:02 ` Mark Rutland
2020-12-09 14:05 ` Jürgen Groß
2020-12-09 18:15 ` Mark Rutland
2020-12-09 18:54 ` Thomas Gleixner
2020-12-10 11:10 ` Mark Rutland
2020-12-10 20:15 ` x86/ioapic: Cleanup the timer_works() irqflags mess Thomas Gleixner
2020-12-10 22:04 ` tip-bot2 for Thomas Gleixner [this message]
2020-12-11 5:10 ` Jürgen Groß
2020-11-27 2:20 ` [x86] 97e8f0134a: fio.write_iops 8.6% improvement kernel test robot
2020-11-20 11:46 ` [PATCH v2 06/12] x86/paravirt: switch time pvops functions to use static_call() Juergen Gross
2020-11-20 12:01 ` Peter Zijlstra
2020-11-20 12:07 ` Jürgen Groß
2020-11-20 11:46 ` [PATCH v2 07/12] x86: add new features for paravirt patching Juergen Gross
2020-12-08 18:43 ` Borislav Petkov
2020-12-09 7:30 ` Jürgen Groß
2020-12-09 12:03 ` Borislav Petkov
2020-12-09 12:22 ` Jürgen Groß
2020-12-10 17:58 ` Borislav Petkov
2020-11-20 11:46 ` [PATCH v2 08/12] x86/paravirt: remove no longer needed 32-bit pvops cruft Juergen Gross
2020-11-20 12:08 ` Peter Zijlstra
2020-11-20 12:16 ` Jürgen Groß
2020-11-20 16:52 ` Arvind Sankar
2020-11-20 11:46 ` [PATCH v2 09/12] x86/paravirt: switch iret pvops to ALTERNATIVE Juergen Gross
2020-11-20 11:46 ` [PATCH v2 10/12] x86/paravirt: add new macros PVOP_ALT* supporting pvops in ALTERNATIVEs Juergen Gross
2020-11-20 11:46 ` [PATCH v2 11/12] x86/paravirt: switch functions with custom code to ALTERNATIVE Juergen Gross
2020-11-20 15:46 ` kernel test robot
2020-11-25 15:46 ` [x86/paravirt] fd8d46a7a2: kernel-selftests.livepatch.test-callbacks.sh.fail kernel test robot
2020-11-20 11:46 ` [PATCH v2 12/12] x86/paravirt: have only one paravirt patch function Juergen Gross
2020-11-20 14:18 ` kernel test robot
2020-11-20 12:53 ` [PATCH v2 00/12] x86: major paravirt cleanup Peter Zijlstra
2020-11-23 13:43 ` Peter Zijlstra
2020-12-15 11:42 ` Jürgen Groß
2020-12-15 14:18 ` Peter Zijlstra
2020-12-15 14:54 ` Peter Zijlstra
2020-12-15 15:07 ` Jürgen Groß
2020-12-16 0:38 ` Josh Poimboeuf
2020-12-16 8:40 ` Peter Zijlstra
2020-12-16 16:56 ` Josh Poimboeuf
2020-12-16 17:58 ` Peter Zijlstra
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