From: Frederic Weisbecker <frederic@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Ard Biesheuvel <ardb@kernel.org>,
James Morse <james.morse@arm.com>,
Quentin Perret <qperret@google.com>,
Mark Rutland <mark.rutland@arm.com>
Subject: [PATCH 3/4] arm64: Implement IRQ exit preemption static call for dynamic preemption
Date: Tue, 21 Sep 2021 01:32:36 +0200 [thread overview]
Message-ID: <20210920233237.90463-4-frederic@kernel.org> (raw)
In-Reply-To: <20210920233237.90463-1-frederic@kernel.org>
arm64 doesn't support generic entry yet, so the architecture's own IRQ
exit preemption path needs to be exposed through the relevant static
call.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Quentin Perret <qperret@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/include/asm/preempt.h | 7 +++++++
arch/arm64/kernel/entry-common.c | 15 ++++++++++++---
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index e83f0982b99c..4fbbe644532f 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -3,6 +3,7 @@
#define __ASM_PREEMPT_H
#include <linux/thread_info.h>
+#include <linux/static_call_types.h>
#define PREEMPT_NEED_RESCHED BIT(32)
#define PREEMPT_ENABLED (PREEMPT_NEED_RESCHED)
@@ -86,4 +87,10 @@ void preempt_schedule_notrace(void);
#define __preempt_schedule_notrace() preempt_schedule_notrace()
#endif /* CONFIG_PREEMPTION */
+#ifdef CONFIG_PREEMPT_DYNAMIC
+void arm64_preempt_schedule_irq(void);
+#define __irqentry_exit_cond_resched_func arm64_preempt_schedule_irq
+DECLARE_STATIC_CALL(irqentry_exit_cond_resched, __irqentry_exit_cond_resched_func);
+#endif /* CONFIG_PREEMPT_DYNAMIC */
+
#endif /* __ASM_PREEMPT_H */
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 32f9796c4ffe..f1c739dd874d 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -12,6 +12,7 @@
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/thread_info.h>
+#include <linux/static_call.h>
#include <asm/cpufeature.h>
#include <asm/daifflags.h>
@@ -235,7 +236,7 @@ static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
exit_to_kernel_mode(regs);
}
-static void __sched arm64_preempt_schedule_irq(void)
+void __sched arm64_preempt_schedule_irq(void)
{
lockdep_assert_irqs_disabled();
@@ -259,6 +260,9 @@ static void __sched arm64_preempt_schedule_irq(void)
if (system_capabilities_finalized())
preempt_schedule_irq();
}
+#ifdef CONFIG_PREEMPT_DYNAMIC
+DEFINE_STATIC_CALL(irqentry_exit_cond_resched, arm64_preempt_schedule_irq);
+#endif
static void do_interrupt_handler(struct pt_regs *regs,
void (*handler)(struct pt_regs *))
@@ -446,8 +450,13 @@ static void noinstr el1_interrupt(struct pt_regs *regs,
* preempt_count().
*/
if (IS_ENABLED(CONFIG_PREEMPTION) &&
- READ_ONCE(current_thread_info()->preempt_count) == 0)
- arm64_preempt_schedule_irq();
+ READ_ONCE(current_thread_info()->preempt_count) == 0) {
+#ifdef CONFIG_PREEMPT_DYNAMIC
+ static_call(irqentry_exit_cond_resched)();
+#else
+ arm64_preempt_schedule_irq();
+#endif
+ }
exit_el1_irq_or_nmi(regs);
}
--
2.25.1
next prev parent reply other threads:[~2021-09-20 23:38 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-20 23:32 [PATCH 0/4] arm64: Support dynamic preemption Frederic Weisbecker
2021-09-20 23:32 ` [PATCH 1/4] sched/preempt: Prepare for supporting !CONFIG_GENERIC_ENTRY " Frederic Weisbecker
2021-09-21 7:10 ` Peter Zijlstra
2021-09-21 13:50 ` Mark Rutland
2021-09-20 23:32 ` [PATCH 2/4] arm64: implement support for static call trampolines Frederic Weisbecker
2021-09-21 7:09 ` Peter Zijlstra
2021-09-21 14:44 ` Ard Biesheuvel
2021-09-21 15:08 ` Peter Zijlstra
2021-09-21 15:33 ` Mark Rutland
2021-09-21 15:55 ` Ard Biesheuvel
2021-09-21 16:28 ` Mark Rutland
2021-09-25 17:46 ` David Laight
2021-09-27 8:58 ` Mark Rutland
2021-09-21 16:10 ` Ard Biesheuvel
2021-09-20 23:32 ` Frederic Weisbecker [this message]
2021-09-20 23:32 ` [PATCH 4/4] arm64: Implement HAVE_PREEMPT_DYNAMIC Frederic Weisbecker
2021-10-25 12:20 [PATCH 0/4] arm64: Support dynamic preemption v2 Frederic Weisbecker
2021-10-25 12:21 ` [PATCH 3/4] arm64: Implement IRQ exit preemption static call for dynamic preemption Frederic Weisbecker
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