From: Sumit Garg <sumit.garg@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de,
jason@lakedaemon.net, maz@kernel.org,
julien.thierry.kdev@gmail.com, dianders@chromium.org,
daniel.thompson@linaro.org, jason.wessel@windriver.com,
kgdb-bugreport@lists.sourceforge.net,
linux-kernel@vger.kernel.org, Sumit Garg <sumit.garg@linaro.org>
Subject: [PATCH v2 1/4] arm64: smp: Introduce a new IPI as IPI_CALL_NMI_FUNC
Date: Wed, 20 May 2020 16:41:52 +0530 [thread overview]
Message-ID: <1589973115-14757-2-git-send-email-sumit.garg@linaro.org> (raw)
In-Reply-To: <1589973115-14757-1-git-send-email-sumit.garg@linaro.org>
Introduce a new inter processor interrupt as IPI_CALL_NMI_FUNC that
can be invoked to run special handlers in NMI context. One such handler
example is kgdb_nmicallback() which is invoked in order to round up CPUs
to enter kgdb context.
As currently pseudo NMIs are supported on specific arm64 platforms which
incorporates GICv3 or later version of interrupt controller. In case a
particular platform doesn't support pseudo NMIs, IPI_CALL_NMI_FUNC will
act as a normal IPI which can still be used to invoke special handlers.
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
arch/arm64/include/asm/hardirq.h | 2 +-
arch/arm64/include/asm/smp.h | 1 +
arch/arm64/kernel/smp.c | 13 ++++++++++++-
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h
index 87ad961..abaa23a 100644
--- a/arch/arm64/include/asm/hardirq.h
+++ b/arch/arm64/include/asm/hardirq.h
@@ -13,7 +13,7 @@
#include <asm/kvm_arm.h>
#include <asm/sysreg.h>
-#define NR_IPI 7
+#define NR_IPI 8
typedef struct {
unsigned int __softirq_pending;
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index bec6ef0..b4602de 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -106,6 +106,7 @@ extern void secondary_entry(void);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+extern void arch_send_call_nmi_func_ipi_mask(const struct cpumask *mask);
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d29823a..236784e 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -81,7 +81,8 @@ enum ipi_msg_type {
IPI_CPU_CRASH_STOP,
IPI_TIMER,
IPI_IRQ_WORK,
- IPI_WAKEUP
+ IPI_WAKEUP,
+ IPI_CALL_NMI_FUNC
};
#ifdef CONFIG_HOTPLUG_CPU
@@ -802,6 +803,7 @@ static const char *ipi_types[NR_IPI] __tracepoint_string = {
S(IPI_TIMER, "Timer broadcast interrupts"),
S(IPI_IRQ_WORK, "IRQ work interrupts"),
S(IPI_WAKEUP, "CPU wake-up interrupts"),
+ S(IPI_CALL_NMI_FUNC, "NMI function call interrupts"),
};
static void smp_cross_call(const struct cpumask *target, unsigned int ipinr);
@@ -855,6 +857,11 @@ void arch_irq_work_raise(void)
}
#endif
+void arch_send_call_nmi_func_ipi_mask(const struct cpumask *mask)
+{
+ smp_cross_call(mask, IPI_CALL_NMI_FUNC);
+}
+
static void local_cpu_stop(void)
{
set_cpu_online(smp_processor_id(), false);
@@ -949,6 +956,10 @@ static void do_handle_IPI(int ipinr)
break;
#endif
+ case IPI_CALL_NMI_FUNC:
+ /* nop, IPI handlers for special features can be added here. */
+ break;
+
default:
pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
break;
--
2.7.4
next prev parent reply other threads:[~2020-05-20 11:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 11:11 [PATCH v2 0/4] arm64: Introduce new IPI as IPI_CALL_NMI_FUNC Sumit Garg
2020-05-20 11:11 ` Sumit Garg [this message]
2020-05-20 11:11 ` [PATCH v2 2/4] irqchip/gic-v3: Enable support for SGIs to act as NMIs Sumit Garg
2020-05-20 11:11 ` [PATCH v2 3/4] arm64: smp: Setup IPI_CALL_NMI_FUNC as a pseudo NMI Sumit Garg
2020-05-20 11:11 ` [PATCH v2 4/4] arm64: kgdb: Round up cpus using IPI_CALL_NMI_FUNC Sumit Garg
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1589973115-14757-2-git-send-email-sumit.garg@linaro.org \
--to=sumit.garg@linaro.org \
--cc=catalin.marinas@arm.com \
--cc=daniel.thompson@linaro.org \
--cc=dianders@chromium.org \
--cc=jason.wessel@windriver.com \
--cc=jason@lakedaemon.net \
--cc=julien.thierry.kdev@gmail.com \
--cc=kgdb-bugreport@lists.sourceforge.net \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).