Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Feedback-ID: i0ad843c9:Fastmail
From:   Samuel Holland <samuel@sholland.org>
To:     Marc Zyngier <maz@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Cc:     Samuel Holland <samuel@sholland.org>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Bartosz Golaszewski <brgl@bgdev.pl>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Borislav Petkov <bp@alien8.de>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@broadcom.com>,
        Chris Zankel <chris@zankel.net>,
        Colin Ian King <colin.king@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Dexuan Cui <decui@microsoft.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Guo Ren <guoren@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Helge Deller <deller@gmx.de>, Ingo Molnar <mingo@redhat.com>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
        Jan Beulich <jbeulich@suse.com>,
        Joerg Roedel <joro@8bytes.org>,
        Juergen Gross <jgross@suse.com>,
        Julia Lawall <Julia.Lawall@inria.fr>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Kees Cook <keescook@chromium.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Matt Turner <mattst88@gmail.com>,
        Max Filippov <jcmvbkbc@gmail.com>,
        Maximilian Heyne <mheyne@amazon.de>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        Rich Felker <dalias@libc.org>,
        Richard Henderson <rth@twiddle.net>,
        Rikard Falkeborn <rikard.falkeborn@gmail.com>,
        Rob Herring <robh@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Serge Semin <fancer.lancer@gmail.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Sven Schnelle <svens@stackframe.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Wei Liu <wei.liu@kernel.org>, Wei Xu <xuwei5@hisilicon.com>,
        Will Deacon <will@kernel.org>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        iommu@lists.linux-foundation.org, iommu@lists.linux.dev,
        linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-hyperv@vger.kernel.org, linux-ia64@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
        linux-parisc@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org,
        x86@kernel.org, xen-devel@lists.xenproject.org
Subject: [PATCH v3 6/8] genirq: Add and use an irq_data_update_affinity helper
Date:   Fri,  1 Jul 2022 15:00:54 -0500
Message-Id: <20220701200056.46555-7-samuel@sholland.org>
In-Reply-To: <20220701200056.46555-1-samuel@sholland.org>
References: <20220701200056.46555-1-samuel@sholland.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Some architectures and irqchip drivers modify the cpumask returned by
irq_data_get_affinity_mask, usually by copying in to it. This is
problematic for uniprocessor configurations, where the affinity mask
should be constant, as it is known at compile time.

Add and use a setter for the affinity mask, following the pattern of
irq_data_update_effective_affinity. This allows the getter function to
return a const cpumask pointer.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes in v3:
 - New patch to introduce irq_data_update_affinity

 arch/alpha/kernel/irq.c          | 2 +-
 arch/ia64/kernel/iosapic.c       | 2 +-
 arch/ia64/kernel/irq.c           | 4 ++--
 arch/ia64/kernel/msi_ia64.c      | 4 ++--
 arch/parisc/kernel/irq.c         | 2 +-
 drivers/irqchip/irq-bcm6345-l1.c | 4 ++--
 drivers/parisc/iosapic.c         | 2 +-
 drivers/sh/intc/chip.c           | 2 +-
 drivers/xen/events/events_base.c | 7 ++++---
 include/linux/irq.h              | 6 ++++++
 10 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/arch/alpha/kernel/irq.c b/arch/alpha/kernel/irq.c
index f6d2946edbd2..15f2effd6baf 100644
--- a/arch/alpha/kernel/irq.c
+++ b/arch/alpha/kernel/irq.c
@@ -60,7 +60,7 @@ int irq_select_affinity(unsigned int irq)
 		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
 	last_cpu = cpu;
 
-	cpumask_copy(irq_data_get_affinity_mask(data), cpumask_of(cpu));
+	irq_data_update_affinity(data, cpumask_of(cpu));
 	chip->irq_set_affinity(data, cpumask_of(cpu), false);
 	return 0;
 }
diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
index 35adcf89035a..99300850abc1 100644
--- a/arch/ia64/kernel/iosapic.c
+++ b/arch/ia64/kernel/iosapic.c
@@ -834,7 +834,7 @@ iosapic_unregister_intr (unsigned int gsi)
 	if (iosapic_intr_info[irq].count == 0) {
 #ifdef CONFIG_SMP
 		/* Clear affinity */
-		cpumask_setall(irq_get_affinity_mask(irq));
+		irq_data_update_affinity(irq_get_irq_data(irq), cpu_all_mask);
 #endif
 		/* Clear the interrupt information */
 		iosapic_intr_info[irq].dest = 0;
diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
index ecef17c7c35b..275b9ea58c64 100644
--- a/arch/ia64/kernel/irq.c
+++ b/arch/ia64/kernel/irq.c
@@ -57,8 +57,8 @@ static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
 {
 	if (irq < NR_IRQS) {
-		cpumask_copy(irq_get_affinity_mask(irq),
-			     cpumask_of(cpu_logical_id(hwid)));
+		irq_data_update_affinity(irq_get_irq_data(irq),
+					 cpumask_of(cpu_logical_id(hwid)));
 		irq_redir[irq] = (char) (redir & 0xff);
 	}
 }
diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
index df5c28f252e3..025e5133c860 100644
--- a/arch/ia64/kernel/msi_ia64.c
+++ b/arch/ia64/kernel/msi_ia64.c
@@ -37,7 +37,7 @@ static int ia64_set_msi_irq_affinity(struct irq_data *idata,
 	msg.data = data;
 
 	pci_write_msi_msg(irq, &msg);
-	cpumask_copy(irq_data_get_affinity_mask(idata), cpumask_of(cpu));
+	irq_data_update_affinity(idata, cpumask_of(cpu));
 
 	return 0;
 }
@@ -132,7 +132,7 @@ static int dmar_msi_set_affinity(struct irq_data *data,
 	msg.address_lo |= MSI_ADDR_DEST_ID_CPU(cpu_physical_id(cpu));
 
 	dmar_msi_write(irq, &msg);
-	cpumask_copy(irq_data_get_affinity_mask(data), mask);
+	irq_data_update_affinity(data, mask);
 
 	return 0;
 }
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 0fe2d79fb123..5ebb1771b4ab 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -315,7 +315,7 @@ unsigned long txn_affinity_addr(unsigned int irq, int cpu)
 {
 #ifdef CONFIG_SMP
 	struct irq_data *d = irq_get_irq_data(irq);
-	cpumask_copy(irq_data_get_affinity_mask(d), cpumask_of(cpu));
+	irq_data_update_affinity(d, cpumask_of(cpu));
 #endif
 
 	return per_cpu(cpu_data, cpu).txn_addr;
diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
index 142a7431745f..6899e37810a8 100644
--- a/drivers/irqchip/irq-bcm6345-l1.c
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -216,11 +216,11 @@ static int bcm6345_l1_set_affinity(struct irq_data *d,
 		enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
 		if (enabled)
 			__bcm6345_l1_mask(d);
-		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+		irq_data_update_affinity(d, dest);
 		if (enabled)
 			__bcm6345_l1_unmask(d);
 	} else {
-		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+		irq_data_update_affinity(d, dest);
 	}
 	raw_spin_unlock_irqrestore(&intc->lock, flags);
 
diff --git a/drivers/parisc/iosapic.c b/drivers/parisc/iosapic.c
index 8a3b0c3a1e92..3a8c98615634 100644
--- a/drivers/parisc/iosapic.c
+++ b/drivers/parisc/iosapic.c
@@ -677,7 +677,7 @@ static int iosapic_set_affinity_irq(struct irq_data *d,
 	if (dest_cpu < 0)
 		return -1;
 
-	cpumask_copy(irq_data_get_affinity_mask(d), cpumask_of(dest_cpu));
+	irq_data_update_affinity(d, cpumask_of(dest_cpu));
 	vi->txn_addr = txn_affinity_addr(d->irq, dest_cpu);
 
 	spin_lock_irqsave(&iosapic_lock, flags);
diff --git a/drivers/sh/intc/chip.c b/drivers/sh/intc/chip.c
index 358df7510186..828d81e02b37 100644
--- a/drivers/sh/intc/chip.c
+++ b/drivers/sh/intc/chip.c
@@ -72,7 +72,7 @@ static int intc_set_affinity(struct irq_data *data,
 	if (!cpumask_intersects(cpumask, cpu_online_mask))
 		return -1;
 
-	cpumask_copy(irq_data_get_affinity_mask(data), cpumask);
+	irq_data_update_affinity(data, cpumask);
 
 	return IRQ_SET_MASK_OK_NOCOPY;
 }
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 46d9295d9a6e..5e8321f43cbd 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -528,9 +528,10 @@ static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
 	BUG_ON(irq == -1);
 
 	if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
-		cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
-		cpumask_copy(irq_get_effective_affinity_mask(irq),
-			     cpumask_of(cpu));
+		struct irq_data *data = irq_get_irq_data(irq);
+
+		irq_data_update_affinity(data, cpumask_of(cpu));
+		irq_data_update_effective_affinity(data, cpumask_of(cpu));
 	}
 
 	xen_evtchn_port_bind_to_cpu(evtchn, cpu, info->cpu);
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 69ee4e2f36ce..adcfebceb777 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -884,6 +884,12 @@ static inline struct cpumask *irq_data_get_affinity_mask(struct irq_data *d)
 	return d->common->affinity;
 }
 
+static inline void irq_data_update_affinity(struct irq_data *d,
+					    const struct cpumask *m)
+{
+	cpumask_copy(d->common->affinity, m);
+}
+
 static inline struct cpumask *irq_get_affinity_mask(int irq)
 {
 	struct irq_data *d = irq_get_irq_data(irq);
-- 
2.35.1