From 6988e0e0d28328467e218f59589b2770675a9ebd Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 8 May 2018 13:14:31 +0100
Subject: [PATCH] genirq/msi: Limit level-triggered MSI to platform devices
Nobody would be insane enough to try and use level triggered
MSIs on PCI, but let's make sure it doesn't happen. Also,
let's mandate that the irqchip backing the platform MSI domain
is providing the IRQCHIP_SUPPORTS_LEVEL_MSI flag.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20180508121438.11301-3-marc.zyngier@arm.com
---
drivers/base/platform-msi.c | 3 +++
drivers/bus/fsl-mc/fsl-mc-msi.c | 2 ++
drivers/pci/msi.c | 3 +++
include/linux/irq.h | 1 +
4 files changed, 9 insertions(+)
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 8e22073aeeeda..60d6cc618f1c4 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -101,6 +101,9 @@ static void platform_msi_update_chip_ops(struct msi_domain_info *info)
chip->irq_set_affinity = msi_domain_set_affinity;
if (!chip->irq_write_msi_msg)
chip->irq_write_msi_msg = platform_msi_write_msg;
+ if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
+ !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)))
+ info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
}
static void platform_msi_free_descs(struct device *dev, int base, int nvec)
diff --git a/drivers/bus/fsl-mc/fsl-mc-msi.c b/drivers/bus/fsl-mc/fsl-mc-msi.c
index ec35e255b4967..8b9c66d7c4ffd 100644
--- a/drivers/bus/fsl-mc/fsl-mc-msi.c
+++ b/drivers/bus/fsl-mc/fsl-mc-msi.c
@@ -163,6 +163,8 @@ struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
{
struct irq_domain *domain;
+ if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
+ info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
fsl_mc_msi_update_dom_ops(info);
if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 30250631efe79..f45b74fcc059a 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1434,6 +1434,9 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
{
struct irq_domain *domain;
+ if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
+ info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
+
if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
pci_msi_domain_update_dom_ops(info);
if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 65916a305f3dd..b2067083aa943 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -512,6 +512,7 @@ enum {
IRQCHIP_SKIP_SET_WAKE = (1 << 4),
IRQCHIP_ONESHOT_SAFE = (1 << 5),
IRQCHIP_EOI_THREADED = (1 << 6),
+ IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7),
};
#include <linux/irqdesc.h>
--
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