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

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 8e22073aeeeda11ff1d0afa3e5723fc446adbf48..60d6cc618f1c4c2d90dad17765494e9e26cbf869 100644 (file)
--- 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 ec35e255b49674b3e16648bd5b1c5bb627d4c795..8b9c66d7c4ffd9af6ffc29840cece136ff4f766c 100644 (file)
--- 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 30250631efe791fde3a9dfcf5afbe240335b5bbd..f45b74fcc059ae15a5734ba0b26e977b097df5a5 100644 (file)
--- 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 65916a305f3ddbb9cb4185b25771c074f42bef50..b2067083aa9436ea3bc9f3a62bd6d1ae980627f7 100644 (file)
--- 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>