linux-kernel - [patch V1A 09/20] genirq/msi: Make msi_get

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Message-ID: <87pmdrta20.ffs@tglx>
Date:   Sun, 13 Nov 2022 11:37:11 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Joerg Roedel <joro@...tes.org>,
        Will Deacon <will@...nel.org>, linux-pci@...r.kernel.org,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
        Marc Zyngier <maz@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jason Gunthorpe <jgg@...lanox.com>,
        Dave Jiang <dave.jiang@...el.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Kevin Tian <kevin.tian@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Logan Gunthorpe <logang@...tatee.com>,
        Ashok Raj <ashok.raj@...el.com>, Jon Mason <jdmason@...zu.us>,
        Allen Hubbe <allenbh@...il.com>,
        "Ahmed S. Darwish" <darwi@...utronix.de>,
        Reinette Chatre <reinette.chatre@...el.com>
Subject: [patch V1A 09/20] genirq/msi: Make msi_get_virq() device domain aware

From: Ahmed S. Darwish <darwi@...utronix.de>

In preparation of the upcoming per device multi MSI domain support, change
the interface to support lookups based on domain id and zero based index
within the domain.

Signed-off-by: Ahmed S. Darwish <darwi@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V1A: Fix the locking leak and a operator precedence issue (Dan, kernel robot)

     This was reported earlier and I missed to fold the fix before
     posting. :(
---
 include/linux/msi_api.h |   14 +++++++++++++-
 kernel/irq/msi.c        |   27 +++++++++++++++++++++------
 2 files changed, 34 insertions(+), 7 deletions(-)

--- a/include/linux/msi_api.h
+++ b/include/linux/msi_api.h
@@ -18,6 +18,18 @@ enum msi_domain_ids {
 	MSI_MAX_DEVICE_IRQDOMAINS,
 };
 
-unsigned int msi_get_virq(struct device *dev, unsigned int index);
+unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index);
+
+/**
+ * msi_get_virq - Lookup the Linux interrupt number for a MSI index on the default interrupt domain
+ * @dev:	Device for which the lookup happens
+ * @index:	The MSI index to lookup
+ *
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
+ */
+static inline unsigned int msi_get_virq(struct device *dev, unsigned int index)
+{
+	return msi_domain_get_virq(dev, MSI_DEFAULT_DOMAIN, index);
+}
 
 #endif
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -351,25 +351,38 @@ struct msi_desc *msi_next_desc(struct de
 EXPORT_SYMBOL_GPL(msi_next_desc);
 
 /**
- * msi_get_virq - Return Linux interrupt number of a MSI interrupt
+ * msi_domain_get_virq - Lookup the Linux interrupt number for a MSI index on a interrupt domain
  * @dev:	Device to operate on
+ * @domid:	Domain ID of the interrupt domain associated to the device
  * @index:	MSI interrupt index to look for (0-based)
  *
  * Return: The Linux interrupt number on success (> 0), 0 if not found
  */
-unsigned int msi_get_virq(struct device *dev, unsigned int index)
+unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)
 {
 	struct msi_desc *desc;
 	unsigned int ret = 0;
-	bool pcimsi;
+	bool pcimsi = false;
+	int base;
 
 	if (!dev->msi.data)
 		return 0;
 
-	pcimsi = dev_is_pci(dev) ? to_pci_dev(dev)->msi_enabled : false;
+	if (WARN_ON_ONCE(index >= MSI_MAX_INDEX))
+		return 0;
+
+	/* This check is only valid for the PCI default MSI domain */
+	if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)
+		pcimsi = to_pci_dev(dev)->msi_enabled;
 
 	msi_lock_descs(dev);
-	desc = xa_load(&dev->msi.data->__store, pcimsi ? 0 : index);
+
+	base = msi_get_domain_base_index(dev, domid);
+	if (base < 0)
+		goto unlock;
+
+	base += pcimsi ? 0 : index;
+	desc = xa_load(&dev->msi.data->__store, base);
 	if (desc && desc->irq) {
 		/*
 		 * PCI-MSI has only one descriptor for multiple interrupts.
@@ -383,10 +396,12 @@ unsigned int msi_get_virq(struct device
 			ret = desc->irq;
 		}
 	}
+
+unlock:
 	msi_unlock_descs(dev);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(msi_get_virq);
+EXPORT_SYMBOL_GPL(msi_domain_get_virq);
 
 #ifdef CONFIG_SYSFS
 static struct attribute *msi_dev_attrs[] = {