Message-ID: <20211126223825.205369150@linutronix.de>
From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Bjorn Helgaas <helgaas@kernel.org>, Marc Zygnier <maz@kernel.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Megha Dey <megha.dey@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, linux-pci@vger.kernel.org,
        Michael Ellerman <mpe@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        linuxppc-dev@lists.ozlabs.org,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        linux-mips@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        sparclinux@vger.kernel.org, x86@kernel.org,
        xen-devel@lists.xenproject.org, ath11k@lists.infradead.org,
        Wei Liu <wei.liu@kernel.org>, linux-hyperv@vger.kernel.org,
        Juergen Gross <jgross@suse.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>
Subject: [patch 19/22] PCI/MSI: Sanitize MSIX table map handling
References: <20211126222700.862407977@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date:   Sat, 27 Nov 2021 02:19:04 +0100 (CET)
Precedence: bulk

Unmapping the MSIX base mapping in the loops which allocate/free MSI
desciptors is daft and in the way of allowing runtime expansion of MSI-X
descriptors.

Store the mapping in struct pci_dev and free it after freeing the MSI-X
descriptors.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/pci/msi/msi.c |   18 ++++++++----------
 include/linux/pci.h   |    1 +
 2 files changed, 9 insertions(+), 10 deletions(-)

--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -241,14 +241,14 @@ static void free_msi_irqs(struct pci_dev
 	pci_msi_teardown_msi_irqs(dev);
 
 	list_for_each_entry_safe(entry, tmp, msi_list, list) {
-		if (entry->pci.msi_attrib.is_msix) {
-			if (list_is_last(&entry->list, msi_list))
-				iounmap(entry->pci.mask_base);
-		}
-
 		list_del(&entry->list);
 		free_msi_entry(entry);
 	}
+
+	if (dev->msix_base) {
+		iounmap(dev->msix_base);
+		dev->msix_base = NULL;
+	}
 }
 
 static void pci_intx_for_msi(struct pci_dev *dev, int enable)
@@ -501,10 +501,6 @@ static int msix_setup_entries(struct pci
 	for (i = 0, curmsk = masks; i < nvec; i++) {
 		entry = alloc_msi_entry(&dev->dev, 1, curmsk);
 		if (!entry) {
-			if (!i)
-				iounmap(base);
-			else
-				free_msi_irqs(dev);
 			/* No enough memory. Don't try again */
 			ret = -ENOMEM;
 			goto out;
@@ -602,12 +598,14 @@ static int msix_capability_init(struct p
 		goto out_disable;
 	}
 
+	dev->msix_base = base;
+
 	/* Ensure that all table entries are masked. */
 	msix_mask_all(base, tsize);
 
 	ret = msix_setup_entries(dev, base, entries, nvec, affd);
 	if (ret)
-		goto out_disable;
+		goto out_free;
 
 	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
 	if (ret)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -473,6 +473,7 @@ struct pci_dev {
 	u8		ptm_granularity;
 #endif
 #ifdef CONFIG_PCI_MSI
+	void __iomem	*msix_base;
 	const struct attribute_group **msi_irq_groups;
 #endif
 	struct pci_vpd	vpd;