[tip: irq/msi] PCI/MSI: Sanitize MSI-X table map handling

tip-bot2 for Thomas Gleixner
2021-12-09T16:07:12Z

The following commit has been merged into the irq/msi branch of tip:

Commit-ID: 85aa607e79f8343f1ea028b29bdf8b6bc99c729a
Gitweb: https://git.kernel.org/tip/85aa607e79f8343f1ea028b29bdf8b6bc99c729a
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 06 Dec 2021 23:27:54 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 09 Dec 2021 11:52:22 +01:00

PCI/MSI: Sanitize MSI-X table map handling

Unmapping the MSI-X base mapping in the loops which allocate/free MSI
descriptors 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>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211206210224.871651518@linutronix.de

---
drivers/pci/msi/msi.c | 18 ++++++++----------
include/linux/pci.h | 1 +
2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 8926a6c..465fe9e 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -241,14 +241,14 @@ static void free_msi_irqs(struct pci_dev *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_dev *dev, void __iomem *base,
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 pci_dev *dev, struct msix_entry *entries,
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)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 18a75c8..8cb1036 100644
--- 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;