[patch V2 19/23] PCI/MSI: Sanitize MSIX table map handling

Thomas Gleixner
2021-12-06T22:29:12Z

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>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
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;