Patch "powerpc/msi: Fix deassociation of MSI descriptors" has been added to the 4.14-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    powerpc/msi: Fix deassociation of MSI descriptors

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-msi-fix-deassociation-of-msi-descriptors.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c61df2f3661313a996d6baa620349e5160ed46c1
Author: Marc Zyngier <maz@xxxxxxxxxx>
Date:   Sat Dec 17 10:46:44 2022 +0000

    powerpc/msi: Fix deassociation of MSI descriptors
    
    [ Upstream commit 4545c6a3d6ba71747eaa984c338ddd745e56e23f ]
    
    Since 2f2940d16823 ("genirq/msi: Remove filter from
    msi_free_descs_free_range()"), the core MSI code relies on the
    msi_desc->irq field to have been cleared before the descriptor
    can be freed, as it indicates that there is no association with
    a device anymore.
    
    The irq domain code provides this guarantee, and so does s390,
    which is one of the two architectures not using irq domains for
    MSIs.
    
    Powerpc, however, is missing this particular requirements,
    leading in a splat and leaked MSI descriptors.
    
    Adding the now required irq reset to the handful of powerpc backends
    that implement MSIs fixes that particular problem.
    
    Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
    Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/70dab88e-6119-0c12-7c6a-61bcbe239f66@xxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/powerpc/platforms/4xx/hsta_msi.c b/arch/powerpc/platforms/4xx/hsta_msi.c
index 9926ad67af76..ac5fbb2492aa 100644
--- a/arch/powerpc/platforms/4xx/hsta_msi.c
+++ b/arch/powerpc/platforms/4xx/hsta_msi.c
@@ -121,6 +121,7 @@ static void hsta_teardown_msi_irqs(struct pci_dev *dev)
 		msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
 		pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
 			 entry->irq, irq);
+		entry->irq = 0;
 	}
 }
 
diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index e98b61c06a81..1c889a9e1a4f 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -299,6 +299,7 @@ static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
 
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 	}
 }
 
diff --git a/arch/powerpc/platforms/pasemi/msi.c b/arch/powerpc/platforms/pasemi/msi.c
index d9cd510c8865..6e54377663db 100644
--- a/arch/powerpc/platforms/pasemi/msi.c
+++ b/arch/powerpc/platforms/pasemi/msi.c
@@ -74,6 +74,7 @@ static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, ALLOC_CHUNK);
 	}
 
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index d43d3d1b27ed..83c6ea6a82e0 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -137,6 +137,7 @@ static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 		msi_data = irq_get_chip_data(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 	}
 
diff --git a/arch/powerpc/sysdev/mpic_u3msi.c b/arch/powerpc/sysdev/mpic_u3msi.c
index cfc1c57d760f..26db91c8feff 100644
--- a/arch/powerpc/sysdev/mpic_u3msi.c
+++ b/arch/powerpc/sysdev/mpic_u3msi.c
@@ -116,6 +116,7 @@ static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
 	}