Patch "powerpc/msi: Fix deassociation of MSI descriptors" has been added to the 4.19-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 4.19-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-4.19 subdirectory.

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



commit 60543a5036bcd01c190e9850578ce71981f05884
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 1c18f2955f7d..8af640339de4 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 946a09ae9fb2..e6b35c25be21 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 44aedb6b9f55..870cff74ecc2 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);
 	}