* [PATCH 5.10 70/99] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error
[not found] <20211220143029.352940568@linuxfoundation.org>
@ 2021-12-20 14:34 ` Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 5.10 71/99] PCI/MSI: Mask MSI-X vectors only on success Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2021-12-20 14:34 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Stefan Roese, Thomas Gleixner,
linux-pci, Bjorn Helgaas, Michal Simek, Marek Vasut
From: Thomas Gleixner <tglx@linutronix.de>
commit 94185adbfad56815c2c8401e16d81bdb74a79201 upstream.
PCI_MSIX_FLAGS_MASKALL is set in the MSI-X control register at MSI-X
interrupt setup time. It's cleared on success, but the error handling path
only clears the PCI_MSIX_FLAGS_ENABLE bit.
That's incorrect as the reset state of the PCI_MSIX_FLAGS_MASKALL bit is
zero. That can be observed via lspci:
Capabilities: [b0] MSI-X: Enable- Count=67 Masked+
Clear the bit in the error path to restore the reset state.
Fixes: 438553958ba1 ("PCI/MSI: Enable and mask MSI-X early")
Reported-by: Stefan Roese <sr@denx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Stefan Roese <sr@denx.de>
Cc: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87tufevoqx.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/msi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -879,7 +879,7 @@ out_free:
free_msi_irqs(dev);
out_disable:
- pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
+ pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
return ret;
}
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH 5.10 71/99] PCI/MSI: Mask MSI-X vectors only on success
[not found] <20211220143029.352940568@linuxfoundation.org>
2021-12-20 14:34 ` [PATCH 5.10 70/99] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error Greg Kroah-Hartman
@ 2021-12-20 14:34 ` Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2021-12-20 14:34 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Stefan Roese, Thomas Gleixner,
linux-pci, Bjorn Helgaas, Michal Simek, Marek Vasut
From: Stefan Roese <sr@denx.de>
commit 83dbf898a2d45289be875deb580e93050ba67529 upstream.
Masking all unused MSI-X entries is done to ensure that a crash kernel
starts from a clean slate, which correponds to the reset state of the
device as defined in the PCI-E specificion 3.0 and later:
Vector Control for MSI-X Table Entries
--------------------------------------
"00: Mask bit: When this bit is set, the function is prohibited from
sending a message using this MSI-X Table entry.
...
This bit’s state after reset is 1 (entry is masked)."
A Marvell NVME device fails to deliver MSI interrupts after trying to
enable MSI-X interrupts due to that masking. It seems to take the MSI-X
mask bits into account even when MSI-X is disabled.
While not specification compliant, this can be cured by moving the masking
into the success path, so that the MSI-X table entries stay in device reset
state when the MSI-X setup fails.
[ tglx: Move it into the success path, add comment and amend changelog ]
Fixes: aa8092c1d1f1 ("PCI/MSI: Mask all unused MSI-X entries")
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211210161025.3287927-1-sr@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/msi.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -828,9 +828,6 @@ static int msix_capability_init(struct p
goto out_disable;
}
- /* 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;
@@ -853,6 +850,16 @@ static int msix_capability_init(struct p
/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
dev->msix_enabled = 1;
+
+ /*
+ * Ensure that all table entries are masked to prevent
+ * stale entries from firing in a crash kernel.
+ *
+ * Done late to deal with a broken Marvell NVME device
+ * which takes the MSI-X mask bits into account even
+ * when MSI-X is disabled, which prevents MSI delivery.
+ */
+ msix_mask_all(base, tsize);
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
pcibios_free_irq(dev);
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-12-20 14:34 ` [PATCH 5.10 70/99] PCI/MSI: Clear PCI_MSIX_FLAGS_MASKALL on error Greg Kroah-Hartman
2021-12-20 14:34 ` [PATCH 5.10 71/99] PCI/MSI: Mask MSI-X vectors only on success Greg Kroah-Hartman
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