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| author |   Jonathan Currier <dullfire@yahoo.com> | 2024-11-17 17:48:42 -0600 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2025-04-15 08:32:18 +0200 |
| commit | cf761e3dacc6ad5f65a4886d00da1f9681e6805a (patch) | |
| tree | 7d5607abc6d650517fa15a070d0f2ba6746ae28e | |
| parent | Linux 6.15-rc2 (diff) | |
| download | wireguard-linux-cf761e3dacc6ad5f65a4886d00da1f9681e6805a.tar.xz wireguard-linux-cf761e3dacc6ad5f65a4886d00da1f9681e6805a.zip | |
PCI/MSI: Add an option to write MSIX ENTRY_DATA before any reads
Commit 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries") introduced a
readl() from ENTRY_VECTOR_CTRL before the writel() to ENTRY_DATA.
This is correct, however some hardware, like the Sun Neptune chips, the NIU
module, will cause an error and/or fatal trap if any MSIX table entry is
read before the corresponding ENTRY_DATA field is written to.
Add an optional early writel() in msix_prepare_msi_desc().
Fixes: 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries")
Signed-off-by: Jonathan Currier <dullfire@yahoo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241117234843.19236-2-dullfire@yahoo.com
| -rw-r--r-- | drivers/pci/msi/msi.c | 3 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c index 6569ba3577fe..8b8848788618 100644 --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -615,6 +615,9 @@ void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc) void __iomem *addr = pci_msix_desc_addr(desc); desc->pci.msi_attrib.can_mask = 1; + /* Workaround for SUN NIU insanity, which requires write before read */ + if (dev->dev_flags & PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST) + writel(0, addr + PCI_MSIX_ENTRY_DATA); desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); } } diff --git a/include/linux/pci.h b/include/linux/pci.h index 0e8e3fd77e96..51e2bd6405cd 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -245,6 +245,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11), /* Device does honor MSI masking despite saying otherwise */ PCI_DEV_FLAGS_HAS_MSI_MASKING = (__force pci_dev_flags_t) (1 << 12), + /* Device requires write to PCI_MSIX_ENTRY_DATA before any MSIX reads */ + PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST = (__force pci_dev_flags_t) (1 << 13), }; enum pci_irq_reroute_variant { |