From cf761e3dacc6ad5f65a4886d00da1f9681e6805a Mon Sep 17 00:00:00 2001 From: Jonathan Currier Date: Sun, 17 Nov 2024 17:48:42 -0600 Subject: 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 Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241117234843.19236-2-dullfire@yahoo.com --- include/linux/pci.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/pci.h') 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 { -- cgit v1.2.3