From: dullfire@yahoo.com
To: "David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Jacob Keller <jacob.e.keller@intel.com>,
Simon Horman <horms@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Mostafa Saleh <smostafa@google.com>,
Marc Zyngier <maz@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org
Cc: Jonathan Currier <dullfire@yahoo.com>, stable@vger.kernel.org
Subject: [PATCH 1/2] PCI/MSI: Add MSIX option to write to ENTRY_DATA before any reads
Date: Sun, 17 Nov 2024 17:48:42 -0600 [thread overview]
Message-ID: <20241117234843.19236-2-dullfire@yahoo.com> (raw)
In-Reply-To: <20241117234843.19236-1-dullfire@yahoo.com>
From: Jonathan Currier <dullfire@yahoo.com>
Commit 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries")
introduces 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. This patch adds an optional early writel() in msix_prepare_msi_desc().
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Currier <dullfire@yahoo.com>
---
drivers/pci/msi/msi.c | 2 ++
include/linux/pci.h | 2 ++
2 files changed, 4 insertions(+)
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 3a45879d85db..50d87fb5e37f 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -611,6 +611,8 @@ void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc)
if (desc->pci.msi_attrib.can_mask) {
void __iomem *addr = pci_msix_desc_addr(desc);
+ 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 37d97bef060f..b8b95b58d522 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 {
--
2.45.2
next prev parent reply other threads:[~2024-11-17 23:59 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20241117234843.19236-1-dullfire.ref@yahoo.com>
2024-11-17 23:48 ` [PATCH 0/2] Fix kernel panic on niu bind dullfire
2024-11-17 23:48 ` dullfire [this message]
2024-11-21 8:55 ` [PATCH 1/2] PCI/MSI: Add MSIX option to write to ENTRY_DATA before any reads Paolo Abeni
2024-11-21 9:22 ` Dullfire
2024-11-21 10:28 ` Paolo Abeni
2025-01-20 12:38 ` Dullfire
2025-04-14 16:22 ` Dullfire
2025-04-14 19:52 ` Thomas Gleixner
2025-04-15 6:36 ` [tip: irq/urgent] PCI/MSI: Add an option to write MSIX " tip-bot2 for Jonathan Currier
2024-11-17 23:48 ` [PATCH 2/2] net/niu: niu requires MSIX ENTRY_DATA fields touch before entry reads dullfire
2025-04-15 6:36 ` [tip: irq/urgent] net/niu: Niu " tip-bot2 for Jonathan Currier
[not found] <20241117233544.18227-1-dullfire@yahoo.com>
2024-11-17 23:35 ` [PATCH 1/2] PCI/MSI: Add MSIX option to write to ENTRY_DATA before any reads dullfire
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