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[3.16.y-ckt,stable] Patch "PCI/MSI: Add device flag indicating that 64-bit MSIs don't work" has been added to staging queue

Message ID 1417799352-21670-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Dec. 5, 2014, 5:09 p.m. UTC
This is a note to let you know that I have just added a patch titled

    PCI/MSI: Add device flag indicating that 64-bit MSIs don't work

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 373fa1f545995c5214c931dba0d1ce6b80132614 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Fri, 3 Oct 2014 15:13:24 +1000
Subject: [PATCH] PCI/MSI: Add device flag indicating that 64-bit MSIs don't
 work

commit f144d1496b47e7450f41b767d0d91c724c2198bc upstream.

This can be set by quirks/drivers to be used by the architecture code
that assigns the MSI addresses.

We additionally add verification in the core MSI code that the values
assigned by the architecture do satisfy the limitation in order to fail
gracefully if they don't (ie. the arch hasn't been updated to deal with
that quirk yet).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/pci/msi.c   | 26 ++++++++++++++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 27 insertions(+)
diff mbox

Patch

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 13f3d3037272..1d6c61ad7da7 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -594,6 +594,20 @@  error_attrs:
 	return ret;
 }

+static int msi_verify_entries(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+
+	list_for_each_entry(entry, &dev->msi_list, list) {
+		if (!dev->no_64bit_msi || !entry->msg.address_hi)
+			continue;
+		dev_err(&dev->dev, "Device has broken 64-bit MSI but arch"
+			" tried to assign one above 4G\n");
+		return -EIO;
+	}
+	return 0;
+}
+
 /**
  * msi_capability_init - configure device's MSI capability structure
  * @dev: pointer to the pci_dev data structure of MSI device function
@@ -647,6 +661,13 @@  static int msi_capability_init(struct pci_dev *dev, int nvec)
 		return ret;
 	}

+	ret = msi_verify_entries(dev);
+	if (ret) {
+		msi_mask_irq(entry, mask, ~mask);
+		free_msi_irqs(dev);
+		return ret;
+	}
+
 	ret = populate_msi_sysfs(dev);
 	if (ret) {
 		msi_mask_irq(entry, mask, ~mask);
@@ -762,6 +783,11 @@  static int msix_capability_init(struct pci_dev *dev,
 	if (ret)
 		goto out_avail;

+	/* Check if all MSI entries honor device restrictions */
+	ret = msi_verify_entries(dev);
+	if (ret)
+		goto out_free;
+
 	/*
 	 * Some devices require MSI-X to be enabled before we can touch the
 	 * MSI-X registers.  We need to mask all the vectors to prevent
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 97fe7ebf2e25..04fdc409eec6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -331,6 +331,7 @@  struct pci_dev {
 	unsigned int	is_added:1;
 	unsigned int	is_busmaster:1; /* device is busmaster */
 	unsigned int	no_msi:1;	/* device may not use msi */
+	unsigned int	no_64bit_msi:1; /* device may only use 32-bit MSIs */
 	unsigned int	block_cfg_access:1;	/* config space access is blocked */
 	unsigned int	broken_parity_status:1;	/* Device generates false positive parity */
 	unsigned int	irq_reroute_variant:2;	/* device needs IRQ rerouting variant */