Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull powerpc fixes from Ben Herrenschmidt:
 "This series fix a nasty issue with radeon adapters on powerpc servers,
  it's all CC'ed stable and has the relevant maintainers ack's/reviews.

  Basically, some (radeon) adapters have issues with MSI addresses above
  1T (only support 40-bits).  We had powerpc specific quirk but it only
  listed a specific revision of an adapter that we shipped with our
  machines and didn't properly handle the audio function which some
  distros enable nowadays.

  So we made the quirk generic and fixed both the graphic and audio
  drivers properly to use it.

  Without that, ppc64 server machines will crash at boot with a radeon
  adapter.

  Note: This has been brewing for a while, it just needed a last respin
  which got delayed due to us moving ozlabs to a new location in town
  and other such things taking priority"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/pci: Remove unused force_32bit_msi quirk
  powerpc/pseries: Honor the generic "no_64bit_msi" flag
  powerpc/powernv: Honor the generic "no_64bit_msi" flag
  sound/radeon: Move 64-bit MSI quirk from arch to driver
  gpu/radeon: Set flag to indicate broken 64-bit MSI
  PCI/MSI: Add device flag indicating that 64-bit MSIs don't work
  ALSA: hda - Limit 40bit DMA for AMD HDMI controllers

2 files changed, 36 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 7784911d78e..00fc59762e0 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -185,6 +185,16 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
 	if (rdev->flags & RADEON_IS_AGP)
 		return false;
 
+	/*
+	 * Older chips have a HW limitation, they can only generate 40 bits
+	 * of address for "64-bit" MSIs which breaks on some platforms, notably
+	 * IBM POWER servers, so we limit them
+	 */
+	if (rdev->family < CHIP_BONAIRE) {
+		dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n");
+		rdev->pdev->no_64bit_msi = 1;
+	}
+
 	/* force MSI on */
 	if (radeon_msi == 1)
 		return true;
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9fab30af0e7..084587d7cd1 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -590,6 +590,20 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev)
 	return entry;
 }
 
+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
@@ -627,6 +641,13 @@ 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);
@@ -739,6 +760,11 @@ 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