[Bugfix v4 0/2] Prevent binding PCI drivers to PCI devices used by non-pci drivers

[Bugfix v4 0/2] Prevent binding PCI drivers to PCI devices used by non-pci drivers

[Jiang Liu]

Hi Joerg,
	I prepared this patchset yesterday but forgot to send them out.
I think it still worth sending out for review, so here we go:)

---
Commit 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and
pcibios_free_irq()") breaks suspend/resume on some AMD platforms.
The root cause is:
1) AMD IOMMU drivers enables MSI on IOMMU PCI devices at early boot stage
2) PCI driver binding code tries to allocate/free PCI legacy IRQ when
   binding other PCI drivers to IOMMU PCI devices at later boot stage,
   and breaks PCI MSI allocation information.
3) System resume breaks when restoring PCI MSI state using the damaged
   data.

We have tried on solution to detect that a PCI is in use by IOMMU driver
by checking pci_msi_enabled(). But that's too specific, actually we should
prevent binding PCI drivers to PCI devices used by non-PCI drivers.

Fortunately, we could prevent binding PCI drivers to PCI devices by setting
pci_dev->match_driver to false. If needed, we could implement a helper
function to manipulate pci_dev->match_driver.

Jiang Liu (2):
  iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices
  ACPI, PCI: Prevent binding other PCI drivers to IOAPIC PCI devices

 drivers/acpi/ioapic.c          |    7 +++++--
 drivers/iommu/amd_iommu_init.c |    3 +++
 2 files changed, 8 insertions(+), 2 deletions(-)

-- 
1.7.10.4

[Bugfix v4 1/2] iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices

[Jiang Liu]

AMD IOMMU driver makes use of IOMMU PCI devices, so prevent binding other
PCI drivers to IOMMU PCI devices.

This fixes a bug reported by Boris that system suspend/resume gets broken
on AMD platforms. For more information, please refer to:
	https://lkml.org/lkml/2015/9/26/89

Fixes: 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()")
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
---
 drivers/iommu/amd_iommu_init.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 5ef347a13cb5..1b066e7d144d 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1256,6 +1256,9 @@ static int iommu_init_pci(struct amd_iommu *iommu)
 	if (!iommu->dev)
 		return -ENODEV;
 
+	/* Prevent binding other PCI device drivers to IOMMU devices */
+	iommu->dev->match_driver = false;
+
 	pci_read_config_dword(iommu->dev, cap_ptr + MMIO_CAP_HDR_OFFSET,
 			      &iommu->cap);
 	pci_read_config_dword(iommu->dev, cap_ptr + MMIO_RANGE_OFFSET,
-- 
1.7.10.4

[Bugfix v4 2/2] ACPI, PCI: Prevent binding other PCI drivers to IOAPIC PCI devices

[Jiang Liu]

The ACPI IOAPIC driver makes use of IOAPIC PCI devices, so prevent
binding other PCI drivers to IOAPIC PCI devices used by ACPI IOAPIC
driver.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
 drivers/acpi/ioapic.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/ioapic.c b/drivers/acpi/ioapic.c
index ccdc8db16bb8..da71b274fc21 100644
--- a/drivers/acpi/ioapic.c
+++ b/drivers/acpi/ioapic.c
@@ -162,12 +162,14 @@ done:
 	list_add(&ioapic->list, &ioapic_list);
 	mutex_unlock(&ioapic_list_lock);
 
-	if (dev)
+	if (dev) {
+		dev->match_driver = false;
 		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
 			 type, res, (u32)gsi_base);
-	else
+	} else {
 		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
 				 type, res, (u32)gsi_base);
+	}
 
 	return AE_OK;
 
@@ -216,6 +218,7 @@ int acpi_ioapic_remove(struct acpi_pci_root *root)
 		if (ioapic->pdev) {
 			pci_release_region(ioapic->pdev, 0);
 			pci_disable_device(ioapic->pdev);
+			ioapic->pdev->match_driver = true;
 			pci_dev_put(ioapic->pdev);
 		} else if (ioapic->res.flags && ioapic->res.parent) {
 			release_resource(&ioapic->res);
-- 
1.7.10.4

Re: [Bugfix v4 2/2] ACPI, PCI: Prevent binding other PCI drivers to IOAPIC PCI devices

[Joerg Roedel]

On Fri, Oct 09, 2015 at 10:07:32PM +0800, Jiang Liu wrote:
> The ACPI IOAPIC driver makes use of IOAPIC PCI devices, so prevent
> binding other PCI drivers to IOAPIC PCI devices used by ACPI IOAPIC
> driver.
> 
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
>  drivers/acpi/ioapic.c |    7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)

Reviewed-by: Joerg Roedel <jroedel@suse.de>

Re: [Bugfix v4 1/2] iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices

[Joerg Roedel]

On Fri, Oct 09, 2015 at 10:07:31PM +0800, Jiang Liu wrote:
> AMD IOMMU driver makes use of IOMMU PCI devices, so prevent binding other
> PCI drivers to IOMMU PCI devices.
> 
> This fixes a bug reported by Boris that system suspend/resume gets broken
> on AMD platforms. For more information, please refer to:
> 	https://lkml.org/lkml/2015/9/26/89
> 
> Fixes: 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()")
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> Cc: Borislav Petkov <bp@alien8.de>

Applied to iommu/fixes, thanks Jiang.