Merge tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI update from Bjorn Helgaas:
 "Host bridge hotplug:
   - Untangle _PRT from struct pci_bus (Bjorn Helgaas)
   - Request _OSC control before scanning root bus (Taku Izumi)
   - Assign resources when adding host bridge (Yinghai Lu)
   - Remove root bus when removing host bridge (Yinghai Lu)
   - Remove _PRT during hot remove (Yinghai Lu)

  SRIOV
    - Add sysfs knobs to control numVFs (Don Dutile)

  Power management
   - Notify devices when power resource turned on (Huang Ying)

  Bug fixes
   - Work around broken _SEG on HP xw9300 (Bjorn Helgaas)
   - Keep runtime PM enabled for unbound PCI devices (Huang Ying)
   - Fix Optimus dual-GPU runtime D3 suspend issue (Dave Airlie)
   - Fix xen frontend shutdown issue (David Vrabel)
   - Work around PLX PCI 9050 BAR alignment erratum (Ian Abbott)

  Miscellaneous
   - Add GPL license for drivers/pci/ioapic (Andrew Cooks)
   - Add standard PCI-X, PCIe ASPM register #defines (Bjorn Helgaas)
   - NumaChip remote PCI support (Daniel Blueman)
   - Fix PCIe Link Capabilities Supported Link Speed definition (Jingoo
     Han)
   - Convert dev_printk() to dev_info(), etc (Joe Perches)
   - Add support for non PCI BAR ROM data (Matthew Garrett)
   - Add x86 support for host bridge translation offset (Mike Yoknis)
   - Report success only when every driver supports AER (Vijay
     Pandarathil)"

Fix up trivial conflicts.

* tag 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (48 commits)
  PCI: Use phys_addr_t for physical ROM address
  x86/PCI: Add NumaChip remote PCI support
  ath9k: Use standard #defines for PCIe Capability ASPM fields
  iwlwifi: Use standard #defines for PCIe Capability ASPM fields
  iwlwifi: collapse wrapper for pcie_capability_read_word()
  iwlegacy: Use standard #defines for PCIe Capability ASPM fields
  iwlegacy: collapse wrapper for pcie_capability_read_word()
  cxgb3: Use standard #defines for PCIe Capability ASPM fields
  PCI: Add standard PCIe Capability Link ASPM field names
  PCI/portdrv: Use PCI Express Capability accessors
  PCI: Use standard PCIe Capability Link register field names
  x86: Use PCI setup data
  PCI: Add support for non-BAR ROMs
  PCI: Add pcibios_add_device
  EFI: Stash ROMs if they're not in the PCI BAR
  PCI: Add and use standard PCI-X Capability register names
  PCI/PM: Keep runtime PM enabled for unbound PCI devices
  xen-pcifront: Handle backend CLOSED without CLOSING
  PCI: SRIOV control and status via sysfs (documentation)
  PCI/AER: Report success only when every device has AER-aware driver
  ...

2 files changed, 78 insertions, 4 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index dff1f48d252d..1ce5ae329c04 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -222,3 +222,37 @@ Description:
 		satisfied too.  Reading this attribute will show the current
 		value of d3cold_allowed bit.  Writing this attribute will set
 		the value of d3cold_allowed bit.
+
+What:		/sys/bus/pci/devices/.../sriov_totalvfs
+Date:		November 2012
+Contact:	Donald Dutile <ddutile@redhat.com>
+Description:
+		This file appears when a physical PCIe device supports SR-IOV.
+		Userspace applications can read this file to determine the
+		maximum number of Virtual Functions (VFs) a PCIe physical
+		function (PF) can support. Typically, this is the value reported
+		in the PF's SR-IOV extended capability structure's TotalVFs
+		element.  Drivers have the ability at probe time to reduce the
+		value read from this file via the pci_sriov_set_totalvfs()
+		function.
+
+What:		/sys/bus/pci/devices/.../sriov_numvfs
+Date:		November 2012
+Contact:	Donald Dutile <ddutile@redhat.com>
+Description:
+		This file appears when a physical PCIe device supports SR-IOV.
+		Userspace applications can read and write to this file to
+		determine and control the enablement or disablement of Virtual
+		Functions (VFs) on the physical function (PF). A read of this
+		file will return the number of VFs that are enabled on this PF.
+		A number written to this file will enable the specified
+		number of VFs. A userspace application would typically read the
+		file and check that the value is zero, and then write the number
+		of VFs that should be enabled on the PF; the value written
+		should be less than or equal to the value in the sriov_totalvfs
+		file. A userspace application wanting to disable the VFs would
+		write a zero to this file. The core ensures that valid values
+		are written to this file, and returns errors when values are not
+		valid.  For example, writing a 2 to this file when sriov_numvfs
+		is not 0 and not 2 already will return an error. Writing a 10
+		when the value of sriov_totalvfs is 8 will return an error.
diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.txt
index fc73ef5d65b8..cfaca7e69893 100644
--- a/Documentation/PCI/pci-iov-howto.txt
+++ b/Documentation/PCI/pci-iov-howto.txt
@@ -2,6 +2,9 @@
 		Copyright (C) 2009 Intel Corporation
 		    Yu Zhao <yu.zhao@intel.com>
 
+		Update: November 2012
+			-- sysfs-based SRIOV enable-/disable-ment
+		Donald Dutile <ddutile@redhat.com>
 
 1. Overview
 
@@ -24,10 +27,21 @@ real existing PCI device.
 
 2.1 How can I enable SR-IOV capability
 
-The device driver (PF driver) will control the enabling and disabling
-of the capability via API provided by SR-IOV core. If the hardware
-has SR-IOV capability, loading its PF driver would enable it and all
-VFs associated with the PF.
+Multiple methods are available for SR-IOV enablement.
+In the first method, the device driver (PF driver) will control the
+enabling and disabling of the capability via API provided by SR-IOV core.
+If the hardware has SR-IOV capability, loading its PF driver would
+enable it and all VFs associated with the PF.  Some PF drivers require
+a module parameter to be set to determine the number of VFs to enable.
+In the second method, a write to the sysfs file sriov_numvfs will
+enable and disable the VFs associated with a PCIe PF.  This method
+enables per-PF, VF enable/disable values versus the first method,
+which applies to all PFs of the same device.  Additionally, the
+PCI SRIOV core support ensures that enable/disable operations are
+valid to reduce duplication in multiple drivers for the same
+checks, e.g., check numvfs == 0 if enabling VFs, ensure
+numvfs <= totalvfs.
+The second method is the recommended method for new/future VF devices.
 
 2.2 How can I use the Virtual Functions
 
@@ -40,13 +54,22 @@ requires device driver that is same as a normal PCI device's.
 3.1 SR-IOV API
 
 To enable SR-IOV capability:
+(a) For the first method, in the driver:
 	int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 	'nr_virtfn' is number of VFs to be enabled.
+(b) For the second method, from sysfs:
+	echo 'nr_virtfn' > \
+        /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_numvfs
 
 To disable SR-IOV capability:
+(a) For the first method, in the driver:
 	void pci_disable_sriov(struct pci_dev *dev);
+(b) For the second method, from sysfs:
+	echo  0 > \
+        /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_numvfs
 
 To notify SR-IOV core of Virtual Function Migration:
+(a) In the driver:
 	irqreturn_t pci_sriov_migration(struct pci_dev *dev);
 
 3.2 Usage example
@@ -88,6 +111,22 @@ static void dev_shutdown(struct pci_dev *dev)
 	...
 }
 
+static int dev_sriov_configure(struct pci_dev *dev, int numvfs)
+{
+	if (numvfs > 0) {
+		...
+		pci_enable_sriov(dev, numvfs);
+		...
+		return numvfs;
+	}
+	if (numvfs == 0) {
+		....
+		pci_disable_sriov(dev);
+		...
+		return 0;
+	}
+}
+
 static struct pci_driver dev_driver = {
 	.name =		"SR-IOV Physical Function driver",
 	.id_table =	dev_id_table,
@@ -96,4 +135,5 @@ static struct pci_driver dev_driver = {
 	.suspend =	dev_suspend,
 	.resume =	dev_resume,
 	.shutdown =	dev_shutdown,
+	.sriov_configure = dev_sriov_configure,
 };