PCI: Remove unused SR-IOV VF Migration support

This reverts commit 74bb1bcc7dbb ("PCI: handle SR-IOV Virtual Function
Migration"), removing this exported interface:

  pci_sriov_migration()

Since pci_sriov_migration() is unused, it is impossible to schedule
sriov_migration_task() or use any of the other migration infrastructure.

This is based on Stephen Hemminger's patch (see link below), but goes a bit
further.

Link: http://lkml.kernel.org/r/20131227132710.7190647c@nehalam.linuxnetplumber.net
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.txt
index 86551cc..2d91ae2 100644 (file)
--- a/Documentation/PCI/pci-iov-howto.txt
+++ b/Documentation/PCI/pci-iov-howto.txt
@@ -68,10 +68,6 @@ To disable SR-IOV capability:
        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
 
 Following piece of code illustrates the usage of the SR-IOV API.

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9dce7c5..de7a747 100644 (file)
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -170,97 +170,6 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)
        pci_dev_put(dev);
 }
 
-static int sriov_migration(struct pci_dev *dev)
-{
-       u16 status;
-       struct pci_sriov *iov = dev->sriov;
-
-       if (!iov->num_VFs)
-               return 0;
-
-       if (!(iov->cap & PCI_SRIOV_CAP_VFM))
-               return 0;
-
-       pci_read_config_word(dev, iov->pos + PCI_SRIOV_STATUS, &status);
-       if (!(status & PCI_SRIOV_STATUS_VFM))
-               return 0;
-
-       schedule_work(&iov->mtask);
-
-       return 1;
-}
-
-static void sriov_migration_task(struct work_struct *work)
-{
-       int i;
-       u8 state;
-       u16 status;
-       struct pci_sriov *iov = container_of(work, struct pci_sriov, mtask);
-
-       for (i = iov->initial_VFs; i < iov->num_VFs; i++) {
-               state = readb(iov->mstate + i);
-               if (state == PCI_SRIOV_VFM_MI) {
-                       writeb(PCI_SRIOV_VFM_AV, iov->mstate + i);
-                       state = readb(iov->mstate + i);
-                       if (state == PCI_SRIOV_VFM_AV)
-                               virtfn_add(iov->self, i, 1);
-               } else if (state == PCI_SRIOV_VFM_MO) {
-                       virtfn_remove(iov->self, i, 1);
-                       writeb(PCI_SRIOV_VFM_UA, iov->mstate + i);
-                       state = readb(iov->mstate + i);
-                       if (state == PCI_SRIOV_VFM_AV)
-                               virtfn_add(iov->self, i, 0);
-               }
-       }
-
-       pci_read_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, &status);
-       status &= ~PCI_SRIOV_STATUS_VFM;
-       pci_write_config_word(iov->self, iov->pos + PCI_SRIOV_STATUS, status);
-}
-
-static int sriov_enable_migration(struct pci_dev *dev, int nr_virtfn)
-{
-       int bir;
-       u32 table;
-       resource_size_t pa;
-       struct pci_sriov *iov = dev->sriov;
-
-       if (nr_virtfn <= iov->initial_VFs)
-               return 0;
-
-       pci_read_config_dword(dev, iov->pos + PCI_SRIOV_VFM, &table);
-       bir = PCI_SRIOV_VFM_BIR(table);
-       if (bir > PCI_STD_RESOURCE_END)
-               return -EIO;
-
-       table = PCI_SRIOV_VFM_OFFSET(table);
-       if (table + nr_virtfn > pci_resource_len(dev, bir))
-               return -EIO;
-
-       pa = pci_resource_start(dev, bir) + table;
-       iov->mstate = ioremap(pa, nr_virtfn);
-       if (!iov->mstate)
-               return -ENOMEM;
-
-       INIT_WORK(&iov->mtask, sriov_migration_task);
-
-       iov->ctrl |= PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR;
-       pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
-
-       return 0;
-}
-
-static void sriov_disable_migration(struct pci_dev *dev)
-{
-       struct pci_sriov *iov = dev->sriov;
-
-       iov->ctrl &= ~(PCI_SRIOV_CTRL_VFM | PCI_SRIOV_CTRL_INTR);
-       pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
-
-       cancel_work_sync(&iov->mtask);
-       iounmap(iov->mstate);
-}
-
 static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 {
        int rc;
@@ -351,12 +260,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
                        goto failed;
        }
 
-       if (iov->cap & PCI_SRIOV_CAP_VFM) {
-               rc = sriov_enable_migration(dev, nr_virtfn);
-               if (rc)
-                       goto failed;
-       }
-
        kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
        iov->num_VFs = nr_virtfn;
 
@@ -387,9 +290,6 @@ static void sriov_disable(struct pci_dev *dev)
        if (!iov->num_VFs)
                return;
 
-       if (iov->cap & PCI_SRIOV_CAP_VFM)
-               sriov_disable_migration(dev);
-
        for (i = 0; i < iov->num_VFs; i++)
                virtfn_remove(dev, i, 0);
 
@@ -687,25 +587,6 @@ void pci_disable_sriov(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_disable_sriov);
 
-/**
- * pci_sriov_migration - notify SR-IOV core of Virtual Function Migration
- * @dev: the PCI device
- *
- * Returns IRQ_HANDLED if the IRQ is handled, or IRQ_NONE if not.
- *
- * Physical Function driver is responsible to register IRQ handler using
- * VF Migration Interrupt Message Number, and call this function when the
- * interrupt is generated by the hardware.
- */
-irqreturn_t pci_sriov_migration(struct pci_dev *dev)
-{
-       if (!dev->is_physfn)
-               return IRQ_NONE;
-
-       return sriov_migration(dev) ? IRQ_HANDLED : IRQ_NONE;
-}
-EXPORT_SYMBOL_GPL(pci_sriov_migration);
-
 /**
  * pci_num_vf - return number of VFs associated with a PF device_release_driver
  * @dev: the PCI device

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4df38df..6bd0822 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1,8 +1,6 @@
 #ifndef DRIVERS_PCI_H
 #define DRIVERS_PCI_H
 
-#include <linux/workqueue.h>
-
 #define PCI_CFG_SPACE_SIZE     256
 #define PCI_CFG_SPACE_EXP_SIZE 4096
 
@@ -240,8 +238,6 @@ struct pci_sriov {
        struct pci_dev *dev;    /* lowest numbered PF */
        struct pci_dev *self;   /* this PF */
        struct mutex lock;      /* lock for VF bus */
-       struct work_struct mtask; /* VF Migration task */
-       u8 __iomem *mstate;     /* VF Migration State Array */
 };
 
 #ifdef CONFIG_PCI_ATS

diff --git a/include/linux/pci.h b/include/linux/pci.h
index fb57c89..230a8da 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -29,7 +29,6 @@
 #include <linux/atomic.h>
 #include <linux/device.h>
 #include <linux/io.h>
-#include <linux/irqreturn.h>
 #include <uapi/linux/pci.h>
 
 #include <linux/pci_ids.h>
@@ -1577,7 +1576,6 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
 #ifdef CONFIG_PCI_IOV
 int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 void pci_disable_sriov(struct pci_dev *dev);
-irqreturn_t pci_sriov_migration(struct pci_dev *dev);
 int pci_num_vf(struct pci_dev *dev);
 int pci_vfs_assigned(struct pci_dev *dev);
 int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs);
@@ -1586,8 +1584,6 @@ int pci_sriov_get_totalvfs(struct pci_dev *dev);
 static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 { return -ENODEV; }
 static inline void pci_disable_sriov(struct pci_dev *dev) { }
-static inline irqreturn_t pci_sriov_migration(struct pci_dev *dev)
-{ return IRQ_NONE; }
 static inline int pci_num_vf(struct pci_dev *dev) { return 0; }
 static inline int pci_vfs_assigned(struct pci_dev *dev)
 { return 0; }