crypto: qat - allow disabling SR-IOV VFs

The QAT driver allows enabling SR-IOV VFs but does not allow them to be
disabled through a write to sysfs.
Disabling SR-IOV VFs can be only achieved by bringing down and up a
device using the attribute /sys/bus/pci/devices/<BDF>/qat/state.

The documentation for the sysfs attribute `sriov_numvfs` specifies
that "a userspace application wanting to disable the VFs would write a
zero to this file".

Add support for disabling SR-IOV VFs by writing '0' to the
'sriov_numvfs' attribute in sysfs.

Enabling or disabling SR-IOV always requires adf_dev_down() to be
called. This action subsequently leads to the deletion of the
ADF_KERNEL_SEC configuration section. The keys ADF_NUM_CY and ADF_NUM_DC
within that section must be set to '0', otherwise, the driver will
register into the Linux Crypto Framework. Because of this, the
configuration in the ADF_KERNEL_SEC section must be added before every
sriov_enable.

Signed-off-by: Michal Witwicki <michal.witwicki@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/intel/qat/qat_common/adf_sriov.c b/drivers/crypto/intel/qat/qat_common/adf_sriov.c
index baf2e1c..c75d0b6 100644 (file)
--- a/drivers/crypto/intel/qat/qat_common/adf_sriov.c
+++ b/drivers/crypto/intel/qat/qat_common/adf_sriov.c
@@ -86,11 +86,133 @@ static int adf_enable_sriov(struct adf_accel_dev *accel_dev)
        return pci_enable_sriov(pdev, totalvfs);
 }
 
+static int adf_add_sriov_configuration(struct adf_accel_dev *accel_dev)
+{
+       unsigned long val = 0;
+       int ret;
+
+       ret = adf_cfg_section_add(accel_dev, ADF_KERNEL_SEC);
+       if (ret)
+               return ret;
+
+       ret = adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC, ADF_NUM_CY,
+                                         &val, ADF_DEC);
+       if (ret)
+               return ret;
+
+       ret = adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC, ADF_NUM_DC,
+                                         &val, ADF_DEC);
+       if (ret)
+               return ret;
+
+       set_bit(ADF_STATUS_CONFIGURED, &accel_dev->status);
+
+       return ret;
+}
+
+static int adf_do_disable_sriov(struct adf_accel_dev *accel_dev)
+{
+       int ret;
+
+       if (adf_dev_in_use(accel_dev)) {
+               dev_err(&GET_DEV(accel_dev),
+                       "Cannot disable SR-IOV, device in use\n");
+               return -EBUSY;
+       }
+
+       if (adf_dev_started(accel_dev)) {
+               if (adf_devmgr_in_reset(accel_dev)) {
+                       dev_err(&GET_DEV(accel_dev),
+                               "Cannot disable SR-IOV, device in reset\n");
+                       return -EBUSY;
+               }
+
+               ret = adf_dev_down(accel_dev);
+               if (ret)
+                       goto err_del_cfg;
+       }
+
+       adf_disable_sriov(accel_dev);
+
+       ret = adf_dev_up(accel_dev, true);
+       if (ret)
+               goto err_del_cfg;
+
+       return 0;
+
+err_del_cfg:
+       adf_cfg_del_all_except(accel_dev, ADF_GENERAL_SEC);
+       return ret;
+}
+
+static int adf_do_enable_sriov(struct adf_accel_dev *accel_dev)
+{
+       struct pci_dev *pdev = accel_to_pci_dev(accel_dev);
+       int totalvfs = pci_sriov_get_totalvfs(pdev);
+       unsigned long val;
+       int ret;
+
+       if (!device_iommu_mapped(&GET_DEV(accel_dev))) {
+               dev_warn(&GET_DEV(accel_dev),
+                        "IOMMU should be enabled for SR-IOV to work correctly\n");
+               return -EINVAL;
+       }
+
+       if (adf_dev_started(accel_dev)) {
+               if (adf_devmgr_in_reset(accel_dev) || adf_dev_in_use(accel_dev)) {
+                       dev_err(&GET_DEV(accel_dev), "Device busy\n");
+                       return -EBUSY;
+               }
+
+               ret = adf_dev_down(accel_dev);
+               if (ret)
+                       return ret;
+       }
+
+       ret = adf_add_sriov_configuration(accel_dev);
+       if (ret)
+               goto err_del_cfg;
+
+       /* Allocate memory for VF info structs */
+       accel_dev->pf.vf_info = kcalloc(totalvfs, sizeof(struct adf_accel_vf_info),
+                                       GFP_KERNEL);
+       ret = -ENOMEM;
+       if (!accel_dev->pf.vf_info)
+               goto err_del_cfg;
+
+       ret = adf_dev_up(accel_dev, false);
+       if (ret) {
+               dev_err(&GET_DEV(accel_dev), "Failed to start qat_dev%d\n",
+                       accel_dev->accel_id);
+               goto err_free_vf_info;
+       }
+
+       ret = adf_enable_sriov(accel_dev);
+       if (ret)
+               goto err_free_vf_info;
+
+       val = 1;
+       ret = adf_cfg_add_key_value_param(accel_dev, ADF_GENERAL_SEC, ADF_SRIOV_ENABLED,
+                                         &val, ADF_DEC);
+       if (ret)
+               goto err_free_vf_info;
+
+       return totalvfs;
+
+err_free_vf_info:
+       adf_dev_down(accel_dev);
+       kfree(accel_dev->pf.vf_info);
+       accel_dev->pf.vf_info = NULL;
+       return ret;
+err_del_cfg:
+       adf_cfg_del_all_except(accel_dev, ADF_GENERAL_SEC);
+       return ret;
+}
+
 void adf_reenable_sriov(struct adf_accel_dev *accel_dev)
 {
        struct pci_dev *pdev = accel_to_pci_dev(accel_dev);
        char cfg[ADF_CFG_MAX_VAL_LEN_IN_BYTES] = {0};
-       unsigned long val = 0;
 
        if (adf_cfg_get_param_value(accel_dev, ADF_GENERAL_SEC,
                                    ADF_SRIOV_ENABLED, cfg))
@@ -99,15 +221,9 @@ void adf_reenable_sriov(struct adf_accel_dev *accel_dev)
        if (!accel_dev->pf.vf_info)
                return;
 
-       if (adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC, ADF_NUM_CY,
-                                       &val, ADF_DEC))
-               return;
-
-       if (adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC, ADF_NUM_DC,
-                                       &val, ADF_DEC))
+       if (adf_add_sriov_configuration(accel_dev))
                return;
 
-       set_bit(ADF_STATUS_CONFIGURED, &accel_dev->status);
        dev_dbg(&pdev->dev, "Re-enabling SRIOV\n");
        adf_enable_sriov(accel_dev);
 }
@@ -168,70 +284,16 @@ EXPORT_SYMBOL_GPL(adf_disable_sriov);
 int adf_sriov_configure(struct pci_dev *pdev, int numvfs)
 {
        struct adf_accel_dev *accel_dev = adf_devmgr_pci_to_accel_dev(pdev);
-       int totalvfs = pci_sriov_get_totalvfs(pdev);
-       unsigned long val;
-       int ret;
 
        if (!accel_dev) {
                dev_err(&pdev->dev, "Failed to find accel_dev\n");
                return -EFAULT;
        }
 
-       if (!device_iommu_mapped(&pdev->dev))
-               dev_warn(&pdev->dev, "IOMMU should be enabled for SR-IOV to work correctly\n");
-
-       if (accel_dev->pf.vf_info) {
-               dev_info(&pdev->dev, "Already enabled for this device\n");
-               return -EINVAL;
-       }
-
-       if (adf_dev_started(accel_dev)) {
-               if (adf_devmgr_in_reset(accel_dev) ||
-                   adf_dev_in_use(accel_dev)) {
-                       dev_err(&GET_DEV(accel_dev), "Device busy\n");
-                       return -EBUSY;
-               }
-
-               ret = adf_dev_down(accel_dev);
-               if (ret)
-                       return ret;
-       }
-
-       if (adf_cfg_section_add(accel_dev, ADF_KERNEL_SEC))
-               return -EFAULT;
-       val = 0;
-       if (adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC,
-                                       ADF_NUM_CY, (void *)&val, ADF_DEC))
-               return -EFAULT;
-       ret = adf_cfg_add_key_value_param(accel_dev, ADF_KERNEL_SEC, ADF_NUM_DC,
-                                         &val, ADF_DEC);
-       if (ret)
-               return ret;
-
-       set_bit(ADF_STATUS_CONFIGURED, &accel_dev->status);
-
-       /* Allocate memory for VF info structs */
-       accel_dev->pf.vf_info = kcalloc(totalvfs,
-                                       sizeof(struct adf_accel_vf_info),
-                                       GFP_KERNEL);
-       if (!accel_dev->pf.vf_info)
-               return -ENOMEM;
-
-       if (adf_dev_up(accel_dev, false)) {
-               dev_err(&GET_DEV(accel_dev), "Failed to start qat_dev%d\n",
-                       accel_dev->accel_id);
-               return -EFAULT;
-       }
-
-       ret = adf_enable_sriov(accel_dev);
-       if (ret)
-               return ret;
-
-       val = 1;
-       adf_cfg_add_key_value_param(accel_dev, ADF_GENERAL_SEC, ADF_SRIOV_ENABLED,
-                                   &val, ADF_DEC);
-
-       return numvfs;
+       if (numvfs)
+               return adf_do_enable_sriov(accel_dev);
+       else
+               return adf_do_disable_sriov(accel_dev);
 }
 EXPORT_SYMBOL_GPL(adf_sriov_configure);