[RFC PATCH v1] PCI: Remove pcie_flr() and convert all callers to use pcie_reset_flr()

[Farhan Ali <alifm@linux.ibm.com>]

The pcie_reset_flr() function includes validation checks to verify FLR
support before performing the reset, while pcie_flr() performs the reset
unconditionally. Having both functions creates unnecessary complexity.

Commit 56f107d7813f ("PCI: Add pcie_reset_flr() with 'probe' argument")
introduced pcie_reset_flr() and removed pcie_has_flr(), converting callers
that previously used the pcie_has_flr() + pcie_flr() to use
pcie_reset_flr() instead. However, it did not convert all pcie_flr()
callers, leaving two different FLR mechanisms in the kernel.

One of the callers of pcie_flr(), the Intel 82599 Virtual Function has a
defect where FLR works despite not advertising FLR support in the PCIe
Device Capability register.  Rather than using pcie_flr() to work around
this, enable the FLR capability bit in devcap via an early quirk. This
allows the device to use the standard pcie_reset_flr() path instead of
requiring a device-specific reset method.

Remove pcie_flr() entirely and convert all remaining callers to
pcie_reset_flr(), ensuring consistent validation across the kernel.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
---
 drivers/crypto/intel/qat/qat_common/adf_aer.c |  2 +-
 drivers/infiniband/hw/hfi1/chip.c             |  4 +-
 .../net/ethernet/broadcom/bnge/bnge_core.c    |  2 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |  4 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |  2 +-
 .../ethernet/cavium/liquidio/octeon_mailbox.c |  3 +-
 drivers/net/ethernet/freescale/enetc/enetc.c  |  2 +-
 .../ethernet/freescale/enetc/enetc_pci_mdio.c |  2 +-
 drivers/net/ethernet/intel/ice/ice_main.c     |  2 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |  2 +-
 drivers/net/ethernet/microsoft/mana/mana_en.c |  3 +-
 drivers/pci/pci.c                             | 38 ++++++------------
 drivers/pci/quirks.c                          | 40 +++++++++----------
 drivers/ptp/ptp_netc.c                        |  2 +-
 include/linux/pci.h                           |  1 -
 15 files changed, 49 insertions(+), 60 deletions(-)

diff --git a/drivers/crypto/intel/qat/qat_common/adf_aer.c b/drivers/crypto/intel/qat/qat_common/adf_aer.c
index ed01fb9ad74e..a2364a59bc7f 100644
--- a/drivers/crypto/intel/qat/qat_common/adf_aer.c
+++ b/drivers/crypto/intel/qat/qat_common/adf_aer.c
@@ -89,7 +89,7 @@ EXPORT_SYMBOL_GPL(adf_reset_sbr);
 
 void adf_reset_flr(struct adf_accel_dev *accel_dev)
 {
-	pcie_flr(accel_to_pci_dev(accel_dev));
+	pcie_reset_flr(accel_to_pci_dev(accel_dev), PCI_RESET_DO_RESET);
 }
 EXPORT_SYMBOL_GPL(adf_reset_flr);
 
diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 44c524e45396..9f53d73e5e76 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -14042,7 +14042,7 @@ static int init_chip(struct hfi1_devdata *dd)
 		dd_dev_info(dd, "Resetting CSRs with FLR\n");
 
 		/* do the FLR, the DC reset will remain */
-		pcie_flr(dd->pcidev);
+		pcie_reset_flr(dd->pcidev, PCI_RESET_DO_RESET);
 
 		/* restore command and BARs */
 		ret = restore_pci_variables(dd);
@@ -14054,7 +14054,7 @@ static int init_chip(struct hfi1_devdata *dd)
 
 		if (is_ax(dd)) {
 			dd_dev_info(dd, "Resetting CSRs with FLR\n");
-			pcie_flr(dd->pcidev);
+			pcie_reset_flr(dd->pcidev, PCI_RESET_DO_RESET);
 			ret = restore_pci_variables(dd);
 			if (ret) {
 				dd_dev_err(dd, "%s: Could not restore PCI variables\n",
diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_core.c b/drivers/net/ethernet/broadcom/bnge/bnge_core.c
index 68b74eb2c3a2..4aec01f53e54 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_core.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_core.c
@@ -274,7 +274,7 @@ static int bnge_probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	if (is_kdump_kernel()) {
 		pci_clear_master(pdev);
-		pcie_flr(pdev);
+		pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 	}
 
 	rc = bnge_pci_enable(pdev);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 35e1f8f663c7..21f8dcbe671e 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -16918,7 +16918,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 */
 	if (is_kdump_kernel()) {
 		pci_clear_master(pdev);
-		pcie_flr(pdev);
+		pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 	}
 
 	max_irqs = bnxt_get_max_irq(pdev);
@@ -17203,7 +17203,7 @@ static void bnxt_shutdown(struct pci_dev *pdev)
 		netif_close(dev);
 
 	if (bnxt_hwrm_func_drv_unrgtr(bp)) {
-		pcie_flr(pdev);
+		pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 		goto shutdown_exit;
 	}
 	bnxt_ptp_clear(bp);
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 43c595f3b84e..7f3557d36341 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -429,7 +429,7 @@ static void octeon_pci_flr(struct octeon_device *oct)
 	pci_write_config_word(oct->pci_dev, PCI_COMMAND,
 			      PCI_COMMAND_INTX_DISABLE);
 
-	pcie_flr(oct->pci_dev);
+	pcie_reset_flr(oct->pci_dev, PCI_RESET_DO_RESET);
 
 	pci_cfg_access_unlock(oct->pci_dev);
 
diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
index ad685f5d0a13..be08e213aa9a 100644
--- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
@@ -260,7 +260,8 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
 		dev_info(&oct->pci_dev->dev,
 			 "got a request for FLR from VF that owns DPI ring %u\n",
 			 mbox->q_no);
-		pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
+		pcie_reset_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
+			       PCI_RESET_DO_RESET);
 		break;
 
 	case OCTEON_PF_CHANGED_VF_MACADDR:
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index aa8a87124b10..c1c1b523abb5 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -3635,7 +3635,7 @@ int enetc_pci_probe(struct pci_dev *pdev, const char *name, int sizeof_priv)
 	size_t alloc_size;
 	int err, len;
 
-	pcie_flr(pdev);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 	err = pci_enable_device_mem(pdev);
 	if (err)
 		return dev_err_probe(&pdev->dev, err, "device enable failed\n");
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
index e108cac8288d..cfccfca1981d 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c
@@ -73,7 +73,7 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev,
 	mdio_priv->mdio_base = ENETC_EMDIO_BASE;
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
 
-	pcie_flr(pdev);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 	err = pci_enable_device_mem(pdev);
 	if (err) {
 		dev_err(dev, "device enable failed\n");
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index e2fbe111f849..14b8a90625a8 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -5180,7 +5180,7 @@ ice_probe(struct pci_dev *pdev, const struct pci_device_id __always_unused *ent)
 	if (is_kdump_kernel()) {
 		pci_save_state(pdev);
 		pci_clear_master(pdev);
-		err = pcie_flr(pdev);
+		err = pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 		if (err)
 			return err;
 		pci_restore_state(pdev);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 2646ee6f295f..d8796a68094f 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8318,7 +8318,7 @@ static void ixgbe_check_for_bad_vf(struct ixgbe_adapter *adapter)
 		if (status_reg != IXGBE_FAILED_READ_CFG_WORD &&
 		    status_reg & PCI_STATUS_REC_MASTER_ABORT) {
 			ixgbe_bad_vf_abort(adapter, vf);
-			pcie_flr(vfdev);
+			pcie_reset_flr(vfdev, PCI_RESET_DO_RESET);
 		}
 	}
 }
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index c9b1df1ed109..e51c1170aba7 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -3305,7 +3305,8 @@ static int mana_dealloc_queues(struct net_device *ndev)
 			}
 			if (atomic_read(&txq->pending_sends)) {
 				err =
-				    pcie_flr(to_pci_dev(gd->gdma_context->dev));
+				    pcie_reset_flr(to_pci_dev(gd->gdma_context->dev),
+						   PCI_RESET_DO_RESET);
 				if (err) {
 					netdev_err(ndev, "flr failed %d with %d pkts pending in txq %u\n",
 						   err,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d34266651ad0..878556ea50de 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4321,16 +4321,25 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev)
 EXPORT_SYMBOL(pci_wait_for_pending_transaction);
 
 /**
- * pcie_flr - initiate a PCIe function level reset
+ * pcie_reset_flr - initiate a PCIe function level reset
  * @dev: device to reset
+ * @probe: if true, return 0 if device can be reset this way
  *
- * Initiate a function level reset unconditionally on @dev without
- * checking any flags and DEVCAP
+ * Initiate a function level reset on @dev.
  */
-int pcie_flr(struct pci_dev *dev)
+int pcie_reset_flr(struct pci_dev *dev, bool probe)
 {
 	int ret;
 
+	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
+		return -ENOTTY;
+
+	if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
+		return -ENOTTY;
+
+	if (probe)
+		return 0;
+
 	if (!pci_wait_for_pending_transaction(dev))
 		pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n");
 
@@ -4357,28 +4366,7 @@ int pcie_flr(struct pci_dev *dev)
 done:
 	pci_dev_reset_iommu_done(dev);
 	return ret;
-}
-EXPORT_SYMBOL_GPL(pcie_flr);
-
-/**
- * pcie_reset_flr - initiate a PCIe function level reset
- * @dev: device to reset
- * @probe: if true, return 0 if device can be reset this way
- *
- * Initiate a function level reset on @dev.
- */
-int pcie_reset_flr(struct pci_dev *dev, bool probe)
-{
-	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
-		return -ENOTTY;
-
-	if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
-		return -ENOTTY;
-
-	if (probe)
-		return 0;
 
-	return pcie_flr(dev);
 }
 EXPORT_SYMBOL_GPL(pcie_reset_flr);
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index caaed1a01dc0..564f581599b8 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2019,6 +2019,23 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_PXH_0,	quirk_pc
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_PXH_1,	quirk_pcie_pxh);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_PXHV,	quirk_pcie_pxh);
 
+#define PCI_DEVICE_ID_INTEL_82599_SFP_VF   0x10ed
+static void quirk_intel_82599_sfp_virtfn(struct pci_dev *dev)
+{
+	/*
+	 * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf
+	 *
+	 * The 82599 supports FLR on VFs, but FLR support is reported only
+	 * in the PF DEVCAP (sec 9.3.10.4), not in the VF DEVCAP (sec 9.5).
+	 * So enable PCI_EXP_DEVCAP_FLR directly without first checking if it is
+	 * supported.
+	 */
+
+	dev->devcap |= PCI_EXP_DEVCAP_FLR;
+}
+
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF, quirk_intel_82599_sfp_virtfn);
+
 /*
  * Some Intel PCI Express chipsets have trouble with downstream device
  * power management.
@@ -3944,20 +3961,6 @@ DECLARE_PCI_FIXUP_SUSPEND_LATE(PCI_VENDOR_ID_INTEL,
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */
-static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, bool probe)
-{
-	/*
-	 * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf
-	 *
-	 * The 82599 supports FLR on VFs, but FLR support is reported only
-	 * in the PF DEVCAP (sec 9.3.10.4), not in the VF DEVCAP (sec 9.5).
-	 * Thus we must call pcie_flr() directly without first checking if it is
-	 * supported.
-	 */
-	if (!probe)
-		pcie_flr(dev);
-	return 0;
-}
 
 #define SOUTH_CHICKEN2		0xc2004
 #define PCH_PP_STATUS		0xc7200
@@ -4058,7 +4061,7 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, bool probe)
 				      PCI_MSIX_FLAGS_ENABLE |
 				      PCI_MSIX_FLAGS_MASKALL);
 
-	pcie_flr(dev);
+	pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 
 	/*
 	 * Restore the configuration information (BAR values, etc.) including
@@ -4070,7 +4073,6 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, bool probe)
 	return 0;
 }
 
-#define PCI_DEVICE_ID_INTEL_82599_SFP_VF   0x10ed
 #define PCI_DEVICE_ID_INTEL_IVB_M_VGA      0x0156
 #define PCI_DEVICE_ID_INTEL_IVB_M2_VGA     0x0166
 
@@ -4150,7 +4152,7 @@ static int nvme_disable_and_flr(struct pci_dev *dev, bool probe)
 
 	pci_iounmap(dev, bar);
 
-	pcie_flr(dev);
+	pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 
 	return 0;
 }
@@ -4207,7 +4209,7 @@ static int reset_hinic_vf_dev(struct pci_dev *pdev, bool probe)
 	val = val | HINIC_VF_FLR_PROC_BIT;
 	iowrite32be(val, bar + HINIC_VF_OP);
 
-	pcie_flr(pdev);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 
 	/*
 	 * The device must recapture its Bus and Device Numbers after FLR
@@ -4238,8 +4240,6 @@ static int reset_hinic_vf_dev(struct pci_dev *pdev, bool probe)
 }
 
 static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
-	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF,
-		 reset_intel_82599_sfp_virtfn },
 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M_VGA,
 		reset_ivb_igd },
 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA,
diff --git a/drivers/ptp/ptp_netc.c b/drivers/ptp/ptp_netc.c
index 94e952ee6990..24bae237926a 100644
--- a/drivers/ptp/ptp_netc.c
+++ b/drivers/ptp/ptp_netc.c
@@ -802,7 +802,7 @@ static int netc_timer_pci_probe(struct pci_dev *pdev)
 	if (!priv)
 		return -ENOMEM;
 
-	pcie_flr(pdev);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 	err = pci_enable_device_mem(pdev);
 	if (err)
 		return dev_err_probe(dev, err, "Failed to enable device\n");
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2c4454583c11..345f0821471a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1468,7 +1468,6 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 int pcie_link_speed_mbps(struct pci_dev *pdev);
 void pcie_print_link_status(struct pci_dev *dev);
 int pcie_reset_flr(struct pci_dev *dev, bool probe);
-int pcie_flr(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
 int pci_reset_function_locked(struct pci_dev *dev);
-- 
2.43.0