[PATCH v2 1/2] PCI: One more parameter to pci_set_pcie_reset_state()

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(),
which allows to check if one particular PCI device can be resetted by the
function. The function will be reused to support PCI device specific methods
maintained in pci_dev_reset_methods[] in subsequent patch.

Cc: Brian King <brking@us.ibm.com>
Cc: Frank Haverkamp <haver@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/eeh.c       | 14 ++++++++++----
 drivers/misc/genwqe/card_base.c |  9 +++++++--
 drivers/pci/pci.c               | 15 +++++++++------
 drivers/scsi/ipr.c              |  5 +++--
 include/linux/pci.h             |  5 +++--
 5 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 19a897c..60a0f15ce 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -720,11 +720,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata)
  * pcibios_set_pcie_slot_reset - Set PCI-E reset state
  * @dev: pci device struct
  * @state: reset state to enter
+ * @probe: check if the device can take the reset
  *
  * Return value:
  * 	0 if success
  */
-int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
+int pcibios_set_pcie_reset_state(struct pci_dev *dev,
+				 enum pcie_reset_state state,
+				 int probe)
 {
 	struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
 	struct eeh_pe *pe = eeh_dev_to_pe(edev);
@@ -732,9 +735,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
 	if (!pe) {
 		pr_err("%s: No PE found on PCI device %s\n",
 			__func__, pci_name(dev));
-		return -EINVAL;
+		return -ENOTTY;
 	}
 
+	if (probe)
+		return 0;
+
 	switch (state) {
 	case pcie_deassert_reset:
 		eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
@@ -756,8 +762,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
 		break;
 	default:
 		eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
-		return -EINVAL;
-	};
+		return -ENOTTY;
+	}
 
 	return 0;
 }
diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c
index 4cf8f82..4871f69 100644
--- a/drivers/misc/genwqe/card_base.c
+++ b/drivers/misc/genwqe/card_base.c
@@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev)
 {
 	int rc;
 
+	/* Probe if the device can take the reset */
+	rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1);
+	if (rc)
+		return rc;
+
 	/*
 	 * lock pci config space access from userspace,
 	 * save state and issue PCIe fundamental reset
 	 */
 	pci_cfg_access_lock(pci_dev);
 	pci_save_state(pci_dev);
-	rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset);
+	rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0);
 	if (!rc) {
 		/* keep PCIe reset asserted for 250ms */
 		msleep(250);
-		pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset);
+		pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0);
 		/* Wait for 2s to reload flash and train the link */
 		msleep(2000);
 	}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 81f06e8..8581a5f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device);
  * pcibios_set_pcie_reset_state - set reset state for device dev
  * @dev: the PCIe device reset
  * @state: Reset state to enter into
- *
+ * @probe: Check if the device can take the reset
  *
  * Sets the PCIe reset state for the device. This is the default
  * implementation. Architecture implementations can override this.
  */
 int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev,
-					enum pcie_reset_state state)
+					enum pcie_reset_state state,
+					int probe)
 {
-	return -EINVAL;
+	return -ENOTTY;
 }
 
 /**
  * pci_set_pcie_reset_state - set reset state for device dev
  * @dev: the PCIe device reset
  * @state: Reset state to enter into
- *
+ * @probe: Check if the device can take the reset
  *
  * Sets the PCI reset state for the device.
  */
-int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
+int pci_set_pcie_reset_state(struct pci_dev *dev,
+			     enum pcie_reset_state state,
+			     int probe)
 {
-	return pcibios_set_pcie_reset_state(dev, state);
+	return pcibios_set_pcie_reset_state(dev, state, probe);
 }
 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
 
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 9219953..89026f4 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd)
 static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd)
 {
 	ENTER;
-	pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset);
+	pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev,
+				 pcie_deassert_reset, 0);
 	ipr_cmd->job_step = ipr_reset_bist_done;
 	ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT);
 	LEAVE;
@@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd)
 	struct pci_dev *pdev = ioa_cfg->pdev;
 
 	ENTER;
-	pci_set_pcie_reset_state(pdev, pcie_warm_reset);
+	pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0);
 	ipr_cmd->job_step = ipr_reset_slot_reset_done;
 	ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT);
 	LEAVE;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 211e9da..c15ca2f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency;
 void pci_set_master(struct pci_dev *dev);
 void pci_clear_master(struct pci_dev *dev);
 
-int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
+int pci_set_pcie_reset_state(struct pci_dev *dev,
+			     enum pcie_reset_state state, int probe);
 int pci_set_cacheline_size(struct pci_dev *dev);
 #define HAVE_PCI_SET_MWI
 int __must_check pci_set_mwi(struct pci_dev *dev);
@@ -1647,7 +1648,7 @@ extern unsigned long pci_hotplug_mem_size;
 void pcibios_disable_device(struct pci_dev *dev);
 void pcibios_set_master(struct pci_dev *dev);
 int pcibios_set_pcie_reset_state(struct pci_dev *dev,
-				 enum pcie_reset_state state);
+				 enum pcie_reset_state state, int probe);
 int pcibios_add_device(struct pci_dev *dev);
 void pcibios_release_device(struct pci_dev *dev);
 void pcibios_penalize_isa_irq(int irq, int active);
-- 
1.8.3.2