[PATCH v2 2/6] mpi3mr: Support PCIe Error Recovery callback handlers

[Ranjan Kumar <ranjan.kumar@broadcom.com>]

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The driver has been upgraded to include support for the
PCIe error recovery callback handler which is crucial for
the recovery of the controllers. This feature is
necessary for addressing the errors reported by
the PCIe AER (Advanced Error Reporting) mechanism.

Signed-off-by: Sathya Prakash <sathya.prakash@broadcom.com>
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
---
 drivers/scsi/mpi3mr/mpi3mr.h    |   5 +
 drivers/scsi/mpi3mr/mpi3mr_os.c | 197 ++++++++++++++++++++++++++++++++
 2 files changed, 202 insertions(+)

diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index 3de1ee05c44e..25e6e3a09468 100644
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -23,6 +23,7 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/aer.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
@@ -1055,6 +1056,8 @@ struct scmd_priv {
  * @ioctl_chain_sge: DMA buffer descriptor for IOCTL chain
  * @ioctl_resp_sge: DMA buffer descriptor for Mgmt cmd response
  * @ioctl_sges_allocated: Flag for IOCTL SGEs allocated or not
+ * @pcie_err_recovery: PCIe error recovery in progress
+ * @block_on_pcie_err: Block IO during PCI error recovery
  */
 struct mpi3mr_ioc {
 	struct list_head list;
@@ -1246,6 +1249,8 @@ struct mpi3mr_ioc {
 	struct dma_memory_desc ioctl_chain_sge;
 	struct dma_memory_desc ioctl_resp_sge;
 	bool ioctl_sges_allocated;
+	bool pcie_err_recovery;
+	bool block_on_pcie_err;
 };
 
 /**
diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 76ba31a9517d..dea47ef53abb 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -5472,6 +5472,195 @@ mpi3mr_resume(struct device *dev)
 	return 0;
 }
 
+/**
+ * mpi3mr_pcierr_detected - PCI error detected callback
+ * @pdev: PCI device instance
+ * @state: channel state
+ *
+ * This function is called by the PCI error recovery driver and
+ * based on the state passed the driver decides what actions to
+ * be recommended back to PCI driver.
+ *
+ * For all of the states if there is no valid mrioc or scsi host
+ * references in the pci device then this function will retyrn
+ * the resul as disconnect.
+ *
+ * For normal state, this function will return the result as can
+ * recover.
+ *
+ * For frozen state, this function will block for any pennding
+ * controller initialization or re-initialization to complete,
+ * stop any new interactions with the controller and return
+ * status as reset required.
+ *
+ * For permanent failure state, this function will mark the
+ * controller as unrecoverable and return status as disconnect.
+ *
+ * Returns: PCI_ERS_RESULT_NEED_RESET or CAN_RECOVER or
+ * DISCONNECT based on the controller state.
+ */
+static pci_ers_result_t
+mpi3mr_pcierr_detected(struct pci_dev *pdev, pci_channel_state_t state)
+{
+	struct Scsi_Host *shost;
+	struct mpi3mr_ioc *mrioc;
+	pci_ers_result_t ret_val = PCI_ERS_RESULT_DISCONNECT;
+
+	dev_info(&pdev->dev, "%s: callback invoked state(%d)\n", __func__,
+	    state);
+
+	if (mpi3mr_get_shost_and_mrioc(pdev, &shost, &mrioc)) {
+		dev_err(&pdev->dev, "device not available\n");
+		return ret_val;
+	}
+
+	switch (state) {
+	case pci_channel_io_normal:
+		ret_val = PCI_ERS_RESULT_CAN_RECOVER;
+		break;
+	case pci_channel_io_frozen:
+		mrioc->pcie_err_recovery = true;
+		mrioc->block_on_pcie_err = true;
+		while (mrioc->reset_in_progress || mrioc->is_driver_loading)
+			ssleep(1);
+		scsi_block_requests(mrioc->shost);
+		mpi3mr_stop_watchdog(mrioc);
+		mpi3mr_cleanup_resources(mrioc);
+		mrioc->pdev = NULL;
+		ret_val = PCI_ERS_RESULT_NEED_RESET;
+		break;
+	case pci_channel_io_perm_failure:
+		mrioc->pcie_err_recovery = true;
+		mrioc->block_on_pcie_err = true;
+		mrioc->unrecoverable = 1;
+		mpi3mr_stop_watchdog(mrioc);
+		mpi3mr_flush_cmds_for_unrecovered_controller(mrioc);
+		ret_val = PCI_ERS_RESULT_DISCONNECT;
+		break;
+	default:
+		break;
+	}
+	return ret_val;
+}
+
+/**
+ * mpi3mr_pcierr_slot_reset_done - Post slot reset callback
+ * @pdev: PCI device instance
+ *
+ * This function is called by the PCI error recovery driver
+ * after a slot or link reset issued by it for the recovery, the
+ * driver is expected to bring back the controller and
+ * initialize it.
+ *
+ * This function restores pci state and reinitializes controller
+ * resoruces and the controller, this blocks for any pending
+ * reset to complete.
+ *
+ * Returns: PCI_ERS_RESULT_DISCONNECT on failure or
+ * PCI_ERS_RESULT_RECOVERED
+ */
+static pci_ers_result_t mpi3mr_pcierr_slot_reset_done(struct pci_dev *pdev)
+{
+	struct Scsi_Host *shost;
+	struct mpi3mr_ioc *mrioc;
+
+
+	dev_info(&pdev->dev, "%s: callback invoked\n", __func__);
+
+	if (mpi3mr_get_shost_and_mrioc(pdev, &shost, &mrioc)) {
+		dev_err(&pdev->dev, "device not available\n");
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+
+	while (mrioc->reset_in_progress)
+		ssleep(1);
+
+	mrioc->pdev = pdev;
+	pci_restore_state(pdev);
+
+	if (mpi3mr_setup_resources(mrioc)) {
+		ioc_err(mrioc, "setup resources failed\n");
+		goto out_failed;
+	}
+	mrioc->unrecoverable = 0;
+	mrioc->pcie_err_recovery = false;
+
+	if (mpi3mr_soft_reset_handler(mrioc, MPI3MR_RESET_FROM_FIRMWARE, 0))
+		goto out_failed;
+
+	return PCI_ERS_RESULT_RECOVERED;
+
+out_failed:
+	mrioc->unrecoverable = 1;
+	mrioc->block_on_pcie_err = false;
+	scsi_unblock_requests(shost);
+	mpi3mr_start_watchdog(mrioc);
+	return PCI_ERS_RESULT_DISCONNECT;
+}
+
+/**
+ * mpi3mr_pcierr_resume - PCI error recovery resume
+ * callback
+ * @pdev: PCI device instance
+ *
+ * This function enables all I/O and IOCTLs post reset issued as
+ * part of the PCI advacned error reporting and handling
+ *
+ * Return: Nothing.
+ */
+static void mpi3mr_pcierr_resume(struct pci_dev *pdev)
+{
+	struct Scsi_Host *shost;
+	struct mpi3mr_ioc *mrioc;
+
+	dev_info(&pdev->dev, "%s: callback invoked\n", __func__);
+
+	if (mpi3mr_get_shost_and_mrioc(pdev, &shost, &mrioc)) {
+		dev_err(&pdev->dev, "device not available\n");
+		return;
+	}
+
+	pci_aer_clear_nonfatal_status(pdev);
+
+	if (mrioc->block_on_pcie_err) {
+		mrioc->block_on_pcie_err = false;
+		scsi_unblock_requests(shost);
+		mpi3mr_start_watchdog(mrioc);
+	}
+
+}
+
+/**
+ * mpi3mr_pcierr_mmio_enabled - PCI error recovery callback
+ * @pdev: PCI device instance
+ *
+ * This is called only if _pcierr_error_detected returns
+ * PCI_ERS_RESULT_CAN_RECOVER.
+ *
+ * Return: PCI_ERS_RESULT_DISCONNECT when the controller is
+ * unrecoverable or when the shost/mnrioc reference cannot be
+ * found, else return PCI_ERS_RESULT_RECOVERED
+ */
+static pci_ers_result_t mpi3mr_pcierr_mmio_enabled(struct pci_dev *pdev)
+{
+
+	struct Scsi_Host *shost;
+	struct mpi3mr_ioc *mrioc;
+/*
+ *
+ */
+	dev_info(&pdev->dev, "%s: callback invoked\n", __func__);
+
+	if (mpi3mr_get_shost_and_mrioc(pdev, &shost, &mrioc)) {
+		dev_err(&pdev->dev, "device not available\n");
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+	if (mrioc->unrecoverable)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
 static const struct pci_device_id mpi3mr_pci_id_table[] = {
 	{
 		PCI_DEVICE_SUB(MPI3_MFGPAGE_VENDORID_BROADCOM,
@@ -5489,6 +5678,13 @@ static const struct pci_device_id mpi3mr_pci_id_table[] = {
 };
 MODULE_DEVICE_TABLE(pci, mpi3mr_pci_id_table);
 
+static struct pci_error_handlers mpi3mr_err_handler = {
+	.error_detected = mpi3mr_pcierr_detected,
+	.mmio_enabled = mpi3mr_pcierr_mmio_enabled,
+	.slot_reset = mpi3mr_pcierr_slot_reset_done,
+	.resume = mpi3mr_pcierr_resume,
+};
+
 static SIMPLE_DEV_PM_OPS(mpi3mr_pm_ops, mpi3mr_suspend, mpi3mr_resume);
 
 static struct pci_driver mpi3mr_pci_driver = {
@@ -5497,6 +5693,7 @@ static struct pci_driver mpi3mr_pci_driver = {
 	.probe = mpi3mr_probe,
 	.remove = mpi3mr_remove,
 	.shutdown = mpi3mr_shutdown,
+	.err_handler = &mpi3mr_err_handler,
 	.driver.pm = &mpi3mr_pm_ops,
 };
 
-- 
2.31.1


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