dmaengine: idxd: Enable IDXD performance monitor support

Add the code needed in the main IDXD driver to interface with the IDXD
perfmon implementation.

[ Based on work originally by Jing Lin. ]

Reviewed-by: Dave Jiang <[e-mail]>
Reviewed-by: Kan Liang <[e-mail]>
Signed-off-by: Tom Zanussi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/idxd/init.c

···
 #include "../dmaengine.h"
 #include "registers.h"
 #include "idxd.h"
+#include "perfmon.h"
 
 MODULE_VERSION(IDXD_DRIVER_VERSION);
 MODULE_LICENSE("GPL v2");
···
 
 	idxd->major = idxd_cdev_get_major(idxd);
 
+	rc = perfmon_pmu_init(idxd);
+	if (rc < 0)
+		dev_warn(dev, "Failed to initialize perfmon. No PMU support: %d\n", rc);
+
 	dev_dbg(dev, "IDXD device %d probed successfully\n", idxd->id);
 	return 0;
 
···
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
 	idxd_unregister_devices(idxd);
+	perfmon_pmu_remove(idxd);
 	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
 }
 
···
 		pr_warn("Platform does not have ENQCMD(S) support.\n");
 	else
 		support_enqcmd = true;
+
+	perfmon_init();
 
 	err = idxd_register_bus_type();
 	if (err < 0)
···
 	pci_unregister_driver(&idxd_pci_driver);
 	idxd_cdev_remove();
 	idxd_unregister_bus_type();
+	perfmon_exit();
 }
 module_exit(idxd_exit_module);

drivers/dma/idxd/irq.c

···
 	}
 
 	if (cause & IDXD_INTC_PERFMON_OVFL) {
-		/*
-		 * Driver does not utilize perfmon counter overflow interrupt
-		 * yet.
-		 */
 		val |= IDXD_INTC_PERFMON_OVFL;
+		perfmon_counter_overflow(idxd);
 	}
 
 	val ^= cause;