1 files changed, 357 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c
new file mode 100644
index 000000000000..c71817963eea
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c
@@ -0,0 +1,357 @@
+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/printk.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/amd-iommu.h>
+#include "kfd_priv.h"
+#include "kfd_dbgmgr.h"
+#include "kfd_topology.h"
+#include "kfd_iommu.h"
+
+static const u32 required_iommu_flags = AMD_IOMMU_DEVICE_FLAG_ATS_SUP |
+					AMD_IOMMU_DEVICE_FLAG_PRI_SUP |
+					AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
+
+/** kfd_iommu_check_device - Check whether IOMMU is available for device
+ */
+int kfd_iommu_check_device(struct kfd_dev *kfd)
+{
+	struct amd_iommu_device_info iommu_info;
+	int err;
+
+	if (!kfd->device_info->needs_iommu_device)
+		return -ENODEV;
+
+	iommu_info.flags = 0;
+	err = amd_iommu_device_info(kfd->pdev, &iommu_info);
+	if (err)
+		return err;
+
+	if ((iommu_info.flags & required_iommu_flags) != required_iommu_flags)
+		return -ENODEV;
+
+	return 0;
+}
+
+/** kfd_iommu_device_init - Initialize IOMMU for device
+ */
+int kfd_iommu_device_init(struct kfd_dev *kfd)
+{
+	struct amd_iommu_device_info iommu_info;
+	unsigned int pasid_limit;
+	int err;
+
+	if (!kfd->device_info->needs_iommu_device)
+		return 0;
+
+	iommu_info.flags = 0;
+	err = amd_iommu_device_info(kfd->pdev, &iommu_info);
+	if (err < 0) {
+		dev_err(kfd_device,
+			"error getting iommu info. is the iommu enabled?\n");
+		return -ENODEV;
+	}
+
+	if ((iommu_info.flags & required_iommu_flags) != required_iommu_flags) {
+		dev_err(kfd_device,
+			"error required iommu flags ats %i, pri %i, pasid %i\n",
+		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_ATS_SUP) != 0,
+		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_PRI_SUP) != 0,
+		       (iommu_info.flags & AMD_IOMMU_DEVICE_FLAG_PASID_SUP)
+									!= 0);
+		return -ENODEV;
+	}
+
+	pasid_limit = min_t(unsigned int,
+			(unsigned int)(1 << kfd->device_info->max_pasid_bits),
+			iommu_info.max_pasids);
+
+	if (!kfd_set_pasid_limit(pasid_limit)) {
+		dev_err(kfd_device, "error setting pasid limit\n");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+/** kfd_iommu_bind_process_to_device - Have the IOMMU bind a process
+ *
+ * Binds the given process to the given device using its PASID. This
+ * enables IOMMUv2 address translation for the process on the device.
+ *
+ * This function assumes that the process mutex is held.
+ */
+int kfd_iommu_bind_process_to_device(struct kfd_process_device *pdd)
+{
+	struct kfd_dev *dev = pdd->dev;
+	struct kfd_process *p = pdd->process;
+	int err;
+
+	if (!dev->device_info->needs_iommu_device || pdd->bound == PDD_BOUND)
+		return 0;
+
+	if (unlikely(pdd->bound == PDD_BOUND_SUSPENDED)) {
+		pr_err("Binding PDD_BOUND_SUSPENDED pdd is unexpected!\n");
+		return -EINVAL;
+	}
+
+	err = amd_iommu_bind_pasid(dev->pdev, p->pasid, p->lead_thread);
+	if (!err)
+		pdd->bound = PDD_BOUND;
+
+	return err;
+}
+
+/** kfd_iommu_unbind_process - Unbind process from all devices
+ *
+ * This removes all IOMMU device bindings of the process. To be used
+ * before process termination.
+ */
+void kfd_iommu_unbind_process(struct kfd_process *p)
+{
+	struct kfd_process_device *pdd;
+
+	list_for_each_entry(pdd, &p->per_device_data, per_device_list)
+		if (pdd->bound == PDD_BOUND)
+			amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
+}
+
+/* Callback for process shutdown invoked by the IOMMU driver */
+static void iommu_pasid_shutdown_callback(struct pci_dev *pdev, int pasid)
+{
+	struct kfd_dev *dev = kfd_device_by_pci_dev(pdev);
+	struct kfd_process *p;
+	struct kfd_process_device *pdd;
+
+	if (!dev)
+		return;
+
+	/*
+	 * Look for the process that matches the pasid. If there is no such
+	 * process, we either released it in amdkfd's own notifier, or there
+	 * is a bug. Unfortunately, there is no way to tell...
+	 */
+	p = kfd_lookup_process_by_pasid(pasid);
+	if (!p)
+		return;
+
+	pr_debug("Unbinding process %d from IOMMU\n", pasid);
+
+	mutex_lock(kfd_get_dbgmgr_mutex());
+
+	if (dev->dbgmgr && dev->dbgmgr->pasid == p->pasid) {
+		if (!kfd_dbgmgr_unregister(dev->dbgmgr, p)) {
+			kfd_dbgmgr_destroy(dev->dbgmgr);
+			dev->dbgmgr = NULL;
+		}
+	}
+
+	mutex_unlock(kfd_get_dbgmgr_mutex());
+
+	mutex_lock(&p->mutex);
+
+	pdd = kfd_get_process_device_data(dev, p);
+	if (pdd)
+		/* For GPU relying on IOMMU, we need to dequeue here
+		 * when PASID is still bound.
+		 */
+		kfd_process_dequeue_from_device(pdd);
+
+	mutex_unlock(&p->mutex);
+
+	kfd_unref_process(p);
+}
+
+/* This function called by IOMMU driver on PPR failure */
+static int iommu_invalid_ppr_cb(struct pci_dev *pdev, int pasid,
+		unsigned long address, u16 flags)
+{
+	struct kfd_dev *dev;
+
+	dev_warn(kfd_device,
+			"Invalid PPR device %x:%x.%x pasid %d address 0x%lX flags 0x%X",
+			PCI_BUS_NUM(pdev->devfn),
+			PCI_SLOT(pdev->devfn),
+			PCI_FUNC(pdev->devfn),
+			pasid,
+			address,
+			flags);
+
+	dev = kfd_device_by_pci_dev(pdev);
+	if (!WARN_ON(!dev))
+		kfd_signal_iommu_event(dev, pasid, address,
+			flags & PPR_FAULT_WRITE, flags & PPR_FAULT_EXEC);
+
+	return AMD_IOMMU_INV_PRI_RSP_INVALID;
+}
+
+/*
+ * Bind processes do the device that have been temporarily unbound
+ * (PDD_BOUND_SUSPENDED) in kfd_unbind_processes_from_device.
+ */
+static int kfd_bind_processes_to_device(struct kfd_dev *kfd)
+{
+	struct kfd_process_device *pdd;
+	struct kfd_process *p;
+	unsigned int temp;
+	int err = 0;
+
+	int idx = srcu_read_lock(&kfd_processes_srcu);
+
+	hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
+		mutex_lock(&p->mutex);
+		pdd = kfd_get_process_device_data(kfd, p);
+
+		if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) {
+			mutex_unlock(&p->mutex);
+			continue;
+		}
+
+		err = amd_iommu_bind_pasid(kfd->pdev, p->pasid,
+				p->lead_thread);
+		if (err < 0) {
+			pr_err("Unexpected pasid %d binding failure\n",
+					p->pasid);
+			mutex_unlock(&p->mutex);
+			break;
+		}
+
+		pdd->bound = PDD_BOUND;
+		mutex_unlock(&p->mutex);
+	}
+
+	srcu_read_unlock(&kfd_processes_srcu, idx);
+
+	return err;
+}
+
+/*
+ * Mark currently bound processes as PDD_BOUND_SUSPENDED. These
+ * processes will be restored to PDD_BOUND state in
+ * kfd_bind_processes_to_device.
+ */
+static void kfd_unbind_processes_from_device(struct kfd_dev *kfd)
+{
+	struct kfd_process_device *pdd;
+	struct kfd_process *p;
+	unsigned int temp;
+
+	int idx = srcu_read_lock(&kfd_processes_srcu);
+
+	hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
+		mutex_lock(&p->mutex);
+		pdd = kfd_get_process_device_data(kfd, p);
+
+		if (WARN_ON(!pdd)) {
+			mutex_unlock(&p->mutex);
+			continue;
+		}
+
+		if (pdd->bound == PDD_BOUND)
+			pdd->bound = PDD_BOUND_SUSPENDED;
+		mutex_unlock(&p->mutex);
+	}
+
+	srcu_read_unlock(&kfd_processes_srcu, idx);
+}
+
+/** kfd_iommu_suspend - Prepare IOMMU for suspend
+ *
+ * This unbinds processes from the device and disables the IOMMU for
+ * the device.
+ */
+void kfd_iommu_suspend(struct kfd_dev *kfd)
+{
+	if (!kfd->device_info->needs_iommu_device)
+		return;
+
+	kfd_unbind_processes_from_device(kfd);
+
+	amd_iommu_set_invalidate_ctx_cb(kfd->pdev, NULL);
+	amd_iommu_set_invalid_ppr_cb(kfd->pdev, NULL);
+	amd_iommu_free_device(kfd->pdev);
+}
+
+/** kfd_iommu_resume - Restore IOMMU after resume
+ *
+ * This reinitializes the IOMMU for the device and re-binds previously
+ * suspended processes to the device.
+ */
+int kfd_iommu_resume(struct kfd_dev *kfd)
+{
+	unsigned int pasid_limit;
+	int err;
+
+	if (!kfd->device_info->needs_iommu_device)
+		return 0;
+
+	pasid_limit = kfd_get_pasid_limit();
+
+	err = amd_iommu_init_device(kfd->pdev, pasid_limit);
+	if (err)
+		return -ENXIO;
+
+	amd_iommu_set_invalidate_ctx_cb(kfd->pdev,
+					iommu_pasid_shutdown_callback);
+	amd_iommu_set_invalid_ppr_cb(kfd->pdev,
+				     iommu_invalid_ppr_cb);
+
+	err = kfd_bind_processes_to_device(kfd);
+	if (err) {
+		amd_iommu_set_invalidate_ctx_cb(kfd->pdev, NULL);
+		amd_iommu_set_invalid_ppr_cb(kfd->pdev, NULL);
+		amd_iommu_free_device(kfd->pdev);
+		return err;
+	}
+
+	return 0;
+}
+
+extern bool amd_iommu_pc_supported(void);
+extern u8 amd_iommu_pc_get_max_banks(u16 devid);
+extern u8 amd_iommu_pc_get_max_counters(u16 devid);
+
+/** kfd_iommu_add_perf_counters - Add IOMMU performance counters to topology
+ */
+int kfd_iommu_add_perf_counters(struct kfd_topology_device *kdev)
+{
+	struct kfd_perf_properties *props;
+
+	if (!(kdev->node_props.capability & HSA_CAP_ATS_PRESENT))
+		return 0;
+
+	if (!amd_iommu_pc_supported())
+		return 0;
+
+	props = kfd_alloc_struct(props);
+	if (!props)
+		return -ENOMEM;
+	strcpy(props->block_name, "iommu");
+	props->max_concurrent = amd_iommu_pc_get_max_banks(0) *
+		amd_iommu_pc_get_max_counters(0); /* assume one iommu */
+	list_add_tail(&props->list, &kdev->perf_props);
+
+	return 0;
+}