1 files changed, 242 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_pci_sriov.c b/drivers/gpu/drm/xe/xe_pci_sriov.c
new file mode 100644
index 000000000000..8813efdcafbb
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_pci_sriov.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023-2024 Intel Corporation
+ */
+
+#include "xe_assert.h"
+#include "xe_device.h"
+#include "xe_gt_sriov_pf_config.h"
+#include "xe_gt_sriov_pf_control.h"
+#include "xe_gt_sriov_printk.h"
+#include "xe_guc_engine_activity.h"
+#include "xe_pci_sriov.h"
+#include "xe_pm.h"
+#include "xe_sriov.h"
+#include "xe_sriov_pf_helpers.h"
+#include "xe_sriov_printk.h"
+
+static int pf_needs_provisioning(struct xe_gt *gt, unsigned int num_vfs)
+{
+	unsigned int n;
+
+	for (n = 1; n <= num_vfs; n++)
+		if (!xe_gt_sriov_pf_config_is_empty(gt, n))
+			return false;
+
+	return true;
+}
+
+static int pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs)
+{
+	struct xe_gt *gt;
+	unsigned int id;
+	int result = 0, err;
+
+	for_each_gt(gt, xe, id) {
+		if (!pf_needs_provisioning(gt, num_vfs))
+			continue;
+		err = xe_gt_sriov_pf_config_set_fair(gt, VFID(1), num_vfs);
+		result = result ?: err;
+	}
+
+	return result;
+}
+
+static void pf_unprovision_vfs(struct xe_device *xe, unsigned int num_vfs)
+{
+	struct xe_gt *gt;
+	unsigned int id;
+	unsigned int n;
+
+	for_each_gt(gt, xe, id)
+		for (n = 1; n <= num_vfs; n++)
+			xe_gt_sriov_pf_config_release(gt, n, true);
+}
+
+static void pf_reset_vfs(struct xe_device *xe, unsigned int num_vfs)
+{
+	struct xe_gt *gt;
+	unsigned int id;
+	unsigned int n;
+
+	for_each_gt(gt, xe, id)
+		for (n = 1; n <= num_vfs; n++)
+			xe_gt_sriov_pf_control_trigger_flr(gt, n);
+}
+
+static struct pci_dev *xe_pci_pf_get_vf_dev(struct xe_device *xe, unsigned int vf_id)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+
+	xe_assert(xe, IS_SRIOV_PF(xe));
+
+	/* caller must use pci_dev_put() */
+	return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+			pdev->bus->number,
+			pci_iov_virtfn_devfn(pdev, vf_id));
+}
+
+static void pf_link_vfs(struct xe_device *xe, int num_vfs)
+{
+	struct pci_dev *pdev_pf = to_pci_dev(xe->drm.dev);
+	struct device_link *link;
+	struct pci_dev *pdev_vf;
+	unsigned int n;
+
+	/*
+	 * When both PF and VF devices are enabled on the host, during system
+	 * resume they are resuming in parallel.
+	 *
+	 * But PF has to complete the provision of VF first to allow any VFs to
+	 * successfully resume.
+	 *
+	 * Create a parent-child device link between PF and VF devices that will
+	 * enforce correct resume order.
+	 */
+	for (n = 1; n <= num_vfs; n++) {
+		pdev_vf = xe_pci_pf_get_vf_dev(xe, n - 1);
+
+		/* unlikely, something weird is happening, abort */
+		if (!pdev_vf) {
+			xe_sriov_err(xe, "Cannot find VF%u device, aborting link%s creation!\n",
+				     n, str_plural(num_vfs));
+			break;
+		}
+
+		link = device_link_add(&pdev_vf->dev, &pdev_pf->dev,
+				       DL_FLAG_AUTOREMOVE_CONSUMER);
+		/* unlikely and harmless, continue with other VFs */
+		if (!link)
+			xe_sriov_notice(xe, "Failed linking VF%u\n", n);
+
+		pci_dev_put(pdev_vf);
+	}
+}
+
+static void pf_engine_activity_stats(struct xe_device *xe, unsigned int num_vfs, bool enable)
+{
+	struct xe_gt *gt;
+	unsigned int id;
+	int ret = 0;
+
+	for_each_gt(gt, xe, id) {
+		ret = xe_guc_engine_activity_function_stats(&gt->uc.guc, num_vfs, enable);
+		if (ret)
+			xe_gt_sriov_info(gt, "Failed to %s engine activity function stats (%pe)\n",
+					 str_enable_disable(enable), ERR_PTR(ret));
+	}
+}
+
+static int pf_enable_vfs(struct xe_device *xe, int num_vfs)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	int total_vfs = xe_sriov_pf_get_totalvfs(xe);
+	int err;
+
+	xe_assert(xe, IS_SRIOV_PF(xe));
+	xe_assert(xe, num_vfs > 0);
+	xe_assert(xe, num_vfs <= total_vfs);
+	xe_sriov_dbg(xe, "enabling %u VF%s\n", num_vfs, str_plural(num_vfs));
+
+	/*
+	 * We must hold additional reference to the runtime PM to keep PF in D0
+	 * during VFs lifetime, as our VFs do not implement the PM capability.
+	 *
+	 * With PF being in D0 state, all VFs will also behave as in D0 state.
+	 * This will also keep GuC alive with all VFs' configurations.
+	 *
+	 * We will release this additional PM reference in pf_disable_vfs().
+	 */
+	xe_pm_runtime_get_noresume(xe);
+
+	err = pf_provision_vfs(xe, num_vfs);
+	if (err < 0)
+		goto failed;
+
+	err = pci_enable_sriov(pdev, num_vfs);
+	if (err < 0)
+		goto failed;
+
+	pf_link_vfs(xe, num_vfs);
+
+	xe_sriov_info(xe, "Enabled %u of %u VF%s\n",
+		      num_vfs, total_vfs, str_plural(total_vfs));
+
+	pf_engine_activity_stats(xe, num_vfs, true);
+
+	return num_vfs;
+
+failed:
+	pf_unprovision_vfs(xe, num_vfs);
+	xe_pm_runtime_put(xe);
+
+	xe_sriov_notice(xe, "Failed to enable %u VF%s (%pe)\n",
+			num_vfs, str_plural(num_vfs), ERR_PTR(err));
+	return err;
+}
+
+static int pf_disable_vfs(struct xe_device *xe)
+{
+	struct device *dev = xe->drm.dev;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	u16 num_vfs = pci_num_vf(pdev);
+
+	xe_assert(xe, IS_SRIOV_PF(xe));
+	xe_sriov_dbg(xe, "disabling %u VF%s\n", num_vfs, str_plural(num_vfs));
+
+	if (!num_vfs)
+		return 0;
+
+	pf_engine_activity_stats(xe, num_vfs, false);
+
+	pci_disable_sriov(pdev);
+
+	pf_reset_vfs(xe, num_vfs);
+
+	pf_unprovision_vfs(xe, num_vfs);
+
+	/* not needed anymore - see pf_enable_vfs() */
+	xe_pm_runtime_put(xe);
+
+	xe_sriov_info(xe, "Disabled %u VF%s\n", num_vfs, str_plural(num_vfs));
+	return 0;
+}
+
+/**
+ * xe_pci_sriov_configure - Configure SR-IOV (enable/disable VFs).
+ * @pdev: the &pci_dev
+ * @num_vfs: number of VFs to enable or zero to disable all VFs
+ *
+ * This is the Xe implementation of struct pci_driver.sriov_configure callback.
+ *
+ * This callback will be called by the PCI subsystem to enable or disable SR-IOV
+ * Virtual Functions (VFs) as requested by the used via the PCI sysfs interface.
+ *
+ * Return: number of configured VFs or a negative error code on failure.
+ */
+int xe_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)
+{
+	struct xe_device *xe = pdev_to_xe_device(pdev);
+	int ret;
+
+	if (!IS_SRIOV_PF(xe))
+		return -ENODEV;
+
+	if (num_vfs < 0)
+		return -EINVAL;
+
+	if (num_vfs > xe_sriov_pf_get_totalvfs(xe))
+		return -ERANGE;
+
+	if (num_vfs && pci_num_vf(pdev))
+		return -EBUSY;
+
+	xe_pm_runtime_get(xe);
+	if (num_vfs > 0)
+		ret = pf_enable_vfs(xe, num_vfs);
+	else
+		ret = pf_disable_vfs(xe);
+	xe_pm_runtime_put(xe);
+
+	return ret;
+}