drm/i915/pxp: add pxp debugfs

2 debugfs files, one to query the current status of the pxp session and one
to trigger an invalidation for testing.

v2: rename debugfs, fix date (Alan)

v12: rebased to latest drm-tip (rename of files/structs from
     debugfs_gt to intel_debugfs_gt caused compiler errors).

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by : Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-16-alan.previn.teres.alexis@intel.com

drivers/gpu/drm/i915/Makefile

@@ -282,6 +282,7 @@ i915-y += i915_perf.o
 i915-$(CONFIG_DRM_I915_PXP) += \
 	pxp/intel_pxp.o \
 	pxp/intel_pxp_cmd.o \
+	pxp/intel_pxp_debugfs.o \
 	pxp/intel_pxp_irq.o \
 	pxp/intel_pxp_pm.o \
 	pxp/intel_pxp_session.o \

drivers/gpu/drm/i915/gt/intel_gt_debugfs.c

@@ -10,6 +10,7 @@
 #include "intel_gt_engines_debugfs.h"
 #include "intel_gt_pm_debugfs.h"
 #include "intel_sseu_debugfs.h"
+#include "pxp/intel_pxp_debugfs.h"
 #include "uc/intel_uc_debugfs.h"
 
 void intel_gt_debugfs_register(struct intel_gt *gt)
@@ -28,6 +29,7 @@ void intel_gt_debugfs_register(struct intel_gt *gt)
 	intel_sseu_debugfs_register(gt, root);
 
 	intel_uc_debugfs_register(&gt->uc, root);
+	intel_pxp_debugfs_register(&gt->pxp, root);
 }
 
 void intel_gt_debugfs_register_files(struct dentry *root,

drivers/gpu/drm/i915/pxp/intel_pxp_debugfs.c

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include <linux/debugfs.h>
+#include <drm/drm_print.h>
+
+#include "gt/intel_gt_debugfs.h"
+#include "pxp/intel_pxp.h"
+#include "pxp/intel_pxp_irq.h"
+#include "i915_drv.h"
+
+static int pxp_info_show(struct seq_file *m, void *data)
+{
+	struct intel_pxp *pxp = m->private;
+	struct drm_printer p = drm_seq_file_printer(m);
+	bool enabled = intel_pxp_is_enabled(pxp);
+
+	if (!enabled) {
+		drm_printf(&p, "pxp disabled\n");
+		return 0;
+	}
+
+	drm_printf(&p, "active: %s\n", yesno(intel_pxp_is_active(pxp)));
+	drm_printf(&p, "instance counter: %u\n", pxp->key_instance);
+
+	return 0;
+}
+DEFINE_INTEL_GT_DEBUGFS_ATTRIBUTE(pxp_info);
+
+static int pxp_terminate_get(void *data, u64 *val)
+{
+	/* nothing to read */
+	return -EPERM;
+}
+
+static int pxp_terminate_set(void *data, u64 val)
+{
+	struct intel_pxp *pxp = data;
+	struct intel_gt *gt = pxp_to_gt(pxp);
+
+	if (!intel_pxp_is_active(pxp))
+		return -ENODEV;
+
+	/* simulate a termination interrupt */
+	spin_lock_irq(&gt->irq_lock);
+	intel_pxp_irq_handler(pxp, GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT);
+	spin_unlock_irq(&gt->irq_lock);
+
+	if (!wait_for_completion_timeout(&pxp->termination,
+					 msecs_to_jiffies(100)))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(pxp_terminate_fops, pxp_terminate_get, pxp_terminate_set, "%llx\n");
+void intel_pxp_debugfs_register(struct intel_pxp *pxp, struct dentry *gt_root)
+{
+	static const struct intel_gt_debugfs_file files[] = {
+		{ "info", &pxp_info_fops, NULL },
+		{ "terminate_state", &pxp_terminate_fops, NULL },
+	};
+	struct dentry *root;
+
+	if (!gt_root)
+		return;
+
+	if (!HAS_PXP((pxp_to_gt(pxp)->i915)))
+		return;
+
+	root = debugfs_create_dir("pxp", gt_root);
+	if (IS_ERR(root))
+		return;
+
+	intel_gt_debugfs_register_files(root, files, ARRAY_SIZE(files), pxp);
+}

drivers/gpu/drm/i915/pxp/intel_pxp_debugfs.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#ifndef __INTEL_PXP_DEBUGFS_H__
+#define __INTEL_PXP_DEBUGFS_H__
+
+struct intel_pxp;
+struct dentry;
+
+#ifdef CONFIG_DRM_I915_PXP
+void intel_pxp_debugfs_register(struct intel_pxp *pxp, struct dentry *root);
+#else
+static inline void
+intel_pxp_debugfs_register(struct intel_pxp *pxp, struct dentry *root)
+{
+}
+#endif
+
+#endif /* __INTEL_PXP_DEBUGFS_H__ */