drm/i915/pxp: Implement arb session teardown

Teardown is triggered when the display topology changes and no
long meets the secure playback requirement, and hardware trashes
all the encryption keys for display. Additionally, we want to emit a
teardown operation to make sure we're clean on boot and resume

v2: emit in the ring, use high prio request (Chris)
v3: better defines, stalling flush, cleaned up and renamed submission
    funcs (Chris)
v12: fix uninitialized variable bug

Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-9-alan.previn.teres.alexis@intel.com

5 files changed, 192 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index 65598487a7b2..6afa87f90eef 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -110,9 +110,14 @@ void intel_pxp_fini(struct intel_pxp *pxp)
 
 void intel_pxp_init_hw(struct intel_pxp *pxp)
 {
+	int ret;
+
 	kcr_pxp_enable(pxp_to_gt(pxp));
 
-	intel_pxp_create_arb_session(pxp);
+	/* always emit a full termination to clean the state */
+	ret = intel_pxp_terminate_arb_session_and_global(pxp);
+	if (!ret)
+		intel_pxp_create_arb_session(pxp);
 }
 
 void intel_pxp_fini_hw(struct intel_pxp *pxp)
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.c b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.c
new file mode 100644
index 000000000000..f41e45763d0d
--- /dev/null
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright(c) 2020, Intel Corporation. All rights reserved.
+ */
+
+#include "intel_pxp.h"
+#include "intel_pxp_cmd.h"
+#include "intel_pxp_session.h"
+#include "gt/intel_context.h"
+#include "gt/intel_engine_pm.h"
+#include "gt/intel_gpu_commands.h"
+#include "gt/intel_ring.h"
+
+#include "i915_trace.h"
+
+/* stall until prior PXP and MFX/HCP/HUC objects are cmopleted */
+#define MFX_WAIT_PXP (MFX_WAIT | \
+		      MFX_WAIT_DW0_PXP_SYNC_CONTROL_FLAG | \
+		      MFX_WAIT_DW0_MFX_SYNC_CONTROL_FLAG)
+
+static u32 *pxp_emit_session_selection(u32 *cs, u32 idx)
+{
+	*cs++ = MFX_WAIT_PXP;
+
+	/* pxp off */
+	*cs++ = MI_FLUSH_DW;
+	*cs++ = 0;
+	*cs++ = 0;
+
+	/* select session */
+	*cs++ = MI_SET_APPID | MI_SET_APPID_SESSION_ID(idx);
+
+	*cs++ = MFX_WAIT_PXP;
+
+	/* pxp on */
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_PROTECTED_MEM_EN |
+		MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_PXP_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = 0;
+
+	*cs++ = MFX_WAIT_PXP;
+
+	return cs;
+}
+
+static u32 *pxp_emit_inline_termination(u32 *cs)
+{
+	/* session inline termination */
+	*cs++ = CRYPTO_KEY_EXCHANGE;
+	*cs++ = 0;
+
+	return cs;
+}
+
+static u32 *pxp_emit_session_termination(u32 *cs, u32 idx)
+{
+	cs = pxp_emit_session_selection(cs, idx);
+	cs = pxp_emit_inline_termination(cs);
+
+	return cs;
+}
+
+static u32 *pxp_emit_wait(u32 *cs)
+{
+	/* wait for cmds to go through */
+	*cs++ = MFX_WAIT_PXP;
+	*cs++ = 0;
+
+	return cs;
+}
+
+/*
+ * if we ever need to terminate more than one session, we can submit multiple
+ * selections and terminations back-to-back with a single wait at the end
+ */
+#define SELECTION_LEN 10
+#define TERMINATION_LEN 2
+#define SESSION_TERMINATION_LEN(x) ((SELECTION_LEN + TERMINATION_LEN) * (x))
+#define WAIT_LEN 2
+
+static void pxp_request_commit(struct i915_request *rq)
+{
+	struct i915_sched_attr attr = { .priority = I915_PRIORITY_MAX };
+	struct intel_timeline * const tl = i915_request_timeline(rq);
+
+	lockdep_unpin_lock(&tl->mutex, rq->cookie);
+
+	trace_i915_request_add(rq);
+	__i915_request_commit(rq);
+	__i915_request_queue(rq, &attr);
+
+	mutex_unlock(&tl->mutex);
+}
+
+int intel_pxp_terminate_session(struct intel_pxp *pxp, u32 id)
+{
+	struct i915_request *rq;
+	struct intel_context *ce = pxp->ce;
+	u32 *cs;
+	int err = 0;
+
+	if (!intel_pxp_is_enabled(pxp))
+		return 0;
+
+	rq = i915_request_create(ce);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
+
+	if (ce->engine->emit_init_breadcrumb) {
+		err = ce->engine->emit_init_breadcrumb(rq);
+		if (err)
+			goto out_rq;
+	}
+
+	cs = intel_ring_begin(rq, SESSION_TERMINATION_LEN(1) + WAIT_LEN);
+	if (IS_ERR(cs)) {
+		err = PTR_ERR(cs);
+		goto out_rq;
+	}
+
+	cs = pxp_emit_session_termination(cs, id);
+	cs = pxp_emit_wait(cs);
+
+	intel_ring_advance(rq, cs);
+
+out_rq:
+	i915_request_get(rq);
+
+	if (unlikely(err))
+		i915_request_set_error_once(rq, err);
+
+	pxp_request_commit(rq);
+
+	if (!err && i915_request_wait(rq, 0, HZ / 5) < 0)
+		err = -ETIME;
+
+	i915_request_put(rq);
+
+	return err;
+}
+
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.h b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.h
new file mode 100644
index 000000000000..6d6299543578
--- /dev/null
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_cmd.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright(c) 2020, Intel Corporation. All rights reserved.
+ */
+
+#ifndef __INTEL_PXP_CMD_H__
+#define __INTEL_PXP_CMD_H__
+
+#include <linux/types.h>
+
+struct intel_pxp;
+
+int intel_pxp_terminate_session(struct intel_pxp *pxp, u32 idx);
+
+#endif /* __INTEL_PXP_CMD_H__ */
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
index 3331868f354c..b8e24adeb1f3 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
@@ -7,6 +7,7 @@
 #include "i915_drv.h"
 
 #include "intel_pxp.h"
+#include "intel_pxp_cmd.h"
 #include "intel_pxp_session.h"
 #include "intel_pxp_tee.h"
 #include "intel_pxp_types.h"
@@ -15,6 +16,9 @@
 
 #define GEN12_KCR_SIP _MMIO(0x32260) /* KCR hwdrm session in play 0-31 */
 
+/* PXP global terminate register for session termination */
+#define PXP_GLOBAL_TERMINATE _MMIO(0x320f8)
+
 static bool intel_pxp_session_is_in_play(struct intel_pxp *pxp, u32 id)
 {
 	struct intel_gt *gt = pxp_to_gt(pxp);
@@ -72,3 +76,28 @@ int intel_pxp_create_arb_session(struct intel_pxp *pxp)
 
 	return 0;
 }
+
+int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
+{
+	int ret;
+	struct intel_gt *gt = pxp_to_gt(pxp);
+
+	pxp->arb_is_valid = false;
+
+	/* terminate the hw sessions */
+	ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
+	if (ret) {
+		drm_err(&gt->i915->drm, "Failed to submit session termination\n");
+		return ret;
+	}
+
+	ret = pxp_wait_for_session_state(pxp, ARB_SESSION, false);
+	if (ret) {
+		drm_err(&gt->i915->drm, "Session state did not clear\n");
+		return ret;
+	}
+
+	intel_uncore_write(gt->uncore, PXP_GLOBAL_TERMINATE, 1);
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.h b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h
index 316c3bebed9c..7354314b1cc4 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h
@@ -11,5 +11,6 @@
 struct intel_pxp;
 
 int intel_pxp_create_arb_session(struct intel_pxp *pxp);
+int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp);
 
 #endif /* __INTEL_PXP_SESSION_H__ */