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

1 files changed, 141 insertions, 0 deletions

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;
+}
+