drm/i915/pxp: Implement PXP irq handler

The HW will generate a teardown interrupt when session termination is required, which requires i915 to submit a terminating batch. Once the HW is done with the termination it will generate another interrupt, at which point it is safe to re-create the session. Since the termination and re-creation flow is something we want to trigger from the driver as well, use a common work function that can be called both from the irq handler and from the driver set-up flows, which has the addded benefit of allowing us to skip any extra locks because the work itself serializes the operations. v2: use struct completion instead of bool (Chris) v3: drop locks, clean up functions and improve comments (Chris), move to common work function. v4: improve comments, simplify wait logic (Rodrigo) v5: unconditionally set interrupts, rename state_attacked var (Rodrigo) v10: remove inclusion of intel_gt_types.h from intel_pxp.h (Jani)

Huang, Sean Z committed 5 years ago

Commit 2ae09681 parent 95c9e1211 files · +284 −16Browse files

Unified · Split

11 files

drivers/gpu/drm/i915/Makefile +1 −0
drivers/gpu/drm/i915/gt/intel_gt_irq.c +7 −0
drivers/gpu/drm/i915/i915_reg.h +1 −0
drivers/gpu/drm/i915/pxp/intel_pxp.c +60 −6
drivers/gpu/drm/i915/pxp/intel_pxp.h +8 −0
drivers/gpu/drm/i915/pxp/intel_pxp_irq.c +100 −0
drivers/gpu/drm/i915/pxp/intel_pxp_irq.h +32 −0
drivers/gpu/drm/i915/pxp/intel_pxp_session.c +51 −3
drivers/gpu/drm/i915/pxp/intel_pxp_session.h +2 −3
drivers/gpu/drm/i915/pxp/intel_pxp_tee.c +4 −4
drivers/gpu/drm/i915/pxp/intel_pxp_types.h +18 −0

drivers/gpu/drm/i915/Makefile+1−0

@@ -282,6 +282,7 @@ i915-y += i915_perf.o · 281 unmodified lines
282	282	i915-$(CONFIG_DRM_I915_PXP) += \
283	283	pxp/intel_pxp.o \
284	284	pxp/intel_pxp_cmd.o \
	285	+ pxp/intel_pxp_irq.o \
285	286	pxp/intel_pxp_session.o \
286	287	pxp/intel_pxp_tee.o
287	288

drivers/gpu/drm/i915/gt/intel_gt_irq.c+7−0

@@ -13,6 +13,7 @@ · 12 unmodified lines
13	13	#include "intel_lrc_reg.h"
14	14	#include "intel_uncore.h"
15	15	#include "intel_rps.h"
	16	+#include "pxp/intel_pxp_irq.h"
16	17
17	18	static void guc_irq_handler(struct intel_guc *guc, u16 iir)
18	19	{
@@ -64,6 +65,9 @@ gen11_other_irq_handler(struct intel_gt *gt, const u8 instance, · 45 unmodified lines
64	65	if (instance == OTHER_GTPM_INSTANCE)
65	66	return gen11_rps_irq_handler(&gt->rps, iir);
66	67
	68	+ if (instance == OTHER_KCR_INSTANCE)
	69	+ return intel_pxp_irq_handler(&gt->pxp, iir);
	70	+
67	71	WARN_ONCE(1, "unhandled other interrupt instance=0x%x, iir=0x%x\n",
68	72	instance, iir);
69	73	}
@@ -196,6 +200,9 @@ void gen11_gt_irq_reset(struct intel_gt *gt) · 126 unmodified lines
196	200	intel_uncore_write(uncore, GEN11_GPM_WGBOXPERF_INTR_MASK, ~0);
197	201	intel_uncore_write(uncore, GEN11_GUC_SG_INTR_ENABLE, 0);
198	202	intel_uncore_write(uncore, GEN11_GUC_SG_INTR_MASK, ~0);
	203	+
	204	+ intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_ENABLE, 0);
	205	+ intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_MASK, ~0);
199	206	}
200	207
201	208	void gen11_gt_irq_postinstall(struct intel_gt *gt)

drivers/gpu/drm/i915/i915_reg.h+1−0

@@ -8124,6 +8124,7 @@ enum { · 8123 unmodified lines
8124	8124	/* irq instances for OTHER_CLASS */
8125	8125	#define OTHER_GUC_INSTANCE 0
8126	8126	#define OTHER_GTPM_INSTANCE 1
	8127	+#define OTHER_KCR_INSTANCE 4
8127	8128
8128	8129	#define GEN11_INTR_IDENTITY_REG(x) _MMIO(0x190060 + ((x) * 4))
8129	8130

drivers/gpu/drm/i915/pxp/intel_pxp.c+60−6

@@ -2,7 +2,9 @@ · 1 unmodified line
2	2	/*
3	3	* Copyright(c) 2020 Intel Corporation.
4	4	*/
	5	+#include <linux/workqueue.h>
5	6	#include "intel_pxp.h"
	7	+#include "intel_pxp_irq.h"
6	8	#include "intel_pxp_session.h"
7	9	#include "intel_pxp_tee.h"
8	10	#include "gt/intel_context.h"
@@ -80,6 +82,16 @@ void intel_pxp_init(struct intel_pxp *pxp) · 71 unmodified lines
80	82
81	83	mutex_init(&pxp->tee_mutex);
82	84
	85	+ /*
	86	+ * we'll use the completion to check if there is a termination pending,
	87	+ * so we start it as completed and we reinit it when a termination
	88	+ * is triggered.
	89	+ */
	90	+ init_completion(&pxp->termination);
	91	+ complete_all(&pxp->termination);
	92	+
	93	+ INIT_WORK(&pxp->session_work, intel_pxp_session_work);
	94	+
83	95	ret = create_vcs_context(pxp);
84	96	if (ret)
85	97	return;
@@ -108,19 +120,61 @@ void intel_pxp_fini(struct intel_pxp *pxp) · 22 unmodified lines
108	120	destroy_vcs_context(pxp);
109	121	}
110	122
111		−void intel_pxp_init_hw(struct intel_pxp *pxp)
	123	+void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp)
112	124	{
113		− int ret;
	125	+ pxp->arb_is_valid = false;
	126	+ reinit_completion(&pxp->termination);
	127	+}
	128	+
	129	+static void intel_pxp_queue_termination(struct intel_pxp *pxp)
	130	+{
	131	+ struct intel_gt *gt = pxp_to_gt(pxp);
	132	+
	133	+ /*
	134	+ * We want to get the same effect as if we received a termination
	135	+ * interrupt, so just pretend that we did.
	136	+ */
	137	+ spin_lock_irq(&gt->irq_lock);
	138	+ intel_pxp_mark_termination_in_progress(pxp);
	139	+ pxp->session_events \|= PXP_TERMINATION_REQUEST;
	140	+ queue_work(system_unbound_wq, &pxp->session_work);
	141	+ spin_unlock_irq(&gt->irq_lock);
	142	+}
114	143
	144	+/*
	145	+ * the arb session is restarted from the irq work when we receive the
	146	+ * termination completion interrupt
	147	+ */
	148	+int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
	149	+{
	150	+ if (!intel_pxp_is_enabled(pxp))
	151	+ return 0;
	152	+
	153	+ if (!wait_for_completion_timeout(&pxp->termination,
	154	+ msecs_to_jiffies(100)))
	155	+ return -ETIMEDOUT;
	156	+
	157	+ if (!pxp->arb_is_valid)
	158	+ return -EIO;
	159	+
	160	+ return 0;
	161	+}
	162	+
	163	+void intel_pxp_init_hw(struct intel_pxp *pxp)
	164	+{
115	165	kcr_pxp_enable(pxp_to_gt(pxp));
	166	+ intel_pxp_irq_enable(pxp);
116	167
117		− /* always emit a full termination to clean the state */
118		− ret = intel_pxp_terminate_arb_session_and_global(pxp);
119		− if (!ret)
120		− intel_pxp_create_arb_session(pxp);
	168	+ /*
	169	+ * the session could've been attacked while we weren't loaded, so
	170	+ * handle it as if it was and re-create it.
	171	+ */
	172	+ intel_pxp_queue_termination(pxp);
121	173	}
122	174
123	175	void intel_pxp_fini_hw(struct intel_pxp *pxp)
124	176	{
125	177	kcr_pxp_disable(pxp_to_gt(pxp));
	178	+
	179	+ intel_pxp_irq_disable(pxp);
126	180	}

drivers/gpu/drm/i915/pxp/intel_pxp.h+8−0

@@ -22,6 +22,9 @@ void intel_pxp_fini(struct intel_pxp *pxp); · 21 unmodified lines
22	22
23	23	void intel_pxp_init_hw(struct intel_pxp *pxp);
24	24	void intel_pxp_fini_hw(struct intel_pxp *pxp);
	25	+
	26	+void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp);
	27	+int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp);
25	28	#else
26	29	static inline void intel_pxp_init(struct intel_pxp *pxp)
27	30	{
@@ -30,6 +33,11 @@ static inline void intel_pxp_init(struct intel_pxp *pxp) · 2 unmodified lines
30	33	static inline void intel_pxp_fini(struct intel_pxp *pxp)
31	34	{
32	35	}
	36	+
	37	+static inline int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
	38	+{
	39	+ return -ENODEV;
	40	+}
33	41	#endif
34	42
35	43	#endif /* __INTEL_PXP_H__ */

drivers/gpu/drm/i915/pxp/intel_pxp_irq.c+100−0

@@ -0,0 +1,100 @@
	1	+// SPDX-License-Identifier: MIT
	2	+/*
	3	+ * Copyright(c) 2020 Intel Corporation.
	4	+ */
	5	+#include <linux/workqueue.h>
	6	+#include "intel_pxp.h"
	7	+#include "intel_pxp_irq.h"
	8	+#include "intel_pxp_session.h"
	9	+#include "gt/intel_gt_irq.h"
	10	+#include "gt/intel_gt_types.h"
	11	+#include "i915_irq.h"
	12	+#include "i915_reg.h"
	13	+
	14	+/**
	15	+ * intel_pxp_irq_handler - Handles PXP interrupts.
	16	+ * @pxp: pointer to pxp struct
	17	+ * @iir: interrupt vector
	18	+ */
	19	+void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
	20	+{
	21	+ struct intel_gt *gt = pxp_to_gt(pxp);
	22	+
	23	+ if (GEM_WARN_ON(!intel_pxp_is_enabled(pxp)))
	24	+ return;
	25	+
	26	+ lockdep_assert_held(&gt->irq_lock);
	27	+
	28	+ if (unlikely(!iir))
	29	+ return;
	30	+
	31	+ if (iir & (GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT \|
	32	+ GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT)) {
	33	+ /* immediately mark PXP as inactive on termination */
	34	+ intel_pxp_mark_termination_in_progress(pxp);
	35	+ pxp->session_events \|= PXP_TERMINATION_REQUEST;
	36	+ }
	37	+
	38	+ if (iir & GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
	39	+ pxp->session_events \|= PXP_TERMINATION_COMPLETE;
	40	+
	41	+ if (pxp->session_events)
	42	+ queue_work(system_unbound_wq, &pxp->session_work);
	43	+}
	44	+
	45	+static inline void __pxp_set_interrupts(struct intel_gt *gt, u32 interrupts)
	46	+{
	47	+ struct intel_uncore *uncore = gt->uncore;
	48	+ const u32 mask = interrupts << 16;
	49	+
	50	+ intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_ENABLE, mask);
	51	+ intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_MASK, ~mask);
	52	+}
	53	+
	54	+static inline void pxp_irq_reset(struct intel_gt *gt)
	55	+{
	56	+ spin_lock_irq(&gt->irq_lock);
	57	+ gen11_gt_reset_one_iir(gt, 0, GEN11_KCR);
	58	+ spin_unlock_irq(&gt->irq_lock);
	59	+}
	60	+
	61	+void intel_pxp_irq_enable(struct intel_pxp *pxp)
	62	+{
	63	+ struct intel_gt *gt = pxp_to_gt(pxp);
	64	+
	65	+ spin_lock_irq(&gt->irq_lock);
	66	+
	67	+ if (!pxp->irq_enabled)
	68	+ WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_KCR));
	69	+
	70	+ __pxp_set_interrupts(gt, GEN12_PXP_INTERRUPTS);
	71	+ pxp->irq_enabled = true;
	72	+
	73	+ spin_unlock_irq(&gt->irq_lock);
	74	+}
	75	+
	76	+void intel_pxp_irq_disable(struct intel_pxp *pxp)
	77	+{
	78	+ struct intel_gt *gt = pxp_to_gt(pxp);
	79	+
	80	+ /*
	81	+ * We always need to submit a global termination when we re-enable the
	82	+ * interrupts, so there is no need to make sure that the session state
	83	+ * makes sense at the end of this function. Just make sure this is not
	84	+ * called in a path were the driver consider the session as valid and
	85	+ * doesn't call a termination on restart.
	86	+ */
	87	+ GEM_WARN_ON(intel_pxp_is_active(pxp));
	88	+
	89	+ spin_lock_irq(&gt->irq_lock);
	90	+
	91	+ pxp->irq_enabled = false;
	92	+ __pxp_set_interrupts(gt, 0);
	93	+
	94	+ spin_unlock_irq(&gt->irq_lock);
	95	+ intel_synchronize_irq(gt->i915);
	96	+
	97	+ pxp_irq_reset(gt);
	98	+
	99	+ flush_work(&pxp->session_work);
	100	+}

drivers/gpu/drm/i915/pxp/intel_pxp_irq.h+32−0

@@ -0,0 +1,32 @@
	1	+/* SPDX-License-Identifier: MIT */
	2	+/*
	3	+ * Copyright(c) 2020, Intel Corporation. All rights reserved.
	4	+ */
	5	+
	6	+#ifndef __INTEL_PXP_IRQ_H__
	7	+#define __INTEL_PXP_IRQ_H__
	8	+
	9	+#include <linux/types.h>
	10	+
	11	+struct intel_pxp;
	12	+
	13	+#define GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT BIT(1)
	14	+#define GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT BIT(2)
	15	+#define GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT BIT(3)
	16	+
	17	+#define GEN12_PXP_INTERRUPTS \
	18	+ (GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT \| \
	19	+ GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT \| \
	20	+ GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
	21	+
	22	+#ifdef CONFIG_DRM_I915_PXP
	23	+void intel_pxp_irq_enable(struct intel_pxp *pxp);
	24	+void intel_pxp_irq_disable(struct intel_pxp *pxp);
	25	+void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir);
	26	+#else
	27	+static inline void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
	28	+{
	29	+}
	30	+#endif
	31	+
	32	+#endif /* __INTEL_PXP_IRQ_H__ */

drivers/gpu/drm/i915/pxp/intel_pxp_session.c+51−3

@@ -48,7 +48,7 @@ static int pxp_wait_for_session_state(struct intel_pxp *pxp, u32 id, bool in_pla · 47 unmodified lines
48	48	return ret;
49	49	}
50	50
51		−int intel_pxp_create_arb_session(struct intel_pxp *pxp)
	51	+static int pxp_create_arb_session(struct intel_pxp *pxp)
52	52	{
53	53	struct intel_gt *gt = pxp_to_gt(pxp);
54	54	int ret;
@@ -77,12 +77,13 @@ int intel_pxp_create_arb_session(struct intel_pxp *pxp) · 22 unmodified lines
77	77	return 0;
78	78	}
79	79
80		−int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
	80	+static int pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
81	81	{
82	82	int ret;
83	83	struct intel_gt *gt = pxp_to_gt(pxp);
84	84
85		− pxp->arb_is_valid = false;
	85	+ /* must mark termination in progress calling this function */
	86	+ GEM_WARN_ON(pxp->arb_is_valid);
86	87
87	88	/* terminate the hw sessions */
88	89	ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
@@ -101,3 +102,50 @@ int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp) · 12 unmodified lines
101	102
102	103	return ret;
103	104	}
	105	+
	106	+static void pxp_terminate(struct intel_pxp *pxp)
	107	+{
	108	+ int ret;
	109	+
	110	+ pxp->hw_state_invalidated = true;
	111	+
	112	+ /*
	113	+ * if we fail to submit the termination there is no point in waiting for
	114	+ * it to complete. PXP will be marked as non-active until the next
	115	+ * termination is issued.
	116	+ */
	117	+ ret = pxp_terminate_arb_session_and_global(pxp);
	118	+ if (ret)
	119	+ complete_all(&pxp->termination);
	120	+}
	121	+
	122	+static void pxp_terminate_complete(struct intel_pxp *pxp)
	123	+{
	124	+ /* Re-create the arb session after teardown handle complete */
	125	+ if (fetch_and_zero(&pxp->hw_state_invalidated))
	126	+ pxp_create_arb_session(pxp);
	127	+
	128	+ complete_all(&pxp->termination);
	129	+}
	130	+
	131	+void intel_pxp_session_work(struct work_struct *work)
	132	+{
	133	+ struct intel_pxp pxp = container_of(work, typeof(pxp), session_work);
	134	+ struct intel_gt *gt = pxp_to_gt(pxp);
	135	+ u32 events = 0;
	136	+
	137	+ spin_lock_irq(&gt->irq_lock);
	138	+ events = fetch_and_zero(&pxp->session_events);
	139	+ spin_unlock_irq(&gt->irq_lock);
	140	+
	141	+ if (!events)
	142	+ return;
	143	+
	144	+ if (events & PXP_TERMINATION_REQUEST) {
	145	+ events &= ~PXP_TERMINATION_COMPLETE;
	146	+ pxp_terminate(pxp);
	147	+ }
	148	+
	149	+ if (events & PXP_TERMINATION_COMPLETE)
	150	+ pxp_terminate_complete(pxp);
	151	+}

drivers/gpu/drm/i915/pxp/intel_pxp_session.h+2−3

@@ -8,9 +8,8 @@ · 7 unmodified lines
8	8
9	9	#include <linux/types.h>
10	10
11		−struct intel_pxp;
	11	+struct work_struct;
12	12
13		−int intel_pxp_create_arb_session(struct intel_pxp *pxp);
14		−int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp);
	13	+void intel_pxp_session_work(struct work_struct *work);
15	14
16	15	#endif /* __INTEL_PXP_SESSION_H__ */

drivers/gpu/drm/i915/pxp/intel_pxp_tee.c+4−4

@@ -80,6 +80,7 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev, · 79 unmodified lines
80	80	{
81	81	struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
82	82	struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
	83	+ int ret;
83	84
84	85	mutex_lock(&pxp->tee_mutex);
85	86	pxp->pxp_component = data;
@@ -88,15 +89,14 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev, · 2 unmodified lines
88	89
89	90	/* the component is required to fully start the PXP HW */
90	91	intel_pxp_init_hw(pxp);
91		−
92		− if (!pxp->arb_is_valid) {
	92	+ ret = intel_pxp_wait_for_arb_start(pxp);
	93	+ if (ret) {
93	94	drm_err(&i915->drm, "Failed to create arb session during bind\n");
94	95	intel_pxp_fini_hw(pxp);
95	96	pxp->pxp_component = NULL;
96		− return -EIO;
97	97	}
98	98
99		− return 0;
	99	+ return ret;
100	100	}
101	101
102	102	static void i915_pxp_tee_component_unbind(struct device *i915_kdev,

drivers/gpu/drm/i915/pxp/intel_pxp_types.h+18−0

@@ -6,8 +6,10 @@ · 5 unmodified lines
6	6	#ifndef __INTEL_PXP_TYPES_H__
7	7	#define __INTEL_PXP_TYPES_H__
8	8
	9	+#include <linux/completion.h>
9	10	#include <linux/mutex.h>
10	11	#include <linux/types.h>
	12	+#include <linux/workqueue.h>
11	13
12	14	struct intel_context;
13	15	struct i915_pxp_component;
@@ -26,6 +28,22 @@ struct intel_pxp { · 12 unmodified lines
26	28	bool arb_is_valid;
27	29
28	30	struct mutex tee_mutex; /* protects the tee channel binding */
	31	+
	32	+ /*
	33	+ * If the HW perceives an attack on the integrity of the encryption it
	34	+ * will invalidate the keys and expect SW to re-initialize the session.
	35	+ * We keep track of this state to make sure we only re-start the arb
	36	+ * session when required.
	37	+ */
	38	+ bool hw_state_invalidated;
	39	+
	40	+ bool irq_enabled;
	41	+ struct completion termination;
	42	+
	43	+ struct work_struct session_work;
	44	+ u32 session_events; /* protected with gt->irq_lock */
	45	+#define PXP_TERMINATION_REQUEST BIT(0)
	46	+#define PXP_TERMINATION_COMPLETE BIT(1)
29	47	};
30	48
31	49	#endif /* __INTEL_PXP_TYPES_H__ */

drm/i915/pxp: Implement PXP irq handler

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