Commit 2ae09687 authored by Huang, Sean Z's avatar Huang, Sean Z Committed by Rodrigo Vivi

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)
Signed-off-by: default avatarAlan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: default avatarHuang, Sean Z <sean.z.huang@intel.com>
Signed-off-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924191452.1539378-10-alan.previn.teres.alexis@intel.com
parent 95c9e122
......@@ -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_irq.o \
pxp/intel_pxp_session.o \
pxp/intel_pxp_tee.o
......
......@@ -13,6 +13,7 @@
#include "intel_lrc_reg.h"
#include "intel_uncore.h"
#include "intel_rps.h"
#include "pxp/intel_pxp_irq.h"
static void guc_irq_handler(struct intel_guc *guc, u16 iir)
{
......@@ -64,6 +65,9 @@ gen11_other_irq_handler(struct intel_gt *gt, const u8 instance,
if (instance == OTHER_GTPM_INSTANCE)
return gen11_rps_irq_handler(&gt->rps, iir);
if (instance == OTHER_KCR_INSTANCE)
return intel_pxp_irq_handler(&gt->pxp, iir);
WARN_ONCE(1, "unhandled other interrupt instance=0x%x, iir=0x%x\n",
instance, iir);
}
......@@ -196,6 +200,9 @@ void gen11_gt_irq_reset(struct intel_gt *gt)
intel_uncore_write(uncore, GEN11_GPM_WGBOXPERF_INTR_MASK, ~0);
intel_uncore_write(uncore, GEN11_GUC_SG_INTR_ENABLE, 0);
intel_uncore_write(uncore, GEN11_GUC_SG_INTR_MASK, ~0);
intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_ENABLE, 0);
intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_MASK, ~0);
}
void gen11_gt_irq_postinstall(struct intel_gt *gt)
......
......@@ -8124,6 +8124,7 @@ enum {
/* irq instances for OTHER_CLASS */
#define OTHER_GUC_INSTANCE 0
#define OTHER_GTPM_INSTANCE 1
#define OTHER_KCR_INSTANCE 4
#define GEN11_INTR_IDENTITY_REG(x) _MMIO(0x190060 + ((x) * 4))
......
......@@ -2,7 +2,9 @@
/*
* Copyright(c) 2020 Intel Corporation.
*/
#include <linux/workqueue.h>
#include "intel_pxp.h"
#include "intel_pxp_irq.h"
#include "intel_pxp_session.h"
#include "intel_pxp_tee.h"
#include "gt/intel_context.h"
......@@ -80,6 +82,16 @@ void intel_pxp_init(struct intel_pxp *pxp)
mutex_init(&pxp->tee_mutex);
/*
* we'll use the completion to check if there is a termination pending,
* so we start it as completed and we reinit it when a termination
* is triggered.
*/
init_completion(&pxp->termination);
complete_all(&pxp->termination);
INIT_WORK(&pxp->session_work, intel_pxp_session_work);
ret = create_vcs_context(pxp);
if (ret)
return;
......@@ -108,19 +120,61 @@ void intel_pxp_fini(struct intel_pxp *pxp)
destroy_vcs_context(pxp);
}
void intel_pxp_init_hw(struct intel_pxp *pxp)
void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp)
{
int ret;
pxp->arb_is_valid = false;
reinit_completion(&pxp->termination);
}
static void intel_pxp_queue_termination(struct intel_pxp *pxp)
{
struct intel_gt *gt = pxp_to_gt(pxp);
/*
* We want to get the same effect as if we received a termination
* interrupt, so just pretend that we did.
*/
spin_lock_irq(&gt->irq_lock);
intel_pxp_mark_termination_in_progress(pxp);
pxp->session_events |= PXP_TERMINATION_REQUEST;
queue_work(system_unbound_wq, &pxp->session_work);
spin_unlock_irq(&gt->irq_lock);
}
/*
* the arb session is restarted from the irq work when we receive the
* termination completion interrupt
*/
int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
{
if (!intel_pxp_is_enabled(pxp))
return 0;
if (!wait_for_completion_timeout(&pxp->termination,
msecs_to_jiffies(100)))
return -ETIMEDOUT;
if (!pxp->arb_is_valid)
return -EIO;
return 0;
}
void intel_pxp_init_hw(struct intel_pxp *pxp)
{
kcr_pxp_enable(pxp_to_gt(pxp));
intel_pxp_irq_enable(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);
/*
* the session could've been attacked while we weren't loaded, so
* handle it as if it was and re-create it.
*/
intel_pxp_queue_termination(pxp);
}
void intel_pxp_fini_hw(struct intel_pxp *pxp)
{
kcr_pxp_disable(pxp_to_gt(pxp));
intel_pxp_irq_disable(pxp);
}
......@@ -22,6 +22,9 @@ void intel_pxp_fini(struct intel_pxp *pxp);
void intel_pxp_init_hw(struct intel_pxp *pxp);
void intel_pxp_fini_hw(struct intel_pxp *pxp);
void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp);
int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp);
#else
static inline void intel_pxp_init(struct intel_pxp *pxp)
{
......@@ -30,6 +33,11 @@ static inline void intel_pxp_init(struct intel_pxp *pxp)
static inline void intel_pxp_fini(struct intel_pxp *pxp)
{
}
static inline int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
{
return -ENODEV;
}
#endif
#endif /* __INTEL_PXP_H__ */
// SPDX-License-Identifier: MIT
/*
* Copyright(c) 2020 Intel Corporation.
*/
#include <linux/workqueue.h>
#include "intel_pxp.h"
#include "intel_pxp_irq.h"
#include "intel_pxp_session.h"
#include "gt/intel_gt_irq.h"
#include "gt/intel_gt_types.h"
#include "i915_irq.h"
#include "i915_reg.h"
/**
* intel_pxp_irq_handler - Handles PXP interrupts.
* @pxp: pointer to pxp struct
* @iir: interrupt vector
*/
void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
{
struct intel_gt *gt = pxp_to_gt(pxp);
if (GEM_WARN_ON(!intel_pxp_is_enabled(pxp)))
return;
lockdep_assert_held(&gt->irq_lock);
if (unlikely(!iir))
return;
if (iir & (GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT |
GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT)) {
/* immediately mark PXP as inactive on termination */
intel_pxp_mark_termination_in_progress(pxp);
pxp->session_events |= PXP_TERMINATION_REQUEST;
}
if (iir & GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
pxp->session_events |= PXP_TERMINATION_COMPLETE;
if (pxp->session_events)
queue_work(system_unbound_wq, &pxp->session_work);
}
static inline void __pxp_set_interrupts(struct intel_gt *gt, u32 interrupts)
{
struct intel_uncore *uncore = gt->uncore;
const u32 mask = interrupts << 16;
intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_ENABLE, mask);
intel_uncore_write(uncore, GEN11_CRYPTO_RSVD_INTR_MASK, ~mask);
}
static inline void pxp_irq_reset(struct intel_gt *gt)
{
spin_lock_irq(&gt->irq_lock);
gen11_gt_reset_one_iir(gt, 0, GEN11_KCR);
spin_unlock_irq(&gt->irq_lock);
}
void intel_pxp_irq_enable(struct intel_pxp *pxp)
{
struct intel_gt *gt = pxp_to_gt(pxp);
spin_lock_irq(&gt->irq_lock);
if (!pxp->irq_enabled)
WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_KCR));
__pxp_set_interrupts(gt, GEN12_PXP_INTERRUPTS);
pxp->irq_enabled = true;
spin_unlock_irq(&gt->irq_lock);
}
void intel_pxp_irq_disable(struct intel_pxp *pxp)
{
struct intel_gt *gt = pxp_to_gt(pxp);
/*
* We always need to submit a global termination when we re-enable the
* interrupts, so there is no need to make sure that the session state
* makes sense at the end of this function. Just make sure this is not
* called in a path were the driver consider the session as valid and
* doesn't call a termination on restart.
*/
GEM_WARN_ON(intel_pxp_is_active(pxp));
spin_lock_irq(&gt->irq_lock);
pxp->irq_enabled = false;
__pxp_set_interrupts(gt, 0);
spin_unlock_irq(&gt->irq_lock);
intel_synchronize_irq(gt->i915);
pxp_irq_reset(gt);
flush_work(&pxp->session_work);
}
/* SPDX-License-Identifier: MIT */
/*
* Copyright(c) 2020, Intel Corporation. All rights reserved.
*/
#ifndef __INTEL_PXP_IRQ_H__
#define __INTEL_PXP_IRQ_H__
#include <linux/types.h>
struct intel_pxp;
#define GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT BIT(1)
#define GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT BIT(2)
#define GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT BIT(3)
#define GEN12_PXP_INTERRUPTS \
(GEN12_DISPLAY_PXP_STATE_TERMINATED_INTERRUPT | \
GEN12_DISPLAY_APP_TERMINATED_PER_FW_REQ_INTERRUPT | \
GEN12_DISPLAY_STATE_RESET_COMPLETE_INTERRUPT)
#ifdef CONFIG_DRM_I915_PXP
void intel_pxp_irq_enable(struct intel_pxp *pxp);
void intel_pxp_irq_disable(struct intel_pxp *pxp);
void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir);
#else
static inline void intel_pxp_irq_handler(struct intel_pxp *pxp, u16 iir)
{
}
#endif
#endif /* __INTEL_PXP_IRQ_H__ */
......@@ -48,7 +48,7 @@ static int pxp_wait_for_session_state(struct intel_pxp *pxp, u32 id, bool in_pla
return ret;
}
int intel_pxp_create_arb_session(struct intel_pxp *pxp)
static int pxp_create_arb_session(struct intel_pxp *pxp)
{
struct intel_gt *gt = pxp_to_gt(pxp);
int ret;
......@@ -77,12 +77,13 @@ int intel_pxp_create_arb_session(struct intel_pxp *pxp)
return 0;
}
int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
static int 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;
/* must mark termination in progress calling this function */
GEM_WARN_ON(pxp->arb_is_valid);
/* terminate the hw sessions */
ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
......@@ -101,3 +102,50 @@ int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
return ret;
}
static void pxp_terminate(struct intel_pxp *pxp)
{
int ret;
pxp->hw_state_invalidated = true;
/*
* if we fail to submit the termination there is no point in waiting for
* it to complete. PXP will be marked as non-active until the next
* termination is issued.
*/
ret = pxp_terminate_arb_session_and_global(pxp);
if (ret)
complete_all(&pxp->termination);
}
static void pxp_terminate_complete(struct intel_pxp *pxp)
{
/* Re-create the arb session after teardown handle complete */
if (fetch_and_zero(&pxp->hw_state_invalidated))
pxp_create_arb_session(pxp);
complete_all(&pxp->termination);
}
void intel_pxp_session_work(struct work_struct *work)
{
struct intel_pxp *pxp = container_of(work, typeof(*pxp), session_work);
struct intel_gt *gt = pxp_to_gt(pxp);
u32 events = 0;
spin_lock_irq(&gt->irq_lock);
events = fetch_and_zero(&pxp->session_events);
spin_unlock_irq(&gt->irq_lock);
if (!events)
return;
if (events & PXP_TERMINATION_REQUEST) {
events &= ~PXP_TERMINATION_COMPLETE;
pxp_terminate(pxp);
}
if (events & PXP_TERMINATION_COMPLETE)
pxp_terminate_complete(pxp);
}
......@@ -8,9 +8,8 @@
#include <linux/types.h>
struct intel_pxp;
struct work_struct;
int intel_pxp_create_arb_session(struct intel_pxp *pxp);
int intel_pxp_terminate_arb_session_and_global(struct intel_pxp *pxp);
void intel_pxp_session_work(struct work_struct *work);
#endif /* __INTEL_PXP_SESSION_H__ */
......@@ -80,6 +80,7 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,
{
struct drm_i915_private *i915 = kdev_to_i915(i915_kdev);
struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
int ret;
mutex_lock(&pxp->tee_mutex);
pxp->pxp_component = data;
......@@ -88,15 +89,14 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,
/* the component is required to fully start the PXP HW */
intel_pxp_init_hw(pxp);
if (!pxp->arb_is_valid) {
ret = intel_pxp_wait_for_arb_start(pxp);
if (ret) {
drm_err(&i915->drm, "Failed to create arb session during bind\n");
intel_pxp_fini_hw(pxp);
pxp->pxp_component = NULL;
return -EIO;
}
return 0;
return ret;
}
static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
......
......@@ -6,8 +6,10 @@
#ifndef __INTEL_PXP_TYPES_H__
#define __INTEL_PXP_TYPES_H__
#include <linux/completion.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <linux/workqueue.h>
struct intel_context;
struct i915_pxp_component;
......@@ -26,6 +28,22 @@ struct intel_pxp {
bool arb_is_valid;
struct mutex tee_mutex; /* protects the tee channel binding */
/*
* If the HW perceives an attack on the integrity of the encryption it
* will invalidate the keys and expect SW to re-initialize the session.
* We keep track of this state to make sure we only re-start the arb
* session when required.
*/
bool hw_state_invalidated;
bool irq_enabled;
struct completion termination;
struct work_struct session_work;
u32 session_events; /* protected with gt->irq_lock */
#define PXP_TERMINATION_REQUEST BIT(0)
#define PXP_TERMINATION_COMPLETE BIT(1)
};
#endif /* __INTEL_PXP_TYPES_H__ */
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