From: "Huang, Sean Z" sean.z.huang@intel.com
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)
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 Cc: Rodrigo Vivi rodrigo.vivi@intel.com Reviewed-by: Rodrigo Vivi rodrigo.vivi@intel.com --- drivers/gpu/drm/i915/Makefile | 1 + drivers/gpu/drm/i915/gt/intel_gt_irq.c | 7 ++ drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/pxp/intel_pxp.c | 66 +++++++++++-- drivers/gpu/drm/i915/pxp/intel_pxp.h | 8 ++ drivers/gpu/drm/i915/pxp/intel_pxp_irq.c | 99 ++++++++++++++++++++ drivers/gpu/drm/i915/pxp/intel_pxp_irq.h | 32 +++++++ drivers/gpu/drm/i915/pxp/intel_pxp_session.c | 54 ++++++++++- drivers/gpu/drm/i915/pxp/intel_pxp_session.h | 5 +- drivers/gpu/drm/i915/pxp/intel_pxp_tee.c | 8 +- drivers/gpu/drm/i915/pxp/intel_pxp_types.h | 18 ++++ 11 files changed, 283 insertions(+), 16 deletions(-) create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_irq.c create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_irq.h
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 4fb663de344d..b22b8c195bb8 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -285,6 +285,7 @@ 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
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c index b2de83be4d97..699a74582d32 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c @@ -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(>->rps, iir);
+ if (instance == OTHER_KCR_INSTANCE) + return intel_pxp_irq_handler(>->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) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index c2853cc005ee..84bc884bd474 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -8117,6 +8117,7 @@ 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))
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c index 26176d43a02d..b0c7edc10cc3 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c @@ -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" @@ -68,6 +70,16 @@ 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; @@ -96,19 +108,61 @@ 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(>->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(>->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); } diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h index 8eeb65af78b1..8f1e86caa53f 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp.h +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h @@ -30,6 +30,9 @@ 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) { @@ -38,6 +41,11 @@ 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__ */ diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c new file mode 100644 index 000000000000..46eca1e81b9b --- /dev/null +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.c @@ -0,0 +1,99 @@ +// 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 "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(>->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(>->irq_lock); + gen11_gt_reset_one_iir(gt, 0, GEN11_KCR); + spin_unlock_irq(>->irq_lock); +} + +void intel_pxp_irq_enable(struct intel_pxp *pxp) +{ + struct intel_gt *gt = pxp_to_gt(pxp); + + spin_lock_irq(>->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(>->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(>->irq_lock); + + pxp->irq_enabled = false; + __pxp_set_interrupts(gt, 0); + + spin_unlock_irq(>->irq_lock); + intel_synchronize_irq(gt->i915); + + pxp_irq_reset(gt); + + flush_work(&pxp->session_work); +} diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_irq.h b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.h new file mode 100644 index 000000000000..8b5793654844 --- /dev/null +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_irq.h @@ -0,0 +1,32 @@ +/* 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__ */ diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c index b8e24adeb1f3..67c30e534d50 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c @@ -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(>->irq_lock); + events = fetch_and_zero(&pxp->session_events); + spin_unlock_irq(>->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); +} diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.h b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h index 7354314b1cc4..ba4c9d2b94b7 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.h +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.h @@ -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__ */ diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c index accbbf9aa6d1..494bd6b48514 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c @@ -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, diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h index d393e46a7d98..5a170e43c959 100644 --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h @@ -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__ */