diff --git a/docs/sdei.rst b/docs/sdei.rst index b81e21a..ed6a85a 100644 --- a/docs/sdei.rst +++ b/docs/sdei.rst @@ -48,8 +48,10 @@ original EL2 execution [13]. Note that the SDEI interrupt remains active until the client handler completes, at which point EL3 does EOI [12]. -SDEI events can be explicitly dispatched in response to other asynchronous -exceptions. See `Explicit dispatch of events`_. +Other than events bound to interrupts (as depicted in the sequence above, SDEI +events can be explicitly dispatched in response to other exceptions, for +example, upon receiving an *SError* or *Synchronous External Abort*. See +`Explicit dispatch of events`_. The remainder of this document only discusses the design and implementation of SDEI dispatcher in TF-A, and assumes that the reader is familiar with the SDEI @@ -71,7 +73,8 @@ - The event number: this must be a positive 32-bit integer. -- The interrupt number the event is bound to: +- For an event that has a backing interrupt, the interrupt number the event is + bound to: - If it's not applicable to an event, this shall be left as ``0``. @@ -82,6 +85,17 @@ To define event 0, the macro ``SDEI_DEFINE_EVENT_0()`` should be used. This macro takes only one parameter: an SGI number to signal other PEs. +To define an event that's meant to be `explicitly dispatched`__ (i.e., not as a +result of receiving an SDEI interrupt), the macro ``SDEI_EXPLICIT_EVENT()`` +should be used. It accepts two parameters: + +.. __: `Explicit dispatch of events`_ + +- The event number (as above); + +- Event priority: ``SDEI_MAPF_CRITICAL`` or ``SDEI_MAPF_NORMAL``, as described + below. + Once the event descriptor arrays are defined, they should be exported to the SDEI dispatcher using the ``REGISTER_SDEI_MAP()`` macro, passing it the pointers to the private and shared event descriptor arrays, respectively. Note that the @@ -99,6 +113,8 @@ - Must be bound to a Secure SGI on the platform. +- Explicit events should only be used in the private array. + - Statically bound shared and private interrupts must be bound to shared and private interrupts on the platform, respectively. See the section on `interrupt configuration`__. @@ -132,8 +148,10 @@ - ``SDEI_MAPF_BOUND``: Marks the event as statically bound to an interrupt. These events cannot be re-bound at runtime. +- ``SDEI_MAPF_NORMAL``: Marks the event as having *Normal* priority. This is + the default priority. + - ``SDEI_MAPF_CRITICAL``: Marks the event as having *Critical* priority. - Without this flag, the event is assumed to have *Normal* priority. Event definition example ------------------------ @@ -150,6 +168,10 @@ /* Dynamic private events */ SDEI_PRIVATE_EVENT(100, SDEI_DYN_IRQ, SDEI_MAPF_DYNAMIC), SDEI_PRIVATE_EVENT(101, SDEI_DYN_IRQ, SDEI_MAPF_DYNAMIC) + + /* Events for explicit dispatch */ + SDEI_EXPLICIT_EVENT(2000, SDEI_MAPF_NORMAL); + SDEI_EXPLICIT_EVENT(2000, SDEI_MAPF_CRITICAL); }; /* Shared event mappings */ @@ -258,7 +280,8 @@ - Event 0 can't be dispatched. -- The event must neither be a dynamic event nor be bound to an interrupt. +- The event must be declared using the ``SDEI_EXPLICIT_EVENT()`` macro + described above. - The event must be private to the PE. diff --git a/include/services/sdei.h b/include/services/sdei.h index ce9a008..ee3531c 100644 --- a/include/services/sdei.h +++ b/include/services/sdei.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -52,6 +52,7 @@ #define _SDEI_MAPF_SIGNALABLE_SHIFT 3 #define _SDEI_MAPF_PRIVATE_SHIFT 4 #define _SDEI_MAPF_CRITICAL_SHIFT 5 +#define _SDEI_MAPF_EXPLICIT_SHIFT 6 /* SDEI event 0 */ #define SDEI_EVENT_0 0 @@ -81,9 +82,12 @@ */ #define SDEI_MAPF_DYNAMIC BIT(_SDEI_MAPF_DYNAMIC_SHIFT) #define SDEI_MAPF_BOUND BIT(_SDEI_MAPF_BOUND_SHIFT) +#define SDEI_MAPF_EXPLICIT BIT(_SDEI_MAPF_EXPLICIT_SHIFT) #define SDEI_MAPF_SIGNALABLE BIT(_SDEI_MAPF_SIGNALABLE_SHIFT) #define SDEI_MAPF_PRIVATE BIT(_SDEI_MAPF_PRIVATE_SHIFT) + +#define SDEI_MAPF_NORMAL 0 #define SDEI_MAPF_CRITICAL BIT(_SDEI_MAPF_CRITICAL_SHIFT) /* Indices of private and shared mappings */ @@ -114,6 +118,9 @@ #define SDEI_DEFINE_EVENT_0(_intr) \ SDEI_PRIVATE_EVENT(SDEI_EVENT_0, _intr, SDEI_MAPF_SIGNALABLE) +#define SDEI_EXPLICIT_EVENT(_event, _pri) \ + SDEI_EVENT_MAP(_event, 0, _pri | SDEI_MAPF_EXPLICIT | SDEI_MAPF_PRIVATE) + /* * Declare shared and private entries for each core. Also declare a global * structure containing private and share entries. diff --git a/services/std_svc/sdei/sdei_intr_mgmt.c b/services/std_svc/sdei/sdei_intr_mgmt.c index c0bd9de..a7104b4 100644 --- a/services/std_svc/sdei/sdei_intr_mgmt.c +++ b/services/std_svc/sdei/sdei_intr_mgmt.c @@ -520,15 +520,8 @@ if (!map) return -1; - /* - * Statically-bound or dynamic maps are dispatched only as a result of - * interrupt, and not upon explicit request. - */ - if (is_map_dynamic(map) || is_map_bound(map)) - return -1; - - /* The event must be private */ - if (is_event_shared(map)) + /* Only explicit events can be dispatched */ + if (!is_map_explicit(map)) return -1; /* Examine state of dispatch stack */ diff --git a/services/std_svc/sdei/sdei_main.c b/services/std_svc/sdei/sdei_main.c index 9589a25..f881ba8 100644 --- a/services/std_svc/sdei/sdei_main.c +++ b/services/std_svc/sdei/sdei_main.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -111,6 +111,9 @@ /* No shared mapping should have signalable property */ assert(!is_event_signalable(map)); + + /* Shared mappings can't be explicit */ + assert(!is_map_explicit(map)); #endif /* Skip initializing the wrong priority */ @@ -162,6 +165,16 @@ /* Make sure it's a private event */ assert(is_event_private(map)); + + /* + * Other than priority, explicit events can only have explicit + * and private flags set. + */ + if (is_map_explicit(map)) { + assert((map->map_flags | SDEI_MAPF_CRITICAL) == + (SDEI_MAPF_EXPLICIT | SDEI_MAPF_PRIVATE + | SDEI_MAPF_CRITICAL)); + } #endif /* Skip initializing the wrong priority */ @@ -174,6 +187,12 @@ assert(map->intr == SDEI_DYN_IRQ); assert(is_event_normal(map)); num_dyn_priv_slots++; + } else if (is_map_explicit(map)) { + /* + * Explicit mappings don't have a backing + * SDEI interrupt, but verify that anyway. + */ + assert(map->intr == SDEI_DYN_IRQ); } else { /* * Private mappings must be bound to private diff --git a/services/std_svc/sdei/sdei_private.h b/services/std_svc/sdei/sdei_private.h index 44db419..45d537f 100644 --- a/services/std_svc/sdei/sdei_private.h +++ b/services/std_svc/sdei/sdei_private.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -137,6 +137,11 @@ map->map_flags |= BIT(_SDEI_MAPF_BOUND_SHIFT); } +static inline int is_map_explicit(sdei_ev_map_t *map) +{ + return ((map->map_flags & BIT(_SDEI_MAPF_EXPLICIT_SHIFT)) != 0); +} + static inline void clr_map_bound(sdei_ev_map_t *map) { map->map_flags &= ~(BIT(_SDEI_MAPF_BOUND_SHIFT));