diff options
Diffstat (limited to 'common/runtime_svc.c')
| -rw-r--r-- | common/runtime_svc.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/common/runtime_svc.c b/common/runtime_svc.c new file mode 100644 index 00000000..0ea4cd09 --- /dev/null +++ b/common/runtime_svc.c @@ -0,0 +1,154 @@ +/* + * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> +#include <debug.h> +#include <errno.h> +#include <runtime_svc.h> +#include <string.h> + +/******************************************************************************* + * The 'rt_svc_descs' array holds the runtime service descriptors exported by + * services by placing them in the 'rt_svc_descs' linker section. + * The 'rt_svc_descs_indices' array holds the index of a descriptor in the + * 'rt_svc_descs' array. When an SMC arrives, the OEN[29:24] bits and the call + * type[31] bit in the function id are combined to get an index into the + * 'rt_svc_descs_indices' array. This gives the index of the descriptor in the + * 'rt_svc_descs' array which contains the SMC handler. + ******************************************************************************/ +#define RT_SVC_DESCS_START ((uintptr_t) (&__RT_SVC_DESCS_START__)) +#define RT_SVC_DESCS_END ((uintptr_t) (&__RT_SVC_DESCS_END__)) +uint8_t rt_svc_descs_indices[MAX_RT_SVCS]; +static rt_svc_desc_t *rt_svc_descs; + +#define RT_SVC_DECS_NUM ((RT_SVC_DESCS_END - RT_SVC_DESCS_START)\ + / sizeof(rt_svc_desc_t)) + +/******************************************************************************* + * Function to invoke the registered `handle` corresponding to the smc_fid. + ******************************************************************************/ +uintptr_t handle_runtime_svc(uint32_t smc_fid, + void *cookie, + void *handle, + unsigned int flags) +{ + u_register_t x1, x2, x3, x4; + int index; + unsigned int idx; + const rt_svc_desc_t *rt_svc_descs; + + assert(handle); + idx = get_unique_oen_from_smc_fid(smc_fid); + assert(idx < MAX_RT_SVCS); + + index = rt_svc_descs_indices[idx]; + if (index < 0 || index >= (int)RT_SVC_DECS_NUM) + SMC_RET1(handle, SMC_UNK); + + rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; + + get_smc_params_from_ctx(handle, x1, x2, x3, x4); + + return rt_svc_descs[index].handle(smc_fid, x1, x2, x3, x4, cookie, + handle, flags); +} + +/******************************************************************************* + * Simple routine to sanity check a runtime service descriptor before using it + ******************************************************************************/ +static int32_t validate_rt_svc_desc(const rt_svc_desc_t *desc) +{ + if (desc == NULL) + return -EINVAL; + + if (desc->start_oen > desc->end_oen) + return -EINVAL; + + if (desc->end_oen >= OEN_LIMIT) + return -EINVAL; + + if (desc->call_type != SMC_TYPE_FAST && + desc->call_type != SMC_TYPE_YIELD) + return -EINVAL; + + /* A runtime service having no init or handle function doesn't make sense */ + if (desc->init == NULL && desc->handle == NULL) + return -EINVAL; + + return 0; +} + +/******************************************************************************* + * This function calls the initialisation routine in the descriptor exported by + * a runtime service. Once a descriptor has been validated, its start & end + * owning entity numbers and the call type are combined to form a unique oen. + * The unique oen is used as an index into the 'rt_svc_descs_indices' array. + * The index of the runtime service descriptor is stored at this index. + ******************************************************************************/ +void runtime_svc_init(void) +{ + int rc = 0; + unsigned int index, start_idx, end_idx; + + /* Assert the number of descriptors detected are less than maximum indices */ + assert((RT_SVC_DESCS_END >= RT_SVC_DESCS_START) && + (RT_SVC_DECS_NUM < MAX_RT_SVCS)); + + /* If no runtime services are implemented then simply bail out */ + if (RT_SVC_DECS_NUM == 0) + return; + + /* Initialise internal variables to invalid state */ + memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices)); + + rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START; + for (index = 0; index < RT_SVC_DECS_NUM; index++) { + rt_svc_desc_t *service = &rt_svc_descs[index]; + + /* + * An invalid descriptor is an error condition since it is + * difficult to predict the system behaviour in the absence + * of this service. + */ + rc = validate_rt_svc_desc(service); + if (rc) { + ERROR("Invalid runtime service descriptor %p\n", + (void *) service); + panic(); + } + + /* + * The runtime service may have separate rt_svc_desc_t + * for its fast smc and yielding smc. Since the service itself + * need to be initialized only once, only one of them will have + * an initialisation routine defined. Call the initialisation + * routine for this runtime service, if it is defined. + */ + if (service->init) { + rc = service->init(); + if (rc) { + ERROR("Error initializing runtime service %s\n", + service->name); + continue; + } + } + + /* + * Fill the indices corresponding to the start and end + * owning entity numbers with the index of the + * descriptor which will handle the SMCs for this owning + * entity range. + */ + start_idx = get_unique_oen(rt_svc_descs[index].start_oen, + service->call_type); + assert(start_idx < MAX_RT_SVCS); + end_idx = get_unique_oen(rt_svc_descs[index].end_oen, + service->call_type); + assert(end_idx < MAX_RT_SVCS); + for (; start_idx <= end_idx; start_idx++) + rt_svc_descs_indices[start_idx] = index; + } +} |