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-rw-r--r--common/runtime_svc.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/common/runtime_svc.c b/common/runtime_svc.c
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+++ b/common/runtime_svc.c
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+/*
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+
+#include <common/debug.h>
+#include <common/runtime_svc.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.
+ ******************************************************************************/
+uint8_t rt_svc_descs_indices[MAX_RT_SVCS];
+
+#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 in
+ * AArch32 mode.
+ ******************************************************************************/
+uintptr_t handle_runtime_svc(uint32_t smc_fid,
+ void *cookie,
+ void *handle,
+ unsigned int flags)
+{
+ u_register_t x1, x2, x3, x4;
+ unsigned int index;
+ unsigned int idx;
+ const rt_svc_desc_t *rt_svc_descs;
+
+ assert(handle != NULL);
+ idx = get_unique_oen_from_smc_fid(smc_fid);
+ assert(idx < MAX_RT_SVCS);
+
+ index = rt_svc_descs_indices[idx];
+ if (index >= 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 __init runtime_svc_init(void)
+{
+ int rc = 0;
+ uint8_t index, start_idx, end_idx;
+ rt_svc_desc_t *rt_svc_descs;
+
+ /* 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 == 0U)
+ return;
+
+ /* Initialise internal variables to invalid state */
+ (void)memset(rt_svc_descs_indices, -1, sizeof(rt_svc_descs_indices));
+
+ rt_svc_descs = (rt_svc_desc_t *) RT_SVC_DESCS_START;
+ for (index = 0U; 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 != 0) {
+ 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 != NULL) {
+ rc = service->init();
+ if (rc != 0) {
+ 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 = (uint8_t)get_unique_oen(service->start_oen,
+ service->call_type);
+ end_idx = (uint8_t)get_unique_oen(service->end_oen,
+ service->call_type);
+ assert(start_idx <= end_idx);
+ assert(end_idx < MAX_RT_SVCS);
+ for (; start_idx <= end_idx; start_idx++)
+ rt_svc_descs_indices[start_idx] = index;
+ }
+}