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-rw-r--r--bl31/interrupt_mgmt.c227
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diff --git a/bl31/interrupt_mgmt.c b/bl31/interrupt_mgmt.c
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+/*
+ * Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+
+#include <common/bl_common.h>
+#include <bl31/interrupt_mgmt.h>
+#include <lib/el3_runtime/context_mgmt.h>
+#include <plat/common/platform.h>
+
+/*******************************************************************************
+ * Local structure and corresponding array to keep track of the state of the
+ * registered interrupt handlers for each interrupt type.
+ * The field descriptions are:
+ *
+ * 'scr_el3[2]' : Mapping of the routing model in the 'flags' field to the
+ * value of the SCR_EL3.IRQ or FIQ bit for each security state.
+ * There are two instances of this field corresponding to the
+ * two security states.
+ *
+ * 'flags' : Bit[0], Routing model for this interrupt type when execution is
+ * not in EL3 in the secure state. '1' implies that this
+ * interrupt will be routed to EL3. '0' implies that this
+ * interrupt will be routed to the current exception level.
+ *
+ * Bit[1], Routing model for this interrupt type when execution is
+ * not in EL3 in the non-secure state. '1' implies that this
+ * interrupt will be routed to EL3. '0' implies that this
+ * interrupt will be routed to the current exception level.
+ *
+ * All other bits are reserved and SBZ.
+ ******************************************************************************/
+typedef struct intr_type_desc {
+ interrupt_type_handler_t handler;
+ u_register_t scr_el3[2];
+ uint32_t flags;
+} intr_type_desc_t;
+
+static intr_type_desc_t intr_type_descs[MAX_INTR_TYPES];
+
+/*******************************************************************************
+ * This function validates the interrupt type.
+ ******************************************************************************/
+static int32_t validate_interrupt_type(uint32_t type)
+{
+ if ((type == INTR_TYPE_S_EL1) || (type == INTR_TYPE_NS) ||
+ (type == INTR_TYPE_EL3))
+ return 0;
+
+ return -EINVAL;
+}
+
+/*******************************************************************************
+* This function validates the routing model for this type of interrupt
+ ******************************************************************************/
+static int32_t validate_routing_model(uint32_t type, uint32_t flags)
+{
+ uint32_t rm_flags = (flags >> INTR_RM_FLAGS_SHIFT) & INTR_RM_FLAGS_MASK;
+
+ if (type == INTR_TYPE_S_EL1)
+ return validate_sel1_interrupt_rm(rm_flags);
+
+ if (type == INTR_TYPE_NS)
+ return validate_ns_interrupt_rm(rm_flags);
+
+ if (type == INTR_TYPE_EL3)
+ return validate_el3_interrupt_rm(rm_flags);
+
+ return -EINVAL;
+}
+
+/*******************************************************************************
+ * This function returns the cached copy of the SCR_EL3 which contains the
+ * routing model (expressed through the IRQ and FIQ bits) for a security state
+ * which was stored through a call to 'set_routing_model()' earlier.
+ ******************************************************************************/
+u_register_t get_scr_el3_from_routing_model(uint32_t security_state)
+{
+ u_register_t scr_el3;
+
+ assert(sec_state_is_valid(security_state));
+ scr_el3 = intr_type_descs[INTR_TYPE_NS].scr_el3[security_state];
+ scr_el3 |= intr_type_descs[INTR_TYPE_S_EL1].scr_el3[security_state];
+ scr_el3 |= intr_type_descs[INTR_TYPE_EL3].scr_el3[security_state];
+ return scr_el3;
+}
+
+/*******************************************************************************
+ * This function uses the 'interrupt_type_flags' parameter to obtain the value
+ * of the trap bit (IRQ/FIQ) in the SCR_EL3 for a security state for this
+ * interrupt type. It uses it to update the SCR_EL3 in the cpu context and the
+ * 'intr_type_desc' for that security state.
+ ******************************************************************************/
+static void set_scr_el3_from_rm(uint32_t type,
+ uint32_t interrupt_type_flags,
+ uint32_t security_state)
+{
+ uint32_t flag, bit_pos;
+
+ flag = get_interrupt_rm_flag(interrupt_type_flags, security_state);
+ bit_pos = plat_interrupt_type_to_line(type, security_state);
+ intr_type_descs[type].scr_el3[security_state] = (u_register_t)flag << bit_pos;
+
+ /*
+ * Update scr_el3 only if there is a context available. If not, it
+ * will be updated later during context initialization which will obtain
+ * the scr_el3 value to be used via get_scr_el3_from_routing_model()
+ */
+ if (cm_get_context(security_state) != NULL)
+ cm_write_scr_el3_bit(security_state, bit_pos, flag);
+}
+
+/*******************************************************************************
+ * This function validates the routing model specified in the 'flags' and
+ * updates internal data structures to reflect the new routing model. It also
+ * updates the copy of SCR_EL3 for each security state with the new routing
+ * model in the 'cpu_context' structure for this cpu.
+ ******************************************************************************/
+int32_t set_routing_model(uint32_t type, uint32_t flags)
+{
+ int32_t rc;
+
+ rc = validate_interrupt_type(type);
+ if (rc != 0)
+ return rc;
+
+ rc = validate_routing_model(type, flags);
+ if (rc != 0)
+ return rc;
+
+ /* Update the routing model in internal data structures */
+ intr_type_descs[type].flags = flags;
+ set_scr_el3_from_rm(type, flags, SECURE);
+ set_scr_el3_from_rm(type, flags, NON_SECURE);
+
+ return 0;
+}
+
+/******************************************************************************
+ * This function disables the routing model of interrupt 'type' from the
+ * specified 'security_state' on the local core. The disable is in effect
+ * till the core powers down or till the next enable for that interrupt
+ * type.
+ *****************************************************************************/
+int disable_intr_rm_local(uint32_t type, uint32_t security_state)
+{
+ uint32_t bit_pos, flag;
+
+ assert(intr_type_descs[type].handler != NULL);
+
+ flag = get_interrupt_rm_flag(INTR_DEFAULT_RM, security_state);
+
+ bit_pos = plat_interrupt_type_to_line(type, security_state);
+ cm_write_scr_el3_bit(security_state, bit_pos, flag);
+
+ return 0;
+}
+
+/******************************************************************************
+ * This function enables the routing model of interrupt 'type' from the
+ * specified 'security_state' on the local core.
+ *****************************************************************************/
+int enable_intr_rm_local(uint32_t type, uint32_t security_state)
+{
+ uint32_t bit_pos, flag;
+
+ assert(intr_type_descs[type].handler != NULL);
+
+ flag = get_interrupt_rm_flag(intr_type_descs[type].flags,
+ security_state);
+
+ bit_pos = plat_interrupt_type_to_line(type, security_state);
+ cm_write_scr_el3_bit(security_state, bit_pos, flag);
+
+ return 0;
+}
+
+/*******************************************************************************
+ * This function registers a handler for the 'type' of interrupt specified. It
+ * also validates the routing model specified in the 'flags' for this type of
+ * interrupt.
+ ******************************************************************************/
+int32_t register_interrupt_type_handler(uint32_t type,
+ interrupt_type_handler_t handler,
+ uint32_t flags)
+{
+ int32_t rc;
+
+ /* Validate the 'handler' parameter */
+ if (handler == NULL)
+ return -EINVAL;
+
+ /* Validate the 'flags' parameter */
+ if ((flags & INTR_TYPE_FLAGS_MASK) != 0U)
+ return -EINVAL;
+
+ /* Check if a handler has already been registered */
+ if (intr_type_descs[type].handler != NULL)
+ return -EALREADY;
+
+ rc = set_routing_model(type, flags);
+ if (rc != 0)
+ return rc;
+
+ /* Save the handler */
+ intr_type_descs[type].handler = handler;
+
+ return 0;
+}
+
+/*******************************************************************************
+ * This function is called when an interrupt is generated and returns the
+ * handler for the interrupt type (if registered). It returns NULL if the
+ * interrupt type is not supported or its handler has not been registered.
+ ******************************************************************************/
+interrupt_type_handler_t get_interrupt_type_handler(uint32_t type)
+{
+ if (validate_interrupt_type(type) != 0)
+ return NULL;
+
+ return intr_type_descs[type].handler;
+}
+