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Diffstat (limited to '')
| -rw-r--r-- | bl31/interrupt_mgmt.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/bl31/interrupt_mgmt.c b/bl31/interrupt_mgmt.c new file mode 100644 index 0000000..b8cc3de --- /dev/null +++ b/bl31/interrupt_mgmt.c @@ -0,0 +1,227 @@ +/* + * 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; +} + |