diff options
Diffstat (limited to 'bl31/interrupt_mgmt.c')
| -rw-r--r-- | bl31/interrupt_mgmt.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/bl31/interrupt_mgmt.c b/bl31/interrupt_mgmt.c new file mode 100644 index 00000000..2b0c7970 --- /dev/null +++ b/bl31/interrupt_mgmt.c @@ -0,0 +1,206 @@ +/* + * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of ARM nor the names of its contributors may be used + * to endorse or promote products derived from this software without specific + * prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <assert.h> +#include <bl_common.h> +#include <context_mgmt.h> +#include <errno.h> +#include <interrupt_mgmt.h> +#include <platform.h> +#include <stdio.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: + * + * '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. + * + * '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. + ******************************************************************************/ +typedef struct intr_type_desc { + interrupt_type_handler_t handler; + uint32_t flags; + uint32_t scr_el3[2]; +} intr_type_desc_t; + +static intr_type_desc_t intr_type_descs[MAX_INTR_TYPES]; + +/******************************************************************************* + * This function validates the interrupt type. EL3 interrupts are currently not + * supported. + ******************************************************************************/ +static int32_t validate_interrupt_type(uint32_t type) +{ + if (type == INTR_TYPE_EL3) + return -ENOTSUP; + + if (type != INTR_TYPE_S_EL1 && type != INTR_TYPE_NS) + return -EINVAL; + + return 0; +} + +/******************************************************************************* +* This function validates the routing model for this type of interrupt + ******************************************************************************/ +static int32_t validate_routing_model(uint32_t type, uint32_t flags) +{ + flags >>= INTR_RM_FLAGS_SHIFT; + flags &= INTR_RM_FLAGS_MASK; + + if (type == INTR_TYPE_S_EL1) + return validate_sel1_interrupt_rm(flags); + + if (type == INTR_TYPE_NS) + return validate_ns_interrupt_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. + ******************************************************************************/ +uint32_t get_scr_el3_from_routing_model(uint32_t security_state) +{ + uint32_t scr_el3; + + assert(security_state <= NON_SECURE); + 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] = flag << bit_pos; + 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) + return rc; + + rc = validate_routing_model(type, flags); + if (rc) + 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 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) + return -EINVAL; + + /* Validate the 'flags' parameter */ + if (flags & INTR_TYPE_FLAGS_MASK) + return -EINVAL; + + /* Check if a handler has already been registered */ + if (intr_type_descs[type].handler) + return -EALREADY; + + rc = set_routing_model(type, flags); + if (rc) + 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)) + return NULL; + + return intr_type_descs[type].handler; +} + |