/* * Copyright (c) 2013-2014, 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 #include #include #include #include #include #include #include #include #include #include /******************************************************************************* * Data structure which holds the pointers to non-secure and secure security * state contexts for each cpu. It is aligned to the cache line boundary to * allow efficient concurrent manipulation of these pointers on different cpus ******************************************************************************/ typedef struct { void *ptr[2]; } __aligned (CACHE_WRITEBACK_GRANULE) context_info_t; static context_info_t cm_context_info[PLATFORM_CORE_COUNT]; /******************************************************************************* * Context management library initialisation routine. This library is used by * runtime services to share pointers to 'cpu_context' structures for the secure * and non-secure states. Management of the structures and their associated * memory is not done by the context management library e.g. the PSCI service * manages the cpu context used for entry from and exit to the non-secure state. * The Secure payload dispatcher service manages the context(s) corresponding to * the secure state. It also uses this library to get access to the non-secure * state cpu context pointers. * Lastly, this library provides the api to make SP_EL3 point to the cpu context * which will used for programming an entry into a lower EL. The same context * will used to save state upon exception entry from that EL. ******************************************************************************/ void cm_init() { /* * The context management library has only global data to intialize, but * that will be done when the BSS is zeroed out */ } /******************************************************************************* * This function returns a pointer to the most recent 'cpu_context' structure * for the CPU identified by MPIDR that was set as the context for the specified * security state. NULL is returned if no such structure has been specified. ******************************************************************************/ void *cm_get_context_by_mpidr(uint64_t mpidr, uint32_t security_state) { uint32_t linear_id = platform_get_core_pos(mpidr); assert(security_state <= NON_SECURE); return cm_context_info[linear_id].ptr[security_state]; } /******************************************************************************* * This function returns a pointer to the most recent 'cpu_context' structure * for the calling CPU that was set as the context for the specified security * state. NULL is returned if no such structure has been specified. ******************************************************************************/ void *cm_get_context(uint32_t security_state) { uint32_t linear_id = platform_get_core_pos(read_mpidr()); assert(security_state <= NON_SECURE); return cm_context_info[linear_id].ptr[security_state]; } /******************************************************************************* * This function sets the pointer to the current 'cpu_context' structure for the * specified security state for the CPU identified by MPIDR ******************************************************************************/ void cm_set_context_by_mpidr(uint64_t mpidr, void *context, uint32_t security_state) { uint32_t linear_id = platform_get_core_pos(mpidr); assert(security_state <= NON_SECURE); cm_context_info[linear_id].ptr[security_state] = context; } /******************************************************************************* * This function sets the pointer to the current 'cpu_context' structure for the * specified security state for the calling CPU ******************************************************************************/ void cm_set_context(void *context, uint32_t security_state) { cm_set_context_by_mpidr(read_mpidr(), context, security_state); } /******************************************************************************* * The next four functions are used by runtime services to save and restore EL3 * and EL1 contexts on the 'cpu_context' structure for the specified security * state. ******************************************************************************/ void cm_el3_sysregs_context_save(uint32_t security_state) { cpu_context_t *ctx; ctx = cm_get_context(security_state); assert(ctx); el3_sysregs_context_save(get_el3state_ctx(ctx)); } void cm_el3_sysregs_context_restore(uint32_t security_state) { cpu_context_t *ctx; ctx = cm_get_context(security_state); assert(ctx); el3_sysregs_context_restore(get_el3state_ctx(ctx)); } void cm_el1_sysregs_context_save(uint32_t security_state) { cpu_context_t *ctx; ctx = cm_get_context(security_state); assert(ctx); el1_sysregs_context_save(get_sysregs_ctx(ctx)); } void cm_el1_sysregs_context_restore(uint32_t security_state) { cpu_context_t *ctx; ctx = cm_get_context(security_state); assert(ctx); el1_sysregs_context_restore(get_sysregs_ctx(ctx)); } /******************************************************************************* * This function populates 'cpu_context' pertaining to the given security state * with the entrypoint, SPSR and SCR values so that an ERET from this security * state correctly restores corresponding values to drop the CPU to the next * exception level ******************************************************************************/ void cm_set_el3_eret_context(uint32_t security_state, uint64_t entrypoint, uint32_t spsr, uint32_t scr) { cpu_context_t *ctx; el3_state_t *state; ctx = cm_get_context(security_state); assert(ctx); /* Program the interrupt routing model for this security state */ scr &= ~SCR_FIQ_BIT; scr &= ~SCR_IRQ_BIT; scr |= get_scr_el3_from_routing_model(security_state); /* Populate EL3 state so that we've the right context before doing ERET */ state = get_el3state_ctx(ctx); write_ctx_reg(state, CTX_SPSR_EL3, spsr); write_ctx_reg(state, CTX_ELR_EL3, entrypoint); write_ctx_reg(state, CTX_SCR_EL3, scr); } /******************************************************************************* * This function populates ELR_EL3 member of 'cpu_context' pertaining to the * given security state with the given entrypoint ******************************************************************************/ void cm_set_elr_el3(uint32_t security_state, uint64_t entrypoint) { cpu_context_t *ctx; el3_state_t *state; ctx = cm_get_context(security_state); assert(ctx); /* Populate EL3 state so that ERET jumps to the correct entry */ state = get_el3state_ctx(ctx); write_ctx_reg(state, CTX_ELR_EL3, entrypoint); } /******************************************************************************* * This function updates a single bit in the SCR_EL3 member of the 'cpu_context' * pertaining to the given security state using the value and bit position * specified in the parameters. It preserves all other bits. ******************************************************************************/ void cm_write_scr_el3_bit(uint32_t security_state, uint32_t bit_pos, uint32_t value) { cpu_context_t *ctx; el3_state_t *state; uint32_t scr_el3; ctx = cm_get_context(security_state); assert(ctx); /* Ensure that the bit position is a valid one */ assert((1 << bit_pos) & SCR_VALID_BIT_MASK); /* Ensure that the 'value' is only a bit wide */ assert(value <= 1); /* * Get the SCR_EL3 value from the cpu context, clear the desired bit * and set it to its new value. */ state = get_el3state_ctx(ctx); scr_el3 = read_ctx_reg(state, CTX_SCR_EL3); scr_el3 &= ~(1 << bit_pos); scr_el3 |= value << bit_pos; write_ctx_reg(state, CTX_SCR_EL3, scr_el3); } /******************************************************************************* * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the * given security state. ******************************************************************************/ uint32_t cm_get_scr_el3(uint32_t security_state) { cpu_context_t *ctx; el3_state_t *state; ctx = cm_get_context(security_state); assert(ctx); /* Populate EL3 state so that ERET jumps to the correct entry */ state = get_el3state_ctx(ctx); return read_ctx_reg(state, CTX_SCR_EL3); } /******************************************************************************* * This function is used to program the context that's used for exception * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for * the required security state ******************************************************************************/ void cm_set_next_eret_context(uint32_t security_state) { cpu_context_t *ctx; #if DEBUG uint64_t sp_mode; #endif ctx = cm_get_context(security_state); assert(ctx); #if DEBUG /* * Check that this function is called with SP_EL0 as the stack * pointer */ __asm__ volatile("mrs %0, SPSel\n" : "=r" (sp_mode)); assert(sp_mode == MODE_SP_EL0); #endif __asm__ volatile("msr spsel, #1\n" "mov sp, %0\n" "msr spsel, #0\n" : : "r" (ctx)); }