diff options
Diffstat (limited to 'bl1/aarch32/bl1_context_mgmt.c')
| -rw-r--r-- | bl1/aarch32/bl1_context_mgmt.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/bl1/aarch32/bl1_context_mgmt.c b/bl1/aarch32/bl1_context_mgmt.c new file mode 100644 index 00000000..6623dfc4 --- /dev/null +++ b/bl1/aarch32/bl1_context_mgmt.c @@ -0,0 +1,177 @@ +/* + * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch_helpers.h> +#include <assert.h> +#include <context.h> +#include <context_mgmt.h> +#include <debug.h> +#include <platform.h> +#include <smcc_helpers.h> +#include "../bl1_private.h" + +/* + * Following arrays will be used for context management. + * There are 2 instances, for the Secure and Non-Secure contexts. + */ +static cpu_context_t bl1_cpu_context[2]; +static smc_ctx_t bl1_smc_context[2]; + +/* Following contains the next cpu context pointer. */ +static void *bl1_next_cpu_context_ptr; + +/* Following contains the next smc context pointer. */ +static void *bl1_next_smc_context_ptr; + +/* Following functions are used for SMC context handling */ +void *smc_get_ctx(unsigned int security_state) +{ + assert(sec_state_is_valid(security_state)); + return &bl1_smc_context[security_state]; +} + +void smc_set_next_ctx(unsigned int security_state) +{ + assert(sec_state_is_valid(security_state)); + bl1_next_smc_context_ptr = &bl1_smc_context[security_state]; +} + +void *smc_get_next_ctx(void) +{ + return bl1_next_smc_context_ptr; +} + +/* Following functions are used for CPU context handling */ +void *cm_get_context(uint32_t security_state) +{ + assert(sec_state_is_valid(security_state)); + return &bl1_cpu_context[security_state]; +} + +void cm_set_next_context(void *cpu_context) +{ + assert(cpu_context); + bl1_next_cpu_context_ptr = cpu_context; +} + +void *cm_get_next_context(void) +{ + return bl1_next_cpu_context_ptr; +} + +/******************************************************************************* + * Following function copies GP regs r0-r4, lr and spsr, + * from the CPU context to the SMC context structures. + ******************************************************************************/ +static void copy_cpu_ctx_to_smc_ctx(const regs_t *cpu_reg_ctx, + smc_ctx_t *next_smc_ctx) +{ + next_smc_ctx->r0 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R0); + next_smc_ctx->r1 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R1); + next_smc_ctx->r2 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R2); + next_smc_ctx->r3 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R3); + next_smc_ctx->lr_mon = read_ctx_reg(cpu_reg_ctx, CTX_LR); + next_smc_ctx->spsr_mon = read_ctx_reg(cpu_reg_ctx, CTX_SPSR); + next_smc_ctx->scr = read_ctx_reg(cpu_reg_ctx, CTX_SCR); +} + +/******************************************************************************* + * Following function flushes the SMC & CPU context pointer and its data. + ******************************************************************************/ +static void flush_smc_and_cpu_ctx(void) +{ + flush_dcache_range((uintptr_t)&bl1_next_smc_context_ptr, + sizeof(bl1_next_smc_context_ptr)); + flush_dcache_range((uintptr_t)bl1_next_smc_context_ptr, + sizeof(smc_ctx_t)); + + flush_dcache_range((uintptr_t)&bl1_next_cpu_context_ptr, + sizeof(bl1_next_cpu_context_ptr)); + flush_dcache_range((uintptr_t)bl1_next_cpu_context_ptr, + sizeof(cpu_context_t)); +} + +/******************************************************************************* + * This function prepares the context for Secure/Normal world images. + * Normal world images are transitioned to HYP(if supported) else SVC. + ******************************************************************************/ +void bl1_prepare_next_image(unsigned int image_id) +{ + unsigned int security_state; + image_desc_t *image_desc; + entry_point_info_t *next_bl_ep; + + /* Get the image descriptor. */ + image_desc = bl1_plat_get_image_desc(image_id); + assert(image_desc); + + /* Get the entry point info. */ + next_bl_ep = &image_desc->ep_info; + + /* Get the image security state. */ + security_state = GET_SECURITY_STATE(next_bl_ep->h.attr); + + /* Prepare the SPSR for the next BL image. */ + if (security_state == SECURE) { + next_bl_ep->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM, + SPSR_E_LITTLE, DISABLE_ALL_EXCEPTIONS); + } else { + /* Use HYP mode if supported else use SVC. */ + if (GET_VIRT_EXT(read_id_pfr1())) { + next_bl_ep->spsr = SPSR_MODE32(MODE32_hyp, SPSR_T_ARM, + SPSR_E_LITTLE, DISABLE_ALL_EXCEPTIONS); + } else { + next_bl_ep->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM, + SPSR_E_LITTLE, DISABLE_ALL_EXCEPTIONS); + } + } + + /* Allow platform to make change */ + bl1_plat_set_ep_info(image_id, next_bl_ep); + + /* Prepare the cpu context for the next BL image. */ + cm_init_my_context(next_bl_ep); + cm_prepare_el3_exit(security_state); + cm_set_next_context(cm_get_context(security_state)); + + /* Prepare the smc context for the next BL image. */ + smc_set_next_ctx(security_state); + copy_cpu_ctx_to_smc_ctx(get_regs_ctx(cm_get_next_context()), + smc_get_next_ctx()); + + /* + * If the next image is non-secure, then we need to program the banked + * non secure sctlr. This is not required when the next image is secure + * because in AArch32, we expect the secure world to have the same + * SCTLR settings. + */ + if (security_state == NON_SECURE) { + cpu_context_t *ctx = cm_get_context(security_state); + u_register_t ns_sctlr; + + /* Temporarily set the NS bit to access NS SCTLR */ + write_scr(read_scr() | SCR_NS_BIT); + isb(); + + ns_sctlr = read_ctx_reg(get_regs_ctx(ctx), CTX_NS_SCTLR); + write_sctlr(ns_sctlr); + isb(); + + write_scr(read_scr() & ~SCR_NS_BIT); + isb(); + } + + /* + * Flush the SMC & CPU context and the (next)pointers, + * to access them after caches are disabled. + */ + flush_smc_and_cpu_ctx(); + + /* Indicate that image is in execution state. */ + image_desc->state = IMAGE_STATE_EXECUTED; + + print_entry_point_info(next_bl_ep); +} |