diff options
Diffstat (limited to 'lib/psci/aarch64/psci_helpers.S')
| -rw-r--r-- | lib/psci/aarch64/psci_helpers.S | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/lib/psci/aarch64/psci_helpers.S b/lib/psci/aarch64/psci_helpers.S new file mode 100644 index 00000000..afe21ebe --- /dev/null +++ b/lib/psci/aarch64/psci_helpers.S @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <asm_macros.S> +#include <assert_macros.S> +#include <platform_def.h> +#include <psci.h> + + .globl psci_do_pwrdown_cache_maintenance + .globl psci_do_pwrup_cache_maintenance + .globl psci_power_down_wfi +#if !ERROR_DEPRECATED + .globl psci_entrypoint +#endif + +/* ----------------------------------------------------------------------- + * void psci_do_pwrdown_cache_maintenance(unsigned int power level); + * + * This function performs cache maintenance for the specified power + * level. The levels of cache affected are determined by the power + * level which is passed as the argument i.e. level 0 results + * in a flush of the L1 cache. Both the L1 and L2 caches are flushed + * for a higher power level. + * + * Additionally, this function also ensures that stack memory is correctly + * flushed out to avoid coherency issues due to a change in its memory + * attributes after the data cache is disabled. + * ----------------------------------------------------------------------- + */ +func psci_do_pwrdown_cache_maintenance + stp x29, x30, [sp,#-16]! + stp x19, x20, [sp,#-16]! + + /* --------------------------------------------- + * Invoke CPU-specific power down operations for + * the appropriate level + * --------------------------------------------- + */ + bl prepare_cpu_pwr_dwn + + /* --------------------------------------------- + * Do stack maintenance by flushing the used + * stack to the main memory and invalidating the + * remainder. + * --------------------------------------------- + */ + bl plat_get_my_stack + + /* --------------------------------------------- + * Calculate and store the size of the used + * stack memory in x1. + * --------------------------------------------- + */ + mov x19, x0 + mov x1, sp + sub x1, x0, x1 + mov x0, sp + bl flush_dcache_range + + /* --------------------------------------------- + * Calculate and store the size of the unused + * stack memory in x1. Calculate and store the + * stack base address in x0. + * --------------------------------------------- + */ + sub x0, x19, #PLATFORM_STACK_SIZE + sub x1, sp, x0 + bl inv_dcache_range + + ldp x19, x20, [sp], #16 + ldp x29, x30, [sp], #16 + ret +endfunc psci_do_pwrdown_cache_maintenance + + +/* ----------------------------------------------------------------------- + * void psci_do_pwrup_cache_maintenance(void); + * + * This function performs cache maintenance after this cpu is powered up. + * Currently, this involves managing the used stack memory before turning + * on the data cache. + * ----------------------------------------------------------------------- + */ +func psci_do_pwrup_cache_maintenance + stp x29, x30, [sp,#-16]! + + /* --------------------------------------------- + * Ensure any inflight stack writes have made it + * to main memory. + * --------------------------------------------- + */ + dmb st + + /* --------------------------------------------- + * Calculate and store the size of the used + * stack memory in x1. Calculate and store the + * stack base address in x0. + * --------------------------------------------- + */ + bl plat_get_my_stack + mov x1, sp + sub x1, x0, x1 + mov x0, sp + bl inv_dcache_range + + /* --------------------------------------------- + * Enable the data cache. + * --------------------------------------------- + */ + mrs x0, sctlr_el3 + orr x0, x0, #SCTLR_C_BIT + msr sctlr_el3, x0 + isb + + ldp x29, x30, [sp], #16 + ret +endfunc psci_do_pwrup_cache_maintenance + +/* ----------------------------------------------------------------------- + * void psci_power_down_wfi(void); + * This function is called to indicate to the power controller that it + * is safe to power down this cpu. It should not exit the wfi and will + * be released from reset upon power up. + * ----------------------------------------------------------------------- + */ +func psci_power_down_wfi + dsb sy // ensure write buffer empty + wfi + no_ret plat_panic_handler +endfunc psci_power_down_wfi + +/* ----------------------------------------------------------------------- + * void psci_entrypoint(void); + * The deprecated entry point for PSCI on warm boot for AArch64. + * ----------------------------------------------------------------------- + */ +func_deprecated psci_entrypoint + b bl31_warm_entrypoint +endfunc_deprecated psci_entrypoint |