| /* |
| * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <asm_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 |
| |
| /* ----------------------------------------------------------------------- |
| * 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 |
| push {r4, lr} |
| |
| /* ---------------------------------------------- |
| * Turn OFF cache and do stack maintenance |
| * prior to cpu operations . This sequence is |
| * different from AArch64 because in AArch32 the |
| * assembler routines for cpu operations utilize |
| * the stack whereas in AArch64 it doesn't. |
| * ---------------------------------------------- |
| */ |
| mov r4, r0 |
| bl do_stack_maintenance |
| |
| /* --------------------------------------------- |
| * Invoke CPU-specifc power down operations for |
| * the appropriate level |
| * --------------------------------------------- |
| */ |
| mov r0, r4 |
| pop {r4, lr} |
| b prepare_cpu_pwr_dwn |
| 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 |
| /* r12 is pushed to meet the 8 byte stack alignment requirement */ |
| push {r12, lr} |
| |
| /* --------------------------------------------- |
| * Ensure any inflight stack writes have made it |
| * to main memory. |
| * --------------------------------------------- |
| */ |
| dmb st |
| |
| /* --------------------------------------------- |
| * Calculate and store the size of the used |
| * stack memory in r1. Calculate and store the |
| * stack base address in r0. |
| * --------------------------------------------- |
| */ |
| bl plat_get_my_stack |
| mov r1, sp |
| sub r1, r0, r1 |
| mov r0, sp |
| bl inv_dcache_range |
| |
| /* --------------------------------------------- |
| * Enable the data cache. |
| * --------------------------------------------- |
| */ |
| ldcopr r0, SCTLR |
| orr r0, r0, #SCTLR_C_BIT |
| stcopr r0, SCTLR |
| isb |
| |
| pop {r12, pc} |
| endfunc psci_do_pwrup_cache_maintenance |
| |
| /* --------------------------------------------- |
| * void do_stack_maintenance(void) |
| * Do stack maintenance by flushing the used |
| * stack to the main memory and invalidating the |
| * remainder. |
| * --------------------------------------------- |
| */ |
| func do_stack_maintenance |
| push {r4, lr} |
| bl plat_get_my_stack |
| |
| /* Turn off the D-cache */ |
| ldcopr r1, SCTLR |
| bic r1, #SCTLR_C_BIT |
| stcopr r1, SCTLR |
| isb |
| |
| /* --------------------------------------------- |
| * Calculate and store the size of the used |
| * stack memory in r1. |
| * --------------------------------------------- |
| */ |
| mov r4, r0 |
| mov r1, sp |
| sub r1, r0, r1 |
| mov r0, sp |
| bl flush_dcache_range |
| |
| /* --------------------------------------------- |
| * Calculate and store the size of the unused |
| * stack memory in r1. Calculate and store the |
| * stack base address in r0. |
| * --------------------------------------------- |
| */ |
| sub r0, r4, #PLATFORM_STACK_SIZE |
| sub r1, sp, r0 |
| bl inv_dcache_range |
| |
| pop {r4, pc} |
| endfunc do_stack_maintenance |
| |
| /* ----------------------------------------------------------------------- |
| * 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 |