Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. |
| 3 | * |
dp-arm | 82cb2c1 | 2017-05-03 09:38:09 +0100 | [diff] [blame^] | 4 | * SPDX-License-Identifier: BSD-3-Clause |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 5 | */ |
| 6 | |
| 7 | #include <asm_macros.S> |
| 8 | #include <platform_def.h> |
| 9 | #include <psci.h> |
| 10 | |
| 11 | .globl psci_do_pwrdown_cache_maintenance |
| 12 | .globl psci_do_pwrup_cache_maintenance |
| 13 | .globl psci_power_down_wfi |
| 14 | |
| 15 | /* ----------------------------------------------------------------------- |
| 16 | * void psci_do_pwrdown_cache_maintenance(unsigned int power level); |
| 17 | * |
| 18 | * This function performs cache maintenance for the specified power |
| 19 | * level. The levels of cache affected are determined by the power |
| 20 | * level which is passed as the argument i.e. level 0 results |
| 21 | * in a flush of the L1 cache. Both the L1 and L2 caches are flushed |
| 22 | * for a higher power level. |
| 23 | * |
| 24 | * Additionally, this function also ensures that stack memory is correctly |
| 25 | * flushed out to avoid coherency issues due to a change in its memory |
| 26 | * attributes after the data cache is disabled. |
| 27 | * ----------------------------------------------------------------------- |
| 28 | */ |
| 29 | func psci_do_pwrdown_cache_maintenance |
| 30 | push {r4, lr} |
| 31 | |
| 32 | /* ---------------------------------------------- |
| 33 | * Turn OFF cache and do stack maintenance |
| 34 | * prior to cpu operations . This sequence is |
| 35 | * different from AArch64 because in AArch32 the |
| 36 | * assembler routines for cpu operations utilize |
| 37 | * the stack whereas in AArch64 it doesn't. |
| 38 | * ---------------------------------------------- |
| 39 | */ |
| 40 | mov r4, r0 |
| 41 | bl do_stack_maintenance |
| 42 | |
| 43 | /* --------------------------------------------- |
Jeenu Viswambharan | 5dd9dbb | 2016-11-18 12:58:28 +0000 | [diff] [blame] | 44 | * Invoke CPU-specifc power down operations for |
| 45 | * the appropriate level |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 46 | * --------------------------------------------- |
| 47 | */ |
Jeenu Viswambharan | 5dd9dbb | 2016-11-18 12:58:28 +0000 | [diff] [blame] | 48 | mov r0, r4 |
| 49 | pop {r4, lr} |
| 50 | b prepare_cpu_pwr_dwn |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 51 | endfunc psci_do_pwrdown_cache_maintenance |
| 52 | |
| 53 | |
| 54 | /* ----------------------------------------------------------------------- |
| 55 | * void psci_do_pwrup_cache_maintenance(void); |
| 56 | * |
| 57 | * This function performs cache maintenance after this cpu is powered up. |
| 58 | * Currently, this involves managing the used stack memory before turning |
| 59 | * on the data cache. |
| 60 | * ----------------------------------------------------------------------- |
| 61 | */ |
| 62 | func psci_do_pwrup_cache_maintenance |
Soby Mathew | 9f3ee61 | 2016-12-06 12:10:51 +0000 | [diff] [blame] | 63 | /* r12 is pushed to meet the 8 byte stack alignment requirement */ |
| 64 | push {r12, lr} |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 65 | |
| 66 | /* --------------------------------------------- |
| 67 | * Ensure any inflight stack writes have made it |
| 68 | * to main memory. |
| 69 | * --------------------------------------------- |
| 70 | */ |
| 71 | dmb st |
| 72 | |
| 73 | /* --------------------------------------------- |
| 74 | * Calculate and store the size of the used |
| 75 | * stack memory in r1. Calculate and store the |
| 76 | * stack base address in r0. |
| 77 | * --------------------------------------------- |
| 78 | */ |
| 79 | bl plat_get_my_stack |
| 80 | mov r1, sp |
| 81 | sub r1, r0, r1 |
| 82 | mov r0, sp |
| 83 | bl inv_dcache_range |
| 84 | |
| 85 | /* --------------------------------------------- |
| 86 | * Enable the data cache. |
| 87 | * --------------------------------------------- |
| 88 | */ |
| 89 | ldcopr r0, SCTLR |
| 90 | orr r0, r0, #SCTLR_C_BIT |
| 91 | stcopr r0, SCTLR |
| 92 | isb |
| 93 | |
Soby Mathew | 9f3ee61 | 2016-12-06 12:10:51 +0000 | [diff] [blame] | 94 | pop {r12, pc} |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 95 | endfunc psci_do_pwrup_cache_maintenance |
| 96 | |
| 97 | /* --------------------------------------------- |
| 98 | * void do_stack_maintenance(void) |
| 99 | * Do stack maintenance by flushing the used |
| 100 | * stack to the main memory and invalidating the |
| 101 | * remainder. |
| 102 | * --------------------------------------------- |
| 103 | */ |
| 104 | func do_stack_maintenance |
| 105 | push {r4, lr} |
| 106 | bl plat_get_my_stack |
| 107 | |
| 108 | /* Turn off the D-cache */ |
| 109 | ldcopr r1, SCTLR |
| 110 | bic r1, #SCTLR_C_BIT |
| 111 | stcopr r1, SCTLR |
| 112 | isb |
| 113 | |
| 114 | /* --------------------------------------------- |
| 115 | * Calculate and store the size of the used |
| 116 | * stack memory in r1. |
| 117 | * --------------------------------------------- |
| 118 | */ |
| 119 | mov r4, r0 |
| 120 | mov r1, sp |
| 121 | sub r1, r0, r1 |
| 122 | mov r0, sp |
| 123 | bl flush_dcache_range |
| 124 | |
| 125 | /* --------------------------------------------- |
| 126 | * Calculate and store the size of the unused |
| 127 | * stack memory in r1. Calculate and store the |
| 128 | * stack base address in r0. |
| 129 | * --------------------------------------------- |
| 130 | */ |
| 131 | sub r0, r4, #PLATFORM_STACK_SIZE |
| 132 | sub r1, sp, r0 |
| 133 | bl inv_dcache_range |
| 134 | |
| 135 | pop {r4, pc} |
| 136 | endfunc do_stack_maintenance |
| 137 | |
| 138 | /* ----------------------------------------------------------------------- |
| 139 | * This function is called to indicate to the power controller that it |
| 140 | * is safe to power down this cpu. It should not exit the wfi and will |
| 141 | * be released from reset upon power up. |
| 142 | * ----------------------------------------------------------------------- |
| 143 | */ |
| 144 | func psci_power_down_wfi |
| 145 | dsb sy // ensure write buffer empty |
| 146 | wfi |
Jeenu Viswambharan | a806dad | 2016-11-30 15:21:11 +0000 | [diff] [blame] | 147 | no_ret plat_panic_handler |
Soby Mathew | 727e523 | 2016-05-05 14:11:23 +0100 | [diff] [blame] | 148 | endfunc psci_power_down_wfi |