cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hwsleep.c (8782B)


      1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
      2/******************************************************************************
      3 *
      4 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
      5 *                   original/legacy sleep/PM registers.
      6 *
      7 * Copyright (C) 2000 - 2022, Intel Corp.
      8 *
      9 *****************************************************************************/
     10
     11#include <acpi/acpi.h>
     12#include "accommon.h"
     13
     14#define _COMPONENT          ACPI_HARDWARE
     15ACPI_MODULE_NAME("hwsleep")
     16
     17#if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
     18/*******************************************************************************
     19 *
     20 * FUNCTION:    acpi_hw_legacy_sleep
     21 *
     22 * PARAMETERS:  sleep_state         - Which sleep state to enter
     23 *
     24 * RETURN:      Status
     25 *
     26 * DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
     27 *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
     28 *
     29 ******************************************************************************/
     30acpi_status acpi_hw_legacy_sleep(u8 sleep_state)
     31{
     32	struct acpi_bit_register_info *sleep_type_reg_info;
     33	struct acpi_bit_register_info *sleep_enable_reg_info;
     34	u32 pm1a_control;
     35	u32 pm1b_control;
     36	u32 in_value;
     37	acpi_status status;
     38
     39	ACPI_FUNCTION_TRACE(hw_legacy_sleep);
     40
     41	sleep_type_reg_info =
     42	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
     43	sleep_enable_reg_info =
     44	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
     45
     46	/* Clear wake status */
     47
     48	status = acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
     49					 ACPI_CLEAR_STATUS);
     50	if (ACPI_FAILURE(status)) {
     51		return_ACPI_STATUS(status);
     52	}
     53
     54	/* Disable all GPEs */
     55	status = acpi_hw_disable_all_gpes();
     56	if (ACPI_FAILURE(status)) {
     57		return_ACPI_STATUS(status);
     58	}
     59	status = acpi_hw_clear_acpi_status();
     60	if (ACPI_FAILURE(status)) {
     61		return_ACPI_STATUS(status);
     62	}
     63	acpi_gbl_system_awake_and_running = FALSE;
     64
     65	 /* Enable all wakeup GPEs */
     66	status = acpi_hw_enable_all_wakeup_gpes();
     67	if (ACPI_FAILURE(status)) {
     68		return_ACPI_STATUS(status);
     69	}
     70
     71	/* Get current value of PM1A control */
     72
     73	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
     74				       &pm1a_control);
     75	if (ACPI_FAILURE(status)) {
     76		return_ACPI_STATUS(status);
     77	}
     78	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
     79			  "Entering sleep state [S%u]\n", sleep_state));
     80
     81	/* Clear the SLP_EN and SLP_TYP fields */
     82
     83	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
     84			  sleep_enable_reg_info->access_bit_mask);
     85	pm1b_control = pm1a_control;
     86
     87	/* Insert the SLP_TYP bits */
     88
     89	pm1a_control |=
     90	    (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
     91	pm1b_control |=
     92	    (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);
     93
     94	/*
     95	 * We split the writes of SLP_TYP and SLP_EN to workaround
     96	 * poorly implemented hardware.
     97	 */
     98
     99	/* Write #1: write the SLP_TYP data to the PM1 Control registers */
    100
    101	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
    102	if (ACPI_FAILURE(status)) {
    103		return_ACPI_STATUS(status);
    104	}
    105
    106	/* Insert the sleep enable (SLP_EN) bit */
    107
    108	pm1a_control |= sleep_enable_reg_info->access_bit_mask;
    109	pm1b_control |= sleep_enable_reg_info->access_bit_mask;
    110
    111	/* Flush caches, as per ACPI specification */
    112
    113	if (sleep_state < ACPI_STATE_S4) {
    114		ACPI_FLUSH_CPU_CACHE();
    115	}
    116
    117	status = acpi_os_enter_sleep(sleep_state, pm1a_control, pm1b_control);
    118	if (status == AE_CTRL_TERMINATE) {
    119		return_ACPI_STATUS(AE_OK);
    120	}
    121	if (ACPI_FAILURE(status)) {
    122		return_ACPI_STATUS(status);
    123	}
    124
    125	/* Write #2: Write both SLP_TYP + SLP_EN */
    126
    127	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
    128	if (ACPI_FAILURE(status)) {
    129		return_ACPI_STATUS(status);
    130	}
    131
    132	if (sleep_state > ACPI_STATE_S3) {
    133		/*
    134		 * We wanted to sleep > S3, but it didn't happen (by virtue of the
    135		 * fact that we are still executing!)
    136		 *
    137		 * Wait ten seconds, then try again. This is to get S4/S5 to work on
    138		 * all machines.
    139		 *
    140		 * We wait so long to allow chipsets that poll this reg very slowly
    141		 * to still read the right value. Ideally, this block would go
    142		 * away entirely.
    143		 */
    144		acpi_os_stall(10 * ACPI_USEC_PER_SEC);
    145
    146		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
    147						sleep_enable_reg_info->
    148						access_bit_mask);
    149		if (ACPI_FAILURE(status)) {
    150			return_ACPI_STATUS(status);
    151		}
    152	}
    153
    154	/* Wait for transition back to Working State */
    155
    156	do {
    157		status =
    158		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
    159		if (ACPI_FAILURE(status)) {
    160			return_ACPI_STATUS(status);
    161		}
    162
    163	} while (!in_value);
    164
    165	return_ACPI_STATUS(AE_OK);
    166}
    167
    168/*******************************************************************************
    169 *
    170 * FUNCTION:    acpi_hw_legacy_wake_prep
    171 *
    172 * PARAMETERS:  sleep_state         - Which sleep state we just exited
    173 *
    174 * RETURN:      Status
    175 *
    176 * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
    177 *              sleep.
    178 *              Called with interrupts ENABLED.
    179 *
    180 ******************************************************************************/
    181
    182acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
    183{
    184	acpi_status status = AE_OK;
    185	struct acpi_bit_register_info *sleep_type_reg_info;
    186	struct acpi_bit_register_info *sleep_enable_reg_info;
    187	u32 pm1a_control;
    188	u32 pm1b_control;
    189
    190	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);
    191
    192	/*
    193	 * Set SLP_TYPE and SLP_EN to state S0.
    194	 * This is unclear from the ACPI Spec, but it is required
    195	 * by some machines.
    196	 */
    197	if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
    198		sleep_type_reg_info =
    199		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
    200		sleep_enable_reg_info =
    201		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);
    202
    203		/* Get current value of PM1A control */
    204
    205		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
    206					       &pm1a_control);
    207		if (ACPI_SUCCESS(status)) {
    208
    209			/* Clear the SLP_EN and SLP_TYP fields */
    210
    211			pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
    212					  sleep_enable_reg_info->
    213					  access_bit_mask);
    214			pm1b_control = pm1a_control;
    215
    216			/* Insert the SLP_TYP bits */
    217
    218			pm1a_control |= (acpi_gbl_sleep_type_a_s0 <<
    219					 sleep_type_reg_info->bit_position);
    220			pm1b_control |= (acpi_gbl_sleep_type_b_s0 <<
    221					 sleep_type_reg_info->bit_position);
    222
    223			/* Write the control registers and ignore any errors */
    224
    225			(void)acpi_hw_write_pm1_control(pm1a_control,
    226							pm1b_control);
    227		}
    228	}
    229
    230	return_ACPI_STATUS(status);
    231}
    232
    233/*******************************************************************************
    234 *
    235 * FUNCTION:    acpi_hw_legacy_wake
    236 *
    237 * PARAMETERS:  sleep_state         - Which sleep state we just exited
    238 *
    239 * RETURN:      Status
    240 *
    241 * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
    242 *              Called with interrupts ENABLED.
    243 *
    244 ******************************************************************************/
    245
    246acpi_status acpi_hw_legacy_wake(u8 sleep_state)
    247{
    248	acpi_status status;
    249
    250	ACPI_FUNCTION_TRACE(hw_legacy_wake);
    251
    252	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */
    253
    254	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
    255	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);
    256
    257	/*
    258	 * GPEs must be enabled before _WAK is called as GPEs
    259	 * might get fired there
    260	 *
    261	 * Restore the GPEs:
    262	 * 1) Disable all GPEs
    263	 * 2) Enable all runtime GPEs
    264	 */
    265	status = acpi_hw_disable_all_gpes();
    266	if (ACPI_FAILURE(status)) {
    267		return_ACPI_STATUS(status);
    268	}
    269
    270	status = acpi_hw_enable_all_runtime_gpes();
    271	if (ACPI_FAILURE(status)) {
    272		return_ACPI_STATUS(status);
    273	}
    274
    275	/*
    276	 * Now we can execute _WAK, etc. Some machines require that the GPEs
    277	 * are enabled before the wake methods are executed.
    278	 */
    279	acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);
    280
    281	/*
    282	 * Some BIOS code assumes that WAK_STS will be cleared on resume
    283	 * and use it to determine whether the system is rebooting or
    284	 * resuming. Clear WAK_STS for compatibility.
    285	 */
    286	(void)acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
    287				      ACPI_CLEAR_STATUS);
    288	acpi_gbl_system_awake_and_running = TRUE;
    289
    290	/* Enable power button */
    291
    292	(void)
    293	    acpi_write_bit_register(acpi_gbl_fixed_event_info
    294				    [ACPI_EVENT_POWER_BUTTON].
    295				    enable_register_id, ACPI_ENABLE_EVENT);
    296
    297	(void)
    298	    acpi_write_bit_register(acpi_gbl_fixed_event_info
    299				    [ACPI_EVENT_POWER_BUTTON].
    300				    status_register_id, ACPI_CLEAR_STATUS);
    301
    302	/* Enable sleep button */
    303
    304	(void)
    305	    acpi_write_bit_register(acpi_gbl_fixed_event_info
    306				    [ACPI_EVENT_SLEEP_BUTTON].
    307				    enable_register_id, ACPI_ENABLE_EVENT);
    308
    309	(void)
    310	    acpi_write_bit_register(acpi_gbl_fixed_event_info
    311				    [ACPI_EVENT_SLEEP_BUTTON].
    312				    status_register_id, ACPI_CLEAR_STATUS);
    313
    314	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
    315	return_ACPI_STATUS(status);
    316}
    317
    318#endif				/* !ACPI_REDUCED_HARDWARE */