cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

olpc-xo1-pm.c (4445B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Support for power management features of the OLPC XO-1 laptop
      4 *
      5 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
      6 * Copyright (C) 2010 One Laptop per Child
      7 * Copyright (C) 2006 Red Hat, Inc.
      8 * Copyright (C) 2006 Advanced Micro Devices, Inc.
      9 */
     10
     11#include <linux/cs5535.h>
     12#include <linux/platform_device.h>
     13#include <linux/export.h>
     14#include <linux/pm.h>
     15#include <linux/suspend.h>
     16#include <linux/olpc-ec.h>
     17
     18#include <asm/io.h>
     19#include <asm/olpc.h>
     20
     21#define DRV_NAME "olpc-xo1-pm"
     22
     23static unsigned long acpi_base;
     24static unsigned long pms_base;
     25
     26static u16 wakeup_mask = CS5536_PM_PWRBTN;
     27
     28static struct {
     29	unsigned long address;
     30	unsigned short segment;
     31} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
     32
     33/* Set bits in the wakeup mask */
     34void olpc_xo1_pm_wakeup_set(u16 value)
     35{
     36	wakeup_mask |= value;
     37}
     38EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
     39
     40/* Clear bits in the wakeup mask */
     41void olpc_xo1_pm_wakeup_clear(u16 value)
     42{
     43	wakeup_mask &= ~value;
     44}
     45EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
     46
     47static int xo1_power_state_enter(suspend_state_t pm_state)
     48{
     49	unsigned long saved_sci_mask;
     50
     51	/* Only STR is supported */
     52	if (pm_state != PM_SUSPEND_MEM)
     53		return -EINVAL;
     54
     55	/*
     56	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
     57	 * wakeup events, which is not necessarily the same event set)
     58	 */
     59	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
     60	saved_sci_mask &= 0xffff0000;
     61
     62	/* Save CPU state */
     63	do_olpc_suspend_lowlevel();
     64
     65	/* Resume path starts here */
     66
     67	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
     68	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
     69
     70	return 0;
     71}
     72
     73asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
     74{
     75	void *pgd_addr = __va(read_cr3_pa());
     76
     77	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
     78	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
     79
     80	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
     81	__asm__("call *(%%edi); cld"
     82		: : "D" (&ofw_bios_entry));
     83	__asm__("movb $0x34, %al\n\t"
     84		"outb %al, $0x70\n\t"
     85		"movb $0x30, %al\n\t"
     86		"outb %al, $0x71\n\t");
     87	return 0;
     88}
     89
     90static void xo1_power_off(void)
     91{
     92	printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
     93
     94	/* Enable all of these controls with 0 delay */
     95	outl(0x40000000, pms_base + CS5536_PM_SCLK);
     96	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
     97	outl(0x40000000, pms_base + CS5536_PM_WKXD);
     98	outl(0x40000000, pms_base + CS5536_PM_WKD);
     99
    100	/* Clear status bits (possibly unnecessary) */
    101	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
    102	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
    103
    104	/* Write SLP_EN bit to start the machinery */
    105	outl(0x00002000, acpi_base + CS5536_PM1_CNT);
    106}
    107
    108static int xo1_power_state_valid(suspend_state_t pm_state)
    109{
    110	/* suspend-to-RAM only */
    111	return pm_state == PM_SUSPEND_MEM;
    112}
    113
    114static const struct platform_suspend_ops xo1_suspend_ops = {
    115	.valid = xo1_power_state_valid,
    116	.enter = xo1_power_state_enter,
    117};
    118
    119static int xo1_pm_probe(struct platform_device *pdev)
    120{
    121	struct resource *res;
    122
    123	/* don't run on non-XOs */
    124	if (!machine_is_olpc())
    125		return -ENODEV;
    126
    127	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
    128	if (!res) {
    129		dev_err(&pdev->dev, "can't fetch device resource info\n");
    130		return -EIO;
    131	}
    132	if (strcmp(pdev->name, "cs5535-pms") == 0)
    133		pms_base = res->start;
    134	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
    135		acpi_base = res->start;
    136
    137	/* If we have both addresses, we can override the poweroff hook */
    138	if (pms_base && acpi_base) {
    139		suspend_set_ops(&xo1_suspend_ops);
    140		pm_power_off = xo1_power_off;
    141		printk(KERN_INFO "OLPC XO-1 support registered\n");
    142	}
    143
    144	return 0;
    145}
    146
    147static int xo1_pm_remove(struct platform_device *pdev)
    148{
    149	if (strcmp(pdev->name, "cs5535-pms") == 0)
    150		pms_base = 0;
    151	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
    152		acpi_base = 0;
    153
    154	pm_power_off = NULL;
    155	return 0;
    156}
    157
    158static struct platform_driver cs5535_pms_driver = {
    159	.driver = {
    160		.name = "cs5535-pms",
    161	},
    162	.probe = xo1_pm_probe,
    163	.remove = xo1_pm_remove,
    164};
    165
    166static struct platform_driver cs5535_acpi_driver = {
    167	.driver = {
    168		.name = "olpc-xo1-pm-acpi",
    169	},
    170	.probe = xo1_pm_probe,
    171	.remove = xo1_pm_remove,
    172};
    173
    174static int __init xo1_pm_init(void)
    175{
    176	int r;
    177
    178	r = platform_driver_register(&cs5535_pms_driver);
    179	if (r)
    180		return r;
    181
    182	r = platform_driver_register(&cs5535_acpi_driver);
    183	if (r)
    184		platform_driver_unregister(&cs5535_pms_driver);
    185
    186	return r;
    187}
    188arch_initcall(xo1_pm_init);