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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pmu.c (2511B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  pmu.c, Power Management Unit routines for NEC VR4100 series.
      4 *
      5 *  Copyright (C) 2003-2007  Yoichi Yuasa <yuasa@linux-mips.org>
      6 */
      7#include <linux/cpu.h>
      8#include <linux/errno.h>
      9#include <linux/init.h>
     10#include <linux/ioport.h>
     11#include <linux/kernel.h>
     12#include <linux/pm.h>
     13#include <linux/sched.h>
     14#include <linux/types.h>
     15
     16#include <asm/cacheflush.h>
     17#include <asm/cpu.h>
     18#include <asm/idle.h>
     19#include <asm/io.h>
     20#include <asm/processor.h>
     21#include <asm/reboot.h>
     22
     23#define PMU_TYPE1_BASE	0x0b0000a0UL
     24#define PMU_TYPE1_SIZE	0x0eUL
     25
     26#define PMU_TYPE2_BASE	0x0f0000c0UL
     27#define PMU_TYPE2_SIZE	0x10UL
     28
     29#define PMUCNT2REG	0x06
     30 #define SOFTRST	0x0010
     31
     32static void __iomem *pmu_base;
     33
     34#define pmu_read(offset)		readw(pmu_base + (offset))
     35#define pmu_write(offset, value)	writew((value), pmu_base + (offset))
     36
     37static void __cpuidle vr41xx_cpu_wait(void)
     38{
     39	local_irq_disable();
     40	if (!need_resched())
     41		/*
     42		 * "standby" sets IE bit of the CP0_STATUS to 1.
     43		 */
     44		__asm__("standby;\n");
     45	else
     46		local_irq_enable();
     47}
     48
     49static inline void software_reset(void)
     50{
     51	uint16_t pmucnt2;
     52
     53	switch (current_cpu_type()) {
     54	case CPU_VR4122:
     55	case CPU_VR4131:
     56	case CPU_VR4133:
     57		pmucnt2 = pmu_read(PMUCNT2REG);
     58		pmucnt2 |= SOFTRST;
     59		pmu_write(PMUCNT2REG, pmucnt2);
     60		break;
     61	default:
     62		set_c0_status(ST0_BEV | ST0_ERL);
     63		change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
     64		__flush_cache_all();
     65		write_c0_wired(0);
     66		__asm__("jr	%0"::"r"(0xbfc00000));
     67		break;
     68	}
     69}
     70
     71static void vr41xx_restart(char *command)
     72{
     73	local_irq_disable();
     74	software_reset();
     75	while (1) ;
     76}
     77
     78static void vr41xx_halt(void)
     79{
     80	local_irq_disable();
     81	printk(KERN_NOTICE "\nYou can turn off the power supply\n");
     82	__asm__("hibernate;\n");
     83}
     84
     85static int __init vr41xx_pmu_init(void)
     86{
     87	unsigned long start, size;
     88
     89	switch (current_cpu_type()) {
     90	case CPU_VR4111:
     91	case CPU_VR4121:
     92		start = PMU_TYPE1_BASE;
     93		size = PMU_TYPE1_SIZE;
     94		break;
     95	case CPU_VR4122:
     96	case CPU_VR4131:
     97	case CPU_VR4133:
     98		start = PMU_TYPE2_BASE;
     99		size = PMU_TYPE2_SIZE;
    100		break;
    101	default:
    102		printk("Unexpected CPU of NEC VR4100 series\n");
    103		return -ENODEV;
    104	}
    105
    106	if (request_mem_region(start, size, "PMU") == NULL)
    107		return -EBUSY;
    108
    109	pmu_base = ioremap(start, size);
    110	if (pmu_base == NULL) {
    111		release_mem_region(start, size);
    112		return -EBUSY;
    113	}
    114
    115	cpu_wait = vr41xx_cpu_wait;
    116	_machine_restart = vr41xx_restart;
    117	_machine_halt = vr41xx_halt;
    118	pm_power_off = vr41xx_halt;
    119
    120	return 0;
    121}
    122
    123core_initcall(vr41xx_pmu_init);