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

alpine_cpu_pm.c (1624B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Low-level power-management support for Alpine platform.
      4 *
      5 * Copyright (C) 2015 Annapurna Labs Ltd.
      6 */
      7
      8#include <linux/io.h>
      9#include <linux/of.h>
     10#include <linux/of_address.h>
     11#include <linux/regmap.h>
     12#include <linux/mfd/syscon.h>
     13
     14#include "alpine_cpu_pm.h"
     15#include "alpine_cpu_resume.h"
     16
     17/* NB registers */
     18#define AL_SYSFAB_POWER_CONTROL(cpu)	(0x2000 + (cpu)*0x100 + 0x20)
     19
     20static struct regmap *al_sysfabric;
     21static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs;
     22static int wakeup_supported;
     23
     24int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr)
     25{
     26	if (!wakeup_supported)
     27		return -ENOSYS;
     28
     29	/*
     30	 * Set CPU resume address -
     31	 * secure firmware running on boot will jump to this address
     32	 * after setting proper CPU mode, and initialiing e.g. secure
     33	 * regs (the same mode all CPUs are booted to - usually HYP)
     34	 */
     35	writel(phys_resume_addr,
     36	       &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr);
     37
     38	/* Power-up the CPU */
     39	regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0);
     40
     41	return 0;
     42}
     43
     44void __init alpine_cpu_pm_init(void)
     45{
     46	struct device_node *np;
     47	uint32_t watermark;
     48
     49	al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service");
     50
     51	np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume");
     52	al_cpu_resume_regs = of_iomap(np, 0);
     53
     54	wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs;
     55
     56	if (wakeup_supported) {
     57		watermark = readl(&al_cpu_resume_regs->watermark);
     58		wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK)
     59				    == AL_CPU_RESUME_MAGIC_NUM;
     60	}
     61}