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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pm.c (3139B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  arch/arm/mach-socfpga/pm.c
      4 *
      5 * Copyright (C) 2014-2015 Altera Corporation. All rights reserved.
      6 *
      7 * with code from pm-imx6.c
      8 * Copyright 2011-2014 Freescale Semiconductor, Inc.
      9 * Copyright 2011 Linaro Ltd.
     10 */
     11
     12#include <linux/bitops.h>
     13#include <linux/genalloc.h>
     14#include <linux/init.h>
     15#include <linux/io.h>
     16#include <linux/of_platform.h>
     17#include <linux/suspend.h>
     18#include <asm/suspend.h>
     19#include <asm/fncpy.h>
     20#include "core.h"
     21
     22/* Pointer to function copied to ocram */
     23static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base);
     24
     25static int socfpga_setup_ocram_self_refresh(void)
     26{
     27	struct platform_device *pdev;
     28	phys_addr_t ocram_pbase;
     29	struct device_node *np;
     30	struct gen_pool *ocram_pool;
     31	unsigned long ocram_base;
     32	void __iomem *suspend_ocram_base;
     33	int ret = 0;
     34
     35	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
     36	if (!np) {
     37		pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
     38		return -ENODEV;
     39	}
     40
     41	pdev = of_find_device_by_node(np);
     42	if (!pdev) {
     43		pr_warn("%s: failed to find ocram device!\n", __func__);
     44		ret = -ENODEV;
     45		goto put_node;
     46	}
     47
     48	ocram_pool = gen_pool_get(&pdev->dev, NULL);
     49	if (!ocram_pool) {
     50		pr_warn("%s: ocram pool unavailable!\n", __func__);
     51		ret = -ENODEV;
     52		goto put_device;
     53	}
     54
     55	ocram_base = gen_pool_alloc(ocram_pool, socfpga_sdram_self_refresh_sz);
     56	if (!ocram_base) {
     57		pr_warn("%s: unable to alloc ocram!\n", __func__);
     58		ret = -ENOMEM;
     59		goto put_device;
     60	}
     61
     62	ocram_pbase = gen_pool_virt_to_phys(ocram_pool, ocram_base);
     63
     64	suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
     65						socfpga_sdram_self_refresh_sz,
     66						false);
     67	if (!suspend_ocram_base) {
     68		pr_warn("%s: __arm_ioremap_exec failed!\n", __func__);
     69		ret = -ENOMEM;
     70		goto put_device;
     71	}
     72
     73	/* Copy the code that puts DDR in self refresh to ocram */
     74	socfpga_sdram_self_refresh_in_ocram =
     75		(void *)fncpy(suspend_ocram_base,
     76			      &socfpga_sdram_self_refresh,
     77			      socfpga_sdram_self_refresh_sz);
     78
     79	WARN(!socfpga_sdram_self_refresh_in_ocram,
     80	     "could not copy function to ocram");
     81	if (!socfpga_sdram_self_refresh_in_ocram)
     82		ret = -EFAULT;
     83
     84put_device:
     85	put_device(&pdev->dev);
     86put_node:
     87	of_node_put(np);
     88
     89	return ret;
     90}
     91
     92static int socfpga_pm_suspend(unsigned long arg)
     93{
     94	u32 ret;
     95
     96	if (!sdr_ctl_base_addr)
     97		return -EFAULT;
     98
     99	ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr);
    100
    101	pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__,
    102		 ret & 0xffff, (ret >> 16) & 0xffff);
    103
    104	return 0;
    105}
    106
    107static int socfpga_pm_enter(suspend_state_t state)
    108{
    109	switch (state) {
    110	case PM_SUSPEND_MEM:
    111		outer_disable();
    112		cpu_suspend(0, socfpga_pm_suspend);
    113		outer_resume();
    114		break;
    115	default:
    116		return -EINVAL;
    117	}
    118	return 0;
    119}
    120
    121static const struct platform_suspend_ops socfpga_pm_ops = {
    122	.valid	= suspend_valid_only_mem,
    123	.enter	= socfpga_pm_enter,
    124};
    125
    126static int __init socfpga_pm_init(void)
    127{
    128	int ret;
    129
    130	ret = socfpga_setup_ocram_self_refresh();
    131	if (ret)
    132		return ret;
    133
    134	suspend_set_ops(&socfpga_pm_ops);
    135	pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n");
    136
    137	return 0;
    138}
    139arch_initcall(socfpga_pm_init);