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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soc-gemini.c (2066B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2017 Linaro Ltd.
      4 *
      5 * Author: Linus Walleij <linus.walleij@linaro.org>
      6 *
      7 * This program is free software; you can redistribute it and/or modify
      8 * it under the terms of the GNU General Public License version 2, as
      9 * published by the Free Software Foundation.
     10 *
     11 */
     12#include <linux/init.h>
     13#include <linux/kernel.h>
     14#include <linux/mfd/syscon.h>
     15#include <linux/regmap.h>
     16#include <linux/of.h>
     17
     18#define GLOBAL_WORD_ID				0x00
     19#define GEMINI_GLOBAL_ARB1_CTRL			0x2c
     20#define GEMINI_ARB1_BURST_MASK			GENMASK(21, 16)
     21#define GEMINI_ARB1_BURST_SHIFT			16
     22/* These all define the priority on the BUS2 backplane */
     23#define GEMINI_ARB1_PRIO_MASK			GENMASK(9, 0)
     24#define GEMINI_ARB1_DMAC_HIGH_PRIO		BIT(0)
     25#define GEMINI_ARB1_IDE_HIGH_PRIO		BIT(1)
     26#define GEMINI_ARB1_RAID_HIGH_PRIO		BIT(2)
     27#define GEMINI_ARB1_SECURITY_HIGH_PRIO		BIT(3)
     28#define GEMINI_ARB1_GMAC0_HIGH_PRIO		BIT(4)
     29#define GEMINI_ARB1_GMAC1_HIGH_PRIO		BIT(5)
     30#define GEMINI_ARB1_USB0_HIGH_PRIO		BIT(6)
     31#define GEMINI_ARB1_USB1_HIGH_PRIO		BIT(7)
     32#define GEMINI_ARB1_PCI_HIGH_PRIO		BIT(8)
     33#define GEMINI_ARB1_TVE_HIGH_PRIO		BIT(9)
     34
     35#define GEMINI_DEFAULT_BURST_SIZE		0x20
     36#define GEMINI_DEFAULT_PRIO			(GEMINI_ARB1_GMAC0_HIGH_PRIO | \
     37						 GEMINI_ARB1_GMAC1_HIGH_PRIO)
     38
     39static int __init gemini_soc_init(void)
     40{
     41	struct regmap *map;
     42	u32 rev;
     43	u32 val;
     44	int ret;
     45
     46	/* Multiplatform guard, only proceed on Gemini */
     47	if (!of_machine_is_compatible("cortina,gemini"))
     48		return 0;
     49
     50	map = syscon_regmap_lookup_by_compatible("cortina,gemini-syscon");
     51	if (IS_ERR(map))
     52		return PTR_ERR(map);
     53	ret = regmap_read(map, GLOBAL_WORD_ID, &rev);
     54	if (ret)
     55		return ret;
     56
     57	val = (GEMINI_DEFAULT_BURST_SIZE << GEMINI_ARB1_BURST_SHIFT) |
     58		GEMINI_DEFAULT_PRIO;
     59
     60	/* Set up system arbitration */
     61	regmap_update_bits(map,
     62			   GEMINI_GLOBAL_ARB1_CTRL,
     63			   GEMINI_ARB1_BURST_MASK | GEMINI_ARB1_PRIO_MASK,
     64			   val);
     65
     66	pr_info("Gemini SoC %04x revision %02x, set arbitration %08x\n",
     67		rev >> 8, rev & 0xff, val);
     68
     69	return 0;
     70}
     71subsys_initcall(gemini_soc_init);