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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auxio_64.c (3160B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* auxio.c: Probing for the Sparc AUXIO register at boot time.
      3 *
      4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
      5 *
      6 * Refactoring for unified NCR/PCIO support 2002 Eric Brower (ebrower@usa.net)
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/kernel.h>
     11#include <linux/init.h>
     12#include <linux/ioport.h>
     13#include <linux/of_device.h>
     14
     15#include <asm/prom.h>
     16#include <asm/io.h>
     17#include <asm/auxio.h>
     18
     19void __iomem *auxio_register = NULL;
     20EXPORT_SYMBOL(auxio_register);
     21
     22enum auxio_type {
     23	AUXIO_TYPE_NODEV,
     24	AUXIO_TYPE_SBUS,
     25	AUXIO_TYPE_EBUS
     26};
     27
     28static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
     29static DEFINE_SPINLOCK(auxio_lock);
     30
     31static void __auxio_rmw(u8 bits_on, u8 bits_off, int ebus)
     32{
     33	if (auxio_register) {
     34		unsigned long flags;
     35		u8 regval, newval;
     36
     37		spin_lock_irqsave(&auxio_lock, flags);
     38
     39		regval = (ebus ?
     40			  (u8) readl(auxio_register) :
     41			  sbus_readb(auxio_register));
     42		newval =  regval | bits_on;
     43		newval &= ~bits_off;
     44		if (!ebus)
     45			newval &= ~AUXIO_AUX1_MASK;
     46		if (ebus)
     47			writel((u32) newval, auxio_register);
     48		else
     49			sbus_writeb(newval, auxio_register);
     50		
     51		spin_unlock_irqrestore(&auxio_lock, flags);
     52	}
     53}
     54
     55static void __auxio_set_bit(u8 bit, int on, int ebus)
     56{
     57	u8 bits_on = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
     58	u8 bits_off = 0;
     59
     60	if (!on) {
     61		u8 tmp = bits_off;
     62		bits_off = bits_on;
     63		bits_on = tmp;
     64	}
     65	__auxio_rmw(bits_on, bits_off, ebus);
     66}
     67
     68void auxio_set_led(int on)
     69{
     70	int ebus = auxio_devtype == AUXIO_TYPE_EBUS;
     71	u8 bit;
     72
     73	bit = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
     74	__auxio_set_bit(bit, on, ebus);
     75}
     76EXPORT_SYMBOL(auxio_set_led);
     77
     78static void __auxio_sbus_set_lte(int on)
     79{
     80	__auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
     81}
     82
     83void auxio_set_lte(int on)
     84{
     85	switch(auxio_devtype) {
     86	case AUXIO_TYPE_SBUS:
     87		__auxio_sbus_set_lte(on);
     88		break;
     89	case AUXIO_TYPE_EBUS:
     90	default:
     91		break;
     92	}
     93}
     94EXPORT_SYMBOL(auxio_set_lte);
     95
     96static const struct of_device_id auxio_match[] = {
     97	{
     98		.name = "auxio",
     99	},
    100	{},
    101};
    102
    103MODULE_DEVICE_TABLE(of, auxio_match);
    104
    105static int auxio_probe(struct platform_device *dev)
    106{
    107	struct device_node *dp = dev->dev.of_node;
    108	unsigned long size;
    109
    110	if (of_node_name_eq(dp->parent, "ebus")) {
    111		auxio_devtype = AUXIO_TYPE_EBUS;
    112		size = sizeof(u32);
    113	} else if (of_node_name_eq(dp->parent, "sbus")) {
    114		auxio_devtype = AUXIO_TYPE_SBUS;
    115		size = 1;
    116	} else {
    117		printk("auxio: Unknown parent bus type [%pOFn]\n",
    118		       dp->parent);
    119		return -ENODEV;
    120	}
    121	auxio_register = of_ioremap(&dev->resource[0], 0, size, "auxio");
    122	if (!auxio_register)
    123		return -ENODEV;
    124
    125	printk(KERN_INFO "AUXIO: Found device at %pOF\n", dp);
    126
    127	if (auxio_devtype == AUXIO_TYPE_EBUS)
    128		auxio_set_led(AUXIO_LED_ON);
    129
    130	return 0;
    131}
    132
    133static struct platform_driver auxio_driver = {
    134	.probe		= auxio_probe,
    135	.driver = {
    136		.name = "auxio",
    137		.of_match_table = auxio_match,
    138	},
    139};
    140
    141static int __init auxio_init(void)
    142{
    143	return platform_driver_register(&auxio_driver);
    144}
    145
    146/* Must be after subsys_initcall() so that busses are probed.  Must
    147 * be before device_initcall() because things like the floppy driver
    148 * need to use the AUXIO register.
    149 */
    150fs_initcall(auxio_init);