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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pcsp.c (5111B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * PC-Speaker driver for Linux
      4 *
      5 * Copyright (C) 1997-2001  David Woodhouse
      6 * Copyright (C) 2001-2008  Stas Sergeev
      7 */
      8
      9#include <linux/init.h>
     10#include <linux/module.h>
     11#include <linux/platform_device.h>
     12#include <sound/core.h>
     13#include <sound/initval.h>
     14#include <sound/pcm.h>
     15#include <linux/input.h>
     16#include <linux/delay.h>
     17#include <linux/bitops.h>
     18#include <linux/mm.h>
     19#include "pcsp_input.h"
     20#include "pcsp.h"
     21
     22MODULE_AUTHOR("Stas Sergeev <stsp@users.sourceforge.net>");
     23MODULE_DESCRIPTION("PC-Speaker driver");
     24MODULE_LICENSE("GPL");
     25MODULE_ALIAS("platform:pcspkr");
     26
     27static int index = SNDRV_DEFAULT_IDX1;	/* Index 0-MAX */
     28static char *id = SNDRV_DEFAULT_STR1;	/* ID for this card */
     29static bool enable = SNDRV_DEFAULT_ENABLE1;	/* Enable this card */
     30static bool nopcm;	/* Disable PCM capability of the driver */
     31
     32module_param(index, int, 0444);
     33MODULE_PARM_DESC(index, "Index value for pcsp soundcard.");
     34module_param(id, charp, 0444);
     35MODULE_PARM_DESC(id, "ID string for pcsp soundcard.");
     36module_param(enable, bool, 0444);
     37MODULE_PARM_DESC(enable, "Enable PC-Speaker sound.");
     38module_param(nopcm, bool, 0444);
     39MODULE_PARM_DESC(nopcm, "Disable PC-Speaker PCM sound. Only beeps remain.");
     40
     41struct snd_pcsp pcsp_chip;
     42
     43static int snd_pcsp_create(struct snd_card *card)
     44{
     45	unsigned int resolution = hrtimer_resolution;
     46	int div, min_div, order;
     47
     48	if (!nopcm) {
     49		if (resolution > PCSP_MAX_PERIOD_NS) {
     50			printk(KERN_ERR "PCSP: Timer resolution is not sufficient "
     51				"(%unS)\n", resolution);
     52			printk(KERN_ERR "PCSP: Make sure you have HPET and ACPI "
     53				"enabled.\n");
     54			printk(KERN_ERR "PCSP: Turned into nopcm mode.\n");
     55			nopcm = 1;
     56		}
     57	}
     58
     59	if (loops_per_jiffy >= PCSP_MIN_LPJ && resolution <= PCSP_MIN_PERIOD_NS)
     60		min_div = MIN_DIV;
     61	else
     62		min_div = MAX_DIV;
     63#if PCSP_DEBUG
     64	printk(KERN_DEBUG "PCSP: lpj=%li, min_div=%i, res=%u\n",
     65	       loops_per_jiffy, min_div, resolution);
     66#endif
     67
     68	div = MAX_DIV / min_div;
     69	order = fls(div) - 1;
     70
     71	pcsp_chip.max_treble = min(order, PCSP_MAX_TREBLE);
     72	pcsp_chip.treble = min(pcsp_chip.max_treble, PCSP_DEFAULT_TREBLE);
     73	pcsp_chip.playback_ptr = 0;
     74	pcsp_chip.period_ptr = 0;
     75	atomic_set(&pcsp_chip.timer_active, 0);
     76	pcsp_chip.enable = 1;
     77	pcsp_chip.pcspkr = 1;
     78
     79	spin_lock_init(&pcsp_chip.substream_lock);
     80
     81	pcsp_chip.card = card;
     82	pcsp_chip.port = 0x61;
     83	pcsp_chip.irq = -1;
     84	pcsp_chip.dma = -1;
     85	card->private_data = &pcsp_chip;
     86
     87	return 0;
     88}
     89
     90static void pcsp_stop_beep(struct snd_pcsp *chip);
     91
     92static void alsa_card_pcsp_free(struct snd_card *card)
     93{
     94	pcsp_stop_beep(card->private_data);
     95}
     96
     97static int snd_card_pcsp_probe(int devnum, struct device *dev)
     98{
     99	struct snd_card *card;
    100	int err;
    101
    102	if (devnum != 0)
    103		return -EINVAL;
    104
    105	hrtimer_init(&pcsp_chip.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
    106	pcsp_chip.timer.function = pcsp_do_timer;
    107
    108	err = snd_devm_card_new(dev, index, id, THIS_MODULE, 0, &card);
    109	if (err < 0)
    110		return err;
    111
    112	err = snd_pcsp_create(card);
    113	if (err < 0)
    114		return err;
    115
    116	if (!nopcm) {
    117		err = snd_pcsp_new_pcm(&pcsp_chip);
    118		if (err < 0)
    119			return err;
    120	}
    121	err = snd_pcsp_new_mixer(&pcsp_chip, nopcm);
    122	if (err < 0)
    123		return err;
    124
    125	strcpy(card->driver, "PC-Speaker");
    126	strcpy(card->shortname, "pcsp");
    127	sprintf(card->longname, "Internal PC-Speaker at port 0x%x",
    128		pcsp_chip.port);
    129
    130	err = snd_card_register(card);
    131	if (err < 0)
    132		return err;
    133	card->private_free = alsa_card_pcsp_free;
    134
    135	return 0;
    136}
    137
    138static int alsa_card_pcsp_init(struct device *dev)
    139{
    140	int err;
    141
    142	err = snd_card_pcsp_probe(0, dev);
    143	if (err) {
    144		printk(KERN_ERR "PC-Speaker initialization failed.\n");
    145		return err;
    146	}
    147
    148	/* Well, CONFIG_DEBUG_PAGEALLOC makes the sound horrible. Lets alert */
    149	if (debug_pagealloc_enabled()) {
    150		printk(KERN_WARNING "PCSP: CONFIG_DEBUG_PAGEALLOC is enabled, "
    151		       "which may make the sound noisy.\n");
    152	}
    153
    154	return 0;
    155}
    156
    157static int pcsp_probe(struct platform_device *dev)
    158{
    159	int err;
    160
    161	err = pcspkr_input_init(&pcsp_chip.input_dev, &dev->dev);
    162	if (err < 0)
    163		return err;
    164
    165	err = alsa_card_pcsp_init(&dev->dev);
    166	if (err < 0)
    167		return err;
    168
    169	platform_set_drvdata(dev, &pcsp_chip);
    170	return 0;
    171}
    172
    173static void pcsp_stop_beep(struct snd_pcsp *chip)
    174{
    175	pcsp_sync_stop(chip);
    176	pcspkr_stop_sound();
    177}
    178
    179#ifdef CONFIG_PM_SLEEP
    180static int pcsp_suspend(struct device *dev)
    181{
    182	struct snd_pcsp *chip = dev_get_drvdata(dev);
    183	pcsp_stop_beep(chip);
    184	return 0;
    185}
    186
    187static SIMPLE_DEV_PM_OPS(pcsp_pm, pcsp_suspend, NULL);
    188#define PCSP_PM_OPS	&pcsp_pm
    189#else
    190#define PCSP_PM_OPS	NULL
    191#endif	/* CONFIG_PM_SLEEP */
    192
    193static void pcsp_shutdown(struct platform_device *dev)
    194{
    195	struct snd_pcsp *chip = platform_get_drvdata(dev);
    196	pcsp_stop_beep(chip);
    197}
    198
    199static struct platform_driver pcsp_platform_driver = {
    200	.driver		= {
    201		.name	= "pcspkr",
    202		.pm	= PCSP_PM_OPS,
    203	},
    204	.probe		= pcsp_probe,
    205	.shutdown	= pcsp_shutdown,
    206};
    207
    208static int __init pcsp_init(void)
    209{
    210	if (!enable)
    211		return -ENODEV;
    212	return platform_driver_register(&pcsp_platform_driver);
    213}
    214
    215static void __exit pcsp_exit(void)
    216{
    217	platform_driver_unregister(&pcsp_platform_driver);
    218}
    219
    220module_init(pcsp_init);
    221module_exit(pcsp_exit);