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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tah.c (3719B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * drivers/net/ethernet/ibm/emac/tah.c
      4 *
      5 * Driver for PowerPC 4xx on-chip ethernet controller, TAH support.
      6 *
      7 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
      8 *                <benh@kernel.crashing.org>
      9 *
     10 * Based on the arch/ppc version of the driver:
     11 *
     12 * Copyright 2004 MontaVista Software, Inc.
     13 * Matt Porter <mporter@kernel.crashing.org>
     14 *
     15 * Copyright (c) 2005 Eugene Surovegin <ebs@ebshome.net>
     16 */
     17#include <linux/of_address.h>
     18#include <asm/io.h>
     19
     20#include "emac.h"
     21#include "core.h"
     22
     23int tah_attach(struct platform_device *ofdev, int channel)
     24{
     25	struct tah_instance *dev = platform_get_drvdata(ofdev);
     26
     27	mutex_lock(&dev->lock);
     28	/* Reset has been done at probe() time... nothing else to do for now */
     29	++dev->users;
     30	mutex_unlock(&dev->lock);
     31
     32	return 0;
     33}
     34
     35void tah_detach(struct platform_device *ofdev, int channel)
     36{
     37	struct tah_instance *dev = platform_get_drvdata(ofdev);
     38
     39	mutex_lock(&dev->lock);
     40	--dev->users;
     41	mutex_unlock(&dev->lock);
     42}
     43
     44void tah_reset(struct platform_device *ofdev)
     45{
     46	struct tah_instance *dev = platform_get_drvdata(ofdev);
     47	struct tah_regs __iomem *p = dev->base;
     48	int n;
     49
     50	/* Reset TAH */
     51	out_be32(&p->mr, TAH_MR_SR);
     52	n = 100;
     53	while ((in_be32(&p->mr) & TAH_MR_SR) && n)
     54		--n;
     55
     56	if (unlikely(!n))
     57		printk(KERN_ERR "%pOF: reset timeout\n", ofdev->dev.of_node);
     58
     59	/* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
     60	out_be32(&p->mr,
     61		 TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
     62		 TAH_MR_DIG);
     63}
     64
     65int tah_get_regs_len(struct platform_device *ofdev)
     66{
     67	return sizeof(struct emac_ethtool_regs_subhdr) +
     68		sizeof(struct tah_regs);
     69}
     70
     71void *tah_dump_regs(struct platform_device *ofdev, void *buf)
     72{
     73	struct tah_instance *dev = platform_get_drvdata(ofdev);
     74	struct emac_ethtool_regs_subhdr *hdr = buf;
     75	struct tah_regs *regs = (struct tah_regs *)(hdr + 1);
     76
     77	hdr->version = 0;
     78	hdr->index = 0; /* for now, are there chips with more than one
     79			 * zmii ? if yes, then we'll add a cell_index
     80			 * like we do for emac
     81			 */
     82	memcpy_fromio(regs, dev->base, sizeof(struct tah_regs));
     83	return regs + 1;
     84}
     85
     86static int tah_probe(struct platform_device *ofdev)
     87{
     88	struct device_node *np = ofdev->dev.of_node;
     89	struct tah_instance *dev;
     90	struct resource regs;
     91	int rc;
     92
     93	rc = -ENOMEM;
     94	dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
     95	if (dev == NULL)
     96		goto err_gone;
     97
     98	mutex_init(&dev->lock);
     99	dev->ofdev = ofdev;
    100
    101	rc = -ENXIO;
    102	if (of_address_to_resource(np, 0, &regs)) {
    103		printk(KERN_ERR "%pOF: Can't get registers address\n", np);
    104		goto err_free;
    105	}
    106
    107	rc = -ENOMEM;
    108	dev->base = (struct tah_regs __iomem *)ioremap(regs.start,
    109					       sizeof(struct tah_regs));
    110	if (dev->base == NULL) {
    111		printk(KERN_ERR "%pOF: Can't map device registers!\n", np);
    112		goto err_free;
    113	}
    114
    115	platform_set_drvdata(ofdev, dev);
    116
    117	/* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
    118	tah_reset(ofdev);
    119
    120	printk(KERN_INFO "TAH %pOF initialized\n", ofdev->dev.of_node);
    121	wmb();
    122
    123	return 0;
    124
    125 err_free:
    126	kfree(dev);
    127 err_gone:
    128	return rc;
    129}
    130
    131static int tah_remove(struct platform_device *ofdev)
    132{
    133	struct tah_instance *dev = platform_get_drvdata(ofdev);
    134
    135	WARN_ON(dev->users != 0);
    136
    137	iounmap(dev->base);
    138	kfree(dev);
    139
    140	return 0;
    141}
    142
    143static const struct of_device_id tah_match[] =
    144{
    145	{
    146		.compatible	= "ibm,tah",
    147	},
    148	/* For backward compat with old DT */
    149	{
    150		.type		= "tah",
    151	},
    152	{},
    153};
    154
    155static struct platform_driver tah_driver = {
    156	.driver = {
    157		.name = "emac-tah",
    158		.of_match_table = tah_match,
    159	},
    160	.probe = tah_probe,
    161	.remove = tah_remove,
    162};
    163
    164int __init tah_init(void)
    165{
    166	return platform_driver_register(&tah_driver);
    167}
    168
    169void tah_exit(void)
    170{
    171	platform_driver_unregister(&tah_driver);
    172}