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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cobalt-flash.c (2384B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  Cobalt NOR flash functions
      4 *
      5 *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
      6 *  All rights reserved.
      7 */
      8
      9#include <linux/mtd/mtd.h>
     10#include <linux/mtd/map.h>
     11#include <linux/mtd/cfi.h>
     12#include <linux/time.h>
     13
     14#include "cobalt-flash.h"
     15
     16#define ADRS(offset) (COBALT_BUS_FLASH_BASE + offset)
     17
     18static struct map_info cobalt_flash_map = {
     19	.name =		"cobalt-flash",
     20	.bankwidth =	2,         /* 16 bits */
     21	.size =		0x4000000, /* 64MB */
     22	.phys =		0,         /* offset  */
     23};
     24
     25static map_word flash_read16(struct map_info *map, unsigned long offset)
     26{
     27	map_word r;
     28
     29	r.x[0] = cobalt_bus_read32(map->virt, ADRS(offset));
     30	if (offset & 0x2)
     31		r.x[0] >>= 16;
     32	else
     33		r.x[0] &= 0x0000ffff;
     34
     35	return r;
     36}
     37
     38static void flash_write16(struct map_info *map, const map_word datum,
     39			  unsigned long offset)
     40{
     41	u16 data = (u16)datum.x[0];
     42
     43	cobalt_bus_write16(map->virt, ADRS(offset), data);
     44}
     45
     46static void flash_copy_from(struct map_info *map, void *to,
     47			    unsigned long from, ssize_t len)
     48{
     49	u32 src = from;
     50	u8 *dest = to;
     51	u32 data;
     52
     53	while (len) {
     54		data = cobalt_bus_read32(map->virt, ADRS(src));
     55		do {
     56			*dest = data >> (8 * (src & 3));
     57			src++;
     58			dest++;
     59			len--;
     60		} while (len && (src % 4));
     61	}
     62}
     63
     64static void flash_copy_to(struct map_info *map, unsigned long to,
     65			  const void *from, ssize_t len)
     66{
     67	const u8 *src = from;
     68	u32 dest = to;
     69
     70	pr_info("%s: offset 0x%x: length %zu\n", __func__, dest, len);
     71	while (len) {
     72		u16 data;
     73
     74		do {
     75			data = *src << (8 * (dest & 1));
     76			src++;
     77			dest++;
     78			len--;
     79		} while (len && (dest % 2));
     80
     81		cobalt_bus_write16(map->virt, ADRS(dest - 2), data);
     82	}
     83}
     84
     85int cobalt_flash_probe(struct cobalt *cobalt)
     86{
     87	struct map_info *map = &cobalt_flash_map;
     88	struct mtd_info *mtd;
     89
     90	BUG_ON(!map_bankwidth_supported(map->bankwidth));
     91	map->virt = cobalt->bar1;
     92	map->read = flash_read16;
     93	map->write = flash_write16;
     94	map->copy_from = flash_copy_from;
     95	map->copy_to = flash_copy_to;
     96
     97	mtd = do_map_probe("cfi_probe", map);
     98	cobalt->mtd = mtd;
     99	if (!mtd) {
    100		cobalt_err("Probe CFI flash failed!\n");
    101		return -1;
    102	}
    103
    104	mtd->owner = THIS_MODULE;
    105	mtd->dev.parent = &cobalt->pci_dev->dev;
    106	mtd_device_register(mtd, NULL, 0);
    107	return 0;
    108}
    109
    110void cobalt_flash_remove(struct cobalt *cobalt)
    111{
    112	if (cobalt->mtd) {
    113		mtd_device_unregister(cobalt->mtd);
    114		map_destroy(cobalt->mtd);
    115	}
    116}