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linux/drivers/soc/ux500/ux500-soc-id.c
Jason A. Donenfeld 65b0e307a1 ARM: ux500: do not directly dereference __iomem
Sparse reports that calling add_device_randomness() on `uid` is a
violation of address spaces. And indeed the next usage uses readl()
properly, but that was left out when passing it toadd_device_
randomness(). So instead copy the whole thing to the stack first.

Fixes: 4040d10a3d ("ARM: ux500: add DB serial number to entropy pool")
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/202210230819.loF90KDh-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20221108123755.207438-1-Jason@zx2c4.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2022-11-08 21:13:56 +01:00

226 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) ST-Ericsson SA 2010
*
* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/sys_soc.h>
#include <asm/cputype.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mach/map.h>
/**
* struct dbx500_asic_id - fields of the ASIC ID
* @process: the manufacturing process, 0x40 is 40 nm 0x00 is "standard"
* @partnumber: hithereto 0x8500 for DB8500
* @revision: version code in the series
*/
struct dbx500_asic_id {
u16 partnumber;
u8 revision;
u8 process;
};
static struct dbx500_asic_id dbx500_id;
static unsigned int __init ux500_read_asicid(phys_addr_t addr)
{
void __iomem *virt = ioremap(addr, 4);
unsigned int asicid;
if (!virt)
return 0;
asicid = readl(virt);
iounmap(virt);
return asicid;
}
static void ux500_print_soc_info(unsigned int asicid)
{
unsigned int rev = dbx500_id.revision;
pr_info("DB%4x ", dbx500_id.partnumber);
if (rev == 0x01)
pr_cont("Early Drop");
else if (rev >= 0xA0)
pr_cont("v%d.%d" , (rev >> 4) - 0xA + 1, rev & 0xf);
else
pr_cont("Unknown");
pr_cont(" [%#010x]\n", asicid);
}
static unsigned int partnumber(unsigned int asicid)
{
return (asicid >> 8) & 0xffff;
}
/*
* SOC MIDR ASICID ADDRESS ASICID VALUE
* DB8500ed 0x410fc090 0x9001FFF4 0x00850001
* DB8500v1 0x411fc091 0x9001FFF4 0x008500A0
* DB8500v1.1 0x411fc091 0x9001FFF4 0x008500A1
* DB8500v2 0x412fc091 0x9001DBF4 0x008500B0
* DB8520v2.2 0x412fc091 0x9001DBF4 0x008500B2
* DB5500v1 0x412fc091 0x9001FFF4 0x005500A0
* DB9540 0x413fc090 0xFFFFDBF4 0x009540xx
*/
static void __init ux500_setup_id(void)
{
unsigned int cpuid = read_cpuid_id();
unsigned int asicid = 0;
phys_addr_t addr = 0;
switch (cpuid) {
case 0x410fc090: /* DB8500ed */
case 0x411fc091: /* DB8500v1 */
addr = 0x9001FFF4;
break;
case 0x412fc091: /* DB8520 / DB8500v2 / DB5500v1 */
asicid = ux500_read_asicid(0x9001DBF4);
if (partnumber(asicid) == 0x8500 ||
partnumber(asicid) == 0x8520)
/* DB8500v2 */
break;
/* DB5500v1 */
addr = 0x9001FFF4;
break;
case 0x413fc090: /* DB9540 */
addr = 0xFFFFDBF4;
break;
}
if (addr)
asicid = ux500_read_asicid(addr);
if (!asicid) {
pr_err("Unable to identify SoC\n");
BUG();
}
dbx500_id.process = asicid >> 24;
dbx500_id.partnumber = partnumber(asicid);
dbx500_id.revision = asicid & 0xff;
ux500_print_soc_info(asicid);
}
static const char * __init ux500_get_machine(void)
{
return kasprintf(GFP_KERNEL, "DB%4x", dbx500_id.partnumber);
}
static const char * __init ux500_get_family(void)
{
return kasprintf(GFP_KERNEL, "ux500");
}
static const char * __init ux500_get_revision(void)
{
unsigned int rev = dbx500_id.revision;
if (rev == 0x01)
return kasprintf(GFP_KERNEL, "%s", "ED");
else if (rev >= 0xA0)
return kasprintf(GFP_KERNEL, "%d.%d",
(rev >> 4) - 0xA + 1, rev & 0xf);
return kasprintf(GFP_KERNEL, "%s", "Unknown");
}
static ssize_t
process_show(struct device *dev, struct device_attribute *attr, char *buf)
{
if (dbx500_id.process == 0x00)
return sprintf(buf, "Standard\n");
return sprintf(buf, "%02xnm\n", dbx500_id.process);
}
static DEVICE_ATTR_RO(process);
static struct attribute *ux500_soc_attrs[] = {
&dev_attr_process.attr,
NULL
};
ATTRIBUTE_GROUPS(ux500_soc);
static const char *db8500_read_soc_id(struct device_node *backupram)
{
void __iomem *base;
const char *retstr;
u32 uid[5];
base = of_iomap(backupram, 0);
if (!base)
return NULL;
memcpy_fromio(uid, base + 0x1fc0, sizeof(uid));
/* Throw these device-specific numbers into the entropy pool */
add_device_randomness(uid, sizeof(uid));
retstr = kasprintf(GFP_KERNEL, "%08x%08x%08x%08x%08x",
uid[0], uid[1], uid[2], uid[3], uid[4]);
iounmap(base);
return retstr;
}
static void __init soc_info_populate(struct soc_device_attribute *soc_dev_attr,
struct device_node *backupram)
{
soc_dev_attr->soc_id = db8500_read_soc_id(backupram);
soc_dev_attr->machine = ux500_get_machine();
soc_dev_attr->family = ux500_get_family();
soc_dev_attr->revision = ux500_get_revision();
soc_dev_attr->custom_attr_group = ux500_soc_groups[0];
}
static int __init ux500_soc_device_init(void)
{
struct soc_device *soc_dev;
struct soc_device_attribute *soc_dev_attr;
struct device_node *backupram;
backupram = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram");
if (!backupram)
return 0;
ux500_setup_id();
soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
if (!soc_dev_attr) {
of_node_put(backupram);
return -ENOMEM;
}
soc_info_populate(soc_dev_attr, backupram);
of_node_put(backupram);
soc_dev = soc_device_register(soc_dev_attr);
if (IS_ERR(soc_dev)) {
kfree(soc_dev_attr);
return PTR_ERR(soc_dev);
}
return 0;
}
subsys_initcall(ux500_soc_device_init);