kernel_optimize_test/arch/mips/kernel/prom.c
Serge Semin 93fa5b2807
mips: Make sure dt memory regions are valid
There are situations when memory regions coming from dts may be
too big for the platform physical address space. This especially
concerns XPA-capable systems. Bootloader may determine more than 4GB
memory available and pass it to the kernel over dts memory node, while
kernel is built without XPA/64BIT support. In this case the region
may either simply be truncated by add_memory_region() method
or by u64->phys_addr_t type casting. But in worst case the method
can even drop the memory region if it exceeds PHYS_ADDR_MAX size.
So lets make sure the retrieved from dts memory regions are valid,
and if some of them aren't, just manually truncate them with a warning
printed out.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Serge Semin <Sergey.Semin@t-platforms.ru>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
2019-05-05 20:11:59 -07:00

96 lines
2.2 KiB
C

/*
* MIPS support for CONFIG_OF device tree support
*
* Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/memblock.h>
#include <linux/debugfs.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <asm/bootinfo.h>
#include <asm/page.h>
#include <asm/prom.h>
static char mips_machine_name[64] = "Unknown";
__init void mips_set_machine_name(const char *name)
{
if (name == NULL)
return;
strlcpy(mips_machine_name, name, sizeof(mips_machine_name));
pr_info("MIPS: machine is %s\n", mips_get_machine_name());
}
char *mips_get_machine_name(void)
{
return mips_machine_name;
}
#ifdef CONFIG_USE_OF
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
if (base >= PHYS_ADDR_MAX) {
pr_warn("Trying to add an invalid memory region, skipped\n");
return;
}
/* Truncate the passed memory region instead of type casting */
if (base + size - 1 >= PHYS_ADDR_MAX || base + size < base) {
pr_warn("Truncate memory region %llx @ %llx to size %llx\n",
size, base, PHYS_ADDR_MAX - base);
size = PHYS_ADDR_MAX - base;
}
add_memory_region(base, size, BOOT_MEM_RAM);
}
int __init early_init_dt_reserve_memory_arch(phys_addr_t base,
phys_addr_t size, bool nomap)
{
add_memory_region(base, size,
nomap ? BOOT_MEM_NOMAP : BOOT_MEM_RESERVED);
return 0;
}
void __init __dt_setup_arch(void *bph)
{
if (!early_init_dt_scan(bph))
return;
mips_set_machine_name(of_flat_dt_get_machine_name());
}
int __init __dt_register_buses(const char *bus0, const char *bus1)
{
static struct of_device_id of_ids[3];
if (!of_have_populated_dt())
panic("device tree not present");
strlcpy(of_ids[0].compatible, bus0, sizeof(of_ids[0].compatible));
if (bus1) {
strlcpy(of_ids[1].compatible, bus1,
sizeof(of_ids[1].compatible));
}
if (of_platform_populate(NULL, of_ids, NULL, NULL))
panic("failed to populate DT");
return 0;
}
#endif