WSL2-Linux-Kernel/arch/mips/bcm47xx/prom.c

117 строки
3.8 KiB
C

/*
* Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
* Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
* Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/ssb/ssb_driver_chipcommon.h>
#include <linux/ssb/ssb_regs.h>
#include <linux/smp.h>
#include <asm/bootinfo.h>
#include <bcm47xx.h>
#include <bcm47xx_board.h>
static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
const char *get_system_type(void)
{
return bcm47xx_system_type;
}
__init void bcm47xx_set_system_type(u16 chip_id)
{
snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
(chip_id > 0x9999) ? "Broadcom BCM%d" :
"Broadcom BCM%04X",
chip_id);
}
static __init void prom_init_mem(void)
{
unsigned long mem;
unsigned long max;
unsigned long off;
struct cpuinfo_mips *c = &current_cpu_data;
/* Figure out memory size by finding aliases.
*
* We should theoretically use the mapping from CFE using cfe_enummem().
* However as the BCM47XX is mostly used on low-memory systems, we
* want to reuse the memory used by CFE (around 4MB). That means cfe_*
* functions stop to work at some point during the boot, we should only
* call them at the beginning of the boot.
*
* BCM47XX uses 128MB for addressing the ram, if the system contains
* less that that amount of ram it remaps the ram more often into the
* available space.
*/
/* Physical address, without mapping to any kernel segment */
off = CPHYSADDR((unsigned long)prom_init);
/* Accessing memory after 128 MiB will cause an exception */
max = 128 << 20;
for (mem = 1 << 20; mem < max; mem += 1 << 20) {
/* Loop condition may be not enough, off may be over 1 MiB */
if (off + mem >= max) {
mem = max;
printk(KERN_DEBUG "assume 128MB RAM\n");
break;
}
if (!memcmp(prom_init, prom_init + mem, 32))
break;
}
/* Ignoring the last page when ddr size is 128M. Cached
* accesses to last page is causing the processor to prefetch
* using address above 128M stepping out of the ddr address
* space.
*/
if (c->cputype == CPU_74K && (mem == (128 << 20)))
mem -= 0x1000;
add_memory_region(0, mem, BOOT_MEM_RAM);
}
/*
* This is the first serial on the chip common core, it is at this position
* for sb (ssb) and ai (bcma) bus.
*/
#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
void __init prom_init(void)
{
prom_init_mem();
setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
}
void __init prom_free_prom_memory(void)
{
}