linux/arch/mips/bcm47xx/prom.c

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/*
* 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 unsigned long lowmem __initdata;
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;
pr_debug("Assume 128MB RAM\n");
break;
}
if (!memcmp(prom_init, prom_init + mem, 32))
break;
}
lowmem = mem;
/* 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)
{
}
#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
#define EXTVBASE 0xc0000000
#define ENTRYLO(x) ((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
#include <asm/tlbflush.h>
/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
* dropped. Calling it at this stage causes a hang.
*/
void early_tlb_init(void)
{
write_c0_pagemask(PM_DEFAULT_MASK);
write_c0_wired(0);
temp_tlb_entry = current_cpu_data.tlbsize - 1;
local_flush_tlb_all();
}
void __init bcm47xx_prom_highmem_init(void)
{
unsigned long off = (unsigned long)prom_init;
unsigned long extmem = 0;
bool highmem_region = false;
if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
return;
if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
highmem_region = true;
if (lowmem != 128 << 20 || !highmem_region)
return;
early_tlb_init();
/* Add one temporary TLB entry to map SDRAM Region 2.
* Physical Virtual
* 0x80000000 0xc0000000 (1st: 256MB)
* 0x90000000 0xd0000000 (2nd: 256MB)
*/
add_temporary_entry(ENTRYLO(0x80000000),
ENTRYLO(0x80000000 + (256 << 20)),
EXTVBASE, PM_256M);
off = EXTVBASE + __pa(off);
for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
if (!memcmp(prom_init, (void *)(off + extmem), 16))
break;
}
extmem -= lowmem;
early_tlb_init();
if (!extmem)
return;
pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
extmem >> 20);
/* TODO: Register extra memory */
}
#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */