LXR linux/arch/mips/bcm47xx/prom.c

   1/*
   2 *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
   3 *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
   4 *  Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
   5 *
   6 *  This program is free software; you can redistribute  it and/or modify it
   7 *  under  the terms of  the GNU General  Public License as published by the
   8 *  Free Software Foundation;  either version 2 of the  License, or (at your
   9 *  option) any later version.
  10 *
  11 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  12 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  13 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  14 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  15 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  16 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  17 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  18 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  19 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  20 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  21 *
  22 *  You should have received a copy of the  GNU General Public License along
  23 *  with this program; if not, write  to the Free Software Foundation, Inc.,
  24 *  675 Mass Ave, Cambridge, MA 02139, USA.
  25 */
  26
  27#include <linux/init.h>
  28#include <linux/types.h>
  29#include <linux/kernel.h>
  30#include <linux/spinlock.h>
  31#include <linux/ssb/ssb_driver_chipcommon.h>
  32#include <linux/ssb/ssb_regs.h>
  33#include <linux/smp.h>
  34#include <asm/bootinfo.h>
  35#include <bcm47xx.h>
  36#include <bcm47xx_board.h>
  37
  38static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
  39
  40const char *get_system_type(void)
  41{
  42        return bcm47xx_system_type;
  43}
  44
  45__init void bcm47xx_set_system_type(u16 chip_id)
  46{
  47        snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
  48                 (chip_id > 0x9999) ? "Broadcom BCM%d" :
  49                                      "Broadcom BCM%04X",
  50                 chip_id);
  51}
  52
  53static unsigned long lowmem __initdata;
  54
  55static __init void prom_init_mem(void)
  56{
  57        unsigned long mem;
  58        unsigned long max;
  59        unsigned long off;
  60        struct cpuinfo_mips *c = &current_cpu_data;
  61
  62        /* Figure out memory size by finding aliases.
  63         *
  64         * We should theoretically use the mapping from CFE using cfe_enummem().
  65         * However as the BCM47XX is mostly used on low-memory systems, we
  66         * want to reuse the memory used by CFE (around 4MB). That means cfe_*
  67         * functions stop to work at some point during the boot, we should only
  68         * call them at the beginning of the boot.
  69         *
  70         * BCM47XX uses 128MB for addressing the ram, if the system contains
  71         * less that that amount of ram it remaps the ram more often into the
  72         * available space.
  73         */
  74
  75        /* Physical address, without mapping to any kernel segment */
  76        off = CPHYSADDR((unsigned long)prom_init);
  77
  78        /* Accessing memory after 128 MiB will cause an exception */
  79        max = 128 << 20;
  80
  81        for (mem = 1 << 20; mem < max; mem += 1 << 20) {
  82                /* Loop condition may be not enough, off may be over 1 MiB */
  83                if (off + mem >= max) {
  84                        mem = max;
  85                        pr_debug("Assume 128MB RAM\n");
  86                        break;
  87                }
  88                if (!memcmp(prom_init, prom_init + mem, 32))
  89                        break;
  90        }
  91        lowmem = mem;
  92
  93        /* Ignoring the last page when ddr size is 128M. Cached
  94         * accesses to last page is causing the processor to prefetch
  95         * using address above 128M stepping out of the ddr address
  96         * space.
  97         */
  98        if (c->cputype == CPU_74K && (mem == (128  << 20)))
  99                mem -= 0x1000;
 100        add_memory_region(0, mem, BOOT_MEM_RAM);
 101}
 102
 103/*
 104 * This is the first serial on the chip common core, it is at this position
 105 * for sb (ssb) and ai (bcma) bus.
 106 */
 107#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
 108
 109void __init prom_init(void)
 110{
 111        prom_init_mem();
 112        setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
 113}
 114
 115void __init prom_free_prom_memory(void)
 116{
 117}
 118
 119#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
 120
 121#define EXTVBASE        0xc0000000
 122#define ENTRYLO(x)      ((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
 123
 124#include <asm/tlbflush.h>
 125
 126/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
 127 * dropped. Calling it at this stage causes a hang.
 128 */
 129void early_tlb_init(void)
 130{
 131        write_c0_pagemask(PM_DEFAULT_MASK);
 132        write_c0_wired(0);
 133        temp_tlb_entry = current_cpu_data.tlbsize - 1;
 134        local_flush_tlb_all();
 135}
 136
 137void __init bcm47xx_prom_highmem_init(void)
 138{
 139        unsigned long off = (unsigned long)prom_init;
 140        unsigned long extmem = 0;
 141        bool highmem_region = false;
 142
 143        if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
 144                return;
 145
 146        if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
 147                highmem_region = true;
 148
 149        if (lowmem != 128 << 20 || !highmem_region)
 150                return;
 151
 152        early_tlb_init();
 153
 154        /* Add one temporary TLB entry to map SDRAM Region 2.
 155         *      Physical        Virtual
 156         *      0x80000000      0xc0000000      (1st: 256MB)
 157         *      0x90000000      0xd0000000      (2nd: 256MB)
 158         */
 159        add_temporary_entry(ENTRYLO(0x80000000),
 160                            ENTRYLO(0x80000000 + (256 << 20)),
 161                            EXTVBASE, PM_256M);
 162
 163        off = EXTVBASE + __pa(off);
 164        for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
 165                if (!memcmp(prom_init, (void *)(off + extmem), 16))
 166                        break;
 167        }
 168        extmem -= lowmem;
 169
 170        early_tlb_init();
 171
 172        if (!extmem)
 173                return;
 174
 175        pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
 176                extmem >> 20);
 177
 178        /* TODO: Register extra memory */
 179}
 180
 181#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */
 182