prom.c (5482B)
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/memblock.h> 31#include <linux/spinlock.h> 32#include <linux/ssb/ssb_driver_chipcommon.h> 33#include <linux/ssb/ssb_regs.h> 34#include <linux/smp.h> 35#include <asm/bootinfo.h> 36#include <bcm47xx.h> 37#include <bcm47xx_board.h> 38 39static char bcm47xx_system_type[20] = "Broadcom BCM47XX"; 40 41const char *get_system_type(void) 42{ 43 return bcm47xx_system_type; 44} 45 46__init void bcm47xx_set_system_type(u16 chip_id) 47{ 48 snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type), 49 (chip_id > 0x9999) ? "Broadcom BCM%d" : 50 "Broadcom BCM%04X", 51 chip_id); 52} 53 54static unsigned long lowmem __initdata; 55 56static __init void prom_init_mem(void) 57{ 58 unsigned long mem; 59 unsigned long max; 60 unsigned long off; 61 struct cpuinfo_mips *c = ¤t_cpu_data; 62 63 /* Figure out memory size by finding aliases. 64 * 65 * We should theoretically use the mapping from CFE using cfe_enummem(). 66 * However as the BCM47XX is mostly used on low-memory systems, we 67 * want to reuse the memory used by CFE (around 4MB). That means cfe_* 68 * functions stop to work at some point during the boot, we should only 69 * call them at the beginning of the boot. 70 * 71 * BCM47XX uses 128MB for addressing the ram, if the system contains 72 * less that that amount of ram it remaps the ram more often into the 73 * available space. 74 */ 75 76 /* Physical address, without mapping to any kernel segment */ 77 off = CPHYSADDR((unsigned long)prom_init); 78 79 /* Accessing memory after 128 MiB will cause an exception */ 80 max = 128 << 20; 81 82 for (mem = 1 << 20; mem < max; mem += 1 << 20) { 83 /* Loop condition may be not enough, off may be over 1 MiB */ 84 if (off + mem >= max) { 85 mem = max; 86 pr_debug("Assume 128MB RAM\n"); 87 break; 88 } 89 if (!memcmp(prom_init, prom_init + mem, 32)) 90 break; 91 } 92 lowmem = mem; 93 94 /* Ignoring the last page when ddr size is 128M. Cached 95 * accesses to last page is causing the processor to prefetch 96 * using address above 128M stepping out of the ddr address 97 * space. 98 */ 99 if (c->cputype == CPU_74K && (mem == (128 << 20))) 100 mem -= 0x1000; 101 memblock_add(0, mem); 102} 103 104/* 105 * This is the first serial on the chip common core, it is at this position 106 * for sb (ssb) and ai (bcma) bus. 107 */ 108#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA) 109 110void __init prom_init(void) 111{ 112 prom_init_mem(); 113 setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0); 114} 115 116#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) 117 118#define EXTVBASE 0xc0000000 119#define ENTRYLO(x) ((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1) 120 121#include <asm/tlbflush.h> 122 123/* Stripped version of tlb_init, with the call to build_tlb_refill_handler 124 * dropped. Calling it at this stage causes a hang. 125 */ 126void early_tlb_init(void) 127{ 128 write_c0_pagemask(PM_DEFAULT_MASK); 129 write_c0_wired(0); 130 temp_tlb_entry = current_cpu_data.tlbsize - 1; 131 local_flush_tlb_all(); 132} 133 134void __init bcm47xx_prom_highmem_init(void) 135{ 136 unsigned long off = (unsigned long)prom_init; 137 unsigned long extmem = 0; 138 bool highmem_region = false; 139 140 if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA)) 141 return; 142 143 if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706) 144 highmem_region = true; 145 146 if (lowmem != 128 << 20 || !highmem_region) 147 return; 148 149 early_tlb_init(); 150 151 /* Add one temporary TLB entry to map SDRAM Region 2. 152 * Physical Virtual 153 * 0x80000000 0xc0000000 (1st: 256MB) 154 * 0x90000000 0xd0000000 (2nd: 256MB) 155 */ 156 add_temporary_entry(ENTRYLO(0x80000000), 157 ENTRYLO(0x80000000 + (256 << 20)), 158 EXTVBASE, PM_256M); 159 160 off = EXTVBASE + __pa(off); 161 for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) { 162 if (!memcmp(prom_init, (void *)(off + extmem), 16)) 163 break; 164 } 165 extmem -= lowmem; 166 167 early_tlb_init(); 168 169 if (!extmem) 170 return; 171 172 pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n", 173 extmem >> 20); 174 175 /* TODO: Register extra memory */ 176} 177 178#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */