cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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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 = &current_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) */