/* * Nios2-specific parts of system setup * * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch> * Copyright (C) 2004 Microtronix Datacom Ltd. * Copyright (C) 2001 Vic Phillips <vic@microtronix.com> * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <linux/export.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/sched.h>#include <linux/sched/task.h>#include <linux/console.h>#include <linux/memblock.h>#include <linux/initrd.h>#include <linux/of_fdt.h> #include <asm/mmu_context.h>#include <asm/sections.h>#include <asm/setup.h>#include <asm/cpuinfo.h> unsigned long memory_start;EXPORT_SYMBOL(memory_start); unsigned long memory_end;EXPORT_SYMBOL(memory_end); static struct pt_regs fake_regs = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,					0, 0, 0, 0, 0, 0,					0}; /* Copy a short hook instruction sequence to the exception address */static inline void copy_exception_handler(unsigned int addr){	unsigned int start = (unsigned int) exception_handler_hook;	volatile unsigned int tmp = 0; 	if (start == addr) {		/* The CPU exception address already points to the handler. */		return;	} 	__asm__ __volatile__ (		"ldw	%2,0(%0)\n"		"stw	%2,0(%1)\n"		"ldw	%2,4(%0)\n"		"stw	%2,4(%1)\n"		"ldw	%2,8(%0)\n"		"stw	%2,8(%1)\n"		"flushd	0(%1)\n"		"flushd	4(%1)\n"		"flushd	8(%1)\n"		"flushi %1\n"		"addi	%1,%1,4\n"		"flushi %1\n"		"addi	%1,%1,4\n"		"flushi %1\n"		"flushp\n"		: /* no output registers */		: "r" (start), "r" (addr), "r" (tmp)		: "memory"	);} /* Copy the fast TLB miss handler */static inline void copy_fast_tlb_miss_handler(unsigned int addr){	unsigned int start = (unsigned int) fast_handler;	unsigned int end = (unsigned int) fast_handler_end;	volatile unsigned int tmp = 0; 	__asm__ __volatile__ (		"1:\n"		"	ldw	%3,0(%0)\n"		"	stw	%3,0(%1)\n"		"	flushd	0(%1)\n"		"	flushi	%1\n"		"	flushp\n"		"	addi	%0,%0,4\n"		"	addi	%1,%1,4\n"		"	bne	%0,%2,1b\n"		: /* no output registers */		: "r" (start), "r" (addr), "r" (end), "r" (tmp)		: "memory"	);} /* * save args passed from u-boot, called from head.S * * @r4: NIOS magic * @r5: initrd start * @r6: initrd end or fdt * @r7: kernel command line */asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6,				       unsigned r7){	unsigned dtb_passed = 0;	char cmdline_passed[COMMAND_LINE_SIZE] __maybe_unused = { 0, }; #if defined(CONFIG_NIOS2_PASS_CMDLINE)	if (r4 == 0x534f494e) { /* r4 is magic NIOS */#if defined(CONFIG_BLK_DEV_INITRD)		if (r5) { /* initramfs */			initrd_start = r5;			initrd_end = r6;		}#endif /* CONFIG_BLK_DEV_INITRD */		dtb_passed = r6; 		if (r7)			strscpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);	}#endif 	early_init_devtree((void *)dtb_passed); #ifndef CONFIG_CMDLINE_FORCE	if (cmdline_passed[0])		strscpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);#ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB	else		strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);#endif#endif 	parse_early_param();} static void __init find_limits(unsigned long *min, unsigned long *max_low,			       unsigned long *max_high){	*max_low = PFN_DOWN(memblock_get_current_limit());	*min = PFN_UP(memblock_start_of_DRAM());	*max_high = PFN_DOWN(memblock_end_of_DRAM());} static void __init adjust_lowmem_bounds(void){	phys_addr_t block_start, block_end;	u64 i;	phys_addr_t memblock_limit = 0; 	for_each_mem_range(i, &block_start, &block_end) {		if (block_end > memblock_limit)			memblock_limit = block_end;	} 	memblock_set_current_limit(memblock_limit);} void __init setup_arch(char **cmdline_p){	console_verbose(); 	memory_start = memblock_start_of_DRAM();	memory_end = memblock_end_of_DRAM(); 	pr_debug("%s: start=%lx, end=%lx\n", __func__, memory_start, memory_end); 	setup_initial_init_mm(_stext, _etext, _edata, _end);	init_task.thread.kregs = &fake_regs; 	/* Keep a copy of command line */	*cmdline_p = boot_command_line; 	adjust_lowmem_bounds();	find_limits(&min_low_pfn, &max_low_pfn, &max_pfn); 	memblock_reserve(__pa_symbol(_stext), _end - _stext);#ifdef CONFIG_BLK_DEV_INITRD	if (initrd_start) {		memblock_reserve(virt_to_phys((void *)initrd_start),				initrd_end - initrd_start);	}#endif /* CONFIG_BLK_DEV_INITRD */ 	early_init_fdt_reserve_self();	early_init_fdt_scan_reserved_mem(); 	unflatten_and_copy_device_tree(); 	setup_cpuinfo(); 	copy_exception_handler(cpuinfo.exception_addr); 	mmu_init(); 	copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr); 	/*	 * Initialize MMU context handling here because data from cpuinfo is	 * needed for this.	 */	mmu_context_init(); 	/*	 * get kmalloc into gear	 */	paging_init();}