/* * 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/bootmem.h>#include <linux/initrd.h>#include <linux/of_fdt.h>#include <linux/screen_info.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); unsigned long memory_size; 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}; #ifdef CONFIG_VTstruct screen_info screen_info;#endif /* 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)			strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE);	}#endif 	early_init_devtree((void *)dtb_passed); #ifndef CONFIG_CMDLINE_FORCE	if (cmdline_passed[0])		strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE);#ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB	else		strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);#endif#endif 	parse_early_param();} void __init setup_arch(char **cmdline_p){	int bootmap_size; 	console_verbose(); 	memory_start = PAGE_ALIGN((unsigned long)__pa(_end));	memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size; 	init_mm.start_code = (unsigned long) _stext;	init_mm.end_code = (unsigned long) _etext;	init_mm.end_data = (unsigned long) _edata;	init_mm.brk = (unsigned long) _end;	init_task.thread.kregs = &fake_regs; 	/* Keep a copy of command line */	*cmdline_p = boot_command_line; 	min_low_pfn = PFN_UP(memory_start);	max_low_pfn = PFN_DOWN(memory_end);	max_mapnr = max_low_pfn; 	/*	 * give all the memory to the bootmap allocator,  tell it to put the	 * boot mem_map at the start of memory	 */	pr_debug("init_bootmem_node(?,%#lx, %#x, %#lx)\n",		min_low_pfn, PFN_DOWN(PHYS_OFFSET), max_low_pfn);	bootmap_size = init_bootmem_node(NODE_DATA(0),					min_low_pfn, PFN_DOWN(PHYS_OFFSET),					max_low_pfn); 	/*	 * free the usable memory,  we have to make sure we do not free	 * the bootmem bitmap so we then reserve it after freeing it :-)	 */	pr_debug("free_bootmem(%#lx, %#lx)\n",		memory_start, memory_end - memory_start);	free_bootmem(memory_start, memory_end - memory_start); 	/*	 * Reserve the bootmem bitmap itself as well. We do this in two	 * steps (first step was init_bootmem()) because this catches	 * the (very unlikely) case of us accidentally initializing the	 * bootmem allocator with an invalid RAM area.	 *	 * Arguments are start, size	 */	pr_debug("reserve_bootmem(%#lx, %#x)\n", memory_start, bootmap_size);	reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT); #ifdef CONFIG_BLK_DEV_INITRD	if (initrd_start) {		reserve_bootmem(virt_to_phys((void *)initrd_start),				initrd_end - initrd_start, BOOTMEM_DEFAULT);	}#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(); #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)	conswitchp = &dummy_con;#endif}