setup.c

底层驱动开发

/*  $Id: setup.c,v 1.72 2002/02/09 19:49:30 davem Exp $
 *  linux/arch/sparc64/kernel/setup.c
 *
 *  Copyright (C) 1995,1996  David S. Miller ([e-mail])
 *  Copyright (C) 1997       Jakub Jelinek ([e-mail])
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <asm/smp.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/tty.h>
#include <linux/delay.h>
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/inet.h>
#include <linux/console.h>
#include <linux/root_dev.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/initrd.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/idprom.h>
#include <asm/head.h>
#include <asm/starfire.h>
#include <asm/mmu_context.h>
#include <asm/timer.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/mmu.h>

#ifdef CONFIG_IP_PNP
#include <net/ipconfig.h>
#endif

struct screen_info screen_info = {
	0, 0,			/* orig-x, orig-y */
	0,			/* unused */
	0,			/* orig-video-page */
	0,			/* orig-video-mode */
	128,			/* orig-video-cols */
	0, 0, 0,		/* unused, ega_bx, unused */
	54,			/* orig-video-lines */
	0,                      /* orig-video-isVGA */
	16                      /* orig-video-points */
};

/* Typing sync at the prom prompt calls the function pointed to by
 * the sync callback which I set to the following function.
 * This should sync all filesystems and return, for now it just
 * prints out pretty messages and returns.
 */

void (*prom_palette)(int);
void (*prom_keyboard)(void);

static void
prom_console_write(struct console *con, const char *s, unsigned n)
{
	prom_write(s, n);
}

static struct console prom_console = {
	.name =		"prom",
	.write =	prom_console_write,
	.flags =	CON_CONSDEV | CON_ENABLED,
	.index =	-1,
};

#define PROM_TRUE	-1
#define PROM_FALSE	0

/* Pretty sick eh? */
int prom_callback(long *args)
{
	struct console *cons, *saved_console = NULL;
	unsigned long flags;
	char *cmd;
	extern spinlock_t prom_entry_lock;

	if (!args)
		return -1;
	if (!(cmd = (char *)args[0]))
		return -1;

	/*
	 * The callback can be invoked on the cpu that first dropped 
	 * into prom_cmdline after taking the serial interrupt, or on 
	 * a slave processor that was smp_captured() if the 
	 * administrator has done a switch-cpu inside obp. In either 
	 * case, the cpu is marked as in-interrupt. Drop IRQ locks.
	 */
	irq_exit();

	/* XXX Revisit the locking here someday.  This is a debugging
	 * XXX feature so it isnt all that critical.  -DaveM
	 */
	local_irq_save(flags);

	spin_unlock(&prom_entry_lock);
	cons = console_drivers;
	while (cons) {
		unregister_console(cons);
		cons->flags &= ~(CON_PRINTBUFFER);
		cons->next = saved_console;
		saved_console = cons;
		cons = console_drivers;
	}
	register_console(&prom_console);
	if (!strcmp(cmd, "sync")) {
		prom_printf("PROM `%s' command...\n", cmd);
		show_free_areas();
		if (current->pid != 0) {
			local_irq_enable();
			sys_sync();
			local_irq_disable();
		}
		args[2] = 0;
		args[args[1] + 3] = -1;
		prom_printf("Returning to PROM\n");
	} else if (!strcmp(cmd, "va>tte-data")) {
		unsigned long ctx, va;
		unsigned long tte = 0;
		long res = PROM_FALSE;

		ctx = args[3];
		va = args[4];
		if (ctx) {
			/*
			 * Find process owning ctx, lookup mapping.
			 */
			struct task_struct *p;
			struct mm_struct *mm = NULL;
			pgd_t *pgdp;
			pud_t *pudp;
			pmd_t *pmdp;
			pte_t *ptep;

			for_each_process(p) {
				mm = p->mm;
				if (CTX_NRBITS(mm->context) == ctx)
					break;
			}
			if (!mm ||
			    CTX_NRBITS(mm->context) != ctx)
				goto done;

			pgdp = pgd_offset(mm, va);
			if (pgd_none(*pgdp))
				goto done;
			pudp = pud_offset(pgdp, va);
			if (pud_none(*pudp))
				goto done;
			pmdp = pmd_offset(pudp, va);
			if (pmd_none(*pmdp))
				goto done;

			/* Preemption implicitly disabled by virtue of
			 * being called from inside OBP.
			 */
			ptep = pte_offset_map(pmdp, va);
			if (pte_present(*ptep)) {
				tte = pte_val(*ptep);
				res = PROM_TRUE;
			}
			pte_unmap(ptep);
			goto done;
		}

		if ((va >= KERNBASE) && (va < (KERNBASE + (4 * 1024 * 1024)))) {
			extern unsigned long sparc64_kern_pri_context;

			/* Spitfire Errata #32 workaround */
			__asm__ __volatile__("stxa	%0, [%1] %2\n\t"
					     "flush	%%g6"
					     : /* No outputs */
					     : "r" (sparc64_kern_pri_context),
					       "r" (PRIMARY_CONTEXT),
					       "i" (ASI_DMMU));

			/*
			 * Locked down tlb entry.
			 */

			if (tlb_type == spitfire)
				tte = spitfire_get_dtlb_data(SPITFIRE_HIGHEST_LOCKED_TLBENT);
			else if (tlb_type == cheetah || tlb_type == cheetah_plus)
				tte = cheetah_get_ldtlb_data(CHEETAH_HIGHEST_LOCKED_TLBENT);

			res = PROM_TRUE;
			goto done;
		}

		if (va < PGDIR_SIZE) {
			/*
			 * vmalloc or prom_inherited mapping.
			 */
			pgd_t *pgdp;
			pud_t *pudp;
			pmd_t *pmdp;
			pte_t *ptep;
			int error;

			if ((va >= LOW_OBP_ADDRESS) && (va < HI_OBP_ADDRESS)) {
				tte = prom_virt_to_phys(va, &error);
				if (!error)
					res = PROM_TRUE;
				goto done;
			}
			pgdp = pgd_offset_k(va);
			if (pgd_none(*pgdp))
				goto done;
			pudp = pud_offset(pgdp, va);
			if (pud_none(*pudp))
				goto done;
			pmdp = pmd_offset(pudp, va);
			if (pmd_none(*pmdp))
				goto done;

			/* Preemption implicitly disabled by virtue of
			 * being called from inside OBP.
			 */
			ptep = pte_offset_kernel(pmdp, va);
			if (pte_present(*ptep)) {
				tte = pte_val(*ptep);
				res = PROM_TRUE;
			}
			goto done;
		}

		if (va < PAGE_OFFSET) {
			/*
			 * No mappings here.
			 */
			goto done;
		}

		if (va & (1UL << 40)) {
			/*
			 * I/O page.
			 */

			tte = (__pa(va) & _PAGE_PADDR) |
			      _PAGE_VALID | _PAGE_SZ4MB |
			      _PAGE_E | _PAGE_P | _PAGE_W;
			res = PROM_TRUE;
			goto done;
		}

		/*
		 * Normal page.
		 */
		tte = (__pa(va) & _PAGE_PADDR) |
		      _PAGE_VALID | _PAGE_SZ4MB |
		      _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W;
		res = PROM_TRUE;

	done:
		if (res == PROM_TRUE) {
			args[2] = 3;
			args[args[1] + 3] = 0;
			args[args[1] + 4] = res;
			args[args[1] + 5] = tte;
		} else {
			args[2] = 2;
			args[args[1] + 3] = 0;
			args[args[1] + 4] = res;
		}
	} else if (!strcmp(cmd, ".soft1")) {
		unsigned long tte;

		tte = args[3];
		prom_printf("%lx:\"%s%s%s%s%s\" ",
			    (tte & _PAGE_SOFT) >> 7,
			    tte & _PAGE_MODIFIED ? "M" : "-",
			    tte & _PAGE_ACCESSED ? "A" : "-",
			    tte & _PAGE_READ     ? "W" : "-",
			    tte & _PAGE_WRITE    ? "R" : "-",
			    tte & _PAGE_PRESENT  ? "P" : "-");

		args[2] = 2;
		args[args[1] + 3] = 0;
		args[args[1] + 4] = PROM_TRUE;
	} else if (!strcmp(cmd, ".soft2")) {
		unsigned long tte;

		tte = args[3];
		prom_printf("%lx ", (tte & 0x07FC000000000000UL) >> 50);

		args[2] = 2;
		args[args[1] + 3] = 0;
		args[args[1] + 4] = PROM_TRUE;
	} else {
		prom_printf("unknown PROM `%s' command...\n", cmd);
	}
	unregister_console(&prom_console);
	while (saved_console) {
		cons = saved_console;
		saved_console = cons->next;
		register_console(cons);
	}
	spin_lock(&prom_entry_lock);
	local_irq_restore(flags);

	/*
	 * Restore in-interrupt status for a resume from obp.
	 */
	irq_enter();
	return 0;
}

unsigned int boot_flags = 0;
#define BOOTME_DEBUG  0x1
#define BOOTME_SINGLE 0x2

/* Exported for mm/init.c:paging_init. */
unsigned long cmdline_memory_size = 0;

static struct console prom_debug_console = {
	.name =		"debug",
	.write =	prom_console_write,
	.flags =	CON_PRINTBUFFER,
	.index =	-1,
};

/* XXX Implement this at some point... */
void kernel_enter_debugger(void)