memory.c

嵌入式系统设计与实例开发源码

	  set_fs (MAKE_MM_SEG(SUPER_DATA));

	  /* The PLPAR instruction causes an access error if the translation
	   * is not possible. To catch this we use the same exception mechanism
	   * as for user space accesses in <asm/uaccess.h>. */
	  asm volatile (".chip 68060\n"
			"1: plpar (%0)\n"
			".chip 68k\n"
			"2:\n"
			".section .fixup,\"ax\"\n"
			"   .even\n"
			"3: lea -1,%0\n"
			"   jra 2b\n"
			".previous\n"
			".section __ex_table,\"a\"\n"
			"   .align 4\n"
			"   .long 1b,3b\n"
			".previous"
			: "=a" (paddr)
			: "0" (vaddr));
	  set_fs (fs);

	  return paddr;

	} else if (CPU_IS_040) {
	  unsigned long mmusr;
	  mm_segment_t fs = get_fs();

	  set_fs (MAKE_MM_SEG(SUPER_DATA));

	  asm volatile (".chip 68040\n\t"
			"ptestr (%1)\n\t"
			"movec %%mmusr, %0\n\t"
			".chip 68k"
			: "=r" (mmusr)
			: "a" (vaddr));
	  set_fs (fs);

	  if (mmusr & MMU_T_040) {
	    return (unsigned long)vaddr;	/* Transparent translation */
	  }
	  if (mmusr & MMU_R_040)
	    return (mmusr & PAGE_MASK) | ((unsigned long)vaddr & (PAGE_SIZE-1));

	  printk("VTOP040: bad virtual address %lx (%lx)", vaddr, mmusr);
	  return -1;
	} else {
	  volatile unsigned short temp;
	  unsigned short mmusr;
	  unsigned long *descaddr;

	  asm volatile ("ptestr #5,%2@,#7,%0\n\t"
			"pmove %/psr,%1@"
			: "=a&" (descaddr)
			: "a" (&temp), "a" (vaddr));
	  mmusr = temp;

	  if (mmusr & (MMU_I|MMU_B|MMU_L))
	    printk("VTOP030: bad virtual address %lx (%x)\n", vaddr, mmusr);

	  descaddr = phys_to_virt((unsigned long)descaddr);

	  switch (mmusr & MMU_NUM) {
	  case 1:
	    return (*descaddr & 0xfe000000) | ((unsigned long)vaddr & 0x01ffffff);
	  case 2:
	    return (*descaddr & 0xfffc0000) | ((unsigned long)vaddr & 0x0003ffff);
	  case 3:
	    return (*descaddr & PAGE_MASK) | ((unsigned long)vaddr & (PAGE_SIZE-1));
	  default:
	    printk("VTOP: bad levels (%u) for virtual address %lx\n", 
		   mmusr & MMU_NUM, vaddr);
	  }
	}

	printk("VTOP: bad virtual address %lx\n", vaddr);
	return -1;
}

#ifndef CONFIG_SINGLE_MEMORY_CHUNK
unsigned long mm_ptov (unsigned long paddr)
{
	int i = 0;
	unsigned long poff, voff = PAGE_OFFSET;

	do {
		poff = paddr - m68k_memory[i].addr;
		if (poff < m68k_memory[i].size) {
#ifdef DEBUGPV
			printk ("PTOV(%lx)=%lx\n", paddr, poff + voff);
#endif
			return poff + voff;
		}
		voff += m68k_memory[i].size;
	} while (++i < m68k_num_memory);

#if DEBUG_INVALID_PTOV
	if (mm_inv_cnt > 0) {
		mm_inv_cnt--;
		printk("Invalid use of phys_to_virt(0x%lx) at 0x%p!\n",
			paddr, __builtin_return_address(0));
	}
#endif
	/*
	 * assume that the kernel virtual address is the same as the
	 * physical address.
	 *
	 * This should be reasonable in most situations:
	 *  1) They shouldn't be dereferencing the virtual address
	 *     unless they are sure that it is valid from kernel space.
	 *  2) The only usage I see so far is converting a page table
	 *     reference to some non-FASTMEM address space when freeing
         *     mmaped "/dev/mem" pages.  These addresses are just passed
	 *     to "free_page", which ignores addresses that aren't in
	 *     the memory list anyway.
	 *
	 */

#ifdef CONFIG_AMIGA
	/*
	 * if on an amiga and address is in first 16M, move it 
	 * to the ZTWO_VADDR range
	 */
	if (MACH_IS_AMIGA && paddr < 16*1024*1024)
		return ZTWO_VADDR(paddr);
#endif
	return -1;
}
#endif

/* invalidate page in both caches */
#define	clear040(paddr)					\
	__asm__ __volatile__ ("nop\n\t"			\
			      ".chip 68040\n\t"		\
			      "cinvp %%bc,(%0)\n\t"	\
			      ".chip 68k"		\
			      : : "a" (paddr))

/* invalidate page in i-cache */
#define	cleari040(paddr)				\
	__asm__ __volatile__ ("nop\n\t"			\
			      ".chip 68040\n\t"		\
			      "cinvp %%ic,(%0)\n\t"	\
			      ".chip 68k"		\
			      : : "a" (paddr))

/* push page in both caches */
#define	push040(paddr)					\
	__asm__ __volatile__ ("nop\n\t"			\
			      ".chip 68040\n\t"		\
			      "cpushp %%bc,(%0)\n\t"	\
			      ".chip 68k"		\
			      : : "a" (paddr))

/* push and invalidate page in both caches, must disable ints
 * to avoid invalidating valid data */
#define	pushcl040(paddr)			\
	do { unsigned long flags;               \
             save_flags(flags);                 \
	     cli();                             \
             push040(paddr);			\
	     if (CPU_IS_060) clear040(paddr);	\
	     restore_flags(flags);              \
	} while(0)

/* push page in both caches, invalidate in i-cache */
/* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */
#define	pushcli040(paddr)			\
	do { push040(paddr);			\
	} while(0)


/*
 * 040: Hit every page containing an address in the range paddr..paddr+len-1.
 * (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s).
 * Hit every page until there is a page or less to go. Hit the next page,
 * and the one after that if the range hits it.
 */
/* ++roman: A little bit more care is required here: The CINVP instruction
 * invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning
 * and the end of the region must be treated differently if they are not
 * exactly at the beginning or end of a page boundary. Else, maybe too much
 * data becomes invalidated and thus lost forever. CPUSHP does what we need:
 * it invalidates the page after pushing dirty data to memory. (Thanks to Jes
 * for discovering the problem!)
 */
/* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set
 * the DPI bit in the CACR; would it cause problems with temporarily changing
 * this?). So we have to push first and then additionally to invalidate.
 */


/*
 * cache_clear() semantics: Clear any cache entries for the area in question,
 * without writing back dirty entries first. This is useful if the data will
 * be overwritten anyway, e.g. by DMA to memory. The range is defined by a
 * _physical_ address.
 */

void cache_clear (unsigned long paddr, int len)
{
    if (CPU_IS_040_OR_060) {
	int tmp;

	/*
	 * We need special treatment for the first page, in case it
	 * is not page-aligned. Page align the addresses to work
	 * around bug I17 in the 68060.
	 */
	if ((tmp = -paddr & (PAGE_SIZE - 1))) {
	    pushcl040(paddr & PAGE_MASK);
	    if ((len -= tmp) <= 0)
		return;
	    paddr += tmp;
	}
	tmp = PAGE_SIZE;
	paddr &= PAGE_MASK;
	while ((len -= tmp) >= 0) {
	    clear040(paddr);
	    paddr += tmp;
	}
	if ((len += tmp))
	    /* a page boundary gets crossed at the end */
	    pushcl040(paddr);
    }
    else /* 68030 or 68020 */
	asm volatile ("movec %/cacr,%/d0\n\t"
		      "oriw %0,%/d0\n\t"
		      "movec %/d0,%/cacr"
		      : : "i" (FLUSH_I_AND_D)
		      : "d0");
#ifdef CONFIG_M68K_L2_CACHE
    if(mach_l2_flush)
    	mach_l2_flush(0);
#endif
}


/*
 * cache_push() semantics: Write back any dirty cache data in the given area,
 * and invalidate the range in the instruction cache. It needs not (but may)
 * invalidate those entries also in the data cache. The range is defined by a
 * _physical_ address.
 */

void cache_push (unsigned long paddr, int len)
{
    if (CPU_IS_040_OR_060) {
	int tmp = PAGE_SIZE;

	/*
         * on 68040 or 68060, push cache lines for pages in the range;
	 * on the '040 this also invalidates the pushed lines, but not on
	 * the '060!
	 */
	len += paddr & (PAGE_SIZE - 1);

	/*
	 * Work around bug I17 in the 68060 affecting some instruction
	 * lines not being invalidated properly.
	 */
	paddr &= PAGE_MASK;

	do {
	    pushcli040(paddr);
	    paddr += tmp;
	} while ((len -= tmp) > 0);
    }
    /*
     * 68030/68020 have no writeback cache. On the other hand,
     * cache_push is actually a superset of cache_clear (the lines
     * get written back and invalidated), so we should make sure
     * to perform the corresponding actions. After all, this is getting
     * called in places where we've just loaded code, or whatever, so
     * flushing the icache is appropriate; flushing the dcache shouldn't
     * be required.
     */
    else /* 68030 or 68020 */
	asm volatile ("movec %/cacr,%/d0\n\t"
		      "oriw %0,%/d0\n\t"
		      "movec %/d0,%/cacr"
		      : : "i" (FLUSH_I)
		      : "d0");
#ifdef CONFIG_M68K_L2_CACHE
    if(mach_l2_flush)
    	mach_l2_flush(1);
#endif
}


#undef clear040
#undef cleari040
#undef push040
#undef pushcl040
#undef pushcli040

#ifndef CONFIG_SINGLE_MEMORY_CHUNK
int mm_end_of_chunk (unsigned long addr, int len)
{
	int i;

	for (i = 0; i < m68k_num_memory; i++)
		if (m68k_memory[i].addr + m68k_memory[i].size == addr + len)
			return 1;
	return 0;
}
#endif