/*
   *  linux/arch/m68k/mm/kmap.c
   *
   *  Copyright (C) 1997 Roman Hodek
   *
   *  10/01/99 cleaned up the code and changing to the same interface
   *	     used by other architectures		/Roman Zippel
   */
  
  #include <linux/module.h>
  #include <linux/mm.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  
  #include <asm/setup.h>
  #include <asm/segment.h>
  #include <asm/page.h>
  #include <asm/pgalloc.h>
  #include <asm/io.h>
  
  #undef DEBUG
  
  #define PTRTREESIZE	(256*1024)
  
  /*
   * For 040/060 we can use the virtual memory area like other architectures,
   * but for 020/030 we want to use early termination page descriptors and we
   * can't mix this with normal page descriptors, so we have to copy that code
   * (mm/vmalloc.c) and return appropriately aligned addresses.
   */
  
  #ifdef CPU_M68040_OR_M68060_ONLY
  
  #define IO_SIZE		PAGE_SIZE
  
  static inline struct vm_struct *get_io_area(unsigned long size)
  {
  	return get_vm_area(size, VM_IOREMAP);
  }
  
  
  static inline void free_io_area(void *addr)
  {
  	vfree((void *)(PAGE_MASK & (unsigned long)addr));
  }
  
  #else
  
  #define IO_SIZE		(256*1024)
  
  static struct vm_struct *iolist;
  
  static struct vm_struct *get_io_area(unsigned long size)
  {
  	unsigned long addr;
  	struct vm_struct **p, *tmp, *area;
  
  	area = kmalloc(sizeof(*area), GFP_KERNEL);
  	if (!area)
  		return NULL;
  	addr = KMAP_START;
  	for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
  		if (size + addr < (unsigned long)tmp->addr)
  			break;
  		if (addr > KMAP_END-size) {
  			kfree(area);
  			return NULL;
  		}
  		addr = tmp->size + (unsigned long)tmp->addr;
  	}
  	area->addr = (void *)addr;
  	area->size = size + IO_SIZE;
  	area->next = *p;
  	*p = area;
  	return area;
  }
  
  static inline void free_io_area(void *addr)
  {
  	struct vm_struct **p, *tmp;
  
  	if (!addr)
  		return;
  	addr = (void *)((unsigned long)addr & -IO_SIZE);
  	for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  		if (tmp->addr == addr) {
  			*p = tmp->next;
  			__iounmap(tmp->addr, tmp->size);
  			kfree(tmp);
  			return;
  		}
  	}
  }
  
  #endif
  
  /*
   * Map some physical address range into the kernel address space.
   */
  /* Rewritten by Andreas Schwab to remove all races. */
  
  void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
  {
  	struct vm_struct *area;
  	unsigned long virtaddr, retaddr;
  	long offset;
  	pgd_t *pgd_dir;
  	pmd_t *pmd_dir;
  	pte_t *pte_dir;
  
  	/*
  	 * Don't allow mappings that wrap..
  	 */
  	if (!size || physaddr > (unsigned long)(-size))
  		return NULL;
  
  #ifdef CONFIG_AMIGA
  	if (MACH_IS_AMIGA) {
  		if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
  		    && (cacheflag == IOMAP_NOCACHE_SER))
  			return (void __iomem *)physaddr;
  	}
  #endif
  
  #ifdef DEBUG
  	printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
  #endif
  	/*
  	 * Mappings have to be aligned
  	 */
  	offset = physaddr & (IO_SIZE - 1);
  	physaddr &= -IO_SIZE;
  	size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
  
  	/*
  	 * Ok, go for it..
  	 */
  	area = get_io_area(size);
  	if (!area)
  		return NULL;
  
  	virtaddr = (unsigned long)area->addr;
  	retaddr = virtaddr + offset;
  #ifdef DEBUG
  	printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
  #endif
  
  	/*
  	 * add cache and table flags to physical address
  	 */
  	if (CPU_IS_040_OR_060) {
  		physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
  			     _PAGE_ACCESSED | _PAGE_DIRTY);
  		switch (cacheflag) {
  		case IOMAP_FULL_CACHING:
  			physaddr |= _PAGE_CACHE040;
  			break;
  		case IOMAP_NOCACHE_SER:
  		default:
  			physaddr |= _PAGE_NOCACHE_S;
  			break;
  		case IOMAP_NOCACHE_NONSER:
  			physaddr |= _PAGE_NOCACHE;
  			break;
  		case IOMAP_WRITETHROUGH:
  			physaddr |= _PAGE_CACHE040W;
  			break;
  		}
  	} else {
  		physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
  			     _PAGE_DIRTY | _PAGE_READWRITE);
  		switch (cacheflag) {
  		case IOMAP_NOCACHE_SER:
  		case IOMAP_NOCACHE_NONSER:
  		default:
  			physaddr |= _PAGE_NOCACHE030;
  			break;
  		case IOMAP_FULL_CACHING:
  		case IOMAP_WRITETHROUGH:
  			break;
  		}
  	}
  
  	while ((long)size > 0) {
  #ifdef DEBUG
  		if (!(virtaddr & (PTRTREESIZE-1)))
  			printk ("
  pa=%#lx va=%#lx ", physaddr, virtaddr);
  #endif
  		pgd_dir = pgd_offset_k(virtaddr);
  		pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
  		if (!pmd_dir) {
  			printk("ioremap: no mem for pmd_dir
  ");
  			return NULL;
  		}
  
  		if (CPU_IS_020_OR_030) {
  			pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
  			physaddr += PTRTREESIZE;
  			virtaddr += PTRTREESIZE;
  			size -= PTRTREESIZE;
  		} else {
  			pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
  			if (!pte_dir) {
  				printk("ioremap: no mem for pte_dir
  ");
  				return NULL;
  			}
  
  			pte_val(*pte_dir) = physaddr;
  			virtaddr += PAGE_SIZE;
  			physaddr += PAGE_SIZE;
  			size -= PAGE_SIZE;
  		}
  	}
  #ifdef DEBUG
  	printk("
  ");
  #endif
  	flush_tlb_all();
  
  	return (void __iomem *)retaddr;
  }
  EXPORT_SYMBOL(__ioremap);
  
  /*
   * Unmap an ioremap()ed region again
   */
  void iounmap(void __iomem *addr)
  {
  #ifdef CONFIG_AMIGA
  	if ((!MACH_IS_AMIGA) ||
  	    (((unsigned long)addr < 0x40000000) ||
  	     ((unsigned long)addr > 0x60000000)))
  			free_io_area((__force void *)addr);
  #else
  	free_io_area((__force void *)addr);
  #endif
  }
  EXPORT_SYMBOL(iounmap);
  
  /*
   * __iounmap unmaps nearly everything, so be careful
   * Currently it doesn't free pointer/page tables anymore but this
   * wasn't used anyway and might be added later.
   */
  void __iounmap(void *addr, unsigned long size)
  {
  	unsigned long virtaddr = (unsigned long)addr;
  	pgd_t *pgd_dir;
  	pmd_t *pmd_dir;
  	pte_t *pte_dir;
  
  	while ((long)size > 0) {
  		pgd_dir = pgd_offset_k(virtaddr);
  		if (pgd_bad(*pgd_dir)) {
  			printk("iounmap: bad pgd(%08lx)
  ", pgd_val(*pgd_dir));
  			pgd_clear(pgd_dir);
  			return;
  		}
  		pmd_dir = pmd_offset(pgd_dir, virtaddr);
  
  		if (CPU_IS_020_OR_030) {
  			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
  			int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
  
  			if (pmd_type == _PAGE_PRESENT) {
  				pmd_dir->pmd[pmd_off] = 0;
  				virtaddr += PTRTREESIZE;
  				size -= PTRTREESIZE;
  				continue;
  			} else if (pmd_type == 0)
  				continue;
  		}
  
  		if (pmd_bad(*pmd_dir)) {
  			printk("iounmap: bad pmd (%08lx)
  ", pmd_val(*pmd_dir));
  			pmd_clear(pmd_dir);
  			return;
  		}
  		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
  
  		pte_val(*pte_dir) = 0;
  		virtaddr += PAGE_SIZE;
  		size -= PAGE_SIZE;
  	}
  
  	flush_tlb_all();
  }
  
  /*
   * Set new cache mode for some kernel address space.
   * The caller must push data for that range itself, if such data may already
   * be in the cache.
   */
  void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
  {
  	unsigned long virtaddr = (unsigned long)addr;
  	pgd_t *pgd_dir;
  	pmd_t *pmd_dir;
  	pte_t *pte_dir;
  
  	if (CPU_IS_040_OR_060) {
  		switch (cmode) {
  		case IOMAP_FULL_CACHING:
  			cmode = _PAGE_CACHE040;
  			break;
  		case IOMAP_NOCACHE_SER:
  		default:
  			cmode = _PAGE_NOCACHE_S;
  			break;
  		case IOMAP_NOCACHE_NONSER:
  			cmode = _PAGE_NOCACHE;
  			break;
  		case IOMAP_WRITETHROUGH:
  			cmode = _PAGE_CACHE040W;
  			break;
  		}
  	} else {
  		switch (cmode) {
  		case IOMAP_NOCACHE_SER:
  		case IOMAP_NOCACHE_NONSER:
  		default:
  			cmode = _PAGE_NOCACHE030;
  			break;
  		case IOMAP_FULL_CACHING:
  		case IOMAP_WRITETHROUGH:
  			cmode = 0;
  		}
  	}
  
  	while ((long)size > 0) {
  		pgd_dir = pgd_offset_k(virtaddr);
  		if (pgd_bad(*pgd_dir)) {
  			printk("iocachemode: bad pgd(%08lx)
  ", pgd_val(*pgd_dir));
  			pgd_clear(pgd_dir);
  			return;
  		}
  		pmd_dir = pmd_offset(pgd_dir, virtaddr);
  
  		if (CPU_IS_020_OR_030) {
  			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
  
  			if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
  				pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
  							 _CACHEMASK040) | cmode;
  				virtaddr += PTRTREESIZE;
  				size -= PTRTREESIZE;
  				continue;
  			}
  		}
  
  		if (pmd_bad(*pmd_dir)) {
  			printk("iocachemode: bad pmd (%08lx)
  ", pmd_val(*pmd_dir));
  			pmd_clear(pmd_dir);
  			return;
  		}
  		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
  
  		pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
  		virtaddr += PAGE_SIZE;
  		size -= PAGE_SIZE;
  	}
  
  	flush_tlb_all();
  }
  EXPORT_SYMBOL(kernel_set_cachemode);