arch/powerpc/include/asm/pgtable-ppc32.h

#ifndef _ASM_POWERPC_PGTABLE_PPC32_H
#define _ASM_POWERPC_PGTABLE_PPC32_H

#include <asm-generic/pgtable-nopmd.h>

#ifndef __ASSEMBLY__
#include <linux/sched.h>
#include <linux/threads.h>
#include <asm/io.h>			/* For sub-arch specific PPC_PIN_SIZE */

extern unsigned long va_to_phys(unsigned long address);
extern pte_t *va_to_pte(unsigned long address);
extern unsigned long ioremap_bot, ioremap_base;

#ifdef CONFIG_44x
extern int icache_44x_need_flush;
#endif

#endif /* __ASSEMBLY__ */

/*
 * The normal case is that PTEs are 32-bits and we have a 1-page
 * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
 *
 * For any >32-bit physical address platform, we can use the following
 * two level page table layout where the pgdir is 8KB and the MS 13 bits
 * are an index to the second level table.  The combined pgdir/pmd first
 * level has 2048 entries and the second level has 512 64-bit PTE entries.
 * -Matt
 */
/* PGDIR_SHIFT determines what a top-level page table entry can map */
#define PGDIR_SHIFT	(PAGE_SHIFT + PTE_SHIFT)
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))

/*
 * entries per page directory level: our page-table tree is two-level, so
 * we don't really have any PMD directory.
 */
#ifndef __ASSEMBLY__
#define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_SHIFT)
#define PGD_TABLE_SIZE	(sizeof(pgd_t) << (32 - PGDIR_SHIFT))
#endif	/* __ASSEMBLY__ */

#define PTRS_PER_PTE	(1 << PTE_SHIFT)
#define PTRS_PER_PMD	1
#define PTRS_PER_PGD	(1 << (32 - PGDIR_SHIFT))

#define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
#define FIRST_USER_ADDRESS	0

#define pte_ERROR(e) \
	printk("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
		(unsigned long long)pte_val(e))
#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))

/*
 * Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 64MB value just means that there will be a 64MB "hole" after the
 * physical memory until the kernel virtual memory starts.  That means that
 * any out-of-bounds memory accesses will hopefully be caught.
 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 * area for the same reason. ;)
 *
 * We no longer map larger than phys RAM with the BATs so we don't have
 * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
 * about clashes between our early calls to ioremap() that start growing down
 * from ioremap_base being run into the VM area allocations (growing upwards
 * from VMALLOC_START).  For this reason we have ioremap_bot to check when
 * we actually run into our mappings setup in the early boot with the VM
 * system.  This really does become a problem for machines with good amounts
 * of RAM.  -- Cort
 */
#define VMALLOC_OFFSET (0x1000000) /* 16M */
#ifdef PPC_PIN_SIZE
#define VMALLOC_START (((_ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
#else
#define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
#endif
#define VMALLOC_END	ioremap_bot

/*
 * Bits in a linux-style PTE.  These match the bits in the
 * (hardware-defined) PowerPC PTE as closely as possible.
 */

#if defined(CONFIG_40x)
#include <asm/pte-40x.h>
#elif defined(CONFIG_44x)
#include <asm/pte-44x.h>
#elif defined(CONFIG_FSL_BOOKE)
#include <asm/pte-fsl-booke.h>
#elif defined(CONFIG_8xx)
#include <asm/pte-8xx.h>
#else /* CONFIG_6xx */
#include <asm/pte-hash32.h>
#endif

/* If _PAGE_SPECIAL is defined, then we advertise our support for it */
#ifdef _PAGE_SPECIAL
#define __HAVE_ARCH_PTE_SPECIAL
#endif

/*
 * Some bits are only used on some cpu families... Make sure that all
 * the undefined gets defined as 0
 */
#ifndef _PAGE_HASHPTE
#define _PAGE_HASHPTE	0
#endif
#ifndef _PTE_NONE_MASK
#define _PTE_NONE_MASK 0
#endif
#ifndef _PAGE_SHARED
#define _PAGE_SHARED	0
#endif
#ifndef _PAGE_HWWRITE
#define _PAGE_HWWRITE	0
#endif
#ifndef _PAGE_HWEXEC
#define _PAGE_HWEXEC	0
#endif
#ifndef _PAGE_EXEC
#define _PAGE_EXEC	0
#endif
#ifndef _PAGE_ENDIAN
#define _PAGE_ENDIAN	0
#endif
#ifndef _PAGE_COHERENT
#define _PAGE_COHERENT	0
#endif
#ifndef _PAGE_WRITETHRU
#define _PAGE_WRITETHRU	0
#endif
#ifndef _PAGE_SPECIAL
#define _PAGE_SPECIAL	0
#endif
#ifndef _PMD_PRESENT_MASK
#define _PMD_PRESENT_MASK	_PMD_PRESENT
#endif
#ifndef _PMD_SIZE
#define _PMD_SIZE	0
#define PMD_PAGE_SIZE(pmd)	bad_call_to_PMD_PAGE_SIZE()
#endif

#define _PAGE_HPTEFLAGS _PAGE_HASHPTE

#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | \
			 _PAGE_SPECIAL)

#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
			 _PAGE_WRITETHRU | _PAGE_ENDIAN | \
			 _PAGE_USER | _PAGE_ACCESSED | \
			 _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \
			 _PAGE_EXEC | _PAGE_HWEXEC)

/*
 * We define 2 sets of base prot bits, one for basic pages (ie,
 * cacheable kernel and user pages) and one for non cacheable
 * pages. We always set _PAGE_COHERENT when SMP is enabled or
 * the processor might need it for DMA coherency.
 */
#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
#else
#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED)
#endif
#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE)

#define _PAGE_WRENABLE	(_PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE)
#define _PAGE_KERNEL	(_PAGE_BASE | _PAGE_SHARED | _PAGE_WRENABLE)
#define _PAGE_KERNEL_NC	(_PAGE_BASE_NC | _PAGE_SHARED | _PAGE_WRENABLE)

#ifdef CONFIG_PPC_STD_MMU
/* On standard PPC MMU, no user access implies kernel read/write access,
 * so to write-protect kernel memory we must turn on user access */
#define _PAGE_KERNEL_RO	(_PAGE_BASE | _PAGE_SHARED | _PAGE_USER)
#else
#define _PAGE_KERNEL_RO	(_PAGE_BASE | _PAGE_SHARED)
#endif

#define _PAGE_IO	(_PAGE_KERNEL_NC | _PAGE_GUARDED)
#define _PAGE_RAM	(_PAGE_KERNEL | _PAGE_HWEXEC)

#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
	defined(CONFIG_KPROBES)
/* We want the debuggers to be able to set breakpoints anywhere, so
 * don't write protect the kernel text */
#define _PAGE_RAM_TEXT	_PAGE_RAM
#else
#define _PAGE_RAM_TEXT	(_PAGE_KERNEL_RO | _PAGE_HWEXEC)
#endif

#define PAGE_NONE	__pgprot(_PAGE_BASE)
#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)

#define PAGE_KERNEL		__pgprot(_PAGE_RAM)
#define PAGE_KERNEL_NOCACHE	__pgprot(_PAGE_IO)

/*
 * The PowerPC can only do execute protection on a segment (256MB) basis,
 * not on a page basis.  So we consider execute permission the same as read.
 * Also, write permissions imply read permissions.
 * This is the closest we can get..
 */
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY_X
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY_X
#define __P100	PAGE_READONLY
#define __P101	PAGE_READONLY_X
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY_X

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY_X
#define __S010	PAGE_SHARED
#define __S011	PAGE_SHARED_X
#define __S100	PAGE_READONLY
#define __S101	PAGE_READONLY_X
#define __S110	PAGE_SHARED
#define __S111	PAGE_SHARED_X

#ifndef __ASSEMBLY__
/* Make sure we get a link error if PMD_PAGE_SIZE is ever called on a
 * kernel without large page PMD support */
extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);

/*
 * Conversions between PTE values and page frame numbers.
 */

/* in some case we want to additionaly adjust where the pfn is in the pte to
 * allow room for more flags */
#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
#define PFN_SHIFT_OFFSET	(PAGE_SHIFT + 8)
#else
#define PFN_SHIFT_OFFSET	(PAGE_SHIFT)
#endif

#define pte_pfn(x)		(pte_val(x) >> PFN_SHIFT_OFFSET)
#define pte_page(x)		pfn_to_page(pte_pfn(x))

#define pfn_pte(pfn, prot)	__pte(((pte_basic_t)(pfn) << PFN_SHIFT_OFFSET) |\
					pgprot_val(prot))
#define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
#endif /* __ASSEMBLY__ */

#define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
#define pte_clear(mm, addr, ptep) \
	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)

#define pmd_none(pmd)		(!pmd_val(pmd))
#define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
#define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
#define	pmd_clear(pmdp)		do { pmd_val(*(pmdp)) = 0; } while (0)

#ifndef __ASSEMBLY__
/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }

static inline pte_t pte_wrprotect(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_mkclean(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_mkold(pte_t pte) {
	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }

static inline pte_t pte_mkwrite(pte_t pte) {
	pte_val(pte) |= _PAGE_RW; return pte; }
static inline pte_t pte_mkdirty(pte_t pte) {
	pte_val(pte) |= _PAGE_DIRTY; return pte; }
static inline pte_t pte_mkyoung(pte_t pte) {
	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
static inline pte_t pte_mkspecial(pte_t pte) {
	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
static inline pgprot_t pte_pgprot(pte_t pte)
{
	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
}

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
	return pte;
}

/*
 * When flushing the tlb entry for a page, we also need to flush the hash
 * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
 */
extern int flush_hash_pages(unsigned context, unsigned long va,
			    unsigned long pmdval, int count);

/* Add an HPTE to the hash table */
extern void add_hash_page(unsigned context, unsigned long va,
			  unsigned long pmdval);

/* Flush an entry from the TLB/hash table */
extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
			     unsigned long address);

/*
 * PTE updates. This function is called whenever an existing
 * valid PTE is updated. This does -not- include set_pte_at()
 * which nowadays only sets a new PTE.
 *
 * Depending on the type of MMU, we may need to use atomic updates
 * and the PTE may be either 32 or 64 bit wide. In the later case,
 * when using atomic updates, only the low part of the PTE is
 * accessed atomically.
 *
 * In addition, on 44x, we also maintain a global flag indicating
 * that an executable user mapping was modified, which is needed
 * to properly flush the virtually tagged instruction cache of
 * those implementations.
 */
#ifndef CONFIG_PTE_64BIT
static inline unsigned long pte_update(pte_t *p,
				       unsigned long clr,
				       unsigned long set)
{
#ifdef PTE_ATOMIC_UPDATES
	unsigned long old, tmp;

	__asm__ __volatile__("\
1:	lwarx	%0,0,%3\n\
	andc	%1,%0,%4\n\
	or	%1,%1,%5\n"
	PPC405_ERR77(0,%3)
"	stwcx.	%1,0,%3\n\
	bne-	1b"
	: "=&r" (old), "=&r" (tmp), "=m" (*p)
	: "r" (p), "r" (clr), "r" (set), "m" (*p)
	: "cc" );
#else /* PTE_ATOMIC_UPDATES */
	unsigned long old = pte_val(*p);
	*p = __pte((old & ~clr) | set);
#endif /* !PTE_ATOMIC_UPDATES */

#ifdef CONFIG_44x
	if ((old & _PAGE_USER) && (old & _PAGE_HWEXEC))
		icache_44x_need_flush = 1;
#endif
	return old;
}
#else /* CONFIG_PTE_64BIT */
static inline unsigned long long pte_update(pte_t *p,
					    unsigned long clr,
					    unsigned long set)
{
#ifdef PTE_ATOMIC_UPDATES
	unsigned long long old;
	unsigned long tmp;

	__asm__ __volatile__("\
1:	lwarx	%L0,0,%4\n\
	lwzx	%0,0,%3\n\
	andc	%1,%L0,%5\n\
	or	%1,%1,%6\n"
	PPC405_ERR77(0,%3)
"	stwcx.	%1,0,%4\n\
	bne-	1b"
	: "=&r" (old), "=&r" (tmp), "=m" (*p)
	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
	: "cc" );
#else /* PTE_ATOMIC_UPDATES */
	unsigned long long old = pte_val(*p);
	*p = __pte((old & ~(unsigned long long)clr) | set);
#endif /* !PTE_ATOMIC_UPDATES */

#ifdef CONFIG_44x
	if ((old & _PAGE_USER) && (old & _PAGE_HWEXEC))
		icache_44x_need_flush = 1;
#endif
	return old;
}
#endif /* CONFIG_PTE_64BIT */

/*
 * 2.6 calls this without flushing the TLB entry; this is wrong
 * for our hash-based implementation, we fix that up here.
 */
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
{
	unsigned long old;
	old = pte_update(ptep, _PAGE_ACCESSED, 0);
#if _PAGE_HASHPTE != 0
	if (old & _PAGE_HASHPTE) {
		unsigned long ptephys = __pa(ptep) & PAGE_MASK;
		flush_hash_pages(context, addr, ptephys, 1);
	}
#endif
	return (old & _PAGE_ACCESSED) != 0;
}
#define ptep_test_and_clear_young(__vma, __addr, __ptep) \
	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
				       pte_t *ptep)
{
	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
}

#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
				      pte_t *ptep)
{
	pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), 0);
}
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
					   unsigned long addr, pte_t *ptep)
{
	ptep_set_wrprotect(mm, addr, ptep);
}


static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
{
	unsigned long bits = pte_val(entry) &
		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW |
		 _PAGE_HWEXEC | _PAGE_EXEC);
	pte_update(ptep, 0, bits);
}

#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)

/*
 * Note that on Book E processors, the pmd contains the kernel virtual
 * (lowmem) address of the pte page.  The physical address is less useful
 * because everything runs with translation enabled (even the TLB miss
 * handler).  On everything else the pmd contains the physical address
 * of the pte page.  -- paulus
 */
#ifndef CONFIG_BOOKE
#define pmd_page_vaddr(pmd)	\
	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
#define pmd_page(pmd)		\
	(mem_map + (pmd_val(pmd) >> PAGE_SHIFT))
#else
#define pmd_page_vaddr(pmd)	\
	((unsigned long) (pmd_val(pmd) & PAGE_MASK))
#define pmd_page(pmd)		\
	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
#endif

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

/* to find an entry in a page-table-directory */
#define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
#define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))

/* Find an entry in the third-level page table.. */
#define pte_index(address)		\
	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir, addr)	\
	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
#define pte_offset_map(dir, addr)		\
	((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE0) + pte_index(addr))
#define pte_offset_map_nested(dir, addr)	\
	((pte_t *) kmap_atomic(pmd_page(*(dir)), KM_PTE1) + pte_index(addr))

#define pte_unmap(pte)		kunmap_atomic(pte, KM_PTE0)
#define pte_unmap_nested(pte)	kunmap_atomic(pte, KM_PTE1)

/*
 * Encode and decode a swap entry.
 * Note that the bits we use in a PTE for representing a swap entry
 * must not include the _PAGE_PRESENT bit, the _PAGE_FILE bit, or the
 *_PAGE_HASHPTE bit (if used).  -- paulus
 */
#define __swp_type(entry)		((entry).val & 0x1f)
#define __swp_offset(entry)		((entry).val >> 5)
#define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
#define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })

/* Encode and decode a nonlinear file mapping entry */
#define PTE_FILE_MAX_BITS	29
#define pte_to_pgoff(pte)	(pte_val(pte) >> 3)
#define pgoff_to_pte(off)	((pte_t) { ((off) << 3) | _PAGE_FILE })

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()	do { } while (0)

extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,
		      pmd_t **pmdp);

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_POWERPC_PGTABLE_PPC32_H */