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linux-next/arch/powerpc/include/asm/pgtable-ppc32.h
Benjamin Herrenschmidt 8d1cf34e7a powerpc/mm: Tweak PTE bit combination definitions 
This patch tweaks the way some PTE bit combinations are defined, in such a
way that the 32 and 64-bit variant become almost identical and that will
make it easier to bring in a new common pte-* file for the new variant
of the Book3-E support.

The combination of bits defining access to kernel pages are now clearly
separated from the combination used by userspace and the core VM. The
resulting generated code should remain identical unless I made a mistake.

Note: While at it, I removed a non-sensical statement related to CONFIG_KGDB
in ppc_mmu_32.c which could cause kernel mappings to be user accessible when
that option is enabled. Probably something that bitrot.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-24 13:47:33 +11:00

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#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
#ifndef _PAGE_KERNEL_RO
#define _PAGE_KERNEL_RO 0
#endif
#ifndef _PAGE_KERNEL_RW
#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
#endif
#define _PAGE_HPTEFLAGS _PAGE_HASHPTE
/* Location of the PFN in the PTE. Most platforms use the same as _PAGE_SHIFT
* here (ie, naturally aligned). Platform who don't just pre-define the
* value so we don't override it here
*/
#ifndef PTE_RPN_SHIFT
#define PTE_RPN_SHIFT (PAGE_SHIFT)
#endif
#ifdef CONFIG_PTE_64BIT
#define PTE_RPN_MAX (1ULL << (64 - PTE_RPN_SHIFT))
#define PTE_RPN_MASK (~((1ULL<<PTE_RPN_SHIFT)-1))
#else
#define PTE_RPN_MAX (1UL << (32 - PTE_RPN_SHIFT))
#define PTE_RPN_MASK (~((1UL<<PTE_RPN_SHIFT)-1))
#endif
/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
* pgprot changes
*/
#define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
_PAGE_ACCESSED | _PAGE_SPECIAL)
/* Mask of bits returned by pte_pgprot() */
#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)
/* Permission masks used for kernel mappings */
#define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
#define PAGE_KERNEL_NC __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
_PAGE_NO_CACHE)
#define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
_PAGE_NO_CACHE | _PAGE_GUARDED)
#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
#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_KERNEL_TEXT PAGE_KERNEL_X
#else
#define PAGE_KERNEL_TEXT PAGE_KERNEL_ROX
#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)
/*
* 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.
*/
#define pte_pfn(x) (pte_val(x) >> PTE_RPN_SHIFT)
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define pfn_pte(pfn, prot) __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |\
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 */
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