linux/arch/tile/include/asm/pgtable_32.h
Chris Metcalf d5d14ed6f2 arch/tile: Allow tilegx to build with either 16K or 64K page size
This change introduces new flags for the hv_install_context()
API that passes a page table pointer to the hypervisor.  Clients
can explicitly request 4K, 16K, or 64K small pages when they
install a new context.  In practice, the page size is fixed at
kernel compile time and the same size is always requested every
time a new page table is installed.

The <hv/hypervisor.h> header changes so that it provides more abstract
macros for managing "page" things like PFNs and page tables.  For
example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old
HV_PAGE_SIZE_SMALL.  The various PFN routines have been eliminated and
only PA- or PTFN-based ones remain (since PTFNs are always expressed
in fixed 2KB "page" size).  The page-table management macros are
renamed with a leading underscore and take page-size arguments with
the presumption that clients will use those macros in some single
place to provide the "real" macros they will use themselves.

I happened to notice the old hv_set_caching() API was totally broken
(it assumed 4KB pages) so I changed it so it would nominally work
correctly with other page sizes.

Tag modules with the page size so you can't load a module built with
a conflicting page size.  (And add a test for SMP while we're at it.)

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-05-25 12:48:24 -04:00

128 lines
4.2 KiB
C

/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
*/
#ifndef _ASM_TILE_PGTABLE_32_H
#define _ASM_TILE_PGTABLE_32_H
/*
* The level-1 index is defined by the huge page size. A PGD is composed
* of PTRS_PER_PGD pgd_t's and is the top level of the page table.
*/
#define PGDIR_SHIFT HPAGE_SHIFT
#define PGDIR_SIZE HPAGE_SIZE
#define PGDIR_MASK (~(PGDIR_SIZE-1))
#define PTRS_PER_PGD _HV_L1_ENTRIES(HPAGE_SHIFT)
#define PGD_INDEX(va) _HV_L1_INDEX(va, HPAGE_SHIFT)
#define SIZEOF_PGD _HV_L1_SIZE(HPAGE_SHIFT)
/*
* The level-2 index is defined by the difference between the huge
* page size and the normal page size. A PTE is composed of
* PTRS_PER_PTE pte_t's and is the bottom level of the page table.
* Note that the hypervisor docs use PTE for what we call pte_t, so
* this nomenclature is somewhat confusing.
*/
#define PTRS_PER_PTE _HV_L2_ENTRIES(HPAGE_SHIFT, PAGE_SHIFT)
#define PTE_INDEX(va) _HV_L2_INDEX(va, HPAGE_SHIFT, PAGE_SHIFT)
#define SIZEOF_PTE _HV_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
#ifndef __ASSEMBLY__
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical
* chunk of RAM.
*
* HOWEVER, if we are using an allocation scheme with slop after the
* end of the page table (e.g. where our L2 page tables are 2KB but
* our pages are 64KB and we are allocating via the page allocator)
* we can't extend it easily.
*/
#define LAST_PKMAP PTRS_PER_PTE
#define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE*LAST_PKMAP) & PGDIR_MASK)
#ifdef CONFIG_HIGHMEM
# define __VMAPPING_END (PKMAP_BASE & ~(HPAGE_SIZE-1))
#else
# define __VMAPPING_END (FIXADDR_START & ~(HPAGE_SIZE-1))
#endif
#ifdef CONFIG_HUGEVMAP
#define HUGE_VMAP_END __VMAPPING_END
#define HUGE_VMAP_BASE (HUGE_VMAP_END - CONFIG_NR_HUGE_VMAPS * HPAGE_SIZE)
#define _VMALLOC_END HUGE_VMAP_BASE
#else
#define _VMALLOC_END __VMAPPING_END
#endif
/*
* Align the vmalloc area to an L2 page table, and leave a guard page
* at the beginning and end. The vmalloc code also puts in an internal
* guard page between each allocation.
*/
#define VMALLOC_END (_VMALLOC_END - PAGE_SIZE)
extern unsigned long VMALLOC_RESERVE /* = CONFIG_VMALLOC_RESERVE */;
#define _VMALLOC_START (_VMALLOC_END - VMALLOC_RESERVE)
#define VMALLOC_START (_VMALLOC_START + PAGE_SIZE)
/* This is the maximum possible amount of lowmem. */
#define MAXMEM (_VMALLOC_START - PAGE_OFFSET)
/* We have no pmd or pud since we are strictly a two-level page table */
#include <asm-generic/pgtable-nopmd.h>
/* We don't define any pgds for these addresses. */
static inline int pgd_addr_invalid(unsigned long addr)
{
return addr >= MEM_HV_INTRPT;
}
/*
* Provide versions of these routines that can be used safely when
* the hypervisor may be asynchronously modifying dirty/accessed bits.
* ptep_get_and_clear() matches the generic one but we provide it to
* be parallel with the 64-bit code.
*/
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
extern int ptep_test_and_clear_young(struct vm_area_struct *,
unsigned long addr, pte_t *);
extern void ptep_set_wrprotect(struct mm_struct *,
unsigned long addr, pte_t *);
#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)
{
pte_t pte = *ptep;
pte_clear(_mm, addr, ptep);
return pte;
}
/*
* pmds are wrappers around pgds, which are the same as ptes.
* It's often convenient to "cast" back and forth and use the pte methods,
* which are the methods supplied by the hypervisor.
*/
#define pmd_pte(pmd) ((pmd).pud.pgd)
#define pmdp_ptep(pmdp) (&(pmdp)->pud.pgd)
#define pte_pmd(pte) ((pmd_t){ { (pte) } })
#endif /* __ASSEMBLY__ */
#endif /* _ASM_TILE_PGTABLE_32_H */