421 lines
12 KiB
C
421 lines
12 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Page table support for the Hexagon architecture
|
|
*
|
|
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
|
|
*/
|
|
|
|
#ifndef _ASM_PGTABLE_H
|
|
#define _ASM_PGTABLE_H
|
|
|
|
/*
|
|
* Page table definitions for Qualcomm Hexagon processor.
|
|
*/
|
|
#include <asm/page.h>
|
|
#include <asm-generic/pgtable-nopmd.h>
|
|
|
|
/* A handy thing to have if one has the RAM. Declared in head.S */
|
|
extern unsigned long empty_zero_page;
|
|
|
|
/*
|
|
* The PTE model described here is that of the Hexagon Virtual Machine,
|
|
* which autonomously walks 2-level page tables. At a lower level, we
|
|
* also describe the RISCish software-loaded TLB entry structure of
|
|
* the underlying Hexagon processor. A kernel built to run on the
|
|
* virtual machine has no need to know about the underlying hardware.
|
|
*/
|
|
#include <asm/vm_mmu.h>
|
|
|
|
/*
|
|
* To maximize the comfort level for the PTE manipulation macros,
|
|
* define the "well known" architecture-specific bits.
|
|
*/
|
|
#define _PAGE_READ __HVM_PTE_R
|
|
#define _PAGE_WRITE __HVM_PTE_W
|
|
#define _PAGE_EXECUTE __HVM_PTE_X
|
|
#define _PAGE_USER __HVM_PTE_U
|
|
|
|
/*
|
|
* We have a total of 4 "soft" bits available in the abstract PTE.
|
|
* The two mandatory software bits are Dirty and Accessed.
|
|
* To make nonlinear swap work according to the more recent
|
|
* model, we want a low order "Present" bit to indicate whether
|
|
* the PTE describes MMU programming or swap space.
|
|
*/
|
|
#define _PAGE_PRESENT (1<<0)
|
|
#define _PAGE_DIRTY (1<<1)
|
|
#define _PAGE_ACCESSED (1<<2)
|
|
|
|
/*
|
|
* For now, let's say that Valid and Present are the same thing.
|
|
* Alternatively, we could say that it's the "or" of R, W, and X
|
|
* permissions.
|
|
*/
|
|
#define _PAGE_VALID _PAGE_PRESENT
|
|
|
|
/*
|
|
* We're not defining _PAGE_GLOBAL here, since there's no concept
|
|
* of global pages or ASIDs exposed to the Hexagon Virtual Machine,
|
|
* and we want to use the same page table structures and macros in
|
|
* the native kernel as we do in the virtual machine kernel.
|
|
* So we'll put up with a bit of inefficiency for now...
|
|
*/
|
|
|
|
/*
|
|
* Top "FOURTH" level (pgd), which for the Hexagon VM is really
|
|
* only the second from the bottom, pgd and pud both being collapsed.
|
|
* Each entry represents 4MB of virtual address space, 4K of table
|
|
* thus maps the full 4GB.
|
|
*/
|
|
#define PGDIR_SHIFT 22
|
|
#define PTRS_PER_PGD 1024
|
|
|
|
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
|
|
#define PGDIR_MASK (~(PGDIR_SIZE-1))
|
|
|
|
#ifdef CONFIG_PAGE_SIZE_4KB
|
|
#define PTRS_PER_PTE 1024
|
|
#endif
|
|
|
|
#ifdef CONFIG_PAGE_SIZE_16KB
|
|
#define PTRS_PER_PTE 256
|
|
#endif
|
|
|
|
#ifdef CONFIG_PAGE_SIZE_64KB
|
|
#define PTRS_PER_PTE 64
|
|
#endif
|
|
|
|
#ifdef CONFIG_PAGE_SIZE_256KB
|
|
#define PTRS_PER_PTE 16
|
|
#endif
|
|
|
|
#ifdef CONFIG_PAGE_SIZE_1MB
|
|
#define PTRS_PER_PTE 4
|
|
#endif
|
|
|
|
/* Any bigger and the PTE disappears. */
|
|
#define pgd_ERROR(e) \
|
|
printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__,\
|
|
pgd_val(e))
|
|
|
|
/*
|
|
* Page Protection Constants. Includes (in this variant) cache attributes.
|
|
*/
|
|
extern unsigned long _dflt_cache_att;
|
|
|
|
#define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_dflt_cache_att)
|
|
#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_READ | _PAGE_EXECUTE | _dflt_cache_att)
|
|
#define PAGE_COPY PAGE_READONLY
|
|
#define PAGE_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_READ | _PAGE_EXECUTE | _dflt_cache_att)
|
|
#define PAGE_COPY_EXEC PAGE_EXEC
|
|
#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
|
|
_PAGE_EXECUTE | _PAGE_WRITE | _dflt_cache_att)
|
|
#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_READ | \
|
|
_PAGE_WRITE | _PAGE_EXECUTE | _dflt_cache_att)
|
|
|
|
|
|
/*
|
|
* Aliases for mapping mmap() protection bits to page protections.
|
|
* These get used for static initialization, so using the _dflt_cache_att
|
|
* variable for the default cache attribute isn't workable. If the
|
|
* default gets changed at boot time, the boot option code has to
|
|
* update data structures like the protaction_map[] array.
|
|
*/
|
|
#define CACHEDEF (CACHE_DEFAULT << 6)
|
|
|
|
/* Private (copy-on-write) page protections. */
|
|
#define __P000 __pgprot(_PAGE_PRESENT | _PAGE_USER | CACHEDEF)
|
|
#define __P001 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | CACHEDEF)
|
|
#define __P010 __P000 /* Write-only copy-on-write */
|
|
#define __P011 __P001 /* Read/Write copy-on-write */
|
|
#define __P100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_EXECUTE | CACHEDEF)
|
|
#define __P101 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_EXECUTE | \
|
|
_PAGE_READ | CACHEDEF)
|
|
#define __P110 __P100 /* Write/execute copy-on-write */
|
|
#define __P111 __P101 /* Read/Write/Execute, copy-on-write */
|
|
|
|
/* Shared page protections. */
|
|
#define __S000 __P000
|
|
#define __S001 __P001
|
|
#define __S010 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_WRITE | CACHEDEF)
|
|
#define __S011 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
|
|
_PAGE_WRITE | CACHEDEF)
|
|
#define __S100 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_EXECUTE | CACHEDEF)
|
|
#define __S101 __P101
|
|
#define __S110 __pgprot(_PAGE_PRESENT | _PAGE_USER | \
|
|
_PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
|
|
#define __S111 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | \
|
|
_PAGE_EXECUTE | _PAGE_WRITE | CACHEDEF)
|
|
|
|
extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* located in head.S */
|
|
|
|
/* HUGETLB not working currently */
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
#define pte_mkhuge(pte) __pte((pte_val(pte) & ~0x3) | HVM_HUGEPAGE_SIZE)
|
|
#endif
|
|
|
|
/*
|
|
* For now, assume that higher-level code will do TLB/MMU invalidations
|
|
* and don't insert that overhead into this low-level function.
|
|
*/
|
|
extern void sync_icache_dcache(pte_t pte);
|
|
|
|
#define pte_present_exec_user(pte) \
|
|
((pte_val(pte) & (_PAGE_EXECUTE | _PAGE_USER)) == \
|
|
(_PAGE_EXECUTE | _PAGE_USER))
|
|
|
|
static inline void set_pte(pte_t *ptep, pte_t pteval)
|
|
{
|
|
/* should really be using pte_exec, if it weren't declared later. */
|
|
if (pte_present_exec_user(pteval))
|
|
sync_icache_dcache(pteval);
|
|
|
|
*ptep = pteval;
|
|
}
|
|
|
|
/*
|
|
* For the Hexagon Virtual Machine MMU (or its emulation), a null/invalid
|
|
* L1 PTE (PMD/PGD) has 7 in the least significant bits. For the L2 PTE
|
|
* (Linux PTE), the key is to have bits 11..9 all zero. We'd use 0x7
|
|
* as a universal null entry, but some of those least significant bits
|
|
* are interpreted by software.
|
|
*/
|
|
#define _NULL_PMD 0x7
|
|
#define _NULL_PTE 0x0
|
|
|
|
static inline void pmd_clear(pmd_t *pmd_entry_ptr)
|
|
{
|
|
pmd_val(*pmd_entry_ptr) = _NULL_PMD;
|
|
}
|
|
|
|
/*
|
|
* Conveniently, a null PTE value is invalid.
|
|
*/
|
|
static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
pte_val(*ptep) = _NULL_PTE;
|
|
}
|
|
|
|
/**
|
|
* pmd_none - check if pmd_entry is mapped
|
|
* @pmd_entry: pmd entry
|
|
*
|
|
* MIPS checks it against that "invalid pte table" thing.
|
|
*/
|
|
static inline int pmd_none(pmd_t pmd)
|
|
{
|
|
return pmd_val(pmd) == _NULL_PMD;
|
|
}
|
|
|
|
/**
|
|
* pmd_present - is there a page table behind this?
|
|
* Essentially the inverse of pmd_none. We maybe
|
|
* save an inline instruction by defining it this
|
|
* way, instead of simply "!pmd_none".
|
|
*/
|
|
static inline int pmd_present(pmd_t pmd)
|
|
{
|
|
return pmd_val(pmd) != (unsigned long)_NULL_PMD;
|
|
}
|
|
|
|
/**
|
|
* pmd_bad - check if a PMD entry is "bad". That might mean swapped out.
|
|
* As we have no known cause of badness, it's null, as it is for many
|
|
* architectures.
|
|
*/
|
|
static inline int pmd_bad(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* pmd_pfn - converts a PMD entry to a page frame number
|
|
*/
|
|
#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
|
|
|
|
/*
|
|
* pmd_page - converts a PMD entry to a page pointer
|
|
*/
|
|
#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
|
|
|
|
/**
|
|
* pte_none - check if pte is mapped
|
|
* @pte: pte_t entry
|
|
*/
|
|
static inline int pte_none(pte_t pte)
|
|
{
|
|
return pte_val(pte) == _NULL_PTE;
|
|
};
|
|
|
|
/*
|
|
* pte_present - check if page is present
|
|
*/
|
|
static inline int pte_present(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_PRESENT;
|
|
}
|
|
|
|
/* mk_pte - make a PTE out of a page pointer and protection bits */
|
|
#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
|
|
|
|
/* pte_page - returns a page (frame pointer/descriptor?) based on a PTE */
|
|
#define pte_page(x) pfn_to_page(pte_pfn(x))
|
|
|
|
/* pte_mkold - mark PTE as not recently accessed */
|
|
static inline pte_t pte_mkold(pte_t pte)
|
|
{
|
|
pte_val(pte) &= ~_PAGE_ACCESSED;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_mkyoung - mark PTE as recently accessed */
|
|
static inline pte_t pte_mkyoung(pte_t pte)
|
|
{
|
|
pte_val(pte) |= _PAGE_ACCESSED;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_mkclean - mark page as in sync with backing store */
|
|
static inline pte_t pte_mkclean(pte_t pte)
|
|
{
|
|
pte_val(pte) &= ~_PAGE_DIRTY;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_mkdirty - mark page as modified */
|
|
static inline pte_t pte_mkdirty(pte_t pte)
|
|
{
|
|
pte_val(pte) |= _PAGE_DIRTY;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_young - "is PTE marked as accessed"? */
|
|
static inline int pte_young(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_ACCESSED;
|
|
}
|
|
|
|
/* pte_dirty - "is PTE dirty?" */
|
|
static inline int pte_dirty(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_DIRTY;
|
|
}
|
|
|
|
/* pte_modify - set protection bits on PTE */
|
|
static inline pte_t pte_modify(pte_t pte, pgprot_t prot)
|
|
{
|
|
pte_val(pte) &= PAGE_MASK;
|
|
pte_val(pte) |= pgprot_val(prot);
|
|
return pte;
|
|
}
|
|
|
|
/* pte_wrprotect - mark page as not writable */
|
|
static inline pte_t pte_wrprotect(pte_t pte)
|
|
{
|
|
pte_val(pte) &= ~_PAGE_WRITE;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_mkwrite - mark page as writable */
|
|
static inline pte_t pte_mkwrite(pte_t pte)
|
|
{
|
|
pte_val(pte) |= _PAGE_WRITE;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_mkexec - mark PTE as executable */
|
|
static inline pte_t pte_mkexec(pte_t pte)
|
|
{
|
|
pte_val(pte) |= _PAGE_EXECUTE;
|
|
return pte;
|
|
}
|
|
|
|
/* pte_read - "is PTE marked as readable?" */
|
|
static inline int pte_read(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_READ;
|
|
}
|
|
|
|
/* pte_write - "is PTE marked as writable?" */
|
|
static inline int pte_write(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_WRITE;
|
|
}
|
|
|
|
|
|
/* pte_exec - "is PTE marked as executable?" */
|
|
static inline int pte_exec(pte_t pte)
|
|
{
|
|
return pte_val(pte) & _PAGE_EXECUTE;
|
|
}
|
|
|
|
/* __pte_to_swp_entry - extract swap entry from PTE */
|
|
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
|
|
|
|
/* __swp_entry_to_pte - extract PTE from swap entry */
|
|
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
|
|
|
|
/* pfn_pte - convert page number and protection value to page table entry */
|
|
#define pfn_pte(pfn, pgprot) __pte((pfn << PAGE_SHIFT) | pgprot_val(pgprot))
|
|
|
|
/* pte_pfn - convert pte to page frame number */
|
|
#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
|
|
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
|
|
|
|
/*
|
|
* set_pte_at - update page table and do whatever magic may be
|
|
* necessary to make the underlying hardware/firmware take note.
|
|
*
|
|
* VM may require a virtual instruction to alert the MMU.
|
|
*/
|
|
#define set_pte_at(mm, addr, ptep, pte) set_pte(ptep, pte)
|
|
|
|
static inline unsigned long pmd_page_vaddr(pmd_t pmd)
|
|
{
|
|
return (unsigned long)__va(pmd_val(pmd) & PAGE_MASK);
|
|
}
|
|
|
|
/* ZERO_PAGE - returns the globally shared zero page */
|
|
#define ZERO_PAGE(vaddr) (virt_to_page(&empty_zero_page))
|
|
|
|
/*
|
|
* Swap/file PTE definitions. If _PAGE_PRESENT is zero, the rest of the PTE is
|
|
* interpreted as swap information. The remaining free bits are interpreted as
|
|
* swap type/offset tuple. Rather than have the TLB fill handler test
|
|
* _PAGE_PRESENT, we're going to reserve the permissions bits and set them to
|
|
* all zeros for swap entries, which speeds up the miss handler at the cost of
|
|
* 3 bits of offset. That trade-off can be revisited if necessary, but Hexagon
|
|
* processor architecture and target applications suggest a lot of TLB misses
|
|
* and not much swap space.
|
|
*
|
|
* Format of swap PTE:
|
|
* bit 0: Present (zero)
|
|
* bits 1-5: swap type (arch independent layer uses 5 bits max)
|
|
* bits 6-9: bits 3:0 of offset
|
|
* bits 10-12: effectively _PAGE_PROTNONE (all zero)
|
|
* bits 13-31: bits 22:4 of swap offset
|
|
*
|
|
* The split offset makes some of the following macros a little gnarly,
|
|
* but there's plenty of precedent for this sort of thing.
|
|
*/
|
|
|
|
/* Used for swap PTEs */
|
|
#define __swp_type(swp_pte) (((swp_pte).val >> 1) & 0x1f)
|
|
|
|
#define __swp_offset(swp_pte) \
|
|
((((swp_pte).val >> 6) & 0xf) | (((swp_pte).val >> 9) & 0x7ffff0))
|
|
|
|
#define __swp_entry(type, offset) \
|
|
((swp_entry_t) { \
|
|
((type << 1) | \
|
|
((offset & 0x7ffff0) << 9) | ((offset & 0xf) << 6)) })
|
|
|
|
#endif
|