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flush icache before set_pte() on ia64: flush icache at set_pte 

Current ia64 kernel flushes icache by lazy_mmu_prot_update() *after*
set_pte().  This is too late.  This patch removes lazy_mmu_prot_update and
add modfied set_pte() for flushing if necessary.

This patch flush icache of a page when
	new pte has exec bit.
	&& new pte has present bit
	&& new pte is user's page.
	&& (old *ptep is not present
            || new pte's pfn is not same to old *ptep's ptn)
	&& new pte's page has no Pg_arch_1 bit.
	   Pg_arch_1 is set when a page is cache consistent.

I think this condition checks are much easier to understand than considering
"Where sync_icache_dcache() should be inserted ?".

pte_user() for ia64 was removed by http://lkml.org/lkml/2007/6/12/67 as
clean-up. So, I added it again.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KAMEZAWA Hiroyuki 2007-10-16 01:25:44 -07:00 committed by Linus Torvalds
parent 97ee052461
commit 954ffcb35f
9 changed files with 33 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
Documentation/cachetlb.txt
View File

@ -133,12 +133,6 @@ changes occur:
The ia64 sn2 platform is one example of a platform
that uses this interface.
8) void lazy_mmu_prot_update(pte_t pte)
This interface is called whenever the protection on
any user PTEs change. This interface provides a notification
to architecture specific code to take appropriate action.
Next, we have the cache flushing interfaces. In general, when Linux
is changing an existing virtual-->physical mapping to a new value,
the sequence will be in one of the following forms:

5
arch/ia64/mm/init.c
View File

@ -54,15 +54,12 @@ struct page *zero_page_memmap_ptr; /* map entry for zero page */
EXPORT_SYMBOL(zero_page_memmap_ptr);
void
lazy_mmu_prot_update (pte_t pte)
__ia64_sync_icache_dcache (pte_t pte)
{
unsigned long addr;
struct page *page;
unsigned long order;
if (!pte_exec(pte))
return; /* not an executable page... */
page = pte_page(pte);
addr = (unsigned long) page_address(page);

4
include/asm-generic/pgtable.h
View File

@ -125,10 +125,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
#endif
#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
#define lazy_mmu_prot_update(pte) do { } while (0)
#endif
#ifndef __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) (pte)
#endif

44
include/asm-ia64/pgtable.h
View File

@ -223,12 +223,6 @@ ia64_phys_addr_valid (unsigned long addr)
* page table.
*/
/*
* On some architectures, special things need to be done when setting
* the PTE in a page table. Nothing special needs to be on IA-64.
*/
#define set_pte(ptep, pteval) (*(ptep) = (pteval))
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
#define VMALLOC_START (RGN_BASE(RGN_GATE) + 0x200000000UL)
#ifdef CONFIG_VIRTUAL_MEM_MAP
@ -320,6 +314,36 @@ ia64_phys_addr_valid (unsigned long addr)
#define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D))
#define pte_mkhuge(pte) (__pte(pte_val(pte)))
/*
* Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
* sync icache and dcache when we insert *new* executable page.
* __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
* if necessary.
*
* set_pte() is also called by the kernel, but we can expect that the kernel
* flushes icache explicitly if necessary.
*/
#define pte_present_exec_user(pte)\
((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
extern void __ia64_sync_icache_dcache(pte_t pteval);
static inline void set_pte(pte_t *ptep, pte_t pteval)
{
/* page is present && page is user && page is executable
* && (page swapin or new page or page migraton
* || copy_on_write with page copying.)
*/
if (pte_present_exec_user(pteval) &&
(!pte_present(*ptep) ||
pte_pfn(*ptep) != pte_pfn(pteval)))
/* load_module() calles flush_icache_range() explicitly*/
__ia64_sync_icache_dcache(pteval);
*ptep = pteval;
}
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
/*
* Make page protection values cacheable, uncacheable, or write-
* combining. Note that "protection" is really a misnomer here as the
@ -489,12 +513,6 @@ extern struct page *zero_page_memmap_ptr;
#define HUGETLB_PGDIR_MASK (~(HUGETLB_PGDIR_SIZE-1))
#endif
/*
* IA-64 doesn't have any external MMU info: the page tables contain all the necessary
* information. However, we use this routine to take care of any (delayed) i-cache
* flushing that may be necessary.
*/
extern void lazy_mmu_prot_update (pte_t pte);
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
/*
@ -584,7 +602,7 @@ extern void lazy_mmu_prot_update (pte_t pte);
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTE_SAME
#define __HAVE_ARCH_PGD_OFFSET_GATE
#define __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
#ifndef CONFIG_PGTABLE_4
#include <asm-generic/pgtable-nopud.h>

2
mm/hugetlb.c
View File

@ -355,7 +355,6 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma,
entry = pte_mkwrite(pte_mkdirty(*ptep));
if (ptep_set_access_flags(vma, address, ptep, entry, 1)) {
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
}
}
@ -708,7 +707,6 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
pte = huge_ptep_get_and_clear(mm, address, ptep);
pte = pte_mkhuge(pte_modify(pte, newprot));
set_huge_pte_at(mm, address, ptep, pte);
lazy_mmu_prot_update(pte);
}
}
spin_unlock(&mm->page_table_lock);

8
mm/memory.c
View File

@ -1611,10 +1611,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = pte_mkyoung(orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
if (ptep_set_access_flags(vma, address, page_table, entry,1)) {
if (ptep_set_access_flags(vma, address, page_table, entry,1))
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
}
ret |= VM_FAULT_WRITE;
goto unlock;
}
@ -1650,7 +1648,6 @@ gotten:
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
lazy_mmu_prot_update(entry);
/*
* Clear the pte entry and flush it first, before updating the
* pte with the new entry. This will avoid a race condition
@ -2180,7 +2177,6 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
/* No need to invalidate - it was non-present before */
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
unlock:
pte_unmap_unlock(page_table, ptl);
return 0;
@ -2333,7 +2329,6 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
/* no need to invalidate: a not-present page won't be cached */
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
} else {
if (anon)
page_cache_release(page);
@ -2505,7 +2500,6 @@ static inline int handle_pte_fault(struct mm_struct *mm,
entry = pte_mkyoung(entry);
if (ptep_set_access_flags(vma, address, pte, entry, write_access)) {
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
} else {
/*
* This is needed only for protection faults but the arch code

1
mm/migrate.c
View File

@ -181,7 +181,6 @@ static void remove_migration_pte(struct vm_area_struct *vma,
/* No need to invalidate - it was non-present before */
update_mmu_cache(vma, addr, pte);
lazy_mmu_prot_update(pte);
out:
pte_unmap_unlock(ptep, ptl);

1
mm/mprotect.c
View File

@ -53,7 +53,6 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
if (dirty_accountable && pte_dirty(ptent))
ptent = pte_mkwrite(ptent);
set_pte_at(mm, addr, pte, ptent);
lazy_mmu_prot_update(ptent);
#ifdef CONFIG_MIGRATION
} else if (!pte_file(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);

1
mm/rmap.c
View File

@ -436,7 +436,6 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
entry = pte_wrprotect(entry);
entry = pte_mkclean(entry);
set_pte_at(mm, address, pte, entry);
lazy_mmu_prot_update(entry);
ret = 1;
}