From 954ffcb35f5aca428661d29b96c4eee82b3c19cd Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 16 Oct 2007 01:25:44 -0700 Subject: [PATCH] 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 Cc: "Luck, Tony" Cc: Christoph Lameter Cc: Hugh Dickins Cc: Nick Piggin Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/cachetlb.txt | 6 ----- arch/ia64/mm/init.c | 5 +--- include/asm-generic/pgtable.h | 4 ---- include/asm-ia64/pgtable.h | 44 ++++++++++++++++++++++++----------- mm/hugetlb.c | 2 -- mm/memory.c | 8 +------ mm/migrate.c | 1 - mm/mprotect.c | 1 - mm/rmap.c | 1 - 9 files changed, 33 insertions(+), 39 deletions(-) diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index 866b76139420..552cabac0608 100644 --- a/Documentation/cachetlb.txt +++ b/Documentation/cachetlb.txt @@ -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: diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index c14abefabafa..a096b30734f3 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -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); diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 5f0d797d33fd..44ef329531c3 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -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 diff --git a/include/asm-ia64/pgtable.h b/include/asm-ia64/pgtable.h index 6b4216edbb9c..0971ec90807e 100644 --- a/include/asm-ia64/pgtable.h +++ b/include/asm-ia64/pgtable.h @@ -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 diff --git a/mm/hugetlb.c b/mm/hugetlb.c index eab8c428cc93..06fd80149e47 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -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); diff --git a/mm/memory.c b/mm/memory.c index b3c42f0f65c2..bd16dcaeefb8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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 diff --git a/mm/migrate.c b/mm/migrate.c index ea11ddb58275..06d0877a66ef 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -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); diff --git a/mm/mprotect.c b/mm/mprotect.c index e8346c30abec..1d4d69790e59 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -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); diff --git a/mm/rmap.c b/mm/rmap.c index 41ac39749ef4..2b9f413c9c00 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -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; } -- 2.20.1