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>
diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt
index 866b761..552caba 100644
--- a/Documentation/cachetlb.txt
+++ b/Documentation/cachetlb.txt
@@ -133,12 +133,6 @@
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 c14abef..a096b30 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -54,15 +54,12 @@
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 5f0d797..44ef329 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -125,10 +125,6 @@
#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 6b4216e..0971ec9 100644
--- a/include/asm-ia64/pgtable.h
+++ b/include/asm-ia64/pgtable.h
@@ -223,12 +223,6 @@
* 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
@@ -321,6 +315,36 @@
#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
* protection value contains the memory attribute bits, dirty bits, and
@@ -489,12 +513,6 @@
#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 @@
#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>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index eab8c42..06fd801 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -355,7 +355,6 @@
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 @@
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 b3c42f0..bd16dca 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1611,10 +1611,8 @@
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 @@
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 @@
/* 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 @@
/* 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 @@
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 ea11ddb..06d0877 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -181,7 +181,6 @@
/* 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 e8346c3..1d4d697 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -53,7 +53,6 @@
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 41ac397..2b9f413 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -436,7 +436,6 @@
entry = pte_wrprotect(entry);
entry = pte_mkclean(entry);
set_pte_at(mm, address, pte, entry);
- lazy_mmu_prot_update(entry);
ret = 1;
}