[PATCH] flush icache before set_pte on ia64 take3
From: KAMEZAWA Hiroyuki
Date: Thu Jul 26 2007 - 04:12:55 EST
This is a patch for flush icache for ia64 take3.
against 2.6.23-rc1. tested on ia64/NUMA.
Comments ? Should I add CONFIG_MONTECITO ?
(It seems header-file dependency is not clean..but...)
Thanks,
-Kame
==
[IA64] flush icache before setting pte
Changelog:
- reviewed the whole patch again and avoid flush_icache which seems unnecessary
- refleshed the whole patch description.
Current ia64 kernel flushes icache *after* set_pte() by lazy_mmu_prot_update().
This behavior is wrong. This patch removes lazy_mmu_prot_update() and implements flush_icache_page() and flush_cache_page() for ia64. By this, icache is flushed
before set_pte().
This patch fixes SIGILL problem on NFS caused by icache inconsistency.
Notes:
- flush_(i)cache_page() just flushes executable pages by fc.i (if possible)
This check uses VM_EXEC bit in vm_area_struct.
- A page which is not neccessary to be flushed is marked as PG_arch_1.
If a page is once flushed, it will be marked as PG_arch_1.
- lazy_mmu_prot_update() flushed icache after set_pte(). this patch flushes
icache befoer set_pte().
- lazy_mmu_prot_update() checked pte's executable bit. This was because old
Linux's anon page has executable bit. Current kernel doesn't set executable
bit on anonymous pages.
- Flushing icache by the kernel is necessary when the kernel fills contents
of pages by instructions before mapping the page as executable mapping.
About details of lazy_mmu_prot_update() removals:
- in do_wp_page() ..... flush_cache_page() is called.
- in do_anonymous_page() ..... *newly* allocated *anon* page is zero-filled and
contains no instruction...seems unnecessary to sync i-cache...
- in do_fault() ..... flush_icache_page() is called.
- in handle_pte_fault() .....seems just update access bit.
ptep_set_access_flags() may flush TLBs. But it seems there are nothing
to do in cache layer.
- in remove_migration() ..... inserted flush_icache_page() before inserting
pte. This seems generic page migration bug ?
- in chage_pte_range() ..... flush_cache_range() is called before here.
- in page_mkclean_one() .... flush_cache_page() is called.
- set_huge_ptep_writable() ..... nothing to do with icache.
- hugetlb_change_protection() .... flush_cache_range() is called.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
arch/ia64/mm/init.c | 10 ++--------
include/asm-generic/pgtable.h | 4 ----
include/asm-ia64/cacheflush.h | 19 ++++++++++++++++---
include/asm-ia64/pgtable.h | 2 --
include/linux/mm.h | 5 +++++
mm/hugetlb.c | 2 --
mm/memory.c | 5 -----
mm/migrate.c | 4 +++-
mm/mprotect.c | 1 -
mm/rmap.c | 1 -
10 files changed, 26 insertions(+), 27 deletions(-)
Index: linux-2.6.23-rc1/arch/ia64/mm/init.c
===================================================================
--- linux-2.6.23-rc1.orig/arch/ia64/mm/init.c
+++ linux-2.6.23-rc1/arch/ia64/mm/init.c
@@ -54,20 +54,14 @@ struct page *zero_page_memmap_ptr; /* ma
EXPORT_SYMBOL(zero_page_memmap_ptr);
void
-lazy_mmu_prot_update (pte_t pte)
+__flush_icache_page_ia64 (struct page *page)
{
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);
-
if (test_bit(PG_arch_1, &page->flags))
return; /* i-cache is already coherent with d-cache */
+ addr = (unsigned long) page_address(page);
if (PageCompound(page)) {
order = compound_order(page);
Index: linux-2.6.23-rc1/include/asm-ia64/cacheflush.h
===================================================================
--- linux-2.6.23-rc1.orig/include/asm-ia64/cacheflush.h
+++ linux-2.6.23-rc1/include/asm-ia64/cacheflush.h
@@ -7,10 +7,11 @@
*/
#include <linux/page-flags.h>
-
+#include <linux/mm.h> // for VM_EXEC
#include <asm/bitops.h>
#include <asm/page.h>
+extern void __flush_icache_page_ia64(struct page *page);
/*
* Cache flushing routines. This is the kind of stuff that can be very expensive, so try
* to avoid them whenever possible.
@@ -20,11 +21,23 @@
#define flush_cache_mm(mm) do { } while (0)
#define flush_cache_dup_mm(mm) do { } while (0)
#define flush_cache_range(vma, start, end) do { } while (0)
-#define flush_cache_page(vma, vmaddr, pfn) do { } while (0)
-#define flush_icache_page(vma,page) do { } while (0)
#define flush_cache_vmap(start, end) do { } while (0)
#define flush_cache_vunmap(start, end) do { } while (0)
+static inline void
+flush_icache_page(struct vm_area_struct *vma, unsigned long pfn) {
+ if ((vma->vm_flags & VM_EXEC) && pfn_valid(pfn))
+ __flush_icache_page_ia64(pfn_to_page(pfn));
+}
+
+static inline void
+flush_cache_page(struct vm_area_struct *vma,
+ unsigned long vmaddr, unsigned long pfn)
+{
+ /* icache should be flushed if VM_EXEC.*/
+ flush_icache_page(vma, pfn);
+}
+
#define flush_dcache_page(page) \
do { \
clear_bit(PG_arch_1, &(page)->flags); \
Index: linux-2.6.23-rc1/mm/memory.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/memory.c
+++ linux-2.6.23-rc1/mm/memory.c
@@ -1699,7 +1699,6 @@ static int do_wp_page(struct mm_struct *
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
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;
@@ -1741,7 +1740,6 @@ 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
@@ -2286,7 +2284,6 @@ static int do_anonymous_page(struct mm_s
/* 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;
@@ -2437,7 +2434,6 @@ static int __do_fault(struct mm_struct *
/* 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);
@@ -2611,7 +2607,6 @@ static inline int handle_pte_fault(struc
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
Index: linux-2.6.23-rc1/mm/migrate.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/migrate.c
+++ linux-2.6.23-rc1/mm/migrate.c
@@ -172,6 +172,9 @@ static void remove_migration_pte(struct
pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (is_write_migration_entry(entry))
pte = pte_mkwrite(pte);
+
+ flush_icache_page(vma, page_to_pfn(new));
+
set_pte_at(mm, addr, ptep, pte);
if (PageAnon(new))
@@ -181,7 +184,6 @@ static void remove_migration_pte(struct
/* 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);
Index: linux-2.6.23-rc1/include/asm-generic/pgtable.h
===================================================================
--- linux-2.6.23-rc1.orig/include/asm-generic/pgtable.h
+++ linux-2.6.23-rc1/include/asm-generic/pgtable.h
@@ -124,10 +124,6 @@ static inline void ptep_set_wrprotect(st
#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
Index: linux-2.6.23-rc1/include/asm-ia64/pgtable.h
===================================================================
--- linux-2.6.23-rc1.orig/include/asm-ia64/pgtable.h
+++ linux-2.6.23-rc1/include/asm-ia64/pgtable.h
@@ -151,7 +151,6 @@
#include <linux/sched.h> /* for mm_struct */
#include <asm/bitops.h>
-#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/processor.h>
@@ -571,7 +570,6 @@ extern struct page *zero_page_memmap_ptr
#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>
Index: linux-2.6.23-rc1/mm/mprotect.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/mprotect.c
+++ linux-2.6.23-rc1/mm/mprotect.c
@@ -53,7 +53,6 @@ static void change_pte_range(struct mm_s
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);
Index: linux-2.6.23-rc1/mm/rmap.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/rmap.c
+++ linux-2.6.23-rc1/mm/rmap.c
@@ -436,7 +436,6 @@ static int page_mkclean_one(struct page
entry = pte_wrprotect(entry);
entry = pte_mkclean(entry);
set_pte_at(mm, address, pte, entry);
- lazy_mmu_prot_update(entry);
ret = 1;
}
Index: linux-2.6.23-rc1/mm/hugetlb.c
===================================================================
--- linux-2.6.23-rc1.orig/mm/hugetlb.c
+++ linux-2.6.23-rc1/mm/hugetlb.c
@@ -352,7 +352,6 @@ static void set_huge_ptep_writable(struc
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);
}
}
@@ -705,7 +704,6 @@ void hugetlb_change_protection(struct vm
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);
Index: linux-2.6.23-rc1/include/linux/mm.h
===================================================================
--- linux-2.6.23-rc1.orig/include/linux/mm.h
+++ linux-2.6.23-rc1/include/linux/mm.h
@@ -255,6 +255,11 @@ struct inode;
*/
#include <linux/page-flags.h>
+/*
+ * Some architecture uses VM_xxx flags as a hint for flushing cache.
+ */
+#include <asm/cacheflush.h>
+
#ifdef CONFIG_DEBUG_VM
#define VM_BUG_ON(cond) BUG_ON(cond)
#else
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/