[PATCH] mm: i386 sh sh64 ready for split ptlock
Use pte_offset_map_lock, instead of pte_offset_map (or inappropriate
pte_offset_kernel) and mm-wide page_table_lock, in sundry arch places.
The i386 vm86 mark_screen_rdonly: yes, there was and is an assumption that the
screen fits inside the one page table, as indeed it does.
The sh __do_page_fault: which handles both kernel faults (without lock) and
user mm faults (locked - though it set_pte without locking before).
The sh64 flush_cache_range and helpers: which wrongly thought callers held
page_table_lock before (only its tlb_start_vma did, and no longer does so);
moved the flush loop down, and adjusted the large versus small range decision
to consider a range which spans page tables as large.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/vm86.c b/arch/i386/kernel/vm86.c
index 16b4850..fc19935 100644
--- a/arch/i386/kernel/vm86.c
+++ b/arch/i386/kernel/vm86.c
@@ -134,17 +134,16 @@
return ret;
}
-static void mark_screen_rdonly(struct task_struct * tsk)
+static void mark_screen_rdonly(struct mm_struct *mm)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte, *mapped;
+ pte_t *pte;
+ spinlock_t *ptl;
int i;
- preempt_disable();
- spin_lock(&tsk->mm->page_table_lock);
- pgd = pgd_offset(tsk->mm, 0xA0000);
+ pgd = pgd_offset(mm, 0xA0000);
if (pgd_none_or_clear_bad(pgd))
goto out;
pud = pud_offset(pgd, 0xA0000);
@@ -153,16 +152,14 @@
pmd = pmd_offset(pud, 0xA0000);
if (pmd_none_or_clear_bad(pmd))
goto out;
- pte = mapped = pte_offset_map(pmd, 0xA0000);
+ pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
for (i = 0; i < 32; i++) {
if (pte_present(*pte))
set_pte(pte, pte_wrprotect(*pte));
pte++;
}
- pte_unmap(mapped);
+ pte_unmap_unlock(pte, ptl);
out:
- spin_unlock(&tsk->mm->page_table_lock);
- preempt_enable();
flush_tlb();
}
@@ -306,7 +303,7 @@
tsk->thread.screen_bitmap = info->screen_bitmap;
if (info->flags & VM86_SCREEN_BITMAP)
- mark_screen_rdonly(tsk);
+ mark_screen_rdonly(tsk->mm);
__asm__ __volatile__(
"xorl %%eax,%%eax; movl %%eax,%%fs; movl %%eax,%%gs\n\t"
"movl %0,%%esp\n\t"
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index 7abba21..775f86c 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -194,10 +194,13 @@
unsigned long address)
{
unsigned long addrmax = P4SEG;
- pgd_t *dir;
+ pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
pte_t entry;
+ struct mm_struct *mm;
+ spinlock_t *ptl;
+ int ret = 1;
#ifdef CONFIG_SH_KGDB
if (kgdb_nofault && kgdb_bus_err_hook)
@@ -208,28 +211,28 @@
addrmax = P4SEG_STORE_QUE + 0x04000000;
#endif
- if (address >= P3SEG && address < addrmax)
- dir = pgd_offset_k(address);
- else if (address >= TASK_SIZE)
+ if (address >= P3SEG && address < addrmax) {
+ pgd = pgd_offset_k(address);
+ mm = NULL;
+ } else if (address >= TASK_SIZE)
return 1;
- else if (!current->mm)
+ else if (!(mm = current->mm))
return 1;
else
- dir = pgd_offset(current->mm, address);
+ pgd = pgd_offset(mm, address);
- pmd = pmd_offset(dir, address);
- if (pmd_none(*pmd))
+ pmd = pmd_offset(pgd, address);
+ if (pmd_none_or_clear_bad(pmd))
return 1;
- if (pmd_bad(*pmd)) {
- pmd_ERROR(*pmd);
- pmd_clear(pmd);
- return 1;
- }
- pte = pte_offset_kernel(pmd, address);
+ if (mm)
+ pte = pte_offset_map_lock(mm, pmd, address, &ptl);
+ else
+ pte = pte_offset_kernel(pmd, address);
+
entry = *pte;
if (pte_none(entry) || pte_not_present(entry)
|| (writeaccess && !pte_write(entry)))
- return 1;
+ goto unlock;
if (writeaccess)
entry = pte_mkdirty(entry);
@@ -251,8 +254,11 @@
set_pte(pte, entry);
update_mmu_cache(NULL, address, entry);
-
- return 0;
+ ret = 0;
+unlock:
+ if (mm)
+ pte_unmap_unlock(pte, ptl);
+ return ret;
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
diff --git a/arch/sh64/mm/cache.c b/arch/sh64/mm/cache.c
index 3b87e25..c0c1b213 100644
--- a/arch/sh64/mm/cache.c
+++ b/arch/sh64/mm/cache.c
@@ -584,32 +584,36 @@
}
}
-static void sh64_dcache_purge_user_page(struct mm_struct *mm, unsigned long eaddr)
+static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
+ unsigned long addr, unsigned long end)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
pte_t entry;
+ spinlock_t *ptl;
unsigned long paddr;
- /* NOTE : all the callers of this have mm->page_table_lock held, so the
- following page table traversal is safe even on SMP/pre-emptible. */
+ if (!mm)
+ return; /* No way to find physical address of page */
- if (!mm) return; /* No way to find physical address of page */
- pgd = pgd_offset(mm, eaddr);
- if (pgd_bad(*pgd)) return;
+ pgd = pgd_offset(mm, addr);
+ if (pgd_bad(*pgd))
+ return;
- pmd = pmd_offset(pgd, eaddr);
- if (pmd_none(*pmd) || pmd_bad(*pmd)) return;
+ pmd = pmd_offset(pgd, addr);
+ if (pmd_none(*pmd) || pmd_bad(*pmd))
+ return;
- pte = pte_offset_kernel(pmd, eaddr);
- entry = *pte;
- if (pte_none(entry) || !pte_present(entry)) return;
-
- paddr = pte_val(entry) & PAGE_MASK;
-
- sh64_dcache_purge_coloured_phy_page(paddr, eaddr);
-
+ pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ do {
+ entry = *pte;
+ if (pte_none(entry) || !pte_present(entry))
+ continue;
+ paddr = pte_val(entry) & PAGE_MASK;
+ sh64_dcache_purge_coloured_phy_page(paddr, addr);
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ pte_unmap_unlock(pte - 1, ptl);
}
/****************************************************************************/
@@ -668,7 +672,7 @@
int n_pages;
n_pages = ((end - start) >> PAGE_SHIFT);
- if (n_pages >= 64) {
+ if (n_pages >= 64 || ((start ^ (end - 1)) & PMD_MASK)) {
#if 1
sh64_dcache_purge_all();
#else
@@ -707,20 +711,10 @@
}
#endif
} else {
- /* 'Small' range */
- unsigned long aligned_start;
- unsigned long eaddr;
- unsigned long last_page_start;
-
- aligned_start = start & PAGE_MASK;
- /* 'end' is 1 byte beyond the end of the range */
- last_page_start = (end - 1) & PAGE_MASK;
-
- eaddr = aligned_start;
- while (eaddr <= last_page_start) {
- sh64_dcache_purge_user_page(mm, eaddr);
- eaddr += PAGE_SIZE;
- }
+ /* Small range, covered by a single page table page */
+ start &= PAGE_MASK; /* should already be so */
+ end = PAGE_ALIGN(end); /* should already be so */
+ sh64_dcache_purge_user_pages(mm, start, end);
}
return;
}
@@ -880,9 +874,7 @@
addresses from the user address space specified by mm, after writing
back any dirty data.
- Note(1), 'end' is 1 byte beyond the end of the range to flush.
-
- Note(2), this is called with mm->page_table_lock held.*/
+ Note, 'end' is 1 byte beyond the end of the range to flush. */
sh64_dcache_purge_user_range(mm, start, end);
sh64_icache_inv_user_page_range(mm, start, end);
@@ -898,7 +890,7 @@
the I-cache must be searched too in case the page in question is
both writable and being executed from (e.g. stack trampolines.)
- Note(1), this is called with mm->page_table_lock held.
+ Note, this is called with pte lock held.
*/
sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);
