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-rw-r--r--kernel/arch/parisc/include/asm/pgalloc.h3
-rw-r--r--kernel/arch/parisc/include/asm/pgtable.h55
-rw-r--r--kernel/arch/parisc/include/asm/tlbflush.h53
3 files changed, 68 insertions, 43 deletions
diff --git a/kernel/arch/parisc/include/asm/pgalloc.h b/kernel/arch/parisc/include/asm/pgalloc.h
index 3a08eae33..3edbb9fc9 100644
--- a/kernel/arch/parisc/include/asm/pgalloc.h
+++ b/kernel/arch/parisc/include/asm/pgalloc.h
@@ -72,7 +72,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
- if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
+ if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
/*
* This is the permanent pmd attached to the pgd;
* cannot free it.
@@ -81,6 +81,7 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
*/
mm_inc_nr_pmds(mm);
return;
+ }
free_pages((unsigned long)pmd, PMD_ORDER);
}
diff --git a/kernel/arch/parisc/include/asm/pgtable.h b/kernel/arch/parisc/include/asm/pgtable.h
index 0a183756d..f93c4a4e6 100644
--- a/kernel/arch/parisc/include/asm/pgtable.h
+++ b/kernel/arch/parisc/include/asm/pgtable.h
@@ -16,7 +16,7 @@
#include <asm/processor.h>
#include <asm/cache.h>
-extern spinlock_t pa_dbit_lock;
+extern spinlock_t pa_tlb_lock;
/*
* kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
@@ -33,6 +33,19 @@ extern spinlock_t pa_dbit_lock;
*/
#define kern_addr_valid(addr) (1)
+/* Purge data and instruction TLB entries. Must be called holding
+ * the pa_tlb_lock. The TLB purge instructions are slow on SMP
+ * machines since the purge must be broadcast to all CPUs.
+ */
+
+static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
+{
+ mtsp(mm->context, 1);
+ pdtlb(addr);
+ if (unlikely(split_tlb))
+ pitlb(addr);
+}
+
/* Certain architectures need to do special things when PTEs
* within a page table are directly modified. Thus, the following
* hook is made available.
@@ -42,15 +55,20 @@ extern spinlock_t pa_dbit_lock;
*(pteptr) = (pteval); \
} while(0)
-extern void purge_tlb_entries(struct mm_struct *, unsigned long);
+#define pte_inserted(x) \
+ ((pte_val(x) & (_PAGE_PRESENT|_PAGE_ACCESSED)) \
+ == (_PAGE_PRESENT|_PAGE_ACCESSED))
-#define set_pte_at(mm, addr, ptep, pteval) \
- do { \
+#define set_pte_at(mm, addr, ptep, pteval) \
+ do { \
+ pte_t old_pte; \
unsigned long flags; \
- spin_lock_irqsave(&pa_dbit_lock, flags); \
- set_pte(ptep, pteval); \
- purge_tlb_entries(mm, addr); \
- spin_unlock_irqrestore(&pa_dbit_lock, flags); \
+ spin_lock_irqsave(&pa_tlb_lock, flags); \
+ old_pte = *ptep; \
+ set_pte(ptep, pteval); \
+ if (pte_inserted(old_pte)) \
+ purge_tlb_entries(mm, addr); \
+ spin_unlock_irqrestore(&pa_tlb_lock, flags); \
} while (0)
#endif /* !__ASSEMBLY__ */
@@ -268,7 +286,7 @@ extern unsigned long *empty_zero_page;
#define pte_none(x) (pte_val(x) == 0)
#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
-#define pte_clear(mm,addr,xp) do { pte_val(*(xp)) = 0; } while (0)
+#define pte_clear(mm, addr, xp) set_pte_at(mm, addr, xp, __pte(0))
#define pmd_flag(x) (pmd_val(x) & PxD_FLAG_MASK)
#define pmd_address(x) ((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
@@ -435,15 +453,15 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned
if (!pte_young(*ptep))
return 0;
- spin_lock_irqsave(&pa_dbit_lock, flags);
+ spin_lock_irqsave(&pa_tlb_lock, flags);
pte = *ptep;
if (!pte_young(pte)) {
- spin_unlock_irqrestore(&pa_dbit_lock, flags);
+ spin_unlock_irqrestore(&pa_tlb_lock, flags);
return 0;
}
set_pte(ptep, pte_mkold(pte));
purge_tlb_entries(vma->vm_mm, addr);
- spin_unlock_irqrestore(&pa_dbit_lock, flags);
+ spin_unlock_irqrestore(&pa_tlb_lock, flags);
return 1;
}
@@ -453,11 +471,12 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t old_pte;
unsigned long flags;
- spin_lock_irqsave(&pa_dbit_lock, flags);
+ spin_lock_irqsave(&pa_tlb_lock, flags);
old_pte = *ptep;
- pte_clear(mm,addr,ptep);
- purge_tlb_entries(mm, addr);
- spin_unlock_irqrestore(&pa_dbit_lock, flags);
+ set_pte(ptep, __pte(0));
+ if (pte_inserted(old_pte))
+ purge_tlb_entries(mm, addr);
+ spin_unlock_irqrestore(&pa_tlb_lock, flags);
return old_pte;
}
@@ -465,10 +484,10 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
unsigned long flags;
- spin_lock_irqsave(&pa_dbit_lock, flags);
+ spin_lock_irqsave(&pa_tlb_lock, flags);
set_pte(ptep, pte_wrprotect(*ptep));
purge_tlb_entries(mm, addr);
- spin_unlock_irqrestore(&pa_dbit_lock, flags);
+ spin_unlock_irqrestore(&pa_tlb_lock, flags);
}
#define pte_same(A,B) (pte_val(A) == pte_val(B))
diff --git a/kernel/arch/parisc/include/asm/tlbflush.h b/kernel/arch/parisc/include/asm/tlbflush.h
index 9d086a599..e84b96478 100644
--- a/kernel/arch/parisc/include/asm/tlbflush.h
+++ b/kernel/arch/parisc/include/asm/tlbflush.h
@@ -13,6 +13,9 @@
* active at any one time on the Merced bus. This tlb purge
* synchronisation is fairly lightweight and harmless so we activate
* it on all systems not just the N class.
+
+ * It is also used to ensure PTE updates are atomic and consistent
+ * with the TLB.
*/
extern spinlock_t pa_tlb_lock;
@@ -24,20 +27,24 @@ extern void flush_tlb_all_local(void *);
#define smp_flush_tlb_all() flush_tlb_all()
+int __flush_tlb_range(unsigned long sid,
+ unsigned long start, unsigned long end);
+
+#define flush_tlb_range(vma, start, end) \
+ __flush_tlb_range((vma)->vm_mm->context, start, end)
+
+#define flush_tlb_kernel_range(start, end) \
+ __flush_tlb_range(0, start, end)
+
/*
* flush_tlb_mm()
*
- * XXX This code is NOT valid for HP-UX compatibility processes,
- * (although it will probably work 99% of the time). HP-UX
- * processes are free to play with the space id's and save them
- * over long periods of time, etc. so we have to preserve the
- * space and just flush the entire tlb. We need to check the
- * personality in order to do that, but the personality is not
- * currently being set correctly.
- *
- * Of course, Linux processes could do the same thing, but
- * we don't support that (and the compilers, dynamic linker,
- * etc. do not do that).
+ * The code to switch to a new context is NOT valid for processes
+ * which play with the space id's. Thus, we have to preserve the
+ * space and just flush the entire tlb. However, the compilers,
+ * dynamic linker, etc, do not manipulate space id's, so there
+ * could be a significant performance benefit in switching contexts
+ * and not flushing the whole tlb.
*/
static inline void flush_tlb_mm(struct mm_struct *mm)
@@ -45,10 +52,18 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
BUG_ON(mm == &init_mm); /* Should never happen */
#if 1 || defined(CONFIG_SMP)
+ /* Except for very small threads, flushing the whole TLB is
+ * faster than using __flush_tlb_range. The pdtlb and pitlb
+ * instructions are very slow because of the TLB broadcast.
+ * It might be faster to do local range flushes on all CPUs
+ * on PA 2.0 systems.
+ */
flush_tlb_all();
#else
/* FIXME: currently broken, causing space id and protection ids
- * to go out of sync, resulting in faults on userspace accesses.
+ * to go out of sync, resulting in faults on userspace accesses.
+ * This approach needs further investigation since running many
+ * small applications (e.g., GCC testsuite) is faster on HP-UX.
*/
if (mm) {
if (mm->context != 0)
@@ -65,22 +80,12 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
{
unsigned long flags, sid;
- /* For one page, it's not worth testing the split_tlb variable */
-
- mb();
sid = vma->vm_mm->context;
purge_tlb_start(flags);
mtsp(sid, 1);
pdtlb(addr);
- pitlb(addr);
+ if (unlikely(split_tlb))
+ pitlb(addr);
purge_tlb_end(flags);
}
-
-void __flush_tlb_range(unsigned long sid,
- unsigned long start, unsigned long end);
-
-#define flush_tlb_range(vma,start,end) __flush_tlb_range((vma)->vm_mm->context,start,end)
-
-#define flush_tlb_kernel_range(start, end) __flush_tlb_range(0,start,end)
-
#endif