Merge branch 'parisc-4.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc fixes from Helge Deller:
 "Three important fixes for the parisc architecture.

  Dave provided two patches: One which purges the TLB before setting a
  PTE entry and a second one which drops unnecessary TLB flushes. Both
  patches have been tested for one week on the debian buildd servers and
  prevent random segmentation faults.

  The patch from me fixes a crash at boot inside the TLB measuring code
  on SMP machines with PA8000-PA8700 CPUs (specifically A500-44 and
  J5000 servers)"

* 'parisc-4.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix TLB related boot crash on SMP machines
  parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm
  parisc: Purge TLB before setting PTE

3 files changed, 16 insertions, 25 deletions

diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index c2c43f714684..3a4ed9f91d57 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -65,9 +65,9 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
                 unsigned long 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);            \
+                set_pte(ptep, pteval);                          \
                 spin_unlock_irqrestore(&pa_tlb_lock, flags);    \
         } while (0)
 
@@ -478,8 +478,8 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned
                 spin_unlock_irqrestore(&pa_tlb_lock, flags);
                 return 0;
         }
-        set_pte(ptep, pte_mkold(pte));
         purge_tlb_entries(vma->vm_mm, addr);
+        set_pte(ptep, pte_mkold(pte));
         spin_unlock_irqrestore(&pa_tlb_lock, flags);
         return 1;
 }
@@ -492,9 +492,9 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 
         spin_lock_irqsave(&pa_tlb_lock, flags);
         old_pte = *ptep;
-        set_pte(ptep, __pte(0));
         if (pte_inserted(old_pte))
                 purge_tlb_entries(mm, addr);
+        set_pte(ptep, __pte(0));
         spin_unlock_irqrestore(&pa_tlb_lock, flags);
 
         return old_pte;
@@ -504,8 +504,8 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 {
         unsigned long flags;
         spin_lock_irqsave(&pa_tlb_lock, flags);
-        set_pte(ptep, pte_wrprotect(*ptep));
         purge_tlb_entries(mm, addr);
+        set_pte(ptep, pte_wrprotect(*ptep));
         spin_unlock_irqrestore(&pa_tlb_lock, flags);
 }
 
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index c263301648f3..977f0a4f5ecf 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -393,6 +393,15 @@ void __init parisc_setup_cache_timing(void)
 
         /* calculate TLB flush threshold */
 
+        /* On SMP machines, skip the TLB measure of kernel text which
+         * has been mapped as huge pages. */
+        if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
+                threshold = max(cache_info.it_size, cache_info.dt_size);
+                threshold *= PAGE_SIZE;
+                threshold /= num_online_cpus();
+                goto set_tlb_threshold;
+        }
+
         alltime = mfctl(16);
         flush_tlb_all();
         alltime = mfctl(16) - alltime;
@@ -411,6 +420,8 @@ void __init parisc_setup_cache_timing(void)
                 alltime, size, rangetime);
 
         threshold = PAGE_ALIGN(num_online_cpus() * size * alltime / rangetime);
+
+set_tlb_threshold:
         if (threshold)
                 parisc_tlb_flush_threshold = threshold;
         printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S
index 1b39a2acaadf..adf7187f8951 100644
--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -892,19 +892,10 @@ ENTRY_CFI(flush_dcache_page_asm)
         fdc,m           r31(%r28)
         fdc,m           r31(%r28)
         fdc,m           r31(%r28)
-        cmpb,COND(<<)           %r28, %r25,1b
+        cmpb,COND(<<)   %r28, %r25,1b
         fdc,m           r31(%r28)
 
         sync
-
-#ifdef CONFIG_PA20
-        pdtlb,l         %r0(%r25)
-#else
-        tlb_lock        %r20,%r21,%r22
-        pdtlb           %r0(%r25)
-        tlb_unlock      %r20,%r21,%r22
-#endif
-
         bv              %r0(%r2)
         nop
         .exit
@@ -979,17 +970,6 @@ ENTRY_CFI(flush_icache_page_asm)
         fic,m           %r31(%sr4,%r28)
 
         sync
-
-#ifdef CONFIG_PA20
-        pdtlb,l         %r0(%r28)
-        pitlb,l         %r0(%sr4,%r25)
-#else
-        tlb_lock        %r20,%r21,%r22
-        pdtlb           %r0(%r28)
-        pitlb           %r0(%sr4,%r25)
-        tlb_unlock      %r20,%r21,%r22
-#endif
-
         bv              %r0(%r2)
         nop
         .exit