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 c2c43f71468498..3a4ed9f91d5727 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 c263301648f34a..977f0a4f5ecf2c 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 1b39a2acaadf43..adf7187f89515e 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