powerpc/64s/radix: Improve preempt handling in TLB code

Preempt should be consistently disabled for mm_is_thread_local tests,
so bring the rest of these under preempt_disable().

Preempt does not need to be disabled for the mm->context.id tests,
which allows simplification and removal of gotos.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index 3a07d7a5e2fe8021c1a3b7ab37d537bad1d3dfcf..67191fe6328392bede265738f10bb586091d605d 100644 (file)
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -186,16 +186,15 @@ void radix__flush_tlb_mm(struct mm_struct *mm)
 {
        unsigned long pid;
 
-       preempt_disable();
        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
-               goto no_context;
+               return;
 
+       preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_pid(pid, RIC_FLUSH_TLB);
        else
                _tlbiel_pid(pid, RIC_FLUSH_TLB);
-no_context:
        preempt_enable();
 }
 EXPORT_SYMBOL(radix__flush_tlb_mm);
@@ -204,16 +203,15 @@ void radix__flush_all_mm(struct mm_struct *mm)
 {
        unsigned long pid;
 
-       preempt_disable();
        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
-               goto no_context;
+               return;
 
+       preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_pid(pid, RIC_FLUSH_ALL);
        else
                _tlbiel_pid(pid, RIC_FLUSH_ALL);
-no_context:
        preempt_enable();
 }
 EXPORT_SYMBOL(radix__flush_all_mm);
@@ -230,15 +228,15 @@ void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
        unsigned long pid;
        unsigned long ap = mmu_get_ap(psize);
 
-       preempt_disable();
        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
-               goto bail;
+               return;
+
+       preempt_disable();
        if (!mm_is_thread_local(mm))
                _tlbie_va(vmaddr, pid, ap, RIC_FLUSH_TLB);
        else
                _tlbiel_va(vmaddr, pid, ap, RIC_FLUSH_TLB);
-bail:
        preempt_enable();
 }
 
@@ -322,46 +320,44 @@ void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start,
 {
        unsigned long pid;
        unsigned long addr;
-       int local = mm_is_thread_local(mm);
+       bool local;
        unsigned long ap = mmu_get_ap(psize);
        unsigned long page_size = 1UL << mmu_psize_defs[psize].shift;
 
-
-       preempt_disable();
        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
-               goto err_out;
+               return;
 
+       preempt_disable();
+       local = mm_is_thread_local(mm);
        if (end == TLB_FLUSH_ALL ||
            (end - start) > tlb_single_page_flush_ceiling * page_size) {
                if (local)
                        _tlbiel_pid(pid, RIC_FLUSH_TLB);
                else
                        _tlbie_pid(pid, RIC_FLUSH_TLB);
-               goto err_out;
-       }
-       for (addr = start; addr < end; addr += page_size) {
+       } else {
+               for (addr = start; addr < end; addr += page_size) {
 
-               if (local)
-                       _tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB);
-               else
-                       _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
+                       if (local)
+                               _tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB);
+                       else
+                               _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
+               }
        }
-err_out:
        preempt_enable();
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
 {
-       int local = mm_is_thread_local(mm);
        unsigned long ap = mmu_get_ap(mmu_virtual_psize);
        unsigned long pid, end;
-
+       bool local;
 
        pid = mm->context.id;
        if (unlikely(pid == MMU_NO_CONTEXT))
-               goto no_context;
+               return;
 
        /* 4k page size, just blow the world */
        if (PAGE_SIZE == 0x1000) {
@@ -369,6 +365,8 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
                return;
        }
 
+       preempt_disable();
+       local = mm_is_thread_local(mm);
        /* Otherwise first do the PWC */
        if (local)
                _tlbiel_pid(pid, RIC_FLUSH_PWC);
@@ -383,7 +381,7 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
                else
                        _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
        }
-no_context:
+
        preempt_enable();
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */