powerpc/mm/64s: Consolidate SLB assertions

The code for assert_slb_exists() and assert_slb_notexists() is almost
identical, except for the polarity of the WARN_ON(). In a future patch
we'll need to modify this code, so consolidate it now into a single
function.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index c3fdf2969d9faec5cacac62dfd9416011f9b17eb..f3e002ee457bed02a9307292a615d8406da87e21 100644 (file)
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -58,7 +58,7 @@ static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
        return __mk_vsid_data(get_kernel_vsid(ea, ssize), ssize, flags);
 }
 
-static void assert_slb_exists(unsigned long ea)
+static void assert_slb_presence(bool present, unsigned long ea)
 {
 #ifdef CONFIG_DEBUG_VM
        unsigned long tmp;
@@ -66,19 +66,8 @@ static void assert_slb_exists(unsigned long ea)
        WARN_ON_ONCE(mfmsr() & MSR_EE);
 
        asm volatile("slbfee. %0, %1" : "=r"(tmp) : "r"(ea) : "cr0");
-       WARN_ON(tmp == 0);
-#endif
-}
 
-static void assert_slb_notexists(unsigned long ea)
-{
-#ifdef CONFIG_DEBUG_VM
-       unsigned long tmp;
-
-       WARN_ON_ONCE(mfmsr() & MSR_EE);
-
-       asm volatile("slbfee. %0, %1" : "=r"(tmp) : "r"(ea) : "cr0");
-       WARN_ON(tmp != 0);
+       WARN_ON(present == (tmp == 0));
 #endif
 }
 
@@ -114,7 +103,7 @@ static inline void create_shadowed_slbe(unsigned long ea, int ssize,
         */
        slb_shadow_update(ea, ssize, flags, index);
 
-       assert_slb_notexists(ea);
+       assert_slb_presence(false, ea);
        asm volatile("slbmte  %0,%1" :
                     : "r" (mk_vsid_data(ea, ssize, flags)),
                       "r" (mk_esid_data(ea, ssize, index))
@@ -137,7 +126,7 @@ void __slb_restore_bolted_realmode(void)
                       "r" (be64_to_cpu(p->save_area[index].esid)));
        }
 
-       assert_slb_exists(local_paca->kstack);
+       assert_slb_presence(true, local_paca->kstack);
 }
 
 /*
@@ -185,7 +174,7 @@ void slb_flush_and_restore_bolted(void)
                     :: "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].vsid)),
                        "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].esid))
                     : "memory");
-       assert_slb_exists(get_paca()->kstack);
+       assert_slb_presence(true, get_paca()->kstack);
 
        get_paca()->slb_cache_ptr = 0;
 
@@ -443,9 +432,9 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
                                ea = (unsigned long)
                                        get_paca()->slb_cache[i] << SID_SHIFT;
                                /*
-                                * Could assert_slb_exists here, but hypervisor
-                                * or machine check could have come in and
-                                * removed the entry at this point.
+                                * Could assert_slb_presence(true) here, but
+                                * hypervisor or machine check could have come
+                                * in and removed the entry at this point.
                                 */
 
                                slbie_data = ea;
@@ -676,7 +665,7 @@ static long slb_insert_entry(unsigned long ea, unsigned long context,
         * User preloads should add isync afterwards in case the kernel
         * accesses user memory before it returns to userspace with rfid.
         */
-       assert_slb_notexists(ea);
+       assert_slb_presence(false, ea);
        asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data));
 
        barrier();