Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[firefly-linux-kernel-4.4.55.git] / arch / powerpc / mm / slb.c
index a73d2d700973e4cd14cda75800484de3979cf639..6c164cec9d2c6018865783f6d8c5fd3dc70f8cbe 100644 (file)
@@ -43,30 +43,37 @@ static void slb_allocate(unsigned long ea)
        slb_allocate_realmode(ea);
 }
 
-static inline unsigned long mk_esid_data(unsigned long ea, unsigned long slot)
+static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
+                                        unsigned long slot)
 {
-       return (ea & ESID_MASK) | SLB_ESID_V | slot;
+       unsigned long mask;
+
+       mask = (ssize == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T;
+       return (ea & mask) | SLB_ESID_V | slot;
 }
 
-static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags)
+#define slb_vsid_shift(ssize)  \
+       ((ssize) == MMU_SEGSIZE_256M? SLB_VSID_SHIFT: SLB_VSID_SHIFT_1T)
+
+static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
+                                        unsigned long flags)
 {
-       return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags;
+       return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
+               ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
 }
 
-static inline void slb_shadow_update(unsigned long ea,
+static inline void slb_shadow_update(unsigned long ea, int ssize,
                                     unsigned long flags,
                                     unsigned long entry)
 {
        /*
         * Clear the ESID first so the entry is not valid while we are
-        * updating it.
+        * updating it.  No write barriers are needed here, provided
+        * we only update the current CPU's SLB shadow buffer.
         */
        get_slb_shadow()->save_area[entry].esid = 0;
-       smp_wmb();
-       get_slb_shadow()->save_area[entry].vsid = mk_vsid_data(ea, flags);
-       smp_wmb();
-       get_slb_shadow()->save_area[entry].esid = mk_esid_data(ea, entry);
-       smp_wmb();
+       get_slb_shadow()->save_area[entry].vsid = mk_vsid_data(ea, ssize, flags);
+       get_slb_shadow()->save_area[entry].esid = mk_esid_data(ea, ssize, entry);
 }
 
 static inline void slb_shadow_clear(unsigned long entry)
@@ -74,12 +81,29 @@ static inline void slb_shadow_clear(unsigned long entry)
        get_slb_shadow()->save_area[entry].esid = 0;
 }
 
+static inline void create_shadowed_slbe(unsigned long ea, int ssize,
+                                       unsigned long flags,
+                                       unsigned long entry)
+{
+       /*
+        * Updating the shadow buffer before writing the SLB ensures
+        * we don't get a stale entry here if we get preempted by PHYP
+        * between these two statements.
+        */
+       slb_shadow_update(ea, ssize, flags, entry);
+
+       asm volatile("slbmte  %0,%1" :
+                    : "r" (mk_vsid_data(ea, ssize, flags)),
+                      "r" (mk_esid_data(ea, ssize, entry))
+                    : "memory" );
+}
+
 void slb_flush_and_rebolt(void)
 {
        /* If you change this make sure you change SLB_NUM_BOLTED
         * appropriately too. */
        unsigned long linear_llp, vmalloc_llp, lflags, vflags;
-       unsigned long ksp_esid_data;
+       unsigned long ksp_esid_data, ksp_vsid_data;
 
        WARN_ON(!irqs_disabled());
 
@@ -88,13 +112,15 @@ void slb_flush_and_rebolt(void)
        lflags = SLB_VSID_KERNEL | linear_llp;
        vflags = SLB_VSID_KERNEL | vmalloc_llp;
 
-       ksp_esid_data = mk_esid_data(get_paca()->kstack, 2);
-       if ((ksp_esid_data & ESID_MASK) == PAGE_OFFSET) {
+       ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, 2);
+       if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) {
                ksp_esid_data &= ~SLB_ESID_V;
+               ksp_vsid_data = 0;
                slb_shadow_clear(2);
        } else {
                /* Update stack entry; others don't change */
-               slb_shadow_update(get_paca()->kstack, lflags, 2);
+               slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, 2);
+               ksp_vsid_data = get_slb_shadow()->save_area[2].vsid;
        }
 
        /* We need to do this all in asm, so we're sure we don't touch
@@ -106,9 +132,9 @@ void slb_flush_and_rebolt(void)
                     /* Slot 2 - kernel stack */
                     "slbmte    %2,%3\n"
                     "isync"
-                    :: "r"(mk_vsid_data(VMALLOC_START, vflags)),
-                       "r"(mk_esid_data(VMALLOC_START, 1)),
-                       "r"(mk_vsid_data(ksp_esid_data, lflags)),
+                    :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)),
+                       "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, 1)),
+                       "r"(ksp_vsid_data),
                        "r"(ksp_esid_data)
                     : "memory");
 }
@@ -118,7 +144,7 @@ void slb_vmalloc_update(void)
        unsigned long vflags;
 
        vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp;
-       slb_shadow_update(VMALLOC_START, vflags, 1);
+       slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
        slb_flush_and_rebolt();
 }
 
@@ -126,7 +152,7 @@ void slb_vmalloc_update(void)
 void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 {
        unsigned long offset = get_paca()->slb_cache_ptr;
-       unsigned long esid_data = 0;
+       unsigned long slbie_data = 0;
        unsigned long pc = KSTK_EIP(tsk);
        unsigned long stack = KSTK_ESP(tsk);
        unsigned long unmapped_base;
@@ -135,9 +161,12 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
                int i;
                asm volatile("isync" : : : "memory");
                for (i = 0; i < offset; i++) {
-                       esid_data = ((unsigned long)get_paca()->slb_cache[i]
-                               << SID_SHIFT) | SLBIE_C;
-                       asm volatile("slbie %0" : : "r" (esid_data));
+                       slbie_data = (unsigned long)get_paca()->slb_cache[i]
+                               << SID_SHIFT; /* EA */
+                       slbie_data |= user_segment_size(slbie_data)
+                               << SLBIE_SSIZE_SHIFT;
+                       slbie_data |= SLBIE_C; /* C set for user addresses */
+                       asm volatile("slbie %0" : : "r" (slbie_data));
                }
                asm volatile("isync" : : : "memory");
        } else {
@@ -146,7 +175,7 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 
        /* Workaround POWER5 < DD2.1 issue */
        if (offset == 1 || offset > SLB_CACHE_ENTRIES)
-               asm volatile("slbie %0" : : "r" (esid_data));
+               asm volatile("slbie %0" : : "r" (slbie_data));
 
        get_paca()->slb_cache_ptr = 0;
        get_paca()->context = mm->context;
@@ -226,12 +255,16 @@ void slb_initialize(void)
        vflags = SLB_VSID_KERNEL | vmalloc_llp;
 
        /* Invalidate the entire SLB (even slot 0) & all the ERATS */
-       slb_shadow_update(PAGE_OFFSET, lflags, 0);
-       asm volatile("isync; slbia; sync; slbmte  %0,%1; isync" ::
-                    "r" (get_slb_shadow()->save_area[0].vsid),
-                    "r" (get_slb_shadow()->save_area[0].esid) : "memory");
-
-       slb_shadow_update(VMALLOC_START, vflags, 1);
-
-       slb_flush_and_rebolt();
+       asm volatile("isync":::"memory");
+       asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
+       asm volatile("isync; slbia; isync":::"memory");
+       create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0);
+
+       create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
+
+       /* We don't bolt the stack for the time being - we're in boot,
+        * so the stack is in the bolted segment.  By the time it goes
+        * elsewhere, we'll call _switch() which will bolt in the new
+        * one. */
+       asm volatile("isync":::"memory");
 }