powerpc/64s: Allocate slb_shadow structures individually

slb_shadow structures are avoided for radix environment.

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

diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c
index 6cddb9bdc151f35a5cbf0e3ee4c8e69e6064a143..2699f9009286c71302a9f24afd03ada53017e351 100644 (file)
--- a/arch/powerpc/kernel/paca.c
+++ b/arch/powerpc/kernel/paca.c
@@ -72,41 +72,28 @@ static void __init free_lppaca(struct lppaca *lp)
 #ifdef CONFIG_PPC_BOOK3S_64
 
 /*
- * 3 persistent SLBs are registered here.  The buffer will be zero
+ * 3 persistent SLBs are allocated here.  The buffer will be zero
  * initially, hence will all be invaild until we actually write them.
  *
  * If you make the number of persistent SLB entries dynamic, please also
  * update PR KVM to flush and restore them accordingly.
  */
-static struct slb_shadow * __initdata slb_shadow;
-
-static void __init allocate_slb_shadows(int nr_cpus, int limit)
-{
-       int size = PAGE_ALIGN(sizeof(struct slb_shadow) * nr_cpus);
-
-       if (early_radix_enabled())
-               return;
-
-       slb_shadow = __va(memblock_alloc_base(size, PAGE_SIZE, limit));
-       memset(slb_shadow, 0, size);
-}
-
-static struct slb_shadow * __init init_slb_shadow(int cpu)
+static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 {
        struct slb_shadow *s;
 
-       if (early_radix_enabled())
-               return NULL;
+       if (cpu != boot_cpuid) {
+               /*
+                * Boot CPU comes here before early_radix_enabled
+                * is parsed (e.g., for disable_radix). So allocate
+                * always and this will be fixed up in free_unused_pacas.
+                */
+               if (early_radix_enabled())
+                       return NULL;
+       }
 
-       s = &slb_shadow[cpu];
-
-       /*
-        * When we come through here to initialise boot_paca, the slb_shadow
-        * buffers are not allocated yet. That's OK, we'll get one later in
-        * boot, but make sure we don't corrupt memory at 0.
-        */
-       if (!slb_shadow)
-               return NULL;
+       s = __va(memblock_alloc_base(sizeof(*s), L1_CACHE_BYTES, limit));
+       memset(s, 0, sizeof(*s));
 
        s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
        s->buffer_length = cpu_to_be32(sizeof(*s));
@@ -114,10 +101,6 @@ static struct slb_shadow * __init init_slb_shadow(int cpu)
        return s;
 }
 
-#else /* !CONFIG_PPC_BOOK3S_64 */
-
-static void __init allocate_slb_shadows(int nr_cpus, int limit) { }
-
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
 /* The Paca is an array with one entry per processor.  Each contains an
@@ -151,7 +134,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
        new_paca->__current = &init_task;
        new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 #ifdef CONFIG_PPC_BOOK3S_64
-       new_paca->slb_shadow_ptr = init_slb_shadow(cpu);
+       new_paca->slb_shadow_ptr = NULL;
 #endif
 
 #ifdef CONFIG_PPC_BOOK3E
@@ -222,13 +205,16 @@ void __init allocate_pacas(void)
        printk(KERN_DEBUG "Allocated %lu bytes for %u pacas\n",
                        size, nr_cpu_ids);
 
-       allocate_slb_shadows(nr_cpu_ids, limit);
-
        /* Can't use for_each_*_cpu, as they aren't functional yet */
        for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
-               initialise_paca(paca_ptrs[cpu], cpu);
+               struct paca_struct *paca = paca_ptrs[cpu];
+
+               initialise_paca(paca, cpu);
 #ifdef CONFIG_PPC_PSERIES
-               paca_ptrs[cpu]->lppaca_ptr = new_lppaca(cpu, limit);
+               paca->lppaca_ptr = new_lppaca(cpu, limit);
+#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+               paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 #endif
        }
 }
@@ -263,6 +249,15 @@ void __init free_unused_pacas(void)
 
        paca_nr_cpu_ids = nr_cpu_ids;
        paca_ptrs_size = new_ptrs_size;
+
+#ifdef CONFIG_PPC_BOOK3S_64
+       if (early_radix_enabled()) {
+               /* Ugly fixup, see new_slb_shadow() */
+               memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
+                               sizeof(struct slb_shadow));
+               paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
+       }
+#endif
 }
 
 void copy_mm_to_paca(struct mm_struct *mm)