powerpc/nohash: Split __early_init_mmu() into boot and secondary

__early_init_mmu() does some things that are really only needed by the
boot cpu.  On FSL booke, This includes calling
memblock_enforce_memory_limit(), which is labelled __init.  Secondary
cpu init code can't be __init as that would break CPU hotplug.

While it's probably a bug that memblock_enforce_memory_limit() isn't
__init_memblock instead, there's no reason why we should be doing this
stuff for secondary cpus in the first place.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index 92cb18d..f38ea4d 100644 (file)
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -581,42 +581,10 @@ static void setup_mmu_htw(void)
 /*
  * Early initialization of the MMU TLB code
  */
-static void __early_init_mmu(int boot_cpu)
+static void early_init_this_mmu(void)
 {
        unsigned int mas4;
 
-       /* XXX This will have to be decided at runtime, but right
-        * now our boot and TLB miss code hard wires it. Ideally
-        * we should find out a suitable page size and patch the
-        * TLB miss code (either that or use the PACA to store
-        * the value we want)
-        */
-       mmu_linear_psize = MMU_PAGE_1G;
-
-       /* XXX This should be decided at runtime based on supported
-        * page sizes in the TLB, but for now let's assume 16M is
-        * always there and a good fit (which it probably is)
-        *
-        * Freescale booke only supports 4K pages in TLB0, so use that.
-        */
-       if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
-               mmu_vmemmap_psize = MMU_PAGE_4K;
-       else
-               mmu_vmemmap_psize = MMU_PAGE_16M;
-
-       /* XXX This code only checks for TLB 0 capabilities and doesn't
-        *     check what page size combos are supported by the HW. It
-        *     also doesn't handle the case where a separate array holds
-        *     the IND entries from the array loaded by the PT.
-        */
-       if (boot_cpu) {
-               /* Look for supported page sizes */
-               setup_page_sizes();
-
-               /* Look for HW tablewalk support */
-               setup_mmu_htw();
-       }
-
        /* Set MAS4 based on page table setting */
 
        mas4 = 0x4 << MAS4_WIMGED_SHIFT;
@@ -650,11 +618,6 @@ static void __early_init_mmu(int boot_cpu)
        }
        mtspr(SPRN_MAS4, mas4);
 
-       /* Set the global containing the top of the linear mapping
-        * for use by the TLB miss code
-        */
-       linear_map_top = memblock_end_of_DRAM();
-
 #ifdef CONFIG_PPC_FSL_BOOK3E
        if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
                unsigned int num_cams;
@@ -662,10 +625,49 @@ static void __early_init_mmu(int boot_cpu)
                /* use a quarter of the TLBCAM for bolted linear map */
                num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
                linear_map_top = map_mem_in_cams(linear_map_top, num_cams);
+       }
+#endif
 
-               /* limit memory so we dont have linear faults */
-               memblock_enforce_memory_limit(linear_map_top);
+       /* A sync won't hurt us after mucking around with
+        * the MMU configuration
+        */
+       mb();
+}
 
+static void __init early_init_mmu_global(void)
+{
+       /* XXX This will have to be decided at runtime, but right
+        * now our boot and TLB miss code hard wires it. Ideally
+        * we should find out a suitable page size and patch the
+        * TLB miss code (either that or use the PACA to store
+        * the value we want)
+        */
+       mmu_linear_psize = MMU_PAGE_1G;
+
+       /* XXX This should be decided at runtime based on supported
+        * page sizes in the TLB, but for now let's assume 16M is
+        * always there and a good fit (which it probably is)
+        *
+        * Freescale booke only supports 4K pages in TLB0, so use that.
+        */
+       if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
+               mmu_vmemmap_psize = MMU_PAGE_4K;
+       else
+               mmu_vmemmap_psize = MMU_PAGE_16M;
+
+       /* XXX This code only checks for TLB 0 capabilities and doesn't
+        *     check what page size combos are supported by the HW. It
+        *     also doesn't handle the case where a separate array holds
+        *     the IND entries from the array loaded by the PT.
+        */
+       /* Look for supported page sizes */
+       setup_page_sizes();
+
+       /* Look for HW tablewalk support */
+       setup_mmu_htw();
+
+#ifdef CONFIG_PPC_FSL_BOOK3E
+       if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
                if (book3e_htw_mode == PPC_HTW_NONE) {
                        extlb_level_exc = EX_TLB_SIZE;
                        patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
@@ -675,22 +677,41 @@ static void __early_init_mmu(int boot_cpu)
        }
 #endif
 
-       /* A sync won't hurt us after mucking around with
-        * the MMU configuration
+       /* Set the global containing the top of the linear mapping
+        * for use by the TLB miss code
         */
-       mb();
+       linear_map_top = memblock_end_of_DRAM();
+}
+
+static void __init early_mmu_set_memory_limit(void)
+{
+#ifdef CONFIG_PPC_FSL_BOOK3E
+       if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+               /*
+                * Limit memory so we dont have linear faults.
+                * Unlike memblock_set_current_limit, which limits
+                * memory available during early boot, this permanently
+                * reduces the memory available to Linux.  We need to
+                * do this because highmem is not supported on 64-bit.
+                */
+               memblock_enforce_memory_limit(linear_map_top);
+       }
+#endif
 
        memblock_set_current_limit(linear_map_top);
 }
 
+/* boot cpu only */
 void __init early_init_mmu(void)
 {
-       __early_init_mmu(1);
+       early_init_mmu_global();
+       early_init_this_mmu();
+       early_mmu_set_memory_limit();
 }
 
 void early_init_mmu_secondary(void)
 {
-       __early_init_mmu(0);
+       early_init_this_mmu();
 }
 
 void setup_initial_memory_limit(phys_addr_t first_memblock_base,