3 files changed, 34 insertions, 15 deletions

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index bb1f88c10377..f3afe3d97f6b 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -169,7 +169,8 @@ unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 }
 
 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
-                                        unsigned long ram, int max_cam_idx)
+                                        unsigned long ram, int max_cam_idx,
+                                        bool dryrun)
 {
         int i;
         unsigned long amount_mapped = 0;
@@ -179,7 +180,9 @@ static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
                 unsigned long cam_sz;
 
                 cam_sz = calc_cam_sz(ram, virt, phys);
-                settlbcam(i, virt, phys, cam_sz, pgprot_val(PAGE_KERNEL_X), 0);
+                if (!dryrun)
+                        settlbcam(i, virt, phys, cam_sz,
+                                  pgprot_val(PAGE_KERNEL_X), 0);
 
                 ram -= cam_sz;
                 amount_mapped += cam_sz;
@@ -187,6 +190,9 @@ static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
                 phys += cam_sz;
         }
 
+        if (dryrun)
+                return amount_mapped;
+
         loadcam_multi(0, i, max_cam_idx);
         tlbcam_index = i;
 
@@ -199,12 +205,12 @@ static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
         return amount_mapped;
 }
 
-unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx)
+unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun)
 {
         unsigned long virt = PAGE_OFFSET;
         phys_addr_t phys = memstart_addr;
 
-        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx);
+        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun);
 }
 
 #ifdef CONFIG_PPC32
@@ -235,7 +241,7 @@ void __init adjust_total_lowmem(void)
         ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 
         i = switch_to_as1();
-        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM);
+        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false);
         restore_to_as0(i, 0, 0, 1);
 
         pr_info("Memory CAM mapping: ");
@@ -303,10 +309,12 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
                 n = switch_to_as1();
                 /* map a 64M area for the second relocation */
                 if (memstart_addr > start)
-                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM);
+                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
+                                        false);
                 else
                         map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
-                                        0x4000000, CONFIG_LOWMEM_CAM_NUM);
+                                        0x4000000, CONFIG_LOWMEM_CAM_NUM,
+                                        false);
                 restore_to_as0(n, offset, __va(dt_ptr), 1);
                 /* We should never reach here */
                 panic("Relocation error");
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 27c3a2d3a4f1..9f58ff44a075 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -141,7 +141,8 @@ extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(unsigned long top);
 
 #elif defined(CONFIG_PPC_FSL_BOOK3E)
-extern unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx);
+extern unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx,
+                                     bool dryrun);
 extern unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
                                  phys_addr_t phys);
 #ifdef CONFIG_PPC32
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index a7381fbdd6ab..bb04e4df3100 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -648,7 +648,7 @@ static void early_init_this_mmu(void)
 
                 if (map)
                         linear_map_top = map_mem_in_cams(linear_map_top,
-                                                         num_cams);
+                                                         num_cams, false);
         }
 #endif
 
@@ -746,10 +746,14 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
          * entries are supported though that may eventually
          * change.
          *
-         * on FSL Embedded 64-bit, we adjust the RMA size to match the
-         * first bolted TLB entry size.  We still limit max to 1G even if
-         * the TLB could cover more.  This is due to what the early init
-         * code is setup to do.
+         * on FSL Embedded 64-bit, usually all RAM is bolted, but with
+         * unusual memory sizes it's possible for some RAM to not be mapped
+         * (such RAM is not used at all by Linux, since we don't support
+         * highmem on 64-bit).  We limit ppc64_rma_size to what would be
+         * mappable if this memblock is the only one.  Additional memblocks
+         * can only increase, not decrease, the amount that ends up getting
+         * mapped.  We still limit max to 1G even if we'll eventually map
+         * more.  This is due to what the early init code is set up to do.
          *
          * We crop it to the size of the first MEMBLOCK to
          * avoid going over total available memory just in case...
@@ -757,8 +761,14 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 #ifdef CONFIG_PPC_FSL_BOOK3E
         if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
                 unsigned long linear_sz;
-                linear_sz = calc_cam_sz(first_memblock_size, PAGE_OFFSET,
-                                        first_memblock_base);
+                unsigned int num_cams;
+
+                /* use a quarter of the TLBCAM for bolted linear map */
+                num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+
+                linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
+                                            true);
+
                 ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
         } else
 #endif