powerpc/fsl-booke-64: Don't limit ppc64_rma_size to one TLB entry

This is required for kdump to work when loaded at at an address that
does not fall within the first TLB entry -- which can easily happen
because while the lower limit is enforced via reserved memory, which
doesn't affect how much is mapped, the upper limit is enforced via a
different mechanism that does.  Thus, more TLB entries are needed than
would normally be used, as the total memory to be mapped might not be a
power of two.

Signed-off-by: Scott Wood <scottwood@freescale.com>

diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index bb1f88c1037712c7651c68230e13576b165fd519..f3afe3d97f6b3bd26ef344e44611a2e2cd0d5460 100644 (file)
--- 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 27c3a2d3a4f144c50ea93673fa4bc97c8bece6c6..9f58ff44a07500870717ea5668e60f3ec7c64793 100644 (file)
--- 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 a7381fbdd6ab74f508e1a82632dd7cd41aa79cdc..bb04e4df31008089e5390619dc52a7c6c26d5f7b 100644 (file)
--- 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