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 at freescale.com>
---
arch/powerpc/mm/fsl_booke_mmu.c | 22 +++++++++++++++-------
arch/powerpc/mm/mmu_decl.h | 3 ++-
arch/powerpc/mm/tlb_nohash.c | 24 +++++++++++++++++-------
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 36d3c55..5eef7d7 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -178,7 +178,8 @@ 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;
@@ -188,7 +189,9 @@ 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);
- preptlbcam(i, virt, phys, cam_sz, pgprot_val(PAGE_KERNEL_X), 0);
+ if (!dryrun)
+ preptlbcam(i, virt, phys, cam_sz,
+ pgprot_val(PAGE_KERNEL_X), 0);
ram -= cam_sz;
amount_mapped += cam_sz;
@@ -196,6 +199,9 @@ 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;
@@ -208,12 +214,12 @@ 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
@@ -244,7 +250,7 @@ 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: ");
@@ -312,10 +318,12 @@ 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 27c3a2d..9f58ff4 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 a7381fb..bb04e4d 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
--
2.1.4
