powerpc/fsl-booke: Fix setup_initial_memory_limit to not blindly map

On FSL Book-E devices we support multiple large TLB sizes and so we can
get into situations in which the initial 1G TLB size is too big and
we're asked for a size that is not mappable by a single entry (like
512M).  The single entry is important because when we bring up secondary
cores they need to ensure any data structure they need to access (eg
PACA or stack) is always mapped.

So we really need to determine what size will actually be mapped by the
first TLB entry to ensure we limit early memory references to that
region.  We refactor the map_mem_in_cams() code to provider a helper
function that we can utilize to determine the size of the first TLB
entry while taking into account size and alignment constraints.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index dd0a2589591d..83eb5d5f53d5 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -142,6 +142,8 @@ 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 calc_cam_sz(unsigned long ram, unsigned long virt,
+				 phys_addr_t phys);
 #ifdef CONFIG_PPC32
 extern void MMU_init_hw(void);
 extern unsigned long mmu_mapin_ram(unsigned long top);