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Commit 55fd766b authored by Kumar Gala's avatar Kumar Gala
Browse files

powerpc/fsl-booke64: Use TLB CAMs to cover linear mapping on FSL 64-bit chips 



On Freescale parts typically have TLB array for large mappings that we can
bolt the linear mapping into.  We utilize the code that already exists
on PPC32 on the 64-bit side to setup the linear mapping to be cover by
bolted TLB entries.  We utilize a quarter of the variable size TLB array
for this purpose.

Additionally, we limit the amount of memory to what we can cover via
bolted entries so we don't get secondary faults in the TLB miss
handlers.  We should fix this limitation in the future.

Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
parent 988cf86d

arch/powerpc/kernel/asm-offsets.c

+2 −2
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ 
#endif

#endif



#if defined(CONFIG_FSL_BOOKE)

#if defined(CONFIG_PPC_FSL_BOOK3E)

#include "../mm/mmu_decl.h"

#endif
@@ -470,7 +470,7 @@ int main(void) 
	DEFINE(PGD_T_LOG2, PGD_T_LOG2);

	DEFINE(PTE_T_LOG2, PTE_T_LOG2);

#endif

#ifdef CONFIG_FSL_BOOKE

#ifdef CONFIG_PPC_FSL_BOOK3E

	DEFINE(TLBCAM_SIZE, sizeof(struct tlbcam));

	DEFINE(TLBCAM_MAS0, offsetof(struct tlbcam, MAS0));

	DEFINE(TLBCAM_MAS1, offsetof(struct tlbcam, MAS1));

arch/powerpc/mm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ obj-$(CONFIG_PPC_STD_MMU) += hash_low_$(CONFIG_WORD_SIZE).o \ 
				   mmu_context_hash$(CONFIG_WORD_SIZE).o

obj-$(CONFIG_40x)		+= 40x_mmu.o

obj-$(CONFIG_44x)		+= 44x_mmu.o

obj-$(CONFIG_FSL_BOOKE)		+= fsl_booke_mmu.o

obj-$(CONFIG_PPC_FSL_BOOK3E)	+= fsl_booke_mmu.o

obj-$(CONFIG_NEED_MULTIPLE_NODES) += numa.o

obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o

ifeq ($(CONFIG_HUGETLB_PAGE),y)

arch/powerpc/mm/fsl_booke_mmu.c

+7 −5
Original line number Diff line number Diff line
@@ -56,11 +56,6 @@ 


unsigned int tlbcam_index;





#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)

#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"

#endif



#define NUM_TLBCAMS	(64)

struct tlbcam TLBCAM[NUM_TLBCAMS];
@@ -185,6 +180,12 @@ unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx) 
	return amount_mapped;

}



#ifdef CONFIG_PPC32



#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)

#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"

#endif



unsigned long __init mmu_mapin_ram(unsigned long top)

{

	return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
@@ -216,3 +217,4 @@ void __init adjust_total_lowmem(void) 


	__initial_memory_limit_addr = memstart_addr + __max_low_memory;

}

#endif

arch/powerpc/mm/mmu_decl.h

+4 −1
Original line number Diff line number Diff line
@@ -140,10 +140,13 @@ extern void wii_memory_fixups(void); 
extern void MMU_init_hw(void);

extern unsigned long mmu_mapin_ram(unsigned long top);



#elif defined(CONFIG_FSL_BOOKE)

#elif defined(CONFIG_PPC_FSL_BOOK3E)

extern unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx);

#ifdef CONFIG_PPC32

extern void MMU_init_hw(void);

extern unsigned long mmu_mapin_ram(unsigned long top);

extern void adjust_total_lowmem(void);

#endif

extern void loadcam_entry(unsigned int index);



struct tlbcam {

arch/powerpc/mm/tlb_nohash.c

+14 −0
Original line number Diff line number Diff line
@@ -541,6 +541,20 @@ static void __early_init_mmu(int boot_cpu) 
	 */

	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;



		/* 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);



		/* limit memory so we dont have linear faults */

		memblock_enforce_memory_limit(linear_map_top);

		memblock_analyze();

	}

#endif



	/* A sync won't hurt us after mucking around with

	 * the MMU configuration

	 */