Hi, Hope someone could answer to this question.. As some of you know, SRMMU(Sparc Reference MMU in Sparc V8) uses top 8, 6, 6 bits of the linear address as PGT, PMD, PTE table index. so PGDIR_SHIFT is 24 and PMD_SHIFT is 18, and PTE_SHIFT is 12. (page size 4096) These shift values are for getting the index to into each table. But in http://lxr.free-electrons.com/source/arch/sparc/include/asm/pgtable_32.h#L35 #define PMD_SHIFT 22. and in http://lxr.free-electrons.com/source/arch/sparc/include/asm/page_32.h#L84 typedef struct { unsigned long pmdv[16]; } pmd_t; Why is it like this? (those sources are for sparc) I'm having some confusion from this.. Could someone please explain it or give me a good reference about this? Best regards, Chan
oh, I'm answerting to my own question again..I've beeing following the initial sparc page table setup. Looks like the PMD table which has 64 entries are managed by 4 blocks of 16 entries and the allocation of PTE table is by each 16 entry-block at one time. This is populating only 1/4 of PMD table and connecting 16 64-entry PTE tables each time. regards, Chan 보낸 사람 : "Chan Kim" <ckim@etri.re.kr> 보낸 날짜 : 2014-05-01 20:49:25 ( +09:00 ) 받는 사람 : kernelnewbies@kernelnewbies.org <kernelnewbies@kernelnewbies.org> 참조 : 제목 : about PMD_SHIFT value (22 or 18?) Hi, Hope someone could answer to this question.. As some of you know, SRMMU(Sparc Reference MMU in Sparc V8) uses top 8, 6, 6 bits of the linear address as PGT, PMD, PTE table index. so PGDIR_SHIFT is 24 and PMD_SHIFT is 18, and PTE_SHIFT is 12. (page size 4096) These shift values are for getting the index to into each table. But in http://lxr.free-electrons.com/source/arch/sparc/include/asm/pgtable_32.h#L35 #define PMD_SHIFT 22. and in http://lxr.free-electrons.com/source/arch/sparc/include/asm/page_32.h#L84 typedef struct { unsigned long pmdv[16]; } pmd_t; Why is it like this? (those sources are for sparc) I'm having some confusion from this.. Could someone please explain it or give me a good reference about this? Best regards, Chan _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
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Chan Kim