From 7e74c3921ad9610c0b49f28b8fc69f7480505841 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Sun, 28 Apr 2013 09:37:36 +0000 Subject: [PATCH] powerpc: Fix hpte_decode to use the correct decoding for page sizes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit As per ISA doc, we encode base and actual page size in the LP bits of PTE. The number of bit used to encode the page sizes depend on actual page size. ISA doc lists this as PTE LP actual page size rrrr rrrz >=8KB rrrr rrzz >=16KB rrrr rzzz >=32KB rrrr zzzz >=64KB rrrz zzzz >=128KB rrzz zzzz >=256KB rzzz zzzz >=512KB zzzz zzzz >=1MB ISA doc also says "The values of the “z” bits used to specify each size, along with all possible values of “r” bits in the LP field, must result in LP values distinct from other LP values for other sizes." based on the above update hpte_decode to use the correct decoding for LP bits. Reviewed-by: David Gibson Acked-by: Paul Mackerras Signed-off-by: Aneesh Kumar K.V Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/hash_native_64.c | 53 +++++++++++++++++----------------------- 1 file changed, 22 insertions(+), 31 deletions(-) diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c index 14e3fe8..bb920ee 100644 --- a/arch/powerpc/mm/hash_native_64.c +++ b/arch/powerpc/mm/hash_native_64.c @@ -245,19 +245,10 @@ static long native_hpte_remove(unsigned long hpte_group) return i; } -static inline int hpte_actual_psize(struct hash_pte *hptep, int psize) +static inline int __hpte_actual_psize(unsigned int lp, int psize) { int i, shift; unsigned int mask; - /* Look at the 8 bit LP value */ - unsigned int lp = (hptep->r >> LP_SHIFT) & ((1 << LP_BITS) - 1); - - if (!(hptep->v & HPTE_V_VALID)) - return -1; - - /* First check if it is large page */ - if (!(hptep->v & HPTE_V_LARGE)) - return MMU_PAGE_4K; /* start from 1 ignoring MMU_PAGE_4K */ for (i = 1; i < MMU_PAGE_COUNT; i++) { @@ -284,6 +275,21 @@ static inline int hpte_actual_psize(struct hash_pte *hptep, int psize) return -1; } +static inline int hpte_actual_psize(struct hash_pte *hptep, int psize) +{ + /* Look at the 8 bit LP value */ + unsigned int lp = (hptep->r >> LP_SHIFT) & ((1 << LP_BITS) - 1); + + if (!(hptep->v & HPTE_V_VALID)) + return -1; + + /* First check if it is large page */ + if (!(hptep->v & HPTE_V_LARGE)) + return MMU_PAGE_4K; + + return __hpte_actual_psize(lp, psize); +} + static long native_hpte_updatepp(unsigned long slot, unsigned long newpp, unsigned long vpn, int psize, int ssize, int local) @@ -425,42 +431,27 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot, int *psize, int *apsize, int *ssize, unsigned long *vpn) { unsigned long avpn, pteg, vpi; - unsigned long hpte_r = hpte->r; unsigned long hpte_v = hpte->v; unsigned long vsid, seg_off; - int i, size, a_size, shift, penc; + int size, a_size, shift; + /* Look at the 8 bit LP value */ + unsigned int lp = (hpte->r >> LP_SHIFT) & ((1 << LP_BITS) - 1); if (!(hpte_v & HPTE_V_LARGE)) { size = MMU_PAGE_4K; a_size = MMU_PAGE_4K; } else { - for (i = 0; i < LP_BITS; i++) { - if ((hpte_r & LP_MASK(i+1)) == LP_MASK(i+1)) - break; - } - penc = LP_MASK(i+1) >> LP_SHIFT; for (size = 0; size < MMU_PAGE_COUNT; size++) { /* valid entries have a shift value */ if (!mmu_psize_defs[size].shift) continue; - for (a_size = 0; a_size < MMU_PAGE_COUNT; a_size++) { - - /* 4K pages are not represented by LP */ - if (a_size == MMU_PAGE_4K) - continue; - /* valid entries have a shift value */ - if (!mmu_psize_defs[a_size].shift) - continue; - - if (penc == mmu_psize_defs[size].penc[a_size]) - goto out; - } + a_size = __hpte_actual_psize(lp, size); + if (a_size != -1) + break; } } - -out: /* This works for all page sizes, and for 256M and 1T segments */ *ssize = hpte_v >> HPTE_V_SSIZE_SHIFT; shift = mmu_psize_defs[size].shift; -- 2.7.4