From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp05.in.ibm.com (e28smtp05.in.ibm.com [122.248.162.5]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp05.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A28ED2C02CB for ; Fri, 22 Feb 2013 03:48:02 +1100 (EST) Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Feb 2013 22:15:58 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id AD2FAE0050 for ; Thu, 21 Feb 2013 22:18:58 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r1LGltCC9044160 for ; Thu, 21 Feb 2013 22:17:55 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r1LGlrTd010970 for ; Fri, 22 Feb 2013 03:47:56 +1100 From: "Aneesh Kumar K.V" To: benh@kernel.crashing.org, paulus@samba.org Subject: [RFC PATCH -V2 12/21] powerpc: Fix hpte_decode to use the correct decoding for page sizes Date: Thu, 21 Feb 2013 22:17:19 +0530 Message-Id: <1361465248-10867-13-git-send-email-aneesh.kumar@linux.vnet.ibm.com> In-Reply-To: <1361465248-10867-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1361465248-10867-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: "Aneesh Kumar K.V" 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. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/hash_native_64.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c index 3bc57e2..5448ad4 100644 --- a/arch/powerpc/mm/hash_native_64.c +++ b/arch/powerpc/mm/hash_native_64.c @@ -428,19 +428,15 @@ 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 = MMU_PAGE_4K, shift, penc; + int size, a_size = MMU_PAGE_4K, shift, mask; + /* Look at the 8 bit LP value */ + unsigned int lp = (hpte->r >> LP_SHIFT) & ((1 << (LP_BITS + 1)) - 1); if (!(hpte_v & HPTE_V_LARGE)) 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++) { /* 4K pages are not represented by LP */ @@ -450,12 +446,23 @@ static void hpte_decode(struct hash_pte *hpte, unsigned long slot, /* valid entries have a shift value */ if (!mmu_psize_defs[size].shift) continue; - for (a_size = 0; a_size < MMU_PAGE_COUNT; a_size++) - if (penc == mmu_psize_defs[size].penc[a_size]) + + for (a_size = 0; a_size < MMU_PAGE_COUNT; a_size++) { + /* valid entries have a shift value */ + if (!mmu_psize_defs[a_size].shift) + continue; + + shift = mmu_psize_defs[a_size].shift - 11; + if (shift > 9) + shift = 9; + mask = (1 << shift) - 1; + if ((lp & mask) == + mmu_psize_defs[size].penc[a_size]) { goto out; + } + } } } - out: /* This works for all page sizes, and for 256M and 1T segments */ *ssize = hpte_v >> HPTE_V_SSIZE_SHIFT; -- 1.7.10