From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx129.postini.com [74.125.245.129]) by kanga.kvack.org (Postfix) with SMTP id 022836B0005 for ; Thu, 11 Apr 2013 01:20:54 -0400 (EDT) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 11 Apr 2013 15:12:02 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 1B1A82BB0050 for ; Thu, 11 Apr 2013 15:20:27 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r3B5KLbo13041926 for ; Thu, 11 Apr 2013 15:20:21 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r3B5KQB8003573 for ; Thu, 11 Apr 2013 15:20:26 +1000 From: "Aneesh Kumar K.V" Subject: Re: [PATCH -V5 13/25] powerpc: Update tlbie/tlbiel as per ISA doc In-Reply-To: <20130411033010.GV8165@truffula.fritz.box> References: <1365055083-31956-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1365055083-31956-14-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20130411033010.GV8165@truffula.fritz.box> Date: Thu, 11 Apr 2013 10:50:12 +0530 Message-ID: <871uahod83.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: David Gibson Cc: benh@kernel.crashing.org, paulus@samba.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org David Gibson writes: > On Thu, Apr 04, 2013 at 11:27:51AM +0530, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> This make sure we handle multiple page size segment correctly. > > This needs a much more detailed message. In what way was the existing > code not matching the ISA documentation? What consequences did that > have? Mostly to make sure we use the right penc values in tlbie. I did test these changes on PowerNV. > >> >> Signed-off-by: Aneesh Kumar K.V >> --- >> arch/powerpc/mm/hash_native_64.c | 30 ++++++++++++++++++++++++++++-- >> 1 file changed, 28 insertions(+), 2 deletions(-) >> >> diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c >> index b461b2d..ac84fa6 100644 >> --- a/arch/powerpc/mm/hash_native_64.c >> +++ b/arch/powerpc/mm/hash_native_64.c >> @@ -61,7 +61,10 @@ static inline void __tlbie(unsigned long vpn, int psize, int apsize, int ssize) >> >> switch (psize) { >> case MMU_PAGE_4K: >> + /* clear out bits after (52) [0....52.....63] */ >> + va &= ~((1ul << (64 - 52)) - 1); >> va |= ssize << 8; >> + va |= mmu_psize_defs[apsize].sllp << 6; > > sllp is the per-segment encoding, so it sure must be looked up via > psize, not apsize. as per ISA doc, for base page size 4K, RB[56:58] must be set to SLB[L|LP] encoded for the page size corresponding to the actual page size specified by the PTE that was used to create the the TLB entry to be invalidated. > >> asm volatile(ASM_FTR_IFCLR("tlbie %0,0", PPC_TLBIE(%1,%0), %2) >> : : "r" (va), "r"(0), "i" (CPU_FTR_ARCH_206) >> : "memory"); >> @@ -69,9 +72,19 @@ static inline void __tlbie(unsigned long vpn, int psize, int apsize, int ssize) >> default: >> /* We need 14 to 14 + i bits of va */ >> penc = mmu_psize_defs[psize].penc[apsize]; >> - va &= ~((1ul << mmu_psize_defs[psize].shift) - 1); >> + va &= ~((1ul << mmu_psize_defs[apsize].shift) - 1); >> va |= penc << 12; >> va |= ssize << 8; >> + /* Add AVAL part */ >> + if (psize != apsize) { >> + /* >> + * MPSS, 64K base page size and 16MB parge page size >> + * We don't need all the bits, but this seems to work. >> + * vpn cover upto 65 bits of va. (0...65) and we need >> + * 58..64 bits of va. > > "seems to work" is not a comment I like to see in core MMU code... > As per ISA spec, the "other bits" in RB[56:62] must be ignored by the processor. Hence I didn't bother to do zero it out. Since we only support one MPSS combination, we could easily zero out using 0xf0. -aneesh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org