From: "Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com>
To: Stephen Rothwell <sfr@canb•auug.org.au>
Cc: linuxppc-dev@lists•ozlabs.org, paulus@samba•org
Subject: Re: [PATCH -V3 03/11] arch/powerpc: Convert virtual address to vpn
Date: Tue, 10 Jul 2012 11:42:47 +0530 [thread overview]
Message-ID: <87a9z8cffk.fsf@skywalker.in.ibm.com> (raw)
In-Reply-To: <20120710084128.6fe4a4347719f4445dd12b4f@canb.auug.org.au>
Stephen Rothwell <sfr@canb•auug.org.au> writes:
> Hi Aneesh,
>
> On Mon, 9 Jul 2012 18:43:33 +0530 "Aneesh Kumar K.V" <aneesh.kumar@linux•vnet.ibm.com> wrote:
>>
>> diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
>> index 1c65a59..1c984a6 100644
>> --- a/arch/powerpc/include/asm/mmu-hash64.h
>> +++ b/arch/powerpc/include/asm/mmu-hash64.h
>> @@ -154,9 +155,25 @@ struct mmu_psize_def
>> #define MMU_SEGSIZE_256M 0
>> #define MMU_SEGSIZE_1T 1
>>
>> +/*
>> + * encode page number shift.
>> + * Inorder to fit the 78 bit va in a 64 bit variable we shift the va by
>> + * 12 bits. This enable us to address upto 76 bit va.
>> + * For hpt hash from a va we can ignore the page size bits of va and for
>> + * hpte encoding we ignore upto 23 bits of va. So ignoring lower 12 bits ensure
>> + * we work in all cases including 4k page size.
>> + */
>> +#define VPN_SHIFT 12
>>
>> +static inline unsigned long hpte_encode_avpn(unsigned long vpn, int psize,
>> + int ssize)
>> +{
>> + unsigned long v;
>> + /*
>> + * The AVA field omits the low-order 23 bits of the 78 bits VA.
>> + * These bits are not needed in the PTE, because the
>> + * low-order b of these bits are part of the byte offset
>> + * into the virtual page and, if b < 23, the high-order
>> + * 23-b of these bits are always used in selecting the
>> + * PTEGs to be searched
>> + */
>> + BUG_ON(VPN_SHIFT > 23);
>
> Could/should this be BUILD_BUG_ON()?
>
Yes. Will update.
-aneesh
next prev parent reply other threads:[~2012-07-10 6:13 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-09 13:13 [PATCH -V3 0/11] arch/powerpc: Add 64TB support to ppc64 Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 01/11] arch/powerpc: Use hpt_va to compute virtual address Aneesh Kumar K.V
2012-07-22 23:17 ` Paul Mackerras
2012-07-09 13:13 ` [PATCH -V3 02/11] arch/powerpc: Simplify hpte_decode Aneesh Kumar K.V
2012-07-22 23:26 ` Paul Mackerras
2012-07-23 5:41 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 03/11] arch/powerpc: Convert virtual address to vpn Aneesh Kumar K.V
2012-07-09 22:41 ` Stephen Rothwell
2012-07-10 6:12 ` Aneesh Kumar K.V [this message]
2012-07-09 23:06 ` Stephen Rothwell
2012-07-10 6:15 ` Aneesh Kumar K.V
2012-07-22 23:42 ` Paul Mackerras
2012-07-23 5:54 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 04/11] arch/powerpc: Rename va " Aneesh Kumar K.V
2012-07-22 23:46 ` Paul Mackerras
2012-07-23 6:14 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 05/11] arch/powerpc: remove masking top 16 bit of va in tlb invalidate Aneesh Kumar K.V
2012-07-22 23:56 ` Paul Mackerras
2012-07-23 1:22 ` Benjamin Herrenschmidt
2012-07-23 3:49 ` Paul Mackerras
2012-07-23 6:44 ` Aneesh Kumar K.V
2012-07-23 6:48 ` Benjamin Herrenschmidt
2012-07-09 13:13 ` [PATCH -V3 06/11] arch/powerpc: Make KERN_VIRT_SIZE not dependend on PGTABLE_RANGE Aneesh Kumar K.V
2012-07-22 23:57 ` Paul Mackerras
2012-07-09 13:13 ` [PATCH -V3 07/11] arch/powerpc: Increase the slice range to 64TB Aneesh Kumar K.V
2012-07-23 0:00 ` Paul Mackerras
2012-07-23 7:13 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 08/11] arch/powerpc: Make some of the PGTABLE_RANGE dependency explicit Aneesh Kumar K.V
2012-07-23 0:20 ` Paul Mackerras
2012-07-23 7:29 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 09/11] arch/powerpc: Use 50 bits of VSID in slbmte Aneesh Kumar K.V
2012-07-23 0:06 ` Paul Mackerras
2012-07-23 8:21 ` Aneesh Kumar K.V
2012-07-23 9:36 ` Paul Mackerras
2012-07-23 10:22 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 10/11] arch/powerpc: Use 32bit array for slb cache Aneesh Kumar K.V
2012-07-23 0:27 ` Paul Mackerras
2012-07-23 8:25 ` Aneesh Kumar K.V
2012-07-09 13:13 ` [PATCH -V3 11/11] arch/powerpc: Add 64TB support Aneesh Kumar K.V
2012-07-23 0:15 ` Paul Mackerras
2012-07-23 8:49 ` Aneesh Kumar K.V
2012-07-23 9:39 ` Paul Mackerras
2012-07-23 10:22 ` Aneesh Kumar K.V
2012-07-23 11:06 ` Paul Mackerras
2012-07-24 8:37 ` Aneesh Kumar K.V
2012-07-24 9:14 ` Aneesh Kumar K.V
2012-07-24 19:50 ` Aneesh Kumar K.V
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