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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH -V5 11/13] arch/powerpc: properly isolate kernel and user proto-VSID
Date: Wed, 01 Aug 2012 13:28:47 +0530	[thread overview]
Message-ID: <87r4rrhwlk.fsf@skywalker.in.ibm.com> (raw)
In-Reply-To: <20120801043147.GA24014@drongo>

Paul Mackerras <paulus@samba.org> writes:

> On Mon, Jul 30, 2012 at 04:52:17PM +0530, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>> 
>> The proto-VSID space is divided into two class
>> User:   0 to 2^(CONTEXT_BITS + USER_ESID_BITS) -1
>> kernel: 2^(CONTEXT_BITS + USER_ESID_BITS) to 2^(VSID_BITS) - 1
>> 
>> With KERNEL_START at 0xc000000000000000, the proto vsid for
>> the kernel ends up with 0xc00000000 (36 bits). With 64TB
>> patchset we need to have kernel proto-VSID in the
>> [2^37 to 2^38 - 1] range due to the increased USER_ESID_BITS.
>
> This needs to be rolled in with the previous patch, otherwise you'll
> break bisection.
>
>> diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
>> index db2cb3f..405d380 100644
>> --- a/arch/powerpc/mm/slb_low.S
>> +++ b/arch/powerpc/mm/slb_low.S
>> @@ -57,8 +57,16 @@ _GLOBAL(slb_allocate_realmode)
>>  _GLOBAL(slb_miss_kernel_load_linear)
>>  	li	r11,0
>>  BEGIN_FTR_SECTION
>> +	li	r9,0x1
>> +	rldimi  r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
>>  	b	slb_finish_load
>>  END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
>> +	li	r9,0x1
>> +	/*
>> +	 * shift 12 bits less here, slb_finish_load_1T will do
>> +	 * the necessary shits
>> +	 */
>> +	rldimi  r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
>>  	b	slb_finish_load_1T
>
> Since you're actually doing exactly the same instructions in the 256M
> and 1T segment cases, why not do the li; rldimi before the
> BEGIN_FTR_SECTION?
>
>> @@ -86,8 +94,16 @@ _GLOBAL(slb_miss_kernel_load_vmemmap)
>>  	li	r11,0
>>  6:
>>  BEGIN_FTR_SECTION
>> +	li	r9,0x1
>> +	rldimi  r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
>>  	b	slb_finish_load
>>  END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
>> +	li	r9,0x1
>> +	/*
>> +	 * shift 12 bits less here, slb_finish_load_1T will do
>> +	 * the necessary shits
>> +	 */
>> +	rldimi  r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
>>  	b	slb_finish_load_1T
>
> And similarly here.
>

Folded to the previous patch and updated

-aneesh

  reply	other threads:[~2012-08-01  7:58 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-30 11:22 [PATCH -V5 0/13] arch/powerpc: Add 64TB support to ppc64 Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 01/13] arch/powerpc: Use hpt_va to compute virtual address Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 02/13] arch/powerpc: Simplify hpte_decode Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 03/13] arch/powerpc: Convert virtual address to vpn Aneesh Kumar K.V
2012-08-01  4:33   ` Paul Mackerras
2012-08-01  7:23     ` Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 04/13] arch/powerpc: Rename va " Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 05/13] arch/powerpc: Make KERN_VIRT_SIZE not dependend on PGTABLE_RANGE Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 06/13] arch/powerpc: Increase the slice range to 64TB Aneesh Kumar K.V
2012-08-01  5:16   ` Paul Mackerras
2012-08-01  7:43     ` Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 07/13] arch/powerpc: Make some of the PGTABLE_RANGE dependency explicit Aneesh Kumar K.V
2012-08-01  5:18   ` Paul Mackerras
2012-08-01  7:45     ` Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 08/13] arch/powerpc: Use the rquired number of VSID bits in slbmte Aneesh Kumar K.V
2012-08-01  5:19   ` Paul Mackerras
2012-07-30 11:22 ` [PATCH -V5 09/13] arch/powerpc: Use 32bit array for slb cache Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 10/13] arch/powerpc: Add 64TB support Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 11/13] arch/powerpc: properly isolate kernel and user proto-VSID Aneesh Kumar K.V
2012-08-01  4:31   ` Paul Mackerras
2012-08-01  7:58     ` Aneesh Kumar K.V [this message]
2012-07-30 11:22 ` [PATCH -V5 12/13] arch/powerpc: Replace open coded CONTEXT_BITS value Aneesh Kumar K.V
2012-08-01  5:29   ` Paul Mackerras
2012-08-01  9:56     ` Aneesh Kumar K.V
2012-07-30 11:22 ` [PATCH -V5 13/13] arch/powerpc: Update VSID allocation documentation Aneesh Kumar K.V
2012-08-01  5:35   ` Paul Mackerras
2012-08-01 10:01     ` Aneesh Kumar K.V

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