[PATCH -V3 2/3] powerpc: Update kernel VSID range
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Wed Mar 13 20:17:06 EST 2013
Paul Mackerras <paulus at samba.org> writes:
> On Tue, Mar 12, 2013 at 05:38:50PM +0530, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
>> This patch change the kernel VSID range so that we limit VSID_BITS to 37.
>> This enables us to support 64TB with 65 bit VA (37+28). Without this patch
>> we have boot hangs on platforms that only support 65 bit VA.
>> With this patch we now have proto vsid generated as below:
>> We first generate a 37-bit "proto-VSID". Proto-VSIDs are generated
>> from mmu context id and effective segment id of the address.
>> For user processes max context id is limited to ((1ul << 19) - 5)
>> for kernel space, we use the top 4 context ids to map address as below
>> 0x7fffc - [ 0xc000000000000000 - 0xc0003fffffffffff ]
>> 0x7fffd - [ 0xd000000000000000 - 0xd0003fffffffffff ]
>> 0x7fffe - [ 0xe000000000000000 - 0xe0003fffffffffff ]
>> 0x7ffff - [ 0xf000000000000000 - 0xf0003fffffffffff ]
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> Mostly looks OK, and it could go in as is, so
> Acked-by: Paul Mackerras <paulus at samba.org>
> Some minor comments below...
>> + * For user processes max context id is limited to ((1ul << 19) - 6)
> should be ((1ul << 19) - 5)
I update the commit message but missed updating this.
Let me know if you want me to send V4 to take care of these review
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