From c60ac5693c47df32a2b4b18af97fca5635def015 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Wed, 13 Mar 2013 03:34:54 +0000 Subject: powerpc: Update kernel VSID range 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 ] Acked-by: Paul Mackerras Signed-off-by: Aneesh Kumar K.V Tested-by: Geoff Levand Signed-off-by: Benjamin Herrenschmidt CC: [v3.8] --- arch/powerpc/mm/mmu_context_hash64.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) (limited to 'arch/powerpc/mm/mmu_context_hash64.c') diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c index 40bc5b0ace54..d1d1b92c5b99 100644 --- a/arch/powerpc/mm/mmu_context_hash64.c +++ b/arch/powerpc/mm/mmu_context_hash64.c @@ -29,15 +29,6 @@ static DEFINE_SPINLOCK(mmu_context_lock); static DEFINE_IDA(mmu_context_ida); -/* - * 256MB segment - * The proto-VSID space has 2^(CONTEX_BITS + USER_ESID_BITS) - 1 segments - * available for user mappings. Each segment contains 2^28 bytes. Each - * context maps 2^46 bytes (64TB) so we can support 2^19-1 contexts - * (19 == 37 + 28 - 46). - */ -#define MAX_CONTEXT ((1UL << CONTEXT_BITS) - 1) - int __init_new_context(void) { int index; @@ -56,7 +47,7 @@ again: else if (err) return err; - if (index > MAX_CONTEXT) { + if (index > MAX_USER_CONTEXT) { spin_lock(&mmu_context_lock); ida_remove(&mmu_context_ida, index); spin_unlock(&mmu_context_lock); -- cgit v1.2.3