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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2012-09-10 04:52:56 +0200
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-09-17 08:31:53 +0200
commitf033d659c3b931d8b2a16625155e20304e173c9f (patch)
tree1e7cdacc0a981a77209ea04e4449b9beb52f097d /arch/powerpc/mm
parentpowerpc/mm: Add 64TB support (diff)
downloadlinux-f033d659c3b931d8b2a16625155e20304e173c9f.tar.xz
linux-f033d659c3b931d8b2a16625155e20304e173c9f.zip
powerpc/mm: Update VSID allocation documentation
This update the proto-VSID and VSID scramble related information to be more generic by using names instead of current values. Reviewed-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm')
-rw-r--r--arch/powerpc/mm/mmu_context_hash64.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c
index daa076c9025c..40bc5b0ace54 100644
--- a/arch/powerpc/mm/mmu_context_hash64.c
+++ b/arch/powerpc/mm/mmu_context_hash64.c
@@ -30,9 +30,11 @@ static DEFINE_SPINLOCK(mmu_context_lock);
static DEFINE_IDA(mmu_context_ida);
/*
- * The proto-VSID space has 2^35 - 1 segments available for user mappings.
- * Each segment contains 2^28 bytes. Each context maps 2^44 bytes,
- * so we can support 2^19-1 contexts (19 == 35 + 28 - 44).
+ * 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)