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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2013-03-13 03:34:54 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-03-17 12:39:06 +1100
commitc60ac5693c47df32a2b4b18af97fca5635def015 (patch)
tree34da014c89f9a941f5c901fc06f4c3f5bca6ad43 /arch/powerpc/mm/mmu_context_hash64.c
parente39d1a471484662620651cd9520250d33843f235 (diff)
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 <paulus@samba.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: <stable@vger.kernel.org> [v3.8]
Diffstat (limited to 'arch/powerpc/mm/mmu_context_hash64.c')
-rw-r--r--arch/powerpc/mm/mmu_context_hash64.c11
1 files changed, 1 insertions, 10 deletions
diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c
index 40bc5b0ace5..d1d1b92c5b9 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);