[PATCH -V4 12/12] arch/powerpc: properly isolate kernel and user proto-VSID
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Wed Jul 25 22:58:05 EST 2012
From: "Aneesh Kumar K.V" <aneesh.kumar at 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.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/mmu-hash64.h | 16 +++++++++++++---
arch/powerpc/kernel/exceptions-64s.S | 4 +++-
arch/powerpc/mm/mmu_context_hash64.c | 2 +-
arch/powerpc/mm/slb_low.S | 8 ++++++++
4 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
index daa3e4b..8e97715 100644
--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h
@@ -516,9 +516,19 @@ typedef struct {
/* This is only valid for addresses >= PAGE_OFFSET */
static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
{
- if (ssize == MMU_SEGSIZE_256M)
- return vsid_scramble(ea >> SID_SHIFT, 256M);
- return vsid_scramble(ea >> SID_SHIFT_1T, 1T);
+ unsigned long proto_vsid;
+ /*
+ * We need to make sure proto_vsid for the kernel is
+ * >= 2^(CONTEXT_BITS + USER_ESID_BITS[_1T])
+ */
+ if (ssize == MMU_SEGSIZE_256M) {
+ proto_vsid = ea >> SID_SHIFT;
+ proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS));
+ return vsid_scramble(proto_vsid, 256M);
+ }
+ proto_vsid = ea >> SID_SHIFT_1T;
+ proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS_1T));
+ return vsid_scramble(proto_vsid, 1T);
}
/* Returns the segment size indicator for a user address */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 1c06d29..40ed208 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -958,7 +958,9 @@ _GLOBAL(do_stab_bolted)
rldimi r10,r11,7,52 /* r10 = first ste of the group */
/* Calculate VSID */
- /* This is a kernel address, so protovsid = ESID */
+ /* This is a kernel address, so protovsid = ESID | 1 << 37 */
+ li r9,0x1
+ rldimi r11,r9,(CONTEXT_BITS + USER_ESID_BITS),0
ASM_VSID_SCRAMBLE(r11, r9, 256M)
rldic r9,r11,12,16 /* r9 = vsid << 12 */
diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c
index 40677aa..daa076c 100644
--- a/arch/powerpc/mm/mmu_context_hash64.c
+++ b/arch/powerpc/mm/mmu_context_hash64.c
@@ -34,7 +34,7 @@ static DEFINE_IDA(mmu_context_ida);
* Each segment contains 2^28 bytes. Each context maps 2^44 bytes,
* so we can support 2^19-1 contexts (19 == 35 + 28 - 44).
*/
-#define MAX_CONTEXT ((1UL << 19) - 1)
+#define MAX_CONTEXT ((1UL << CONTEXT_BITS) - 1)
int __init_new_context(void)
{
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 7bd8438..2777ba9 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -57,9 +57,13 @@ _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)
srdi r10,r10,40-28 /* get 1T ESID */
+ li r9,0x1
+ rldimi r10,r9,(CONTEXT_BITS + USER_ESID_BITS_1T),0
b slb_finish_load_1T
1:
@@ -87,9 +91,13 @@ _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)
srdi r10,r10,40-28 /* get 1T ESID */
+ li r9,0x1
+ rldimi r10,r9,(CONTEXT_BITS + USER_ESID_BITS_1T),0
b slb_finish_load_1T
0: /* user address: proto-VSID = context << 15 | ESID. First check
--
1.7.10
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