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]
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 1a16ca2..77aafaa 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -31,10 +31,15 @@
* No other registers are examined or changed.
*/
_GLOBAL(slb_allocate_realmode)
- /* r3 = faulting address */
+ /*
+ * check for bad kernel/user address
+ * (ea & ~REGION_MASK) >= PGTABLE_RANGE
+ */
+ rldicr. r9,r3,4,(63 - 46 - 4)
+ bne- 8f
srdi r9,r3,60 /* get region */
- srdi r10,r3,28 /* get esid */
+ srdi r10,r3,SID_SHIFT /* get esid */
cmpldi cr7,r9,0xc /* cmp PAGE_OFFSET for later use */
/* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */
@@ -56,12 +61,14 @@
*/
_GLOBAL(slb_miss_kernel_load_linear)
li r11,0
- li r9,0x1
/*
- * for 1T we shift 12 bits more. slb_finish_load_1T will do
- * the necessary adjustment
+ * context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
+ * r9 = region id.
*/
- rldimi r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
+ addis r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@ha
+ addi r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@l
+
+
BEGIN_FTR_SECTION
b slb_finish_load
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
@@ -91,24 +98,19 @@
_GLOBAL(slb_miss_kernel_load_io)
li r11,0
6:
- li r9,0x1
/*
- * for 1T we shift 12 bits more. slb_finish_load_1T will do
- * the necessary adjustment
+ * context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
+ * r9 = region id.
*/
- rldimi r10,r9,(CONTEXT_BITS + USER_ESID_BITS),0
+ addis r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@ha
+ addi r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@l
+
BEGIN_FTR_SECTION
b slb_finish_load
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
b slb_finish_load_1T
-0: /* user address: proto-VSID = context << 15 | ESID. First check
- * if the address is within the boundaries of the user region
- */
- srdi. r9,r10,USER_ESID_BITS
- bne- 8f /* invalid ea bits set */
-
-
+0:
/* when using slices, we extract the psize off the slice bitmaps
* and then we need to get the sllp encoding off the mmu_psize_defs
* array.
@@ -164,15 +166,13 @@
ld r9,PACACONTEXTID(r13)
BEGIN_FTR_SECTION
cmpldi r10,0x1000
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
- rldimi r10,r9,USER_ESID_BITS,0
-BEGIN_FTR_SECTION
bge slb_finish_load_1T
END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
b slb_finish_load
8: /* invalid EA */
li r10,0 /* BAD_VSID */
+ li r9,0 /* BAD_VSID */
li r11,SLB_VSID_USER /* flags don't much matter */
b slb_finish_load
@@ -221,8 +221,6 @@
/* get context to calculate proto-VSID */
ld r9,PACACONTEXTID(r13)
- rldimi r10,r9,USER_ESID_BITS,0
-
/* fall through slb_finish_load */
#endif /* __DISABLED__ */
@@ -231,9 +229,10 @@
/*
* Finish loading of an SLB entry and return
*
- * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
+ * r3 = EA, r9 = context, r10 = ESID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
*/
slb_finish_load:
+ rldimi r10,r9,USER_ESID_BITS,0
ASM_VSID_SCRAMBLE(r10,r9,256M)
/*
* bits above VSID_BITS_256M need to be ignored from r10
@@ -298,10 +297,11 @@
/*
* Finish loading of a 1T SLB entry (for the kernel linear mapping) and return.
*
- * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9
+ * r3 = EA, r9 = context, r10 = ESID(256MB), r11 = flags, clobbers r9
*/
slb_finish_load_1T:
- srdi r10,r10,40-28 /* get 1T ESID */
+ srdi r10,r10,(SID_SHIFT_1T - SID_SHIFT) /* get 1T ESID */
+ rldimi r10,r9,USER_ESID_BITS_1T,0
ASM_VSID_SCRAMBLE(r10,r9,1T)
/*
* bits above VSID_BITS_1T need to be ignored from r10