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/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 6ec6c19..f410c3e 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -195,6 +195,11 @@
unsigned long vpn = hpt_vpn(vaddr, vsid, ssize);
unsigned long tprot = prot;
+ /*
+ * If we hit a bad address return error.
+ */
+ if (!vsid)
+ return -1;
/* Make kernel text executable */
if (overlaps_kernel_text(vaddr, vaddr + step))
tprot &= ~HPTE_R_N;
@@ -924,11 +929,6 @@
DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
ea, access, trap);
- if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) {
- DBG_LOW(" out of pgtable range !\n");
- return 1;
- }
-
/* Get region & vsid */
switch (REGION_ID(ea)) {
case USER_REGION_ID:
@@ -959,6 +959,11 @@
}
DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
+ /* Bad address. */
+ if (!vsid) {
+ DBG_LOW("Bad address!\n");
+ return 1;
+ }
/* Get pgdir */
pgdir = mm->pgd;
if (pgdir == NULL)
@@ -1128,6 +1133,8 @@
/* Get VSID */
ssize = user_segment_size(ea);
vsid = get_vsid(mm->context.id, ea, ssize);
+ if (!vsid)
+ return;
/* Hash doesn't like irqs */
local_irq_save(flags);
@@ -1235,6 +1242,9 @@
hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
+ /* Don't create HPTE entries for bad address */
+ if (!vsid)
+ return;
ret = ppc_md.hpte_insert(hpteg, vpn, __pa(vaddr),
mode, HPTE_V_BOLTED,
mmu_linear_psize, mmu_kernel_ssize);