Fix ia64_do_tlb_purge, its broken in too many ways
1. Make all calls to GET_THIS_PADDR before purging the DTR for PERCPU.
This is because the kernel registers are saved in per_cpu data to allow
the real kernel registers to be used by domains.
2. Wrap the purging of the DTR for PERCPU in #ifdef XEN as Linux
doesn't seem to do this (any more?)
3. Use the per_cpu variable to derive CURRENT_STACK_OFFSET rather
than reading it from a kernel register. See 1) for explanation
of why.
4. Fix VHPT purging code to treat what is at the IA64_DOMAIN_FLAGS_OFFSET
offset as a litteral value (flag) rather than a pointer to a literal.
5. In the VHPT pruning code, don't use r25 as ia64_jump_to_sal,
which branches to ia64_do_tlb_purge expects r25 to be preserved.
There seems no reason not to use r2 as per the other purges
done in ia64_do_tlb_purge. Furthermore use r16 and r18 instead
of r20 and r24 for consistency reasons.
6. Move __va_ul(vcpu_vhpt_maddr(v)) comment outside of
#if VHPT_ENABLED as it also applies to code further down that
is outside the #if
7. There is no 7th change
Cc: Tristan Gingold <tgingold@xxxxxxx>,
Cc: Yutaka Ezaki <yutaka.ezaki@xxxxxxxxxxxxxx>,
Cc: Masaki Kanno <kanno.masaki@xxxxxxxxxxxxxx>,
Cc: Kazuhiro Suzuki <kaz@xxxxxxxxxxxxxx>,
Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
Index: xen-unstable.hg/xen/arch/ia64/linux-xen/mca_asm.S
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/linux-xen/mca_asm.S 2007-07-11
12:05:33.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/linux-xen/mca_asm.S 2007-07-11
13:13:56.000000000 +0900
@@ -195,6 +195,10 @@
*/
ia64_do_tlb_purge:
+#ifdef XEN
+ // This needs to be called in order for GET_THIS_PADDR to work
+ SET_PER_CPU_DATA();;
+#endif
#define O(member) IA64_CPUINFO_##member##_OFFSET
GET_THIS_PADDR(r2, cpu_info) // load phys addr of cpu_info into r2
@@ -244,6 +248,7 @@ ia64_do_tlb_purge:
;;
srlz.d
;;
+#ifdef XEN
// 2. Purge DTR for PERCPU data.
movl r16=PERCPU_ADDR
mov r18=PERCPU_PAGE_SHIFT<<2
@@ -252,6 +257,7 @@ ia64_do_tlb_purge:
;;
srlz.d
;;
+#endif
// 3. Purge ITR for PAL code.
GET_THIS_PADDR(r2, ia64_mca_pal_base)
;;
@@ -263,7 +269,16 @@ ia64_do_tlb_purge:
srlz.i
;;
// 4. Purge DTR for stack.
+#ifdef XEN
+ // Kernel registers are saved in a per_cpu cpu_kr_ia64_t
+ // to allow the kernel registers themselves to be used by domains.
+ GET_THIS_PADDR(r2, cpu_kr);;
+ add r2=IA64_KR_CURRENT_STACK_OFFSET,r2
+ ;;
+ ld8 r16=[r2]
+#else
mov r16=IA64_KR(CURRENT_STACK)
+#endif
;;
shl r16=r16,IA64_GRANULE_SHIFT
movl r19=PAGE_OFFSET
@@ -277,8 +292,8 @@ ia64_do_tlb_purge:
;;
#ifdef XEN
// 5. VHPT
+ // r2 = __va_ul(vcpu_vhpt_maddr(v));
#if VHPT_ENABLED
- // r25 = __va_ul(vcpu_vhpt_maddr(v));
GET_THIS_PADDR(r2,cpu_kr);;
add r2=IA64_KR_CURRENT_OFFSET,r2;;
ld8 r2=[r2];;
@@ -289,25 +304,24 @@ ia64_do_tlb_purge:
ld8 r3=[r3];;
dep r3=0,r3,60,4;; // virtual to physical
add r3=IA64_DOMAIN_FLAGS_OFFSET,r3;;
- ld8 r3=[r3];;
and r3=HAS_PERVCPU_VHPT_MASK,r3;;
cmp.eq p6,p0=r3,r0;;
(p6) br.cond.sptk .not_pervcpu_vhpt
add r2=IA64_VCPU_VHPT_MADDR_OFFSET,r2;;
dep r2=0,r2,60,4;; // virtual to physical
ld8 r2=[r2];;
- dep r25=-1,r2,60,4;; // physical to virtual
+ dep r2=-1,r2,60,4;; // physical to virtual
br.sptk .percpu_vhpt_done
#endif
.not_pervcpu_vhpt:
GET_THIS_PADDR(r2, vhpt_paddr);;
ld8 r2=[r2];;
- dep r25=-1,r2,60,4;; // physical to virtual
+ dep r2=-1,r2,60,4;; // physical to virtual
.percpu_vhpt_done:
- dep r20=0,r25,0,IA64_GRANULE_SHIFT
- mov r24=IA64_GRANULE_SHIFT<<2
+ dep r16=0,r2,0,IA64_GRANULE_SHIFT
+ mov r18=IA64_GRANULE_SHIFT<<2
;;
- ptr.d r20,r24
+ ptr.d r16,r18
;;
srlz.d
;;
--
--
Horms
H: http://www.vergenet.net/~horms/
W: http://www.valinux.co.jp/en/
_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel
|
Home