paravirtualize ar.itc and ar.itm in order to support save/restore.
Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
arch/ia64/include/asm/xen/inst.h | 21 +++++++++
arch/ia64/include/asm/xen/interface.h | 9 ++++
arch/ia64/include/asm/xen/minstate.h | 11 ++++-
arch/ia64/include/asm/xen/privop.h | 2 +
arch/ia64/kernel/asm-offsets.c | 2 +
arch/ia64/xen/xen_pv_ops.c | 80 ++++++++++++++++++++++++++++++++-
6 files changed, 123 insertions(+), 2 deletions(-)
diff --git a/arch/ia64/include/asm/xen/inst.h b/arch/ia64/include/asm/xen/inst.h
index e8e01b2..90537dc 100644
--- a/arch/ia64/include/asm/xen/inst.h
+++ b/arch/ia64/include/asm/xen/inst.h
@@ -113,6 +113,27 @@
.endm
#define MOV_FROM_PSR(pred, reg, clob) __MOV_FROM_PSR pred, reg, clob
+/* assuming ar.itc is read with interrupt disabled. */
+#define MOV_FROM_ITC(pred, pred_clob, reg, clob) \
+(pred) movl clob = XSI_ITC_OFFSET; \
+ ;; \
+(pred) ld8 clob = [clob]; \
+(pred) mov reg = ar.itc; \
+ ;; \
+(pred) add reg = reg, clob; \
+ ;; \
+(pred) movl clob = XSI_ITC_LAST; \
+ ;; \
+(pred) ld8 clob = [clob]; \
+ ;; \
+(pred) cmp.geu.unc pred_clob, p0 = clob, reg; \
+ ;; \
+(pred_clob) add reg = 1, clob; \
+ ;; \
+(pred) movl clob = XSI_ITC_LAST; \
+ ;; \
+(pred) st8 [clob] = reg
+
#define MOV_TO_IFA(reg, clob) \
movl clob = XSI_IFA; \
diff --git a/arch/ia64/include/asm/xen/interface.h
b/arch/ia64/include/asm/xen/interface.h
index f00fab4..e951e74 100644
--- a/arch/ia64/include/asm/xen/interface.h
+++ b/arch/ia64/include/asm/xen/interface.h
@@ -209,6 +209,15 @@ struct mapped_regs {
unsigned long krs[8]; /* kernel registers */
unsigned long tmp[16]; /* temp registers
(e.g. for hyperprivops) */
+
+ /* itc paravirtualization
+ * vAR.ITC = mAR.ITC + itc_offset
+ * itc_last is one which was lastly passed to
+ * the guest OS in order to prevent it from
+ * going backwords.
+ */
+ unsigned long itc_offset;
+ unsigned long itc_last;
};
};
};
diff --git a/arch/ia64/include/asm/xen/minstate.h
b/arch/ia64/include/asm/xen/minstate.h
index 4d92d9b..c57fa91 100644
--- a/arch/ia64/include/asm/xen/minstate.h
+++ b/arch/ia64/include/asm/xen/minstate.h
@@ -1,3 +1,12 @@
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+/* read ar.itc in advance, and use it before leaving bank 0 */
+#define XEN_ACCOUNT_GET_STAMP \
+ MOV_FROM_ITC(pUStk, p6, r20, r2);
+#else
+#define XEN_ACCOUNT_GET_STAMP
+#endif
+
/*
* DO_SAVE_MIN switches to the kernel stacks (if necessary) and saves
* the minimum state necessary that allows us to turn psr.ic back
@@ -123,7 +132,7 @@
;;
\
.mem.offset 0,0; st8.spill [r16]=r2,16;
\
.mem.offset 8,0; st8.spill [r17]=r3,16;
\
- ACCOUNT_GET_STAMP
\
+ XEN_ACCOUNT_GET_STAMP
\
adds r2=IA64_PT_REGS_R16_OFFSET,r1;
\
;;
\
EXTRA;
\
diff --git a/arch/ia64/include/asm/xen/privop.h
b/arch/ia64/include/asm/xen/privop.h
index 71ec754..2261dda 100644
--- a/arch/ia64/include/asm/xen/privop.h
+++ b/arch/ia64/include/asm/xen/privop.h
@@ -55,6 +55,8 @@
#define XSI_BANK1_R16 (XSI_BASE + XSI_BANK1_R16_OFS)
#define XSI_BANKNUM (XSI_BASE + XSI_BANKNUM_OFS)
#define XSI_IHA (XSI_BASE + XSI_IHA_OFS)
+#define XSI_ITC_OFFSET (XSI_BASE + XSI_ITC_OFFSET_OFS)
+#define XSI_ITC_LAST (XSI_BASE + XSI_ITC_LAST_OFS)
#endif
#ifndef __ASSEMBLY__
diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index 742dbb1..af56501 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -316,5 +316,7 @@ void foo(void)
DEFINE_MAPPED_REG_OFS(XSI_BANK1_R16_OFS, bank1_regs[0]);
DEFINE_MAPPED_REG_OFS(XSI_B0NATS_OFS, vbnat);
DEFINE_MAPPED_REG_OFS(XSI_B1NATS_OFS, vnat);
+ DEFINE_MAPPED_REG_OFS(XSI_ITC_OFFSET_OFS, itc_offset);
+ DEFINE_MAPPED_REG_OFS(XSI_ITC_LAST_OFS, itc_last);
#endif /* CONFIG_XEN */
}
diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c
index 46b418a..e83ede7 100644
--- a/arch/ia64/xen/xen_pv_ops.c
+++ b/arch/ia64/xen/xen_pv_ops.c
@@ -183,6 +183,75 @@ struct pv_fsys_data xen_fsys_data __initdata = {
* intrinsics hooks.
*/
+static void
+xen_set_itm_with_offset(unsigned long val)
+{
+ /* ia64_cpu_local_tick() calls this with interrupt enabled. */
+ /* WARN_ON(!irqs_disabled()); */
+ xen_set_itm(val - XEN_MAPPEDREGS->itc_offset);
+}
+
+static unsigned long
+xen_get_itm_with_offset(void)
+{
+ /* unused at this moment */
+ printk(KERN_DEBUG "%s is called.\n", __func__);
+
+ WARN_ON(!irqs_disabled());
+ return ia64_native_getreg(_IA64_REG_CR_ITM) +
+ XEN_MAPPEDREGS->itc_offset;
+}
+
+/* ia64_set_itc() is only called by
+ * cpu_init() with ia64_set_itc(0) and ia64_sync_itc().
+ * So XEN_MAPPEDRESG->itc_offset cal be considered as almost constant.
+ */
+static void
+xen_set_itc(unsigned long val)
+{
+ unsigned long mitc;
+
+ WARN_ON(!irqs_disabled());
+ mitc = ia64_native_getreg(_IA64_REG_AR_ITC);
+ XEN_MAPPEDREGS->itc_offset = val - mitc;
+ XEN_MAPPEDREGS->itc_last = val;
+}
+
+static unsigned long
+xen_get_itc(void)
+{
+ unsigned long res;
+ unsigned long itc_offset;
+ unsigned long itc_last;
+ unsigned long ret_itc_last;
+
+ itc_offset = XEN_MAPPEDREGS->itc_offset;
+ do {
+ itc_last = XEN_MAPPEDREGS->itc_last;
+ res = ia64_native_getreg(_IA64_REG_AR_ITC);
+ res += itc_offset;
+ if (itc_last >= res)
+ res = itc_last + 1;
+ ret_itc_last = cmpxchg(&XEN_MAPPEDREGS->itc_last,
+ itc_last, res);
+ } while (unlikely(ret_itc_last != itc_last));
+ return res;
+
+#if 0
+ /* ia64_itc_udelay() calls ia64_get_itc() with interrupt enabled.
+ Should it be paravirtualized instead? */
+ WARN_ON(!irqs_disabled());
+ itc_offset = XEN_MAPPEDREGS->itc_offset;
+ itc_last = XEN_MAPPEDREGS->itc_last;
+ res = ia64_native_getreg(_IA64_REG_AR_ITC);
+ res += itc_offset;
+ if (itc_last >= res)
+ res = itc_last + 1;
+ XEN_MAPPEDREGS->itc_last = res;
+ return res;
+#endif
+}
+
static void xen_setreg(int regnum, unsigned long val)
{
switch (regnum) {
@@ -194,11 +263,14 @@ static void xen_setreg(int regnum, unsigned long val)
xen_set_eflag(val);
break;
#endif
+ case _IA64_REG_AR_ITC:
+ xen_set_itc(val);
+ break;
case _IA64_REG_CR_TPR:
xen_set_tpr(val);
break;
case _IA64_REG_CR_ITM:
- xen_set_itm(val);
+ xen_set_itm_with_offset(val);
break;
case _IA64_REG_CR_EOI:
xen_eoi(val);
@@ -222,6 +294,12 @@ static unsigned long xen_getreg(int regnum)
res = xen_get_eflag();
break;
#endif
+ case _IA64_REG_AR_ITC:
+ res = xen_get_itc();
+ break;
+ case _IA64_REG_CR_ITM:
+ res = xen_get_itm_with_offset();
+ break;
case _IA64_REG_CR_IVR:
res = xen_get_ivr();
break;
--
1.6.0.2
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