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ia64/pv_ops/xen: paravirtualize read/write ar.itc and ar.itm

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paravirtualize ar.itc and ar.itm in order to support save/restore.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Isaku Yamahata 2009-03-04 21:05:39 +09:00 committed by Tony Luck
parent 94752a794d
commit 496203b15b
6 changed files with 123 additions and 2 deletions
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21
arch/ia64/include/asm/xen/inst.h
View file

@ -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; \

9
arch/ia64/include/asm/xen/interface.h
View file

@ -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;
};
};
};

11
arch/ia64/include/asm/xen/minstate.h
View file

@ -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; \

2
arch/ia64/include/asm/xen/privop.h
View file

@ -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__

2
arch/ia64/kernel/asm-offsets.c
View file

@ -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 */
}

80
arch/ia64/xen/xen_pv_ops.c
View file

@ -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;