From 496203b15b7249599712525c2b6aafe231b4628d Mon Sep 17 00:00:00 2001 From: Isaku Yamahata Date: Wed, 4 Mar 2009 21:05:39 +0900 Subject: ia64/pv_ops/xen: paravirtualize read/write ar.itc and ar.itm paravirtualize ar.itc and ar.itm in order to support save/restore. Signed-off-by: Isaku Yamahata Signed-off-by: Tony Luck --- arch/ia64/xen/xen_pv_ops.c | 80 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 79 insertions(+), 1 deletion(-) (limited to 'arch/ia64/xen') diff --git a/arch/ia64/xen/xen_pv_ops.c b/arch/ia64/xen/xen_pv_ops.c index fe72308..d913361 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; -- cgit v1.1