From: Isaku Yamahata Date: Wed, 4 Mar 2009 12:05:39 +0000 (+0900) Subject: ia64/pv_ops/xen: paravirtualize read/write ar.itc and ar.itm X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=496203b15b7249599712525c2b6aafe231b4628d;p=linux-2.6-omap-h63xx.git 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 --- diff --git a/arch/ia64/include/asm/xen/inst.h b/arch/ia64/include/asm/xen/inst.h index e8e01b28d2a..90537dc15ef 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 f00fab40854..e951e740bdf 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 4d92d9bbda7..c57fa910f2c 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 71ec7546e10..2261dda578f 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 742dbb1d5a4..af565016904 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 fe72308321b..d9133611434 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;