From: Kei Tokunaga <ktokunag@redhat.com>
Subject: [RHEL5.1 PATCH 8/21] evtchn_callback fix and clean
Date: Thu, 07 Jun 2007 03:37:55 -0400
Bugzilla: 242126
Message-Id: <4667B5D3.6080305@redhat.com>
Changelog: [xen] ia64: evtchn_callback fix and clean


bz242126
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=242126

Backport of cset#13084.

Since we had changed to use event callback to deliver interrupts,

1. The pending_interruption is changed to pending_event.

2. get_ivr, set_tpr, get_trp and set_eoi are not used or only used
   in the initialization phase. There is no need to write this code
   in assembly.  This code is deleted.

3. hyper_ssm_i needs to be rewritten to jump to entchn_callback_handler
   instead of iva+0x3000 interrupt handler.  I will do this later.

Thanks,
Kei



rh bug 242126

# HG changeset patch
# User awilliam@xenbuild2.aw
# Date 1166462434 25200
# Node ID ea2dc4a3c8eb5ee780dbbc6d12447b6bda2ee2b4
# Parent  893b786cc66ae67bf761fbe1ff814435dae30210
[IA64] evtchn_callback fix and clean

Since we had changed to use event callback to deliver interrupts,

1. The pending_interruption is changed to pending_event.

2. get_ivr, set_tpr, get_trp and set_eoi are not used or only used
   in the initialization phase. There is no need to write this code
   in assembly.  This code is deleted.

3. hyper_ssm_i needs to be rewritten to jump to entchn_callback_handler
   instead of iva+0x3000 interrupt handler.  I will do this later.

Signed-off-by: Anthony Xu  <anthony.xu@intel.com>


---

 linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/kernel/asm-offsets.c |    1 
 linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/kernel/gate.S        |    9 ++-
 linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/xen/hypercall.S      |   14 ++---
 linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/xen/xenivt.S         |   25 ++++++----
 linux-2.6.18-21.el5-gerd-order-kei/include/asm-ia64/xen/privop.h  |    3 -
 5 files changed, 31 insertions(+), 21 deletions(-)

diff -puN arch/ia64/kernel/asm-offsets.c~13084-IA64_evtchn_callback_fix_and_clean arch/ia64/kernel/asm-offsets.c
--- linux-2.6.18-21.el5-gerd-order/arch/ia64/kernel/asm-offsets.c~13084-IA64_evtchn_callback_fix_and_clean	2007-06-07 02:44:29.000000000 -0400
+++ linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/kernel/asm-offsets.c	2007-06-07 02:44:29.000000000 -0400
@@ -288,7 +288,6 @@ void foo(void)
 	DEFINE_MAPPED_REG_OFS(XSI_IHA_OFS, iha);
 	DEFINE_MAPPED_REG_OFS(XSI_ITIR_OFS, itir);
 	DEFINE_MAPPED_REG_OFS(XSI_PSR_IC_OFS, interrupt_collection_enabled);
-	DEFINE_MAPPED_REG_OFS(XSI_PEND_OFS, pending_interruption);
 	DEFINE_MAPPED_REG_OFS(XSI_INCOMPL_REGFR_OFS, incomplete_regframe);
 	DEFINE_MAPPED_REG_OFS(XSI_BANKNUM_OFS, banknum);
 	DEFINE_MAPPED_REG_OFS(XSI_BANK0_R16_OFS, bank0_regs[0]);
diff -puN arch/ia64/kernel/gate.S~13084-IA64_evtchn_callback_fix_and_clean arch/ia64/kernel/gate.S
--- linux-2.6.18-21.el5-gerd-order/arch/ia64/kernel/gate.S~13084-IA64_evtchn_callback_fix_and_clean	2007-06-07 02:44:29.000000000 -0400
+++ linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/kernel/gate.S	2007-06-07 02:44:29.000000000 -0400
@@ -126,9 +126,9 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
 	;;
 #ifdef CONFIG_XEN_IA64_VDSO_PARAVIRT
 	// r20 = 1
-	// r22 = &vcpu->evtchn_mask
+	// r22 = &vcpu->vcpu_info->evtchn_upcall_mask
 	// r23 = &vpsr.ic
-	// r24 = &vcpu->pending_interruption
+	// r24 = &vcpu->vcpu_info->evtchn_upcall_pending
 	// r25 = tmp
 	// r28 = &running_on_xen
 	// r30 = running_on_xen
@@ -142,8 +142,11 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
 #define isRaw	p13
 	LOAD_RUNNING_ON_XEN(r28)
 	movl r22=XSI_PSR_I_ADDR
+	;;
+	ld8 r22=[r22]
+	;;
 	movl r23=XSI_PSR_IC
-	movl r24=XSI_PSR_I_ADDR+(XSI_PEND_OFS-XSI_PSR_I_ADDR_OFS)
+	adds r24=-1,r22
 	mov r20=1
 	;;
 	ld4 r30=[r28]
diff -puN arch/ia64/xen/hypercall.S~13084-IA64_evtchn_callback_fix_and_clean arch/ia64/xen/hypercall.S
--- linux-2.6.18-21.el5-gerd-order/arch/ia64/xen/hypercall.S~13084-IA64_evtchn_callback_fix_and_clean	2007-06-07 02:44:29.000000000 -0400
+++ linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/xen/hypercall.S	2007-06-07 02:44:29.000000000 -0400
@@ -355,8 +355,6 @@ END(xen_send_ipi)
 // Those are vdso specialized.
 // In fsys mode, call, ret can't be used.
 GLOBAL_ENTRY(xen_rsm_be_i)
-	ld8 r22=[r22]
-	;; 
 	st1 [r22]=r20
 	st4 [r23]=r0
 	XEN_HYPER_RSM_BE
@@ -379,23 +377,23 @@ GLOBAL_ENTRY(xen_get_psr)
 END(xen_get_psr)
 
 	// see xen_ssm_i() in privop.h
-	// r22 = &vcpu->evtchn_mask
+	// r22 = &vcpu->vcpu_info->evtchn_upcall_mask
 	// r23 = &vpsr.ic
-	// r24 = &vcpu->pending_interruption
+	// r24 = &vcpu->vcpu_info->evtchn_upcall_pending
 	// r25 = tmp
 	// r31 = tmp
 	// p11 = tmp
 	// p14 = tmp
 #define XEN_SET_PSR_I			\
-	ld4 r31=[r22];			\
-	ld4 r25=[r24];			\
+	ld1 r31=[r22];			\
+	ld1 r25=[r24];			\
 	;;				\
-	st4 [r22]=r0;			\
+	st1 [r22]=r0;			\
 	cmp.ne.unc p14,p0=r0,r31;	\
 	;;				\
 (p14)	cmp.ne.unc p11,p0=r0,r25;	\
 	;;				\
-(p11)	st4 [r22]=r20;			\
+(p11)	st1 [r22]=r20;			\
 (p11)	st4 [r23]=r0;			\
 (p11)	XEN_HYPER_SSM_I;
 		
diff -puN arch/ia64/xen/xenivt.S~13084-IA64_evtchn_callback_fix_and_clean arch/ia64/xen/xenivt.S
--- linux-2.6.18-21.el5-gerd-order/arch/ia64/xen/xenivt.S~13084-IA64_evtchn_callback_fix_and_clean	2007-06-07 02:44:29.000000000 -0400
+++ linux-2.6.18-21.el5-gerd-order-kei/arch/ia64/xen/xenivt.S	2007-06-07 02:44:29.000000000 -0400
@@ -735,10 +735,10 @@ xen_page_fault:
 	;;
 (p15)	ld8 r3=[r3]
 	;;
-(p15)	st1 [r3]=r0,XSI_PEND_OFS-XSI_PSR_I_ADDR_OFS	// if (p15) vpsr.i = 1
+(p15)	st1 [r3]=r0,-1	// if (p15) vpsr.i = 1
 	mov r14=r0
 	;;
-(p15)	ld4 r14=[r3]				// if (pending_interrupts)
+(p15)	ld1 r14=[r3]				// if (pending_events)
 	adds r3=8,r2				// re-set up second base pointer
 	;;
 (p15)	cmp.ne	p15,p0=r14,r0
@@ -1168,10 +1168,10 @@ ENTRY(break_fault)
 #ifdef CONFIG_XEN
 (p15)	ld8 r16=[r16]				// vpsr.i
 	;;
-(p15)	st1 [r16]=r0,XSI_PEND_OFS-XSI_PSR_I_ADDR_OFS	// if (p15) vpsr.i = 1
+(p15)	st1 [r16]=r0,-1		// if (p15) vpsr.i = 1
 	mov r2=r0
 	;;
-(p15)	ld4 r2=[r16]				// if (pending_interrupts)
+(p15)	ld1 r2=[r16]				// if (pending_events)
 	;;
 	cmp.ne	p6,p0=r2,r0
 	;;
@@ -2157,13 +2157,22 @@ GLOBAL_ENTRY(xen_event_callback)
 	;;
 	SAVE_REST
 	;;
+1:
 	alloc r14=ar.pfs,0,0,1,0 // must be first in an insn group
 	add out0=16,sp		// pass pointer to pt_regs as first arg
 	;;
-	srlz.d			// make sure we see the effect of cr.ivr
-	movl r14=ia64_leave_kernel
+	br.call.sptk.many b0=evtchn_do_upcall
 	;;
-	mov rp=r14
-	br.call.sptk.many b6=evtchn_do_upcall
+	movl r20=XSI_PSR_I_ADDR
+	;;
+	ld8 r20=[r20]
+	;;
+	adds r20=-1,r20		// vcpu_info->evtchn_upcall_pending
+	;;
+	ld1 r20=[r20]
+	;;
+	cmp.ne p6,p0=r20,r0	// if there are pending events,
+	(p6) br.spnt.few 1b	// call evtchn_do_upcall again.
+	br.sptk.many ia64_leave_kernel
 END(xen_event_callback)
 #endif
diff -puN include/asm-ia64/xen/privop.h~13084-IA64_evtchn_callback_fix_and_clean include/asm-ia64/xen/privop.h
--- linux-2.6.18-21.el5-gerd-order/include/asm-ia64/xen/privop.h~13084-IA64_evtchn_callback_fix_and_clean	2007-06-07 02:44:29.000000000 -0400
+++ linux-2.6.18-21.el5-gerd-order-kei/include/asm-ia64/xen/privop.h	2007-06-07 02:44:29.000000000 -0400
@@ -113,7 +113,8 @@ extern void xen_set_eflag(unsigned long)
 	({ XSI_PSR_I = (uint8_t)(_val) ? 0 : 1; })
 #define xen_set_virtual_psr_ic(_val)	\
 	({ XEN_MAPPEDREGS->interrupt_collection_enabled = _val ? 1 : 0; })
-#define xen_get_virtual_pend()		(XEN_MAPPEDREGS->pending_interruption)
+#define xen_get_virtual_pend()		\
+	(*(((uint8_t *)XEN_MAPPEDREGS->interrupt_mask_addr) - 1))
 
 /* Hyperprivops are "break" instructions with a well-defined API.
  * In particular, the virtual psr.ic bit must be off; in this way

_