bitkeeper revision 1.1713.1.9 (42af306adOSGlJaEmolMoERc4oAXYg)

[PATCH] x86_64 entry.S cleanup - take 3

This patch cleans up x86_64 entry.S.  Namely, it updates the Xen relevant
macros to be the simpler version that's found in i386.  This means that:

 - XEN_[UN]BLOCK_EVENTS interface now takes care of dealing with
   SMP issues and is no longer conditionally defined
 - XEN_LOCKED_[UN]BLOCK_EVENTS is identical in both cases (SMP and UP)
   and no longer needs to be conditionally defined
 - XEN_[UN]LOCK_VPCU_INFO_SMP is dropped in favor of XEN_GET/PUT_VCPU_INFO

This cleans up the code, minimizes the differences with i386 code, and
lays the groundwork for SMP support (the real reason I did this ;-).
It's booting, executing syscalls, taking interrupts, etc (it's what I'm
using to send this e-mail).

Signed-off-by: Chris Wright <chrisw@osdl.org>
===== linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/entry.S 1.10 vs edited =====

diff --git a/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/entry.S b/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/entry.S
index 3b1504f58e7cae6a1f09f028e934f81b6c18eb9e..e01fdd064a68855bd9dbe6b91cecb41e79fa3b5d 100644 (file)
--- a/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/entry.S
+++ b/linux-2.6.11-xen-sparse/arch/xen/x86_64/kernel/entry.S
@@ -63,42 +63,28 @@ VGCF_IN_SYSCALL = (1<<8)
 #define sizeof_vcpu_shift              3
 
 #ifdef CONFIG_SMP
-#define XEN_GET_VCPU_INFO(reg)
-#define preempt_disable(reg)   incl TI_preempt_count(reg)
-#define preempt_enable(reg)    decl TI_preempt_count(reg)
-#define XEN_LOCK_VCPU_INFO_SMP(reg) preempt_disable(%rbp)              ; \
-                               movq TI_cpu(%rbp),reg                   ; \
+#define preempt_disable(reg)   incl threadinfo_preempt_count(reg)
+#define preempt_enable(reg)    decl threadinfo_preempt_count(reg)
+#define XEN_GET_VCPU_INFO(reg) preempt_disable(%rbp)                   ; \
+                               movq %gs:pda_cpunumber,reg              ; \
                                shl  $sizeof_vcpu_shift,reg             ; \
                                addq HYPERVISOR_shared_info,reg
-#define XEN_UNLOCK_VCPU_INFO_SMP(reg) preempt_enable(%rbp)
-#define XEN_UNLOCK_VCPU_INFO_SMP_fixup .byte 0xff,0xff,0xff
-#define Ux00 0xff
-#define XEN_LOCKED_BLOCK_EVENTS(reg)   movb $1,evtchn_upcall_mask(reg)
-#define XEN_BLOCK_EVENTS(reg)  XEN_LOCK_VCPU_INFO_SMP(reg)             ; \
-                               XEN_LOCKED_BLOCK_EVENTS(reg)            ; \
-                               XEN_UNLOCK_VCPU_INFO_SMP(reg)
-#define XEN_UNBLOCK_EVENTS(reg)        XEN_LOCK_VCPU_INFO_SMP(reg)             ; \
-                               movb $0,evtchn_upcall_mask(reg)         ; \
-                               XEN_UNLOCK_VCPU_INFO_SMP(reg)
-#define XEN_SAVE_UPCALL_MASK(reg,tmp,off) GET_THREAD_INFO(%rbp)                ; \
-                               XEN_LOCK_VCPU_INFO_SMP(reg)             ; \
-                               movb evtchn_upcall_mask(reg), tmp       ; \
-                               movb tmp, off(%rsp)                     ; \
-                               XEN_UNLOCK_VCPU_INFO_SMP(reg)
+#define XEN_PUT_VCPU_INFO(reg) preempt_enable(%rbp)                    ; \
+#define XEN_PUT_VCPU_INFO_fixup .byte 0xff,0xff,0xff
 #else
 #define XEN_GET_VCPU_INFO(reg) movq HYPERVISOR_shared_info,reg
-#define XEN_LOCK_VCPU_INFO_SMP(reg) movq HYPERVISOR_shared_info,reg
-#define XEN_UNLOCK_VCPU_INFO_SMP(reg)
-#define XEN_UNLOCK_VCPU_INFO_SMP_fixup
-#define Ux00 0x00
-#define XEN_LOCKED_BLOCK_EVENTS(reg)   movb $1,evtchn_upcall_mask(reg)
-#define XEN_BLOCK_EVENTS(reg)  XEN_LOCKED_BLOCK_EVENTS(reg)
-#define XEN_UNBLOCK_EVENTS(reg)        movb $0,evtchn_upcall_mask(reg)
-#define XEN_SAVE_UPCALL_MASK(reg,tmp,off) \
-       movb evtchn_upcall_mask(reg), tmp; \
-       movb tmp, off(%rsp)
+#define XEN_PUT_VCPU_INFO(reg)
+#define XEN_PUT_VCPU_INFO_fixup
 #endif
 
+#define XEN_LOCKED_BLOCK_EVENTS(reg)   movb $1,evtchn_upcall_mask(reg)
+#define XEN_LOCKED_UNBLOCK_EVENTS(reg) movb $0,evtchn_upcall_mask(reg)
+#define XEN_BLOCK_EVENTS(reg)  XEN_GET_VCPU_INFO(reg)                  ; \
+                               XEN_LOCKED_BLOCK_EVENTS(reg)            ; \
+                               XEN_PUT_VCPU_INFO(reg)
+#define XEN_UNBLOCK_EVENTS(reg)        XEN_GET_VCPU_INFO(reg)                  ; \
+                               XEN_LOCKED_UNBLOCK_EVENTS(reg)          ; \
+                               XEN_PUT_VCPU_INFO(reg)
 #define XEN_TEST_PENDING(reg)  testb $0xFF,evtchn_upcall_pending(reg)
 
        .code64
@@ -256,8 +242,6 @@ ENTRY(system_call)
        CFI_STARTPROC
        SAVE_ARGS -8,0
        movq  %rax,ORIG_RAX-ARGOFFSET(%rsp) 
-        XEN_GET_VCPU_INFO(%r11)
-        XEN_SAVE_UPCALL_MASK(%r11,%cl,EVENT_MASK-ARGOFFSET)      # saved %rcx          
         XEN_UNBLOCK_EVENTS(%r11)        
        GET_THREAD_INFO(%rcx)
        testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),threadinfo_flags(%rcx)
@@ -277,7 +261,6 @@ ret_from_sys_call:
        /* edi: flagmask */
 sysret_check:          
        GET_THREAD_INFO(%rcx)
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_BLOCK_EVENTS(%rsi)        
        movl threadinfo_flags(%rcx),%edx
        andl %edi,%edx
@@ -291,7 +274,6 @@ sysret_check:
 sysret_careful:
        bt $TIF_NEED_RESCHED,%edx
        jnc sysret_signal
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_BLOCK_EVENTS(%rsi)        
        pushq %rdi
        call schedule
@@ -301,7 +283,6 @@ sysret_careful:
        /* Handle a signal */ 
 sysret_signal:
 /*     sti */
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_UNBLOCK_EVENTS(%rsi)        
        testl $(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SINGLESTEP),%edx
        jz    1f
@@ -345,7 +326,6 @@ badsys:
  * Has correct top of stack, but partial stack frame.
  */    
 ENTRY(int_ret_from_sys_call)   
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_BLOCK_EVENTS(%rsi)
        testb $3,CS-ARGOFFSET(%rsp)
         jnz 1f
@@ -369,7 +349,6 @@ int_careful:
        bt $TIF_NEED_RESCHED,%edx
        jnc  int_very_careful
 /*     sti */
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_UNBLOCK_EVENTS(%rsi)
        pushq %rdi
        call schedule
@@ -379,7 +358,6 @@ int_careful:
        /* handle signals and tracing -- both require a full stack frame */
 int_very_careful:
 /*     sti */
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_UNBLOCK_EVENTS(%rsi)
        SAVE_REST
        /* Check for syscall exit trace */      
@@ -529,11 +507,11 @@ retint_check:
 retint_restore_args:
         movb EVENT_MASK-REST_SKIP(%rsp), %al
         notb %al                       # %al == ~saved_mask
-        XEN_LOCK_VCPU_INFO_SMP(%rsi)
+        XEN_GET_VCPU_INFO(%rsi)
         andb evtchn_upcall_mask(%rsi),%al
        andb $1,%al                     # %al == mask & ~saved_mask
        jnz restore_all_enable_events   # != 0 => reenable event delivery      
-        XEN_UNLOCK_VCPU_INFO_SMP(%rsi)
+        XEN_PUT_VCPU_INFO(%rsi)
                
        RESTORE_ARGS 0,8,0                                              
        testb $3,8(%rsp)                # check CS
@@ -548,13 +526,11 @@ user_mode:
 retint_careful:
        bt    $TIF_NEED_RESCHED,%edx
        jnc   retint_signal
-       XEN_GET_VCPU_INFO(%rsi)
        XEN_UNBLOCK_EVENTS(%rsi)
 /*     sti */        
        pushq %rdi
        call  schedule
        popq %rdi               
-       XEN_GET_VCPU_INFO(%rsi)        
        XEN_BLOCK_EVENTS(%rsi)          
        GET_THREAD_INFO(%rcx)
 /*     cli */
@@ -563,7 +539,6 @@ retint_careful:
 retint_signal:
        testl $(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SINGLESTEP),%edx
        jz    retint_restore_args
-        XEN_GET_VCPU_INFO(%rsi)
         XEN_UNBLOCK_EVENTS(%rsi)
        SAVE_REST
        movq $-1,ORIG_RAX(%rsp)                         
@@ -571,7 +546,6 @@ retint_signal:
        movq %rsp,%rdi          # &pt_regs
        call do_notify_resume
        RESTORE_REST
-        XEN_GET_VCPU_INFO(%rsi)        
         XEN_BLOCK_EVENTS(%rsi)         
        movl $_TIF_NEED_RESCHED,%edi
        GET_THREAD_INFO(%rcx)   
@@ -590,10 +564,8 @@ retint_kernel:
        jc   retint_restore_args
        movl $PREEMPT_ACTIVE,threadinfo_preempt_count(%rcx)
 /*     sti */
-       XEN_GET_VCPU_INFO(%rsi)
        XEN_UNBLOCK_EVENTS(%rsi)
        call schedule
-       XEN_GET_VCPU_INFO(%rsi) /* %esi can be different */
        XEN_BLOCK_EVENTS(%rsi)
 /*     cli */
        GET_THREAD_INFO(%rcx)
@@ -728,17 +700,10 @@ error_call_handler:
        movq %rsp,%rdi
        movq ORIG_RAX(%rsp),%rsi        # get error code 
        movq $-1,ORIG_RAX(%rsp)
-        leaq do_hypervisor_callback,%rcx
-        cmpq %rax,%rcx
-        je 0f                           # don't save event mask for callbacks
-        XEN_GET_VCPU_INFO(%r11)
-        XEN_SAVE_UPCALL_MASK(%r11,%cl,EVENT_MASK)
-0:              
        call *%rax
 error_exit:            
        RESTORE_REST
 /*     cli */
-       XEN_GET_VCPU_INFO(%rsi)        
        XEN_BLOCK_EVENTS(%rsi)          
        GET_THREAD_INFO(%rcx)   
        testb $3,CS-ARGOFFSET(%rsp)
@@ -807,7 +772,7 @@ restore_all_enable_events:
 scrit: /**** START OF CRITICAL REGION ****/
        XEN_TEST_PENDING(%rsi)
        jnz  14f                        # process more events if necessary...
-       XEN_UNLOCK_VCPU_INFO_SMP(%rsi)
+       XEN_PUT_VCPU_INFO(%rsi)
         RESTORE_ARGS 0,8,0
         testb $3,8(%rsp)                # check CS
         jnz  crit_user_mode
@@ -817,7 +782,7 @@ crit_user_mode:
         SWITCH_TO_USER 0
         
 14:    XEN_LOCKED_BLOCK_EVENTS(%rsi)
-       XEN_UNLOCK_VCPU_INFO_SMP(%rsi)
+       XEN_PUT_VCPU_INFO(%rsi)
        SAVE_REST
         movq %rsp,%rdi                  # set the argument again
        jmp  11b