[IA64] fsys_getcpu for IA64

On 1.6GHz Montectio Tiger4, the following performance data is measured with
kernel built with defconfig which has NUMA configured:

Fastest sys_getcpu: 502 itc counts.
Fastest fsys_getcpu: 28 itc counts.

fsys_getcpu performance is largly impacted by whether data (node_to_cpu_map
etc) is in cache. It can take fsys_getcpu up to ~150 itc counts in cold
cache case.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

2 files changed, 106 insertions, 0 deletions

diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c
index 75a2a2c12258..2236fabbb3c6 100644
--- a/arch/ia64/kernel/asm-offsets.c
+++ b/arch/ia64/kernel/asm-offsets.c
@@ -35,6 +35,7 @@ void foo(void)
         BLANK();
 
         DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
+        DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
         DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));
 
         BLANK();
diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S
index 7a05b1cb2ad5..8589e84a27c6 100644
--- a/arch/ia64/kernel/fsys.S
+++ b/arch/ia64/kernel/fsys.S
@@ -10,6 +10,8 @@
  *                      probably broke it along the way... ;-)
  * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make
  *                      it capable of using memory based clocks without falling back to C code.
+ * 08-Feb-07 Fenghua Yu Implement fsys_getcpu.
+ *
  */
 
 #include <asm/asmmacro.h>
@@ -505,6 +507,59 @@ EX(.fail_efault, (p15) st8 [r34]=r3)
 #endif
 END(fsys_rt_sigprocmask)
 
+/*
+ * fsys_getcpu doesn't use the third parameter in this implementation. It reads
+ * current_thread_info()->cpu and corresponding node in cpu_to_node_map.
+ */
+ENTRY(fsys_getcpu)
+        .prologue
+        .altrp b6
+        .body
+        ;;
+        add r2=TI_FLAGS+IA64_TASK_SIZE,r16
+        tnat.nz p6,p0 = r32                     // guard against NaT argument
+        add r3=TI_CPU+IA64_TASK_SIZE,r16
+        ;;
+        ld4 r3=[r3]                             // M r3 = thread_info->cpu
+        ld4 r2=[r2]                             // M r2 = thread_info->flags
+(p6)    br.cond.spnt.few .fail_einval           // B
+        ;;
+        tnat.nz p7,p0 = r33                     // I guard against NaT argument
+(p7)    br.cond.spnt.few .fail_einval           // B
+#ifdef CONFIG_NUMA
+        movl r17=cpu_to_node_map
+        ;;
+EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
+EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
+        shladd r18=r3,1,r17
+        ;;
+        ld2 r20=[r18]                           // r20 = cpu_to_node_map[cpu]
+        and r2 = TIF_ALLWORK_MASK,r2
+        ;;
+        cmp.ne p8,p0=0,r2
+(p8)    br.spnt.many fsys_fallback_syscall
+        ;;
+        ;;
+EX(.fail_efault, st4 [r32] = r3)
+EX(.fail_efault, st2 [r33] = r20)
+        mov r8=0
+        ;;
+#else
+EX(.fail_efault, probe.w.fault r32, 3)          // M This takes 5 cycles
+EX(.fail_efault, probe.w.fault r33, 3)          // M This takes 5 cycles
+        and r2 = TIF_ALLWORK_MASK,r2
+        ;;
+        cmp.ne p8,p0=0,r2
+(p8)    br.spnt.many fsys_fallback_syscall
+        ;;
+EX(.fail_efault, st4 [r32] = r3)
+EX(.fail_efault, st2 [r33] = r0)
+        mov r8=0
+        ;;
+#endif
+        FSYS_RETURN
+END(fsys_getcpu)
+
 ENTRY(fsys_fallback_syscall)
         .prologue
         .altrp b6
@@ -878,6 +933,56 @@ fsyscall_table:
         data8 0                         // timer_delete
         data8 0                         // clock_settime
         data8 fsys_clock_gettime        // clock_gettime
+        data8 0                         // clock_getres         // 1255
+        data8 0                         // clock_nanosleep
+        data8 0                         // fstatfs64
+        data8 0                         // statfs64
+        data8 0                         // mbind
+        data8 0                         // get_mempolicy        // 1260
+        data8 0                         // set_mempolicy
+        data8 0                         // mq_open
+        data8 0                         // mq_unlink
+        data8 0                         // mq_timedsend
+        data8 0                         // mq_timedreceive      // 1265
+        data8 0                         // mq_notify
+        data8 0                         // mq_getsetattr
+        data8 0                         // kexec_load
+        data8 0                         // vserver
+        data8 0                         // waitid               // 1270
+        data8 0                         // add_key
+        data8 0                         // request_key
+        data8 0                         // keyctl
+        data8 0                         // ioprio_set
+        data8 0                         // ioprio_get           // 1275
+        data8 0                         // move_pages
+        data8 0                         // inotify_init
+        data8 0                         // inotify_add_watch
+        data8 0                         // inotify_rm_watch
+        data8 0                         // migrate_pages        // 1280
+        data8 0                         // openat
+        data8 0                         // mkdirat
+        data8 0                         // mknodat
+        data8 0                         // fchownat
+        data8 0                         // futimesat            // 1285
+        data8 0                         // newfstatat
+        data8 0                         // unlinkat
+        data8 0                         // renameat
+        data8 0                         // linkat
+        data8 0                         // symlinkat            // 1290
+        data8 0                         // readlinkat
+        data8 0                         // fchmodat
+        data8 0                         // faccessat
+        data8 0
+        data8 0                                                 // 1295
+        data8 0                         // unshare
+        data8 0                         // splice
+        data8 0                         // set_robust_list
+        data8 0                         // get_robust_list
+        data8 0                         // sync_file_range      // 1300
+        data8 0                         // tee
+        data8 0                         // vmsplice
+        data8 0
+        data8 fsys_getcpu               // getcpu               // 1304
 
         // fill in zeros for the remaining entries
         .zero: