[IA64] New IA64 core/thread detection patch

IPF SDM 2.2 changes definition of PAL_LOGICAL_TO_PHYSICAL to add
proc_number=-1 to get core/thread mapping info on the running processer.

Based on this change, we had better to update existing core/thread
detection in IA64 kernel correspondingly. The attached patch implements
this change. It simplifies detection code and eliminates potential race
condition. It also runs a bit faster and has better scalability especially
when cores and threads number grows up in one package.

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

diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index c4b633b36daba12b16b9ebe650b54f009c349fd9..44e9547878ac7310b6f11502d1a709fd5805bd66 100644 (file)
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -624,31 +624,7 @@ void __devinit smp_prepare_boot_cpu(void)
        per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 }
 
-/*
- * mt_info[] is a temporary store for all info returned by
- * PAL_LOGICAL_TO_PHYSICAL, to be copied into cpuinfo_ia64 when the
- * specific cpu comes.
- */
-static struct {
-       __u32   socket_id;
-       __u16   core_id;
-       __u16   thread_id;
-       __u16   proc_fixed_addr;
-       __u8    valid;
-} mt_info[NR_CPUS] __devinitdata;
-
 #ifdef CONFIG_HOTPLUG_CPU
-static inline void
-remove_from_mtinfo(int cpu)
-{
-       int i;
-
-       for_each_cpu(i)
-               if (mt_info[i].valid &&  mt_info[i].socket_id ==
-                                               cpu_data(cpu)->socket_id)
-                       mt_info[i].valid = 0;
-}
-
 static inline void
 clear_cpu_sibling_map(int cpu)
 {
@@ -678,12 +654,6 @@ remove_siblinginfo(int cpu)
 
        /* remove it from all sibling map's */
        clear_cpu_sibling_map(cpu);
-
-       /* if this cpu is the last in the core group, remove all its info 
-        * from mt_info structure
-        */
-       if (last)
-               remove_from_mtinfo(cpu);
 }
 
 extern void fixup_irqs(void);
@@ -878,40 +848,6 @@ init_smp_config(void)
                       ia64_sal_strerror(sal_ret));
 }
 
-static inline int __devinit
-check_for_mtinfo_index(void)
-{
-       int i;
-       
-       for_each_cpu(i)
-               if (!mt_info[i].valid)
-                       return i;
-
-       return -1;
-}
-
-/*
- * Search the mt_info to find out if this socket's cid/tid information is
- * cached or not. If the socket exists, fill in the core_id and thread_id 
- * in cpuinfo
- */
-static int __devinit
-check_for_new_socket(__u16 logical_address, struct cpuinfo_ia64 *c)
-{
-       int i;
-       __u32 sid = c->socket_id;
-
-       for_each_cpu(i) {
-               if (mt_info[i].valid && mt_info[i].proc_fixed_addr == logical_address
-                   && mt_info[i].socket_id == sid) {
-                       c->core_id = mt_info[i].core_id;
-                       c->thread_id = mt_info[i].thread_id;
-                       return 1; /* not a new socket */
-               }
-       }
-       return 0;
-}
-
 /*
  * identify_siblings(cpu) gets called from identify_cpu. This populates the 
  * information related to logical execution units in per_cpu_data structure.
@@ -921,14 +857,12 @@ identify_siblings(struct cpuinfo_ia64 *c)
 {
        s64 status;
        u16 pltid;
-       u64 proc_fixed_addr;
-       int count, i;
        pal_logical_to_physical_t info;
 
        if (smp_num_cpucores == 1 && smp_num_siblings == 1)
                return;
 
-       if ((status = ia64_pal_logical_to_phys(0, &info)) != PAL_STATUS_SUCCESS) {
+       if ((status = ia64_pal_logical_to_phys(-1, &info)) != PAL_STATUS_SUCCESS) {
                printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
                       status);
                return;
@@ -937,47 +871,12 @@ identify_siblings(struct cpuinfo_ia64 *c)
                printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
                return;
        }
-       if ((status = ia64_pal_fixed_addr(&proc_fixed_addr)) != PAL_STATUS_SUCCESS) {
-               printk(KERN_ERR "ia64_pal_fixed_addr failed with %ld\n", status);
-               return;
-       }
 
        c->socket_id =  (pltid << 8) | info.overview_ppid;
        c->cores_per_socket = info.overview_cpp;
        c->threads_per_core = info.overview_tpc;
-       count = c->num_log = info.overview_num_log;
+       c->num_log = info.overview_num_log;
 
-       /* If the thread and core id information is already cached, then
-        * we will simply update cpu_info and return. Otherwise, we will
-        * do the PAL calls and cache core and thread id's of all the siblings.
-        */
-       if (check_for_new_socket(proc_fixed_addr, c))
-               return;
-
-       for (i = 0; i < count; i++) {
-               int index;
-
-               if (i && (status = ia64_pal_logical_to_phys(i, &info))
-                         != PAL_STATUS_SUCCESS) {
-                       printk(KERN_ERR "ia64_pal_logical_to_phys failed"
-                                       " with %ld\n", status);
-                       return;
-               }
-               if (info.log2_la == proc_fixed_addr) {
-                       c->core_id = info.log1_cid;
-                       c->thread_id = info.log1_tid;
-               }
-
-               index = check_for_mtinfo_index();
-               /* We will not do the mt_info caching optimization in this case.
-                */
-               if (index < 0)
-                       continue;
-
-               mt_info[index].valid = 1;
-               mt_info[index].socket_id = c->socket_id;
-               mt_info[index].core_id = info.log1_cid;
-               mt_info[index].thread_id = info.log1_tid;
-               mt_info[index].proc_fixed_addr = info.log2_la;
-       }
+       c->core_id = info.log1_cid;
+       c->thread_id = info.log1_tid;
 }

diff --git a/include/asm-ia64/pal.h b/include/asm-ia64/pal.h
index 7708ec669a336b055390db4408906ee277a5385a..4e7e6f23b08c829651333389b837696865c17436 100644 (file)
--- a/include/asm-ia64/pal.h
+++ b/include/asm-ia64/pal.h
@@ -1640,8 +1640,7 @@ ia64_pal_logical_to_phys(u64 proc_number, pal_logical_to_physical_t *mapping)
 
        if (iprv.status == PAL_STATUS_SUCCESS)
        {
-               if (proc_number == 0)
-                       mapping->overview.overview_data = iprv.v0;
+               mapping->overview.overview_data = iprv.v0;
                mapping->ppli1.ppli1_data = iprv.v1;
                mapping->ppli2.ppli2_data = iprv.v2;
        }