From: Tang Yuantian <yuantian.t...@freescale.com>

Freescale E6500 core-based platforms, like t4240, support
disabling/enabling CPU dynamically.
This patch adds this feature on those platforms.

Signed-off-by: Chenhui Zhao <chenhui.z...@freescale.com>
Signed-off-by: Tang Yuantian <yuantian.t...@feescale.com>
---
 arch/powerpc/include/asm/smp.h    |  1 +
 arch/powerpc/kernel/head_64.S     | 10 +++++--
 arch/powerpc/platforms/85xx/smp.c | 63 ++++++++++++++++++++++++++-------------
 3 files changed, 52 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index bf37d17..c7bd27d 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -198,6 +198,7 @@ extern void generic_secondary_thread_init(void);
 extern unsigned long __secondary_hold_spinloop;
 extern unsigned long __secondary_hold_acknowledge;
 extern char __secondary_hold;
+extern unsigned int booting_cpu_hwid;
 
 extern void __early_start(void);
 #endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index d48125d..c47544d 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -181,6 +181,10 @@ exception_marker:
 #endif
 
 #ifdef CONFIG_PPC_BOOK3E
+       .globl  booting_cpu_hwid
+booting_cpu_hwid:
+       .long  0x0
+       .align 3
 _GLOBAL(fsl_secondary_thread_init)
        /* Enable branch prediction */
        lis     r3,BUCSR_INIT@h
@@ -197,8 +201,10 @@ _GLOBAL(fsl_secondary_thread_init)
         * but the low bit right by two bits so that the cpu numbering is
         * continuous.
         */
-       mfspr   r3, SPRN_PIR
-       rlwimi  r3, r3, 30, 2, 30
+       bl      10f
+10:    mflr    r22
+       addi    r22,r22,(booting_cpu_hwid - 10b)
+       lwz     r3,0(r22)
        mtspr   SPRN_PIR, r3
 #endif
 
diff --git a/arch/powerpc/platforms/85xx/smp.c 
b/arch/powerpc/platforms/85xx/smp.c
index 7f0dadb..8652a49 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -189,15 +189,22 @@ static inline u32 read_spin_table_addr_l(void *spin_table)
 static void wake_hw_thread(void *info)
 {
        void fsl_secondary_thread_init(void);
-       unsigned long imsr1, inia1;
+       unsigned long imsr, inia;
        int nr = *(const int *)info;
-
-       imsr1 = MSR_KERNEL;
-       inia1 = *(unsigned long *)fsl_secondary_thread_init;
-
-       mttmr(TMRN_IMSR1, imsr1);
-       mttmr(TMRN_INIA1, inia1);
-       mtspr(SPRN_TENS, TEN_THREAD(1));
+       int hw_cpu = get_hard_smp_processor_id(nr);
+       int thread_idx = cpu_thread_in_core(hw_cpu);
+
+       booting_cpu_hwid = (u32)hw_cpu;
+       imsr = MSR_KERNEL;
+       inia = *(unsigned long *)fsl_secondary_thread_init;
+       if (thread_idx == 0) {
+               mttmr(TMRN_IMSR0, imsr);
+               mttmr(TMRN_INIA0, inia);
+       } else {
+               mttmr(TMRN_IMSR1, imsr);
+               mttmr(TMRN_INIA1, inia);
+       }
+       mtspr(SPRN_TENS, TEN_THREAD(thread_idx));
 
        smp_generic_kick_cpu(nr);
 }
@@ -219,27 +226,43 @@ static int smp_85xx_kick_cpu(int nr)
        pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
 
 #ifdef CONFIG_PPC64
-       /* Threads don't use the spin table */
-       if (cpu_thread_in_core(nr) != 0) {
+       if (threads_per_core > 1) {
                int primary = cpu_first_thread_sibling(nr);
 
                if (WARN_ON_ONCE(!cpu_has_feature(CPU_FTR_SMT)))
                        return -ENOENT;
 
-               if (cpu_thread_in_core(nr) != 1) {
-                       pr_err("%s: cpu %d: invalid hw thread %d\n",
-                              __func__, nr, cpu_thread_in_core(nr));
-                       return -ENOENT;
+               /*
+                * If either one of threads in the same core is online,
+                * use the online one to start the other.
+                */
+               if (cpu_online(primary) || cpu_online(primary + 1)) {
+                       qoriq_pm_ops->cpu_up(nr);
+                       if (cpu_online(primary))
+                               smp_call_function_single(primary,
+                                               wake_hw_thread, &nr, 1);
+                       else
+                               smp_call_function_single(primary + 1,
+                                               wake_hw_thread, &nr, 1);
+                       return 0;
                }
 
-               if (!cpu_online(primary)) {
-                       pr_err("%s: cpu %d: primary %d not online\n",
-                              __func__, nr, primary);
-                       return -ENOENT;
+               /*
+                * If both threads are offline, reset core to start.
+                * When core is up, Thread 0 always gets up first,
+                * so bind the current logical cpu with Thread 0.
+                */
+               if (hw_cpu != cpu_first_thread_sibling(hw_cpu)) {
+                       int hw_cpu1, hw_cpu2;
+
+                       hw_cpu1 = get_hard_smp_processor_id(primary);
+                       hw_cpu2 = get_hard_smp_processor_id(primary + 1);
+                       set_hard_smp_processor_id(primary, hw_cpu2);
+                       set_hard_smp_processor_id(primary + 1, hw_cpu1);
+                       /* get new physical cpu id */
+                       hw_cpu = get_hard_smp_processor_id(nr);
                }
 
-               smp_call_function_single(primary, wake_hw_thread, &nr, 0);
-               return 0;
        }
 #endif
 
-- 
2.1.0.27.g96db324

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to