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Message-ID: <1438334444-31919-3-git-send-email-b29983@freescale.com>
Date: Fri, 31 Jul 2015 17:20:44 +0800
From: <b29983@...escale.com>
To: <b07421@...escale.com>
CC: <linux-kernel@...r.kernel.org>,
Tang Yuantian <Yuantian.Tang@...escale.com>,
Chenhui Zhao <chenhui.zhao@...escale.com>,
Tang Yuantian <Yuantian.Tang@...scale.com>
Subject: [PATCH 3/3] PowerPC/mpc85xx: Add hotplug support on E6500 cores
From: Tang Yuantian <Yuantian.Tang@...escale.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.zhao@...escale.com>
Signed-off-by: Tang Yuantian <Yuantian.Tang@...scale.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
--
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