[PATCH v2,5/5] PowerPC/mpc85xx: Add CPU hotplug support for E6500
From: Chenhui Zhao
Date: Wed Aug 26 2015 - 08:10:12 EST
Support Freescale E6500 core-based platforms, like t4240.
Support disabling/enabling individual CPU thread dynamically.
Signed-off-by: Chenhui Zhao <chenhui.zhao@xxxxxxxxxxxxx>
---
major changes for v2:
* start Thread1 by Thread0 when we want to boot Thread1 only replacing
the method of changing cpu physical id
arch/powerpc/include/asm/cputhreads.h | 9 +++++
arch/powerpc/include/asm/smp.h | 1 +
arch/powerpc/kernel/head_64.S | 69 ++++++++++++++++++++++++++++++++++-
arch/powerpc/platforms/85xx/smp.c | 53 ++++++++++++++-------------
arch/powerpc/sysdev/fsl_rcpm.c | 2 +-
5 files changed, 106 insertions(+), 28 deletions(-)
diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
index ba42e46..9920f61 100644
--- a/arch/powerpc/include/asm/cputhreads.h
+++ b/arch/powerpc/include/asm/cputhreads.h
@@ -1,6 +1,7 @@
#ifndef _ASM_POWERPC_CPUTHREADS_H
#define _ASM_POWERPC_CPUTHREADS_H
+#ifndef __ASSEMBLY__
#include <linux/cpumask.h>
/*
@@ -95,6 +96,14 @@ static inline int cpu_last_thread_sibling(int cpu)
}
+#ifdef CONFIG_PPC_BOOK3E
+void book3e_start_thread(int thread, unsigned long addr);
+void book3e_stop_thread(int thread);
+#endif
+
+#endif /* __ASSEMBLY__ */
+
+#define INVALID_THREAD_HWID 0x0fff
#endif /* _ASM_POWERPC_CPUTHREADS_H */
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 4ff5b71..a1faa4c 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -200,6 +200,7 @@ 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_thread_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..6df2aa4 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -40,6 +40,7 @@
#include <asm/kvm_book3s_asm.h>
#include <asm/ptrace.h>
#include <asm/hw_irq.h>
+#include <asm/cputhreads.h>
/* The physical memory is laid out such that the secondary processor
* spin code sits at 0x0000...0x00ff. On server, the vectors follow
@@ -181,6 +182,44 @@ exception_marker:
#endif
#ifdef CONFIG_PPC_BOOK3E
+ .globl booting_thread_hwid
+booting_thread_hwid:
+ .long INVALID_THREAD_HWID
+ .align 3
+/*
+ * start threads in the same cpu
+ * input parameters:
+ * r3 = the thread physical id
+ * r4 = the entry point where thread starts
+ */
+_GLOBAL(book3e_start_thread)
+ LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
+ cmpi 0, r3, 0
+ bne 10f
+ mttmr TMRN_IMSR0, r5
+ mttmr TMRN_INIA0, r4
+ b 11f
+10:
+ mttmr TMRN_IMSR1, r5
+ mttmr TMRN_INIA1, r4
+11:
+ isync
+ li r6, 1
+ sld r6, r6, r3
+ mtspr SPRN_TENS, r6
+ isync
+ blr
+
+/*
+ * r3 = the thread physical id
+ */
+_GLOBAL(book3e_stop_thread)
+ li r4, 1
+ sld r4, r4, r3
+ mtspr SPRN_TENC, r4
+ isync
+ blr
+
_GLOBAL(fsl_secondary_thread_init)
/* Enable branch prediction */
lis r3,BUCSR_INIT@h
@@ -197,8 +236,10 @@ _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 r5
+ addi r5,r5,(booting_thread_hwid - 10b)
+ lwz r3,0(r5)
mtspr SPRN_PIR, r3
#endif
@@ -245,6 +286,30 @@ _GLOBAL(generic_secondary_smp_init)
mr r3,r24
mr r4,r25
bl book3e_secondary_core_init
+
+/*
+ * If we want to boot Thread1, start Thread1 and stop Thread0.
+ * Note that only Thread0 will run the piece of code.
+ */
+ LOAD_REG_ADDR(r3, booting_thread_hwid)
+ lwz r4, 0(r3)
+ cmpwi r4, INVALID_THREAD_HWID
+ beq 20f
+ cmpw r4, r24
+ beq 20f
+
+ /* start Thread1 */
+ LOAD_REG_ADDR(r5, fsl_secondary_thread_init)
+ ld r4, 0(r5)
+ li r3, 1
+ bl book3e_start_thread
+
+ /* stop Thread0 */
+ li r3, 0
+ bl book3e_stop_thread
+10:
+ b 10b
+20:
#endif
generic_secondary_common_init:
diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index 73eb994..61f68ad 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -181,17 +181,11 @@ 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;
- int nr = *(const int *)info;
+ unsigned long inia;
+ int hw_cpu = get_hard_smp_processor_id(*(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));
-
- smp_generic_kick_cpu(nr);
+ inia = *(unsigned long *)fsl_secondary_thread_init;
+ book3e_start_thread(cpu_thread_in_core(hw_cpu), inia);
}
#endif
@@ -279,7 +273,6 @@ static int smp_85xx_kick_cpu(int nr)
int ret = 0;
#ifdef CONFIG_PPC64
int primary = nr;
- int primary_hw = get_hard_smp_processor_id(primary);
#endif
WARN_ON(nr < 0 || nr >= num_possible_cpus());
@@ -287,33 +280,43 @@ static int smp_85xx_kick_cpu(int nr)
pr_debug("kick CPU #%d\n", nr);
#ifdef CONFIG_PPC64
+ booting_thread_hwid = INVALID_THREAD_HWID;
/* Threads don't use the spin table */
- if (cpu_thread_in_core(nr) != 0) {
- int primary = cpu_first_thread_sibling(nr);
+ if (threads_per_core == 2) {
+ booting_thread_hwid = get_hard_smp_processor_id(nr);
+ 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 (!cpu_online(primary)) {
- pr_err("%s: cpu %d: primary %d not online\n",
- __func__, nr, primary);
- return -ENOENT;
+ /*
+ * If either one of threads in the same core is online,
+ * use the online one to start the other.
+ */
+ if (qoriq_pm_ops)
+ qoriq_pm_ops->cpu_up_prepare(nr);
+
+ if (cpu_online(primary)) {
+ smp_call_function_single(primary,
+ wake_hw_thread, &nr, 1);
+ goto done;
+ } else if (cpu_online(primary + 1)) {
+ smp_call_function_single(primary + 1,
+ wake_hw_thread, &nr, 1);
+ goto done;
}
- smp_call_function_single(primary, wake_hw_thread, &nr, 0);
- return 0;
+ /* If both threads are offline, continue to star primary cpu */
+ } else if (threads_per_core > 2) {
+ pr_err("Do not support more than 2 threads per CPU.");
+ return -EINVAL;
}
ret = smp_85xx_start_cpu(primary);
if (ret)
return ret;
+done:
paca[nr].cpu_start = 1;
generic_set_cpu_up(nr);
diff --git a/arch/powerpc/sysdev/fsl_rcpm.c b/arch/powerpc/sysdev/fsl_rcpm.c
index ed59881..f52d02a 100644
--- a/arch/powerpc/sysdev/fsl_rcpm.c
+++ b/arch/powerpc/sysdev/fsl_rcpm.c
@@ -140,7 +140,7 @@ static void qoriq_disable_thread(int cpu)
int hw_cpu = get_hard_smp_processor_id(cpu);
int thread = cpu_thread_in_core(hw_cpu);
- mtspr(SPRN_TENC, TEN_THREAD(thread));
+ book3e_stop_thread(thread);
}
#endif
--
1.9.1
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