From 6becef7ea04a695f64299238fe13d41e41607469 Mon Sep 17 00:00:00 2001 From: chenhui zhao Date: Fri, 20 Nov 2015 17:14:02 +0800 Subject: [PATCH] powerpc/mpc85xx: Add CPU hotplug support for E6500 Support Freescale E6500 core-based platforms, like t4240. Support disabling/enabling individual CPU thread dynamically. Signed-off-by: Chenhui Zhao --- arch/powerpc/include/asm/cputhreads.h | 6 +++ arch/powerpc/include/asm/smp.h | 1 + arch/powerpc/kernel/head_64.S | 78 +++++++++++++++++++++++++++ arch/powerpc/platforms/85xx/smp.c | 70 +++++++++++++----------- 4 files changed, 124 insertions(+), 31 deletions(-) diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h index 81f5b338c76d..666bef4ebfae 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 /* @@ -103,7 +104,12 @@ static inline u32 get_tensr(void) return 1; } +void book3e_start_thread(int thread, unsigned long addr); void book3e_stop_thread(int thread); +#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 bdb811116d85..174271ef2767 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 603625368ceb..291628320fbe 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -40,6 +40,7 @@ #include #include #include +#include /* The physical memory is laid out such that the secondary processor * spin code sits at 0x0000...0x00ff. On server, the vectors follow @@ -181,6 +182,45 @@ exception_marker: #endif #ifdef CONFIG_PPC_BOOK3E +/* + * The booting_thread_hwid holds the thread id we want to boot in cpu + * hotplug case. It is set by cpu hotplug code, and is invalid by default. + * The thread id is the same as the initial value of SPRN_PIR[THREAD_ID] + * bit field. + */ + .globl booting_thread_hwid +booting_thread_hwid: + .long INVALID_THREAD_HWID + .align 3 +/* + * start a thread in the same core + * 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 + beq 10f + cmpi 0, r3, 1 + beq 11f + /* If the thread id is invalid, just exit. */ + b 13f +10: + mttmr TMRN_IMSR0, r5 + mttmr TMRN_INIA0, r4 + b 12f +11: + mttmr TMRN_IMSR1, r5 + mttmr TMRN_INIA1, r4 +12: + isync + li r6, 1 + sld r6, r6, r3 + mtspr SPRN_TENS, r6 +13: + blr + /* * stop a thread in the same core * input parameter: @@ -280,6 +320,44 @@ _GLOBAL(generic_secondary_smp_init) mr r3,r24 mr r4,r25 bl book3e_secondary_core_init + +/* + * After common core init has finished, check if the current thread is the + * one we wanted to boot. If not, start the specified thread and stop the + * current thread. + */ + LOAD_REG_ADDR(r4, booting_thread_hwid) + lwz r3, 0(r4) + li r5, INVALID_THREAD_HWID + cmpw r3, r5 + beq 20f + + /* + * The value of booting_thread_hwid has been stored in r3, + * so make it invalid. + */ + stw r5, 0(r4) + + /* + * Get the current thread id and check if it is the one we wanted. + * If not, start the one specified in booting_thread_hwid and stop + * the current thread. + */ + mfspr r8, SPRN_TIR + cmpw r3, r8 + beq 20f + + /* start the specified thread */ + LOAD_REG_ADDR(r5, fsl_secondary_thread_init) + ld r4, 0(r5) + bl book3e_start_thread + + /* stop the current thread */ + mr r3, r8 + 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 d7cc538ca9dd..fe9f19e5e935 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -180,24 +180,11 @@ 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 imsr, inia; - int nr = *(const int *)info; + unsigned long inia; + int cpu = *(const int *)info; - imsr = MSR_KERNEL; inia = *(unsigned long *)fsl_secondary_thread_init; - - if (cpu_thread_in_core(nr) == 0) { - /* For when we boot on a secondary thread with kdump */ - mttmr(TMRN_IMSR0, imsr); - mttmr(TMRN_INIA0, inia); - mtspr(SPRN_TENS, TEN_THREAD(0)); - } else { - mttmr(TMRN_IMSR1, imsr); - mttmr(TMRN_INIA1, inia); - mtspr(SPRN_TENS, TEN_THREAD(1)); - } - - smp_generic_kick_cpu(nr); + book3e_start_thread(cpu_thread_in_core(cpu), inia); } #endif @@ -292,33 +279,54 @@ static int smp_85xx_kick_cpu(int nr) pr_debug("kick CPU #%d\n", nr); #ifdef CONFIG_PPC64 - /* 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) { 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; + booting_thread_hwid = cpu_thread_in_core(nr); + primary = cpu_first_thread_sibling(nr); + + if (qoriq_pm_ops) + qoriq_pm_ops->cpu_up_prepare(nr); + + /* + * If either thread in the core is online, use it to start + * the other. + */ + 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; } - if (!cpu_online(primary)) { - pr_err("%s: cpu %d: primary %d not online\n", - __func__, nr, primary); - return -ENOENT; - } + /* + * If getting here, it means both threads in the core are + * offline. So start the primary thread, then it will start + * the thread specified in booting_thread_hwid, the one + * corresponding to nr. + */ - smp_call_function_single(primary, wake_hw_thread, &nr, 0); - return 0; + } else if (threads_per_core == 1) { + /* + * If one core has only one thread, set booting_thread_hwid to + * an invalid value. + */ + booting_thread_hwid = INVALID_THREAD_HWID; + + } 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);