From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from am1outboundpool.messaging.microsoft.com (am1ehsobe006.messaging.microsoft.com [213.199.154.209]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Microsoft Secure Server Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 33C98B6FFE for ; Fri, 11 May 2012 21:53:52 +1000 (EST) From: Zhao Chenhui To: Subject: [PATCH v5 1/5] powerpc/85xx: implement hardware timebase sync Date: Fri, 11 May 2012 19:53:51 +0800 Message-ID: <1336737235-15370-1-git-send-email-chenhui.zhao@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Cc: scottwood@freescale.com, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Do hardware timebase sync. Firstly, stop all timebases, and transfer the timebase value of the boot core to the other core. Finally, start all timebases. Only apply to dual-core chips, such as MPC8572, P2020, etc. Signed-off-by: Zhao Chenhui Signed-off-by: Li Yang --- arch/powerpc/include/asm/fsl_guts.h | 2 + arch/powerpc/platforms/85xx/smp.c | 93 +++++++++++++++++++++++++++++++++-- 2 files changed, 91 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/fsl_guts.h b/arch/powerpc/include/asm/fsl_guts.h index aa4c488..dd5ba2c 100644 --- a/arch/powerpc/include/asm/fsl_guts.h +++ b/arch/powerpc/include/asm/fsl_guts.h @@ -48,6 +48,8 @@ struct ccsr_guts { __be32 dmuxcr; /* 0x.0068 - DMA Mux Control Register */ u8 res06c[0x70 - 0x6c]; __be32 devdisr; /* 0x.0070 - Device Disable Control */ +#define CCSR_GUTS_DEVDISR_TB1 0x00001000 +#define CCSR_GUTS_DEVDISR_TB0 0x00004000 __be32 devdisr2; /* 0x.0074 - Device Disable Control 2 */ u8 res078[0x7c - 0x78]; __be32 pmjcr; /* 0x.007c - 4 Power Management Jog Control Register */ diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index ff42490..6862dda 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -115,13 +116,70 @@ smp_85xx_kick_cpu(int nr) struct smp_ops_t smp_85xx_ops = { .kick_cpu = smp_85xx_kick_cpu, -#ifdef CONFIG_KEXEC - .give_timebase = smp_generic_give_timebase, - .take_timebase = smp_generic_take_timebase, -#endif }; #ifdef CONFIG_KEXEC +static struct ccsr_guts __iomem *guts; +static u64 timebase; +static int tb_req; +static int tb_valid; + +static void mpc85xx_timebase_freeze(int freeze) +{ + unsigned int mask; + + if (!guts) + return; + + mask = CCSR_GUTS_DEVDISR_TB0 | CCSR_GUTS_DEVDISR_TB1; + if (freeze) + setbits32(&guts->devdisr, mask); + else + clrbits32(&guts->devdisr, mask); + + in_be32(&guts->devdisr); +} + +static void mpc85xx_give_timebase(void) +{ + unsigned long flags; + + local_irq_save(flags); + + while (!tb_req) + barrier(); + tb_req = 0; + + mpc85xx_timebase_freeze(1); + timebase = get_tb(); + mb(); + tb_valid = 1; + + while (tb_valid) + barrier(); + + mpc85xx_timebase_freeze(0); + + local_irq_restore(flags); +} + +static void mpc85xx_take_timebase(void) +{ + unsigned long flags; + + local_irq_save(flags); + + tb_req = 1; + while (!tb_valid) + barrier(); + + set_tb(timebase >> 32, timebase & 0xffffffff); + mb(); + tb_valid = 0; + + local_irq_restore(flags); +} + atomic_t kexec_down_cpus = ATOMIC_INIT(0); void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary) @@ -228,6 +286,20 @@ smp_85xx_setup_cpu(int cpu_nr) doorbell_setup_this_cpu(); } +#ifdef CONFIG_KEXEC +static const struct of_device_id guts_ids[] = { + { .compatible = "fsl,mpc8572-guts", }, + { .compatible = "fsl,mpc8560-guts", }, + { .compatible = "fsl,mpc8536-guts", }, + { .compatible = "fsl,p1020-guts", }, + { .compatible = "fsl,p1021-guts", }, + { .compatible = "fsl,p1022-guts", }, + { .compatible = "fsl,p1023-guts", }, + { .compatible = "fsl,p2020-guts", }, + {}, +}; +#endif + void __init mpc85xx_smp_init(void) { struct device_node *np; @@ -249,6 +321,19 @@ void __init mpc85xx_smp_init(void) smp_85xx_ops.cause_ipi = doorbell_cause_ipi; } +#ifdef CONFIG_KEXEC + np = of_find_matching_node(NULL, guts_ids); + if (np) { + guts = of_iomap(np, 0); + smp_85xx_ops.give_timebase = mpc85xx_give_timebase; + smp_85xx_ops.take_timebase = mpc85xx_take_timebase; + of_node_put(np); + } else { + smp_85xx_ops.give_timebase = smp_generic_give_timebase; + smp_85xx_ops.take_timebase = smp_generic_take_timebase; + } +#endif + smp_ops = &smp_85xx_ops; #ifdef CONFIG_KEXEC -- 1.6.4.1