Re: [PATCH v2 07/15] powerpc/85xx: add time base sync for SoCs based on e500mc/e5500

[Scott Wood <scottwood@freescale.com>]

On 04/19/2013 05:47:40 AM, Zhao Chenhui wrote:
> From: Chen-Hui Zhao <chenhui.zhao@freescale.com>
> 
> In the case of SMP, during the time base sync period, all time bases  
> of
> online cores must stop, then start simultaneously.
> 
> There is a RCPM (Run Control/Power Management) module in CoreNet  
> based SoCs.
> Define a struct ccsr_rcpm to describe the register map.
> 
> This patch supports SoCs based on e500mc/e5500, such as P4080, P5020,
> etc.
> 
> Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
> Signed-off-by: Li Yang <leoli@freescale.com>
> ---
>  arch/powerpc/include/asm/fsl_guts.h |   38  
> +++++++++++++++++++++++++++++++++++
>  arch/powerpc/platforms/85xx/smp.c   |   32  
> +++++++++++++++++++++++++++++
>  2 files changed, 70 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/fsl_guts.h  
> b/arch/powerpc/include/asm/fsl_guts.h
> index 77ced0b..4eac1cf 100644
> --- a/arch/powerpc/include/asm/fsl_guts.h
> +++ b/arch/powerpc/include/asm/fsl_guts.h
> @@ -106,6 +106,44 @@ struct ccsr_guts {
>  /* Alternate function signal multiplex control */
>  #define MPC85xx_PMUXCR_QE(x) (0x8000 >> (x))
> 
> +struct ccsr_rcpm {
> +	u8	res0000[4];
> +	__be32	cdozsr;		/* 0x0004 - Core Doze Status Register */
> +	u8	res0008[4];
> +	__be32	cdozcr;		/* 0x000c - Core Doze Control Register  
> */
> +	u8	res0010[4];
> +	__be32	cnapsr;		/* 0x0014 - Core Nap Status Register */
> +	u8	res0018[4];
> +	__be32	cnapcr;		/* 0x001c - Core Nap Control Register */
> +	u8	res0020[4];
> +	__be32	cdozpsr;	/* 0x0024 - Core Doze Previous Status  
> Register */
> +	u8	res0028[4];
> +	__be32	cnappsr;	/* 0x002c - Core Nap Previous Status  
> Register */
> +	u8	res0030[4];
> +	__be32	cwaitsr;	/* 0x0034 - Core Wait Status Register */
> +	u8	res0038[4];
> +	__be32	cwdtdsr;	/* 0x003c - Core watchdog detect status  
> register */
> +	__be32	powmgtcsr;	/* 0x0040 - Power Mangement Control &  
> Status Register */
> +	u8	res0044[12];
> +	__be32	ippdexpcr;	/* 0x0050 - IP Powerdown Exception  
> Control Register */
> +	u8	res0054[16];
> +	__be32	cpmimr;		/* 0x0064 - Core PM IRQ Mask Register */
> +	u8	res0068[4];
> +	__be32	cpmcimr;	/* 0x006c - Core PM Critical IRQ Mask  
> Register */
> +	u8	res0070[4];
> +	__be32	cpmmcmr;	/* 0x0074 - Core PM Machine Check Mask  
> Register */
> +	u8	res0078[4];
> +	__be32	cpmnmimr;	/* 0x007c - Core PM NMI Mask Register */
> +	u8	res0080[4];
> +	__be32	ctbenr;		/* 0x0084 - Core Time Base Enable  
> Register */
> +	u8	res0088[4];
> +	__be32	ctbckselr;	/* 0x008c - Core Time Base Clock Select  
> Register */
> +	u8	res0090[4];
> +	__be32	ctbhltcr;	/* 0x0094 - Core Time Base Halt Control  
> Register */
> +	u8	res0098[4];
> +	__be32	cmcpmaskcr;	/* 0x00a4 - Core machine check mask  
> control register */
> +};
> +
>  #ifdef CONFIG_PPC_86xx
> 
>  #define CCSR_GUTS_DMACR_DEV_SSI	0	/* DMA  
> controller/channel set to SSI */
> diff --git a/arch/powerpc/platforms/85xx/smp.c  
> b/arch/powerpc/platforms/85xx/smp.c
> index 6a17599..6c2fe6b 100644
> --- a/arch/powerpc/platforms/85xx/smp.c
> +++ b/arch/powerpc/platforms/85xx/smp.c
> @@ -44,7 +44,36 @@ static struct ccsr_guts __iomem *guts;
>  static u64 timebase;
>  static int tb_req;
>  static int tb_valid;
> +static u32 cur_booting_core;
> 
> +#ifdef CONFIG_PPC_E500MC
> +/* get a physical mask of online cores and booting core */
> +static inline u32 get_phy_cpu_mask(void)
> +{
> +	u32 mask;
> +	int cpu;
> +
> +	mask = 1 << cur_booting_core;
> +	for_each_online_cpu(cpu)
> +		mask |= 1 << get_hard_smp_processor_id(cpu);
> +
> +	return mask;
> +}
> +
> +static void mpc85xx_timebase_freeze(int freeze)
> +{
> +	struct ccsr_rcpm __iomem *rcpm = (typeof(rcpm))guts;
> +	u32 mask = get_phy_cpu_mask();
> +
> +	if (freeze)
> +		clrbits32(&rcpm->ctbenr, mask);
> +	else
> +		setbits32(&rcpm->ctbenr, mask);
> +
> +	/* read back to push the previos write */
> +	in_be32(&rcpm->ctbenr);
> +}
> +#else

Please determine the timebase sync implementation at runtime, rather  
than relying on our current inability to have e500v2 and e500mc in the  
same kernel.  e6500 will be different from e5500, but both can be in  
the same kernel image.

-Scott