linux-kernel - Re: [PATCH v5 6/6] platform/x86: intel_pmc_ipc: use gcr mem base for S0ix counter read

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Date:   Tue, 4 Apr 2017 16:51:51 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
Cc:     Andy Shevchenko <andy@...radead.org>,
        Zha Qipeng <qipeng.zha@...el.com>,
        "dvhart@...radead.org" <dvhart@...radead.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Wim Van Sebroeck <wim@...ana.be>,
        Sathyanarayanan Kuppuswamy Natarajan <sathyaosid@...il.com>,
        David Box <david.e.box@...ux.intel.com>,
        Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        linux-watchdog@...r.kernel.org
Subject: Re: [PATCH v5 6/6] platform/x86: intel_pmc_ipc: use gcr mem base for
 S0ix counter read

On Tue, Apr 4, 2017 at 3:24 AM, Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@...ux.intel.com> wrote:
> To maintain the uniformity in accessing GCR registers, this patch
> modifies the S0ix counter read function to use GCR address base
> instead of ipc address base.
>

This one looks good.

--- 8< --- 8< ---

Overall, I do not like this spreading interface where we have more and
more functions which use some global variable without clear
understanding of device / initialization dependencies.

Better approach would be something using opaque pointers and API which
takes it as an input.
I didn't investigate yet about something similar to UCLASS_SYSCON
(this is nice model of dependency used in U-Boot) in Linux kernel, it
would be cool to use it.

So, the priority number #2 (number #1 is to fix interrupt handling for
Whiskey Cove) is to refactor this all mess.

Like we agreed it would be last series I'm going to apply without
refactoring done.

--- 8< --- 8< ---

> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
> Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>
> Tested-by: Shanth Murthy <shanth.murthy@...el.com>
> ---
>  arch/x86/include/asm/intel_pmc_ipc.h |  2 ++
>  drivers/platform/x86/intel_pmc_ipc.c | 10 +++-------
>  2 files changed, 5 insertions(+), 7 deletions(-)
>
> Changes since v4:
>  * Rebased on top of latest changes.
>
> Changes since v3:
>  * Rebased on top of latest changes.
>
> diff --git a/arch/x86/include/asm/intel_pmc_ipc.h b/arch/x86/include/asm/intel_pmc_ipc.h
> index 8402efe..fac89eb 100644
> --- a/arch/x86/include/asm/intel_pmc_ipc.h
> +++ b/arch/x86/include/asm/intel_pmc_ipc.h
> @@ -25,6 +25,8 @@
>
>  /* GCR reg offsets from gcr base*/
>  #define PMC_GCR_PMC_CFG_REG            0x08
> +#define PMC_GCR_TELEM_DEEP_S0IX_REG    0x78
> +#define PMC_GCR_TELEM_SHLW_S0IX_REG    0x80
>
>  #if IS_ENABLED(CONFIG_INTEL_PMC_IPC)
>
> diff --git a/drivers/platform/x86/intel_pmc_ipc.c b/drivers/platform/x86/intel_pmc_ipc.c
> index 3d0d6f17..b61f569 100644
> --- a/drivers/platform/x86/intel_pmc_ipc.c
> +++ b/drivers/platform/x86/intel_pmc_ipc.c
> @@ -57,10 +57,6 @@
>  #define IPC_WRITE_BUFFER       0x80
>  #define IPC_READ_BUFFER                0x90
>
> -/* PMC Global Control Registers */
> -#define GCR_TELEM_DEEP_S0IX_OFFSET     0x1078
> -#define GCR_TELEM_SHLW_S0IX_OFFSET     0x1080
> -
>  /* Residency with clock rate at 19.2MHz to usecs */
>  #define S0IX_RESIDENCY_IN_USECS(d, s)          \
>  ({                                             \
> @@ -203,7 +199,7 @@ static inline u32 ipc_data_readl(u32 offset)
>
>  static inline u64 gcr_data_readq(u32 offset)
>  {
> -       return readq(ipcdev.ipc_base + offset);
> +       return readq(ipcdev.gcr_mem_base + offset);
>  }
>
>  static inline int is_gcr_valid(u32 offset)
> @@ -906,8 +902,8 @@ int intel_pmc_s0ix_counter_read(u64 *data)
>         if (!ipcdev.has_gcr_regs)
>                 return -EACCES;
>
> -       deep = gcr_data_readq(GCR_TELEM_DEEP_S0IX_OFFSET);
> -       shlw = gcr_data_readq(GCR_TELEM_SHLW_S0IX_OFFSET);
> +       deep = gcr_data_readq(PMC_GCR_TELEM_DEEP_S0IX_REG);
> +       shlw = gcr_data_readq(PMC_GCR_TELEM_SHLW_S0IX_REG);
>
>         *data = S0IX_RESIDENCY_IN_USECS(deep, shlw);
>
> --
> 2.7.4
>



-- 
With Best Regards,
Andy Shevchenko