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Message-ID: <a89bdd10-9388-01f5-6a7c-894af793e1c1@huawei.com>
Date:   Wed, 27 Sep 2023 10:07:15 +0800
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Subject: Re: [PATCH 1/3] ACPI: PCC: Add PCC shared memory region command and
 status bitfields
To:     Sudeep Holla <sudeep.holla@arm.com>, <linux-hwmon@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
        <linux-acpi@vger.kernel.org>
CC:     "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Andi Shyti <andi.shyti@kernel.org>,
        Jean Delvare <jdelvare@suse.com>,
        Guenter Roeck <linux@roeck-us.net>, <lihuisong@huawei.com>
References: <20230926-pcc_defines-v1-0-0f925a1658fd@arm.com>
 <20230926-pcc_defines-v1-1-0f925a1658fd@arm.com>
From:   "lihuisong (C)" <lihuisong@huawei.com>
In-Reply-To: <20230926-pcc_defines-v1-1-0f925a1658fd@arm.com>
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Hi Sudeep,

在 2023/9/26 20:28, Sudeep Holla 写道:
> Define the common macros to use when referring to various bitfields in
> the PCC generic communications channel command and status fields.
Can you define the bit0 macros in the "flags" for Extended PCC Subspace 
Shared Memory Region?
>
> Currently different drivers that need to use these bitfields have defined
> these locally. This common macro is intended to consolidate and replace
> those.
>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>   include/acpi/pcc.h | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h
> index 73e806fe7ce7..66d9934c2ee4 100644
> --- a/include/acpi/pcc.h
> +++ b/include/acpi/pcc.h
> @@ -18,7 +18,18 @@ struct pcc_mbox_chan {
>   	u16 min_turnaround_time;
>   };
>   
> +/* Generic Communications Channel Shared Memory Region */
> +#define PCC_SIGNATURE			0x50424300
Why is this signature 0x50424300?
In ACPI spec, this signature is all 0x50434303.
> +/* Generic Communications Channel Command Field */
> +#define PCC_CMD_GENERATE_DB_INTR	BIT(15)
> +/* Generic Communications Channel Status Field */
> +#define PCC_STATUS_CMD_COMPLETE		BIT(0)
> +#define PCC_STATUS_SCI_DOORBELL		BIT(1)
> +#define PCC_STATUS_ERROR		BIT(2)
> +#define PCC_STATUS_PLATFORM_NOTIFY	BIT(3)
> +
>   #define MAX_PCC_SUBSPACES	256
> +
>   #ifdef CONFIG_PCC
>   extern struct pcc_mbox_chan *
>   pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);
>